* [PATCH v5 0/7] Clean up and unify the vDSO
@ 2014-05-05 19:19 Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap Andy Lutomirski
` (6 more replies)
0 siblings, 7 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
This rewrites a bunch of the vdso code. After these patches, the vvar
and hpet pages are mapped directly after the vdso text on all five
vdso variants. The fixmaps are gone on 64-bit systems.
It would be possible to build the x32 vdso the normal way on top of
these patches.
I haven't touched the pvclock code. In a discussion with Marcello
Tosatti, I think we concluded that the kvmclock code could be
significantly simplified and sped up without breaking anything, but I
want to save that for later.
There's a further change for 32-bit in here: the fixmap is now always
aligned to a PMD (i.e. 4M) boundary. This may waste up to 4M-4k of
address space if a hypervisor is in use. If that's a problem, then that
part of this change could be reverted, but the existing code was asking
for trouble.
This should apply to -linus or to tip/x86/vdso. It's also here:
https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=vdso/cleanups
Changed from v4:
- Fixed the alignment of fixmap (build / functionality fix)
Changes from v3:
- Improve the changelog message for patch 2.
Changes from v2:
- Fixed the 32-bit build. Hopefully I didn't screw
up bisection.
Changes from v1:
- Rebased
- I think Gold is working (this is a side effect of the rebase)
Andy Lutomirski (7):
x86,mm: Ensure correct alignment of the fixmap
x86: Clean up 32-bit vs 64-bit vdso params
x86: Move syscall and sysenter setup into kernel/cpu/common.c
x86: Reimplement vdso.so preparation in build-time C
x86: Move the 32-bit vdso special pages after the text
x86: Move the vvar and hpet mappings next to the 64-bit vDSO
x86: Remove vestiges of VDSO_PRELINK and some outdated comments
arch/x86/ia32/ia32_signal.c | 8 +-
arch/x86/include/asm/elf.h | 35 +++---
arch/x86/include/asm/fixmap.h | 11 +-
arch/x86/include/asm/mmu.h | 2 +-
arch/x86/include/asm/proto.h | 2 -
arch/x86/include/asm/vdso.h | 74 +++++-------
arch/x86/include/asm/vdso32.h | 11 --
arch/x86/include/asm/vvar.h | 20 +---
arch/x86/include/uapi/asm/vsyscall.h | 7 +-
arch/x86/kernel/cpu/common.c | 33 ++++++
arch/x86/kernel/hpet.c | 3 -
arch/x86/kernel/signal.c | 6 +-
arch/x86/kernel/vsyscall_64.c | 15 +--
arch/x86/mm/fault.c | 5 +-
arch/x86/mm/init_64.c | 13 +-
arch/x86/mm/ioremap.c | 6 +
arch/x86/mm/pgtable.c | 6 +-
arch/x86/um/vdso/vma.c | 2 +-
arch/x86/vdso/.gitignore | 5 +-
arch/x86/vdso/Makefile | 90 +++++---------
arch/x86/vdso/vclock_gettime.c | 26 ++--
arch/x86/vdso/vdso-layout.lds.S | 40 ++++---
arch/x86/vdso/vdso.S | 3 -
arch/x86/vdso/vdso.lds.S | 7 +-
arch/x86/vdso/vdso2c.c | 156 ++++++++++++++++++++++++
arch/x86/vdso/vdso2c.h | 154 ++++++++++++++++++++++++
arch/x86/vdso/vdso32-setup.c | 196 ++++---------------------------
arch/x86/vdso/vdso32.S | 9 --
arch/x86/vdso/vdso32/vdso32.lds.S | 15 +--
arch/x86/vdso/vdsox32.S | 3 -
arch/x86/vdso/vdsox32.lds.S | 7 +-
arch/x86/vdso/vma.c | 222 +++++++++++++++++++----------------
arch/x86/xen/mmu.c | 8 +-
arch/x86/xen/setup.c | 11 +-
kernel/sysctl.c | 5 +
35 files changed, 657 insertions(+), 559 deletions(-)
delete mode 100644 arch/x86/include/asm/vdso32.h
delete mode 100644 arch/x86/vdso/vdso.S
create mode 100644 arch/x86/vdso/vdso2c.c
create mode 100644 arch/x86/vdso/vdso2c.h
delete mode 100644 arch/x86/vdso/vdso32.S
delete mode 100644 arch/x86/vdso/vdsox32.S
--
1.9.0
^ permalink raw reply [flat|nested] 39+ messages in thread
* [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, mm: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 2/7] x86: Clean up 32-bit vs 64-bit vdso params Andy Lutomirski
` (5 subsequent siblings)
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
The early_ioremap code requires that its buffers not span a PMD
boundary. The logic for ensuring that only works if the fixmap is
aligned, so assert that it's aligned correctly.
To make this work reliably, reserve_top_address needs to be
adjusted.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/mm/ioremap.c | 6 ++++++
arch/x86/mm/pgtable.c | 6 +++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 597ac15..6ef98c5 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -355,6 +355,12 @@ void __init early_ioremap_init(void)
{
pmd_t *pmd;
+#ifdef CONFIG_X86_64
+ BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#else
+ WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#endif
+
early_ioremap_setup();
pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index c96314a..5f8bdda 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -449,9 +449,9 @@ void __init reserve_top_address(unsigned long reserve)
{
#ifdef CONFIG_X86_32
BUG_ON(fixmaps_set > 0);
- printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
- (int)-reserve);
- __FIXADDR_TOP = -reserve - PAGE_SIZE;
+ __FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE;
+ printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n",
+ -reserve, __FIXADDR_TOP + PAGE_SIZE);
#endif
}
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 2/7] x86: Clean up 32-bit vs 64-bit vdso params
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 3/7] x86: Move syscall and sysenter setup into kernel/cpu/common.c Andy Lutomirski
` (4 subsequent siblings)
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
Rather than using 'vdso_enabled' and an awful #define, just call the
parameters vdso32_enabled and vdso64_enabled.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/include/asm/elf.h | 20 +++++++++++++-------
arch/x86/um/vdso/vma.c | 2 +-
arch/x86/vdso/vdso32-setup.c | 19 ++++++++-----------
arch/x86/vdso/vma.c | 6 +++---
kernel/sysctl.c | 5 +++++
5 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 2c71182..e96df2c 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -75,7 +75,12 @@ typedef struct user_fxsr_struct elf_fpxregset_t;
#include <asm/vdso.h>
-extern unsigned int vdso_enabled;
+#ifdef CONFIG_X86_64
+extern unsigned int vdso64_enabled;
+#endif
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+extern unsigned int vdso32_enabled;
+#endif
/*
* This is used to ensure we don't load something for the wrong architecture.
@@ -269,9 +274,9 @@ extern int force_personality32;
struct task_struct;
-#define ARCH_DLINFO_IA32(vdso_enabled) \
+#define ARCH_DLINFO_IA32 \
do { \
- if (vdso_enabled) { \
+ if (vdso32_enabled) { \
NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
} \
@@ -281,7 +286,7 @@ do { \
#define STACK_RND_MASK (0x7ff)
-#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
+#define ARCH_DLINFO ARCH_DLINFO_IA32
/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
@@ -292,14 +297,15 @@ do { \
#define ARCH_DLINFO \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)
+/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
#define ARCH_DLINFO_X32 \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)
@@ -310,7 +316,7 @@ do { \
if (test_thread_flag(TIF_X32)) \
ARCH_DLINFO_X32; \
else \
- ARCH_DLINFO_IA32(sysctl_vsyscall32)
+ ARCH_DLINFO_IA32
#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index af91901..916cda4 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -12,7 +12,7 @@
#include <asm/page.h>
#include <linux/init.h>
-unsigned int __read_mostly vdso_enabled = 1;
+static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;
extern unsigned long task_size;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0034898..5a657d9 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -37,7 +37,6 @@
#endif
#ifdef CONFIG_X86_64
-#define vdso_enabled sysctl_vsyscall32
#define arch_setup_additional_pages syscall32_setup_pages
#endif
@@ -45,13 +44,13 @@
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
-unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
-static int __init vdso_setup(char *s)
+static int __init vdso32_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso32_enabled = simple_strtoul(s, NULL, 0);
- if (vdso_enabled > 1)
+ if (vdso32_enabled > 1)
pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
return 1;
@@ -62,12 +61,10 @@ static int __init vdso_setup(char *s)
* behavior on both 64-bit and 32-bit kernels.
* On 32-bit kernels, vdso=[012] means the same thing.
*/
-__setup("vdso32=", vdso_setup);
+__setup("vdso32=", vdso32_setup);
#ifdef CONFIG_X86_32
-__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
-
-EXPORT_SYMBOL_GPL(vdso_enabled);
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif
static struct page **vdso32_pages;
@@ -160,7 +157,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return x32_setup_additional_pages(bprm, uses_interp);
#endif
- if (vdso_enabled != 1) /* Other values all mean "disabled" */
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
down_write(&mm->mmap_sem);
@@ -244,7 +241,7 @@ subsys_initcall(sysenter_setup);
static struct ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
- .data = &sysctl_vsyscall32,
+ .data = &vdso32_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 1ad1026..8b79039 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -17,7 +17,7 @@
#include <asm/page.h>
#if defined(CONFIG_X86_64)
-unsigned int __read_mostly vdso_enabled = 1;
+unsigned int __read_mostly vdso64_enabled = 1;
DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
@@ -160,7 +160,7 @@ static int setup_additional_pages(struct linux_binprm *bprm,
unsigned long addr;
int ret;
- if (!vdso_enabled)
+ if (!vdso64_enabled)
return 0;
down_write(&mm->mmap_sem);
@@ -203,7 +203,7 @@ int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
static __init int vdso_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso64_enabled = simple_strtoul(s, NULL, 0);
return 0;
}
__setup("vdso=", vdso_setup);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b58..420d77a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1418,8 +1418,13 @@ static struct ctl_table vm_table[] = {
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
.procname = "vdso_enabled",
+#ifdef CONFIG_X86_32
+ .data = &vdso32_enabled,
+ .maxlen = sizeof(vdso32_enabled),
+#else
.data = &vdso_enabled,
.maxlen = sizeof(vdso_enabled),
+#endif
.mode = 0644,
.proc_handler = proc_dointvec,
.extra1 = &zero,
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 3/7] x86: Move syscall and sysenter setup into kernel/cpu/common.c
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 2/7] x86: Clean up 32-bit vs 64-bit vdso params Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 4/7] x86: Reimplement vdso.so preparation in build-time C Andy Lutomirski
` (3 subsequent siblings)
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
This code is used during CPU setup, and it isn't strictly speaking
related to the 32-bit vdso. It's easier to understand how this
works when the code is closer to its callers.
This also lets syscall32_cpu_init be static, which might save some
trivial amount of kernel text.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/include/asm/proto.h | 2 --
arch/x86/kernel/cpu/common.c | 32 ++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso32-setup.c | 30 ------------------------------
3 files changed, 32 insertions(+), 32 deletions(-)
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 6fd3fd7..a90f897 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -12,8 +12,6 @@ void ia32_syscall(void);
void ia32_cstar_target(void);
void ia32_sysenter_target(void);
-void syscall32_cpu_init(void);
-
void x86_configure_nx(void);
void x86_report_nx(void);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index a135239..7c65b46 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -953,6 +953,38 @@ static void vgetcpu_set_mode(void)
else
vgetcpu_mode = VGETCPU_LSL;
}
+
+/* May not be __init: called during resume */
+static void syscall32_cpu_init(void)
+{
+ /* Load these always in case some future AMD CPU supports
+ SYSENTER from compat mode too. */
+ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
+ wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
+ wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
+
+ wrmsrl(MSR_CSTAR, ia32_cstar_target);
+}
+#endif
+
+#ifdef CONFIG_X86_32
+void enable_sep_cpu(void)
+{
+ int cpu = get_cpu();
+ struct tss_struct *tss = &per_cpu(init_tss, cpu);
+
+ if (!boot_cpu_has(X86_FEATURE_SEP)) {
+ put_cpu();
+ return;
+ }
+
+ tss->x86_tss.ss1 = __KERNEL_CS;
+ tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
+ wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+ wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
+ wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
+ put_cpu();
+}
#endif
void __init identify_boot_cpu(void)
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 5a657d9..9c78d5b 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -75,41 +75,11 @@ static unsigned vdso32_size;
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
-/* May not be __init: called during resume */
-void syscall32_cpu_init(void)
-{
- /* Load these always in case some future AMD CPU supports
- SYSENTER from compat mode too. */
- wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
- wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
- wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
-
- wrmsrl(MSR_CSTAR, ia32_cstar_target);
-}
-
#else /* CONFIG_X86_32 */
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
#define vdso32_syscall() (0)
-void enable_sep_cpu(void)
-{
- int cpu = get_cpu();
- struct tss_struct *tss = &per_cpu(init_tss, cpu);
-
- if (!boot_cpu_has(X86_FEATURE_SEP)) {
- put_cpu();
- return;
- }
-
- tss->x86_tss.ss1 = __KERNEL_CS;
- tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
- wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
- wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
- wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
- put_cpu();
-}
-
#endif /* CONFIG_X86_64 */
int __init sysenter_setup(void)
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 4/7] x86: Reimplement vdso.so preparation in build-time C
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
` (2 preceding siblings ...)
2014-05-05 19:19 ` [PATCH v5 3/7] x86: Move syscall and sysenter setup into kernel/cpu/common.c Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 5/7] x86: Move the 32-bit vdso special pages after the text Andy Lutomirski
` (2 subsequent siblings)
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
Currently, vdso.so files are prepared and analyzed by a combination
of objcopy, nm, some linker script tricks, and some simple ELF
parsers in the kernel. Replace all of that with plain C code that
runs at build time.
All five vdso images now generate .c files that are compiled and
linked in to the kernel image.
This should cause only one userspace-visible change: the loaded vDSO
images are stripped more heavily than they used to be. Everything
outside the loadable segment is dropped. In particular, this causes
the section table and section name strings to be missing. This
should be fine: real dynamic loaders don't load or inspect these
tables anyway. The result is roughly equivalent to eu-strip's
--strip-sections option.
The purpose of this change is to enable the vvar and hpet mappings
to be moved to the page following the vDSO load segment. Currently,
it is possible for the section table to extend into the page after
the load segment, so, if we map it, it risks overlapping the vvar or
hpet page. This happens whenever the load segment is just under a
multiple of PAGE_SIZE.
The only real subtlety here is that the old code had a C file with
inline assembler that did 'call VDSO32_vsyscall' and a linker script
that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most
likely worked by accident: the linker script entry defines a symbol
associated with an address as opposed to an alias for the real
dynamic symbol __kernel_vsyscall. That caused ld to relocate the
reference at link time instead of leaving an interposable dynamic
relocation. Since the VDSO32_vsyscall hack is no longer needed, I
now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
work. vdso2c will generate an error and abort the build if the
resulting image contains any dynamic relocations, so we won't
silently generate bad vdso images.
(Dynamic relocations are a problem because nothing will even attempt
to relocate the vdso.)
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/ia32/ia32_signal.c | 8 +--
arch/x86/include/asm/elf.h | 7 +-
arch/x86/include/asm/mmu.h | 2 +-
arch/x86/include/asm/vdso.h | 70 +++++++------------
arch/x86/kernel/signal.c | 6 +-
arch/x86/mm/init_64.c | 3 +-
arch/x86/vdso/.gitignore | 5 +-
arch/x86/vdso/Makefile | 90 +++++++++---------------
arch/x86/vdso/vclock_gettime.c | 4 +-
arch/x86/vdso/vdso.S | 3 -
arch/x86/vdso/vdso2c.c | 142 ++++++++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso2c.h | 137 ++++++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso32-setup.c | 50 ++++++--------
arch/x86/vdso/vdso32.S | 9 ---
arch/x86/vdso/vdso32/vdso32.lds.S | 10 ---
arch/x86/vdso/vdsox32.S | 3 -
arch/x86/vdso/vma.c | 100 +++++----------------------
arch/x86/xen/setup.c | 11 ++-
18 files changed, 400 insertions(+), 260 deletions(-)
delete mode 100644 arch/x86/vdso/vdso.S
create mode 100644 arch/x86/vdso/vdso2c.c
create mode 100644 arch/x86/vdso/vdso2c.h
delete mode 100644 arch/x86/vdso/vdso32.S
delete mode 100644 arch/x86/vdso/vdsox32.S
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 2206757..f9e181a 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -383,8 +383,8 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
} else {
/* Return stub is in 32bit vsyscall page */
if (current->mm->context.vdso)
- restorer = VDSO32_SYMBOL(current->mm->context.vdso,
- sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
}
@@ -462,8 +462,8 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else
- restorer = VDSO32_SYMBOL(current->mm->context.vdso,
- rt_sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_rt_sigreturn;
put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
/*
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index e96df2c..65b21bc 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -299,7 +299,7 @@ do { \
do { \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
- (unsigned long)current->mm->context.vdso); \
+ (unsigned long __force)current->mm->context.vdso); \
} while (0)
/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
@@ -307,7 +307,7 @@ do { \
do { \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
- (unsigned long)current->mm->context.vdso); \
+ (unsigned long __force)current->mm->context.vdso); \
} while (0)
#define AT_SYSINFO 32
@@ -325,7 +325,8 @@ else \
#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
#define VDSO_ENTRY \
- ((unsigned long)VDSO32_SYMBOL(VDSO_CURRENT_BASE, vsyscall))
+ ((unsigned long)current->mm->context.vdso + \
+ selected_vdso32->sym___kernel_vsyscall)
struct linux_binprm;
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 5f55e69..876e74e 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -18,7 +18,7 @@ typedef struct {
#endif
struct mutex lock;
- void *vdso;
+ void __user *vdso;
} mm_context_t;
#ifdef CONFIG_SMP
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index d1dc554..389fe2c 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -3,63 +3,43 @@
#include <asm/page_types.h>
#include <linux/linkage.h>
+#include <linux/init.h>
-#ifdef __ASSEMBLER__
+#ifndef __ASSEMBLER__
-#define DEFINE_VDSO_IMAGE(symname, filename) \
-__PAGE_ALIGNED_DATA ; \
- .globl symname##_start, symname##_end ; \
- .align PAGE_SIZE ; \
- symname##_start: ; \
- .incbin filename ; \
- symname##_end: ; \
- .align PAGE_SIZE /* extra data here leaks to userspace. */ ; \
- \
-.previous ; \
- \
- .globl symname##_pages ; \
- .bss ; \
- .align 8 ; \
- .type symname##_pages, @object ; \
- symname##_pages: ; \
- .zero (symname##_end - symname##_start + PAGE_SIZE - 1) / PAGE_SIZE * (BITS_PER_LONG / 8) ; \
- .size symname##_pages, .-symname##_pages
+struct vdso_image {
+ void *data;
+ unsigned long size; /* Always a multiple of PAGE_SIZE */
+ struct page **pages; /* Big enough for data/size page pointers */
-#else
+ unsigned long alt, alt_len;
-#define DECLARE_VDSO_IMAGE(symname) \
- extern char symname##_start[], symname##_end[]; \
- extern struct page *symname##_pages[]
+ unsigned long sym_VDSO32_NOTE_MASK;
+ unsigned long sym___kernel_sigreturn;
+ unsigned long sym___kernel_rt_sigreturn;
+ unsigned long sym___kernel_vsyscall;
+ unsigned long sym_VDSO32_SYSENTER_RETURN;
+};
-#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
+#ifdef CONFIG_X86_64
+extern const struct vdso_image vdso_image_64;
+#endif
-#include <asm/vdso32.h>
+#ifdef CONFIG_X86_X32
+extern const struct vdso_image vdso_image_x32;
+#endif
-DECLARE_VDSO_IMAGE(vdso32_int80);
+#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
+extern const struct vdso_image vdso_image_32_int80;
#ifdef CONFIG_COMPAT
-DECLARE_VDSO_IMAGE(vdso32_syscall);
+extern const struct vdso_image vdso_image_32_syscall;
#endif
-DECLARE_VDSO_IMAGE(vdso32_sysenter);
+extern const struct vdso_image vdso_image_32_sysenter;
-/*
- * Given a pointer to the vDSO image, find the pointer to VDSO32_name
- * as that symbol is defined in the vDSO sources or linker script.
- */
-#define VDSO32_SYMBOL(base, name) \
-({ \
- extern const char VDSO32_##name[]; \
- (void __user *)(VDSO32_##name + (unsigned long)(base)); \
-})
+extern const struct vdso_image *selected_vdso32;
#endif
-/*
- * These symbols are defined with the addresses in the vsyscall page.
- * See vsyscall-sigreturn.S.
- */
-extern void __user __kernel_sigreturn;
-extern void __user __kernel_rt_sigreturn;
-
-void __init patch_vdso32(void *vdso, size_t len);
+extern void __init init_vdso_image(const struct vdso_image *image);
#endif /* __ASSEMBLER__ */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 9e5de68..a0da58d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -298,7 +298,8 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
}
if (current->mm->context.vdso)
- restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
@@ -361,7 +362,8 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
save_altstack_ex(&frame->uc.uc_stack, regs->sp);
/* Set up to return from userspace. */
- restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
put_user_ex(restorer, &frame->pretcode);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f35c66c..5638496 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1223,7 +1223,8 @@ int in_gate_area_no_mm(unsigned long addr)
const char *arch_vma_name(struct vm_area_struct *vma)
{
- if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
+ if (vma->vm_mm && vma->vm_start ==
+ (long __force)vma->vm_mm->context.vdso)
return "[vdso]";
if (vma == &gate_vma)
return "[vsyscall]";
diff --git a/arch/x86/vdso/.gitignore b/arch/x86/vdso/.gitignore
index 3282874..aae8ffd 100644
--- a/arch/x86/vdso/.gitignore
+++ b/arch/x86/vdso/.gitignore
@@ -1,8 +1,7 @@
vdso.lds
-vdso-syms.lds
vdsox32.lds
-vdsox32-syms.lds
-vdso32-syms.lds
vdso32-syscall-syms.lds
vdso32-sysenter-syms.lds
vdso32-int80-syms.lds
+vdso-image-*.c
+vdso2c
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index c580d12..895d4b1 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -24,15 +24,30 @@ vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
# files to link into kernel
obj-y += vma.o
-obj-$(VDSO64-y) += vdso.o
-obj-$(VDSOX32-y) += vdsox32.o
-obj-$(VDSO32-y) += vdso32.o vdso32-setup.o
+
+# vDSO images to build
+vdso_img-$(VDSO64-y) += 64
+vdso_img-$(VDSOX32-y) += x32
+vdso_img-$(VDSO32-y) += 32-int80
+vdso_img-$(CONFIG_COMPAT) += 32-syscall
+vdso_img-$(VDSO32-y) += 32-sysenter
+
+obj-$(VDSO32-y) += vdso32-setup.o
vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
$(obj)/vdso.o: $(obj)/vdso.so
-targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
+targets += vdso.lds $(vobjs-y)
+
+# Build the vDSO image C files and link them in.
+vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
+vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
+vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
+obj-y += $(vdso_img_objs)
+targets += $(vdso_img_cfiles)
+targets += $(vdso_img_sodbg)
+.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
export CPPFLAGS_vdso.lds += -P -C
@@ -41,14 +56,18 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
$(DISABLE_LTO)
-$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
-
-$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
+$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
$(call if_changed,vdso)
-$(obj)/%.so: OBJCOPYFLAGS := -S
-$(obj)/%.so: $(obj)/%.so.dbg FORCE
- $(call if_changed,objcopy)
+hostprogs-y += vdso2c
+
+quiet_cmd_vdso2c = VDSO2C $@
+define cmd_vdso2c
+ $(obj)/vdso2c $< $@
+endef
+
+$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
+ $(call if_changed,vdso2c)
#
# Don't omit frame pointers for ease of userspace debugging, but do
@@ -68,22 +87,6 @@ CFLAGS_REMOVE_vclock_gettime.o = -pg
CFLAGS_REMOVE_vgetcpu.o = -pg
CFLAGS_REMOVE_vvar.o = -pg
-targets += vdso-syms.lds
-obj-$(VDSO64-y) += vdso-syms.lds
-
-#
-# Match symbols in the DSO that look like VDSO*; produce a file of constants.
-#
-sed-vdsosym := -e 's/^00*/0/' \
- -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
-quiet_cmd_vdsosym = VDSOSYM $@
-define cmd_vdsosym
- $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
-endef
-
-$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
- $(call if_changed,vdsosym)
-
#
# X32 processes use x32 vDSO to access 64bit kernel data.
#
@@ -94,9 +97,6 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
# so that it can reach 64bit address space with 64bit pointers.
#
-targets += vdsox32-syms.lds
-obj-$(VDSOX32-y) += vdsox32-syms.lds
-
CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
-Wl,-soname=linux-vdso.so.1 \
@@ -113,9 +113,7 @@ quiet_cmd_x32 = X32 $@
$(obj)/%-x32.o: $(obj)/%.o FORCE
$(call if_changed,x32)
-targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
-
-$(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
+targets += vdsox32.lds $(vobjx32s-y)
$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
$(call if_changed,vdso)
@@ -123,7 +121,6 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
#
# Build multiple 32-bit vDSO images to choose from at boot time.
#
-obj-$(VDSO32-y) += vdso32-syms.lds
vdso32.so-$(VDSO32-y) += int80
vdso32.so-$(CONFIG_COMPAT) += syscall
vdso32.so-$(VDSO32-y) += sysenter
@@ -138,10 +135,8 @@ VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
targets += vdso32/vdso32.lds
-targets += $(vdso32-images) $(vdso32-images:=.dbg)
targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
-
-extra-y += $(vdso32-images)
+targets += vdso32/vclock_gettime.o
$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
@@ -166,27 +161,6 @@ $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
$(obj)/vdso32/%.o
$(call if_changed,vdso)
-# Make vdso32-*-syms.lds from each image, and then make sure they match.
-# The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
-
-targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
-
-quiet_cmd_vdso32sym = VDSOSYM $@
-define cmd_vdso32sym
- if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
- $(foreach H,$(filter-out FORCE,$^),\
- if grep -q VDSO32_SYSENTER_RETURN $H; \
- then diff -u $(@D)/.tmp_$(@F) $H; \
- else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
- diff -u - $H; fi &&) : ;\
- then mv -f $(@D)/.tmp_$(@F) $@; \
- else rm -f $(@D)/.tmp_$(@F); exit 1; \
- fi
-endef
-
-$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
- $(call if_changed,vdso32sym)
-
#
# The DSO images are built using a special linker script.
#
@@ -197,7 +171,7 @@ quiet_cmd_vdso = VDSO $@
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
- $(LTO_CFLAGS)
+ -Wl,-Bsymbolic $(LTO_CFLAGS)
GCOV_PROFILE := n
#
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 16d6861..091554c 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -154,7 +154,7 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
- "call VDSO32_vsyscall \n"
+ "call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
@@ -169,7 +169,7 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
- "call VDSO32_vsyscall \n"
+ "call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
diff --git a/arch/x86/vdso/vdso.S b/arch/x86/vdso/vdso.S
deleted file mode 100644
index be3f23b..0000000
--- a/arch/x86/vdso/vdso.S
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdso, "arch/x86/vdso/vdso.so")
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
new file mode 100644
index 0000000..976e8e4
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.c
@@ -0,0 +1,142 @@
+#include <inttypes.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <err.h>
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <linux/elf.h>
+#include <linux/types.h>
+
+/* Symbols that we need in vdso2c. */
+char const * const required_syms[] = {
+ "VDSO32_NOTE_MASK",
+ "VDSO32_SYSENTER_RETURN",
+ "__kernel_vsyscall",
+ "__kernel_sigreturn",
+ "__kernel_rt_sigreturn",
+};
+
+__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
+static void fail(const char *format, ...)
+{
+ va_list ap;
+ va_start(ap, format);
+ fprintf(stderr, "Error: ");
+ vfprintf(stderr, format, ap);
+ exit(1);
+ va_end(ap);
+}
+
+#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
+
+#define BITS 64
+#define GOFUNC go64
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Phdr Elf64_Phdr
+#define Elf_Sym Elf64_Sym
+#define Elf_Dyn Elf64_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+#define BITS 32
+#define GOFUNC go32
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Phdr Elf32_Phdr
+#define Elf_Sym Elf32_Sym
+#define Elf_Dyn Elf32_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+static int go(void *addr, size_t len, FILE *outfile, const char *name)
+{
+ Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
+
+ if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
+ return go64(addr, len, outfile, name);
+ } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
+ return go32(addr, len, outfile, name);
+ } else {
+ fprintf(stderr, "Error: unknown ELF class\n");
+ return 1;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int fd;
+ off_t len;
+ void *addr;
+ FILE *outfile;
+ int ret;
+ char *name, *tmp;
+ int namelen;
+
+ if (argc != 3) {
+ printf("Usage: vdso2c INPUT OUTPUT\n");
+ return 1;
+ }
+
+ /*
+ * Figure out the struct name. If we're writing to a .so file,
+ * generate raw output insted.
+ */
+ name = strdup(argv[2]);
+ namelen = strlen(name);
+ if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
+ name = NULL;
+ } else {
+ tmp = strrchr(name, '/');
+ if (tmp)
+ name = tmp + 1;
+ tmp = strchr(name, '.');
+ if (tmp)
+ *tmp = '\0';
+ for (tmp = name; *tmp; tmp++)
+ if (*tmp == '-')
+ *tmp = '_';
+ }
+
+ fd = open(argv[1], O_RDONLY);
+ if (fd == -1)
+ err(1, "%s", argv[1]);
+
+ len = lseek(fd, 0, SEEK_END);
+ if (len == (off_t)-1)
+ err(1, "lseek");
+
+ addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ if (addr == MAP_FAILED)
+ err(1, "mmap");
+
+ outfile = fopen(argv[2], "w");
+ if (!outfile)
+ err(1, "%s", argv[2]);
+
+ ret = go(addr, (size_t)len, outfile, name);
+
+ munmap(addr, len);
+ fclose(outfile);
+
+ return ret;
+}
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
new file mode 100644
index 0000000..9276e52
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.h
@@ -0,0 +1,137 @@
+/*
+ * This file is included twice from vdso2c.c. It generates code for 32-bit
+ * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
+ * are built for 32-bit userspace.
+ */
+
+static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+{
+ int found_load = 0;
+ unsigned long load_size = -1; /* Work around bogus warning */
+ unsigned long data_size;
+ Elf_Ehdr *hdr = (Elf_Ehdr *)addr;
+ int i;
+ unsigned long j;
+ Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
+ *alt_sec = NULL;
+ Elf_Dyn *dyn = 0, *dyn_end = 0;
+ const char *secstrings;
+ uint64_t syms[NSYMS] = {};
+
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
+
+ /* Walk the segment table. */
+ for (i = 0; i < hdr->e_phnum; i++) {
+ if (pt[i].p_type == PT_LOAD) {
+ if (found_load)
+ fail("multiple PT_LOAD segs\n");
+
+ if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
+ fail("PT_LOAD in wrong place\n");
+
+ if (pt[i].p_memsz != pt[i].p_filesz)
+ fail("cannot handle memsz != filesz\n");
+
+ load_size = pt[i].p_memsz;
+ found_load = 1;
+ } else if (pt[i].p_type == PT_DYNAMIC) {
+ dyn = addr + pt[i].p_offset;
+ dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
+ }
+ }
+ if (!found_load)
+ fail("no PT_LOAD seg\n");
+ data_size = (load_size + 4095) / 4096 * 4096;
+
+ /* Walk the dynamic table */
+ for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
+ if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
+ dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
+ fail("vdso image contains dynamic relocations\n");
+ }
+
+ /* Walk the section table */
+ secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
+ secstrings = addr + secstrings_hdr->sh_offset;
+ for (i = 0; i < hdr->e_shnum; i++) {
+ Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
+ if (sh->sh_type == SHT_SYMTAB)
+ symtab_hdr = sh;
+
+ if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
+ alt_sec = sh;
+ }
+
+ if (!symtab_hdr) {
+ fail("no symbol table\n");
+ return 1;
+ }
+
+ strtab_hdr = addr + hdr->e_shoff +
+ hdr->e_shentsize * symtab_hdr->sh_link;
+
+ /* Walk the symbol table */
+ for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
+ int k;
+ Elf_Sym *sym = addr + symtab_hdr->sh_offset +
+ symtab_hdr->sh_entsize * i;
+ const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
+ for (k = 0; k < NSYMS; k++) {
+ if (!strcmp(name, required_syms[k])) {
+ if (syms[k]) {
+ fail("duplicate symbol %s\n",
+ required_syms[k]);
+ }
+ syms[k] = sym->st_value;
+ }
+ }
+ }
+
+ /* Remove sections. */
+ hdr->e_shoff = 0;
+ hdr->e_shentsize = 0;
+ hdr->e_shnum = 0;
+ hdr->e_shstrndx = SHN_UNDEF;
+
+ if (!name) {
+ fwrite(addr, load_size, 1, outfile);
+ return 0;
+ }
+
+ fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
+ fprintf(outfile, "#include <linux/linkage.h>\n");
+ fprintf(outfile, "#include <asm/page_types.h>\n");
+ fprintf(outfile, "#include <asm/vdso.h>\n");
+ fprintf(outfile, "\n");
+ fprintf(outfile,
+ "static unsigned char raw_data[%lu] __page_aligned_data = {",
+ data_size);
+ for (j = 0; j < load_size; j++) {
+ if (j % 10 == 0)
+ fprintf(outfile, "\n\t");
+ fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]);
+ }
+ fprintf(outfile, "\n};\n\n");
+
+ fprintf(outfile, "static struct page *pages[%lu];\n\n",
+ data_size / 4096);
+
+ fprintf(outfile, "const struct vdso_image %s = {\n", name);
+ fprintf(outfile, "\t.data = raw_data,\n");
+ fprintf(outfile, "\t.size = %lu,\n", data_size);
+ fprintf(outfile, "\t.pages = pages,\n");
+ if (alt_sec) {
+ fprintf(outfile, "\t.alt = %lu,\n",
+ (unsigned long)alt_sec->sh_offset);
+ fprintf(outfile, "\t.alt_len = %lu,\n",
+ (unsigned long)alt_sec->sh_size);
+ }
+ for (i = 0; i < NSYMS; i++) {
+ if (syms[i])
+ fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n",
+ required_syms[i], syms[i]);
+ }
+ fprintf(outfile, "};\n");
+
+ return 0;
+}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 9c78d5b..d414601 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -29,6 +29,7 @@
#include <asm/fixmap.h>
#include <asm/hpet.h>
#include <asm/vvar.h>
+#include <asm/vdso32.h>
#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT 0
@@ -67,9 +68,6 @@ __setup("vdso32=", vdso32_setup);
__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif
-static struct page **vdso32_pages;
-static unsigned vdso32_size;
-
#ifdef CONFIG_X86_64
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
@@ -82,34 +80,23 @@ static unsigned vdso32_size;
#endif /* CONFIG_X86_64 */
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+const struct vdso_image *selected_vdso32;
+#endif
+
int __init sysenter_setup(void)
{
- char *vdso32_start, *vdso32_end;
- int npages, i;
-
#ifdef CONFIG_COMPAT
- if (vdso32_syscall()) {
- vdso32_start = vdso32_syscall_start;
- vdso32_end = vdso32_syscall_end;
- vdso32_pages = vdso32_syscall_pages;
- } else
+ if (vdso32_syscall())
+ selected_vdso32 = &vdso_image_32_syscall;
+ else
#endif
- if (vdso32_sysenter()) {
- vdso32_start = vdso32_sysenter_start;
- vdso32_end = vdso32_sysenter_end;
- vdso32_pages = vdso32_sysenter_pages;
- } else {
- vdso32_start = vdso32_int80_start;
- vdso32_end = vdso32_int80_end;
- vdso32_pages = vdso32_int80_pages;
- }
-
- npages = ((vdso32_end - vdso32_start) + PAGE_SIZE - 1) / PAGE_SIZE;
- vdso32_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdso32_pages[i] = virt_to_page(vdso32_start + i*PAGE_SIZE);
+ if (vdso32_sysenter())
+ selected_vdso32 = &vdso_image_32_sysenter;
+ else
+ selected_vdso32 = &vdso_image_32_int80;
- patch_vdso32(vdso32_start, vdso32_size);
+ init_vdso_image(selected_vdso32);
return 0;
}
@@ -121,6 +108,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
unsigned long addr;
int ret = 0;
struct vm_area_struct *vma;
+ unsigned long vdso32_size = selected_vdso32->size;
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
@@ -140,7 +128,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
addr += VDSO_OFFSET(VDSO_PREV_PAGES);
- current->mm->context.vdso = (void *)addr;
+ current->mm->context.vdso = (void __user *)addr;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
@@ -150,7 +138,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
vdso32_size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso32_pages);
+ selected_vdso32->pages);
if (ret)
goto up_fail;
@@ -188,8 +176,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
}
#endif
- current_thread_info()->sysenter_return =
- VDSO32_SYMBOL(addr, SYSENTER_RETURN);
+ if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
+ current_thread_info()->sysenter_return =
+ current->mm->context.vdso +
+ selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
up_fail:
if (ret)
diff --git a/arch/x86/vdso/vdso32.S b/arch/x86/vdso/vdso32.S
deleted file mode 100644
index 018bcd9..0000000
--- a/arch/x86/vdso/vdso32.S
+++ /dev/null
@@ -1,9 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdso32_int80, "arch/x86/vdso/vdso32-int80.so")
-
-#ifdef CONFIG_COMPAT
-DEFINE_VDSO_IMAGE(vdso32_syscall, "arch/x86/vdso/vdso32-syscall.so")
-#endif
-
-DEFINE_VDSO_IMAGE(vdso32_sysenter, "arch/x86/vdso/vdso32-sysenter.so")
diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S
index aadb8b9..f072095 100644
--- a/arch/x86/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/vdso/vdso32/vdso32.lds.S
@@ -38,13 +38,3 @@ VERSION
local: *;
};
}
-
-/*
- * Symbols we define here called VDSO* get their values into vdso32-syms.h.
- */
-VDSO32_vsyscall = __kernel_vsyscall;
-VDSO32_sigreturn = __kernel_sigreturn;
-VDSO32_rt_sigreturn = __kernel_rt_sigreturn;
-VDSO32_clock_gettime = clock_gettime;
-VDSO32_gettimeofday = gettimeofday;
-VDSO32_time = time;
diff --git a/arch/x86/vdso/vdsox32.S b/arch/x86/vdso/vdsox32.S
deleted file mode 100644
index f4aa34e..0000000
--- a/arch/x86/vdso/vdsox32.S
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdsox32, "arch/x86/vdso/vdsox32.so")
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 8b79039..cf21762 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -19,99 +19,31 @@
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
-DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
-static unsigned vdso_size;
-
-#ifdef CONFIG_X86_X32_ABI
-DECLARE_VDSO_IMAGE(vdsox32);
-static unsigned vdsox32_size;
-#endif
#endif
-#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \
- defined(CONFIG_COMPAT)
-void __init patch_vdso32(void *vdso, size_t len)
+void __init init_vdso_image(const struct vdso_image *image)
{
- Elf32_Ehdr *hdr = vdso;
- Elf32_Shdr *sechdrs, *alt_sec = 0;
- char *secstrings;
- void *alt_data;
int i;
+ int npages = (image->size) / PAGE_SIZE;
- BUG_ON(len < sizeof(Elf32_Ehdr));
- BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
-
- sechdrs = (void *)hdr + hdr->e_shoff;
- secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-
- for (i = 1; i < hdr->e_shnum; i++) {
- Elf32_Shdr *shdr = &sechdrs[i];
- if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
- alt_sec = shdr;
- goto found;
- }
- }
-
- /* If we get here, it's probably a bug. */
- pr_warning("patch_vdso32: .altinstructions not found\n");
- return; /* nothing to patch */
+ BUG_ON(image->size % PAGE_SIZE != 0);
+ for (i = 0; i < npages; i++)
+ image->pages[i] = virt_to_page(image->data + i*PAGE_SIZE);
-found:
- alt_data = (void *)hdr + alt_sec->sh_offset;
- apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
+ apply_alternatives((struct alt_instr *)(image->data + image->alt),
+ (struct alt_instr *)(image->data + image->alt +
+ image->alt_len));
}
-#endif
-
-#if defined(CONFIG_X86_64)
-static void __init patch_vdso64(void *vdso, size_t len)
-{
- Elf64_Ehdr *hdr = vdso;
- Elf64_Shdr *sechdrs, *alt_sec = 0;
- char *secstrings;
- void *alt_data;
- int i;
- BUG_ON(len < sizeof(Elf64_Ehdr));
- BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
-
- sechdrs = (void *)hdr + hdr->e_shoff;
- secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-
- for (i = 1; i < hdr->e_shnum; i++) {
- Elf64_Shdr *shdr = &sechdrs[i];
- if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
- alt_sec = shdr;
- goto found;
- }
- }
-
- /* If we get here, it's probably a bug. */
- pr_warning("patch_vdso64: .altinstructions not found\n");
- return; /* nothing to patch */
-
-found:
- alt_data = (void *)hdr + alt_sec->sh_offset;
- apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
-}
+#if defined(CONFIG_X86_64)
static int __init init_vdso(void)
{
- int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE;
- int i;
-
- patch_vdso64(vdso_start, vdso_end - vdso_start);
-
- vdso_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE);
+ init_vdso_image(&vdso_image_64);
#ifdef CONFIG_X86_X32_ABI
- patch_vdso32(vdsox32_start, vdsox32_end - vdsox32_start);
- npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE;
- vdsox32_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdsox32_pages[i] = virt_to_page(vdsox32_start + i*PAGE_SIZE);
+ init_vdso_image(&vdso_image_x32);
#endif
return 0;
@@ -171,7 +103,7 @@ static int setup_additional_pages(struct linux_binprm *bprm,
goto up_fail;
}
- current->mm->context.vdso = (void *)addr;
+ current->mm->context.vdso = (void __user *)addr;
ret = install_special_mapping(mm, addr, size,
VM_READ|VM_EXEC|
@@ -189,15 +121,15 @@ up_fail:
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_pages,
- vdso_size);
+ return setup_additional_pages(bprm, uses_interp, vdso_image_64.pages,
+ vdso_image_64.size);
}
#ifdef CONFIG_X86_X32_ABI
int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdsox32_pages,
- vdsox32_size);
+ return setup_additional_pages(bprm, uses_interp, vdso_image_x32.pages,
+ vdso_image_x32.size);
}
#endif
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 0982233..7225a95 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -516,10 +516,17 @@ char * __init xen_memory_setup(void)
static void __init fiddle_vdso(void)
{
#ifdef CONFIG_X86_32
+ /*
+ * This could be called before selected_vdso32 is initialized, so
+ * just fiddle with both possible images. vdso_image_32_syscall
+ * can't be selected, since it only exists on 64-bit systems.
+ */
u32 *mask;
- mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
+ mask = vdso_image_32_int80.data +
+ vdso_image_32_int80.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
- mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
+ mask = vdso_image_32_sysenter.data +
+ vdso_image_32_sysenter.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
#endif
}
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 5/7] x86: Move the 32-bit vdso special pages after the text
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
` (3 preceding siblings ...)
2014-05-05 19:19 ` [PATCH v5 4/7] x86: Reimplement vdso.so preparation in build-time C Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 6/7] x86: Move the vvar and hpet mappings next to the 64-bit vDSO Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 7/7] x86: Remove vestiges of VDSO_PRELINK and some outdated comments Andy Lutomirski
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
This unifies the vdso mapping code and teaches it how to map special
pages at addresses corresponding to symbols in the vdso image. The
new code is used for all vdso variants, but so far only the 32-bit
variants use the new vvar page position.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/include/asm/elf.h | 8 +--
arch/x86/include/asm/vdso.h | 4 ++
arch/x86/include/asm/vdso32.h | 11 ----
arch/x86/vdso/vdso-layout.lds.S | 42 ++++++++-----
arch/x86/vdso/vdso2c.c | 14 +++++
arch/x86/vdso/vdso2c.h | 17 ++++++
arch/x86/vdso/vdso32-setup.c | 115 +-----------------------------------
arch/x86/vdso/vma.c | 128 +++++++++++++++++++++++++++++++++-------
8 files changed, 173 insertions(+), 166 deletions(-)
delete mode 100644 arch/x86/include/asm/vdso32.h
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 65b21bc..1a055c8 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -333,11 +333,9 @@ struct linux_binprm;
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
-extern int x32_setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp);
-
-extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
-#define compat_arch_setup_additional_pages syscall32_setup_pages
+extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp);
+#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 389fe2c..d0a2c90 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -14,6 +14,10 @@ struct vdso_image {
unsigned long alt, alt_len;
+ unsigned long sym_end_mapping; /* Total size of the mapping */
+
+ unsigned long sym_vvar_page;
+ unsigned long sym_hpet_page;
unsigned long sym_VDSO32_NOTE_MASK;
unsigned long sym___kernel_sigreturn;
unsigned long sym___kernel_rt_sigreturn;
diff --git a/arch/x86/include/asm/vdso32.h b/arch/x86/include/asm/vdso32.h
deleted file mode 100644
index 7efb701..0000000
--- a/arch/x86/include/asm/vdso32.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef _ASM_X86_VDSO32_H
-#define _ASM_X86_VDSO32_H
-
-#define VDSO_BASE_PAGE 0
-#define VDSO_VVAR_PAGE 1
-#define VDSO_HPET_PAGE 2
-#define VDSO_PAGES 3
-#define VDSO_PREV_PAGES 2
-#define VDSO_OFFSET(x) ((x) * PAGE_SIZE)
-
-#endif
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index 9df017a..e177c08 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -1,3 +1,5 @@
+#include <asm/vdso.h>
+
/*
* Linker script for vDSO. This is an ELF shared object prelinked to
* its virtual address, and with only one read-only segment.
@@ -6,20 +8,6 @@
SECTIONS
{
-#ifdef BUILD_VDSO32
-#include <asm/vdso32.h>
-
- hpet_page = . - VDSO_OFFSET(VDSO_HPET_PAGE);
-
- vvar = . - VDSO_OFFSET(VDSO_VVAR_PAGE);
-
- /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar + offset;
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR
-#endif
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
@@ -59,11 +47,33 @@ SECTIONS
.text : { *(.text*) } :text =0x90909090,
+#ifdef BUILD_VDSO32
/*
- * The comma above works around a bug in gold:
- * https://sourceware.org/bugzilla/show_bug.cgi?id=16804
+ * The remainder of the vDSO consists of special pages that are
+ * shared between the kernel and userspace. It needs to be at the
+ * end so that it doesn't overlap the mapping of the actual
+ * vDSO image.
*/
+ . = ALIGN(PAGE_SIZE);
+ vvar_page = .;
+
+ /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+ . = vvar_page + PAGE_SIZE;
+
+ hpet_page = .;
+ . = . + PAGE_SIZE;
+#endif
+
+ . = ALIGN(PAGE_SIZE);
+ end_mapping = .;
+
/DISCARD/ : {
*(.discard)
*(.discard.*)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 976e8e4..81edd1e 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -15,7 +15,21 @@
#include <linux/types.h>
/* Symbols that we need in vdso2c. */
+enum {
+ sym_vvar_page,
+ sym_hpet_page,
+ sym_end_mapping,
+};
+
+const int special_pages[] = {
+ sym_vvar_page,
+ sym_hpet_page,
+};
+
char const * const required_syms[] = {
+ [sym_vvar_page] = "vvar_page",
+ [sym_hpet_page] = "hpet_page",
+ [sym_end_mapping] = "end_mapping",
"VDSO32_NOTE_MASK",
"VDSO32_SYSENTER_RETURN",
"__kernel_vsyscall",
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 9276e52..ed2e894 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -87,6 +87,23 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
}
}
+ /* Validate mapping addresses. */
+ for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
+ if (!syms[i])
+ continue; /* The mapping isn't used; ignore it. */
+
+ if (syms[i] % 4096)
+ fail("%s must be a multiple of 4096\n",
+ required_syms[i]);
+ if (syms[i] < data_size)
+ fail("%s must be after the text mapping\n",
+ required_syms[i]);
+ if (syms[sym_end_mapping] < syms[i] + 4096)
+ fail("%s overruns end_mapping\n", required_syms[i]);
+ }
+ if (syms[sym_end_mapping] % 4096)
+ fail("end_mapping must be a multiple of 4096\n");
+
/* Remove sections. */
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index d414601..c3ed708 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -8,28 +8,12 @@
#include <linux/init.h>
#include <linux/smp.h>
-#include <linux/thread_info.h>
-#include <linux/sched.h>
-#include <linux/gfp.h>
-#include <linux/string.h>
-#include <linux/elf.h>
-#include <linux/mm.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
#include <asm/cpufeature.h>
-#include <asm/msr.h>
-#include <asm/pgtable.h>
-#include <asm/unistd.h>
-#include <asm/elf.h>
-#include <asm/tlbflush.h>
+#include <asm/processor.h>
#include <asm/vdso.h>
-#include <asm/proto.h>
-#include <asm/fixmap.h>
-#include <asm/hpet.h>
-#include <asm/vvar.h>
-#include <asm/vdso32.h>
#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT 0
@@ -37,10 +21,6 @@
#define VDSO_DEFAULT 1
#endif
-#ifdef CONFIG_X86_64
-#define arch_setup_additional_pages syscall32_setup_pages
-#endif
-
/*
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
@@ -101,95 +81,6 @@ int __init sysenter_setup(void)
return 0;
}
-/* Setup a VMA at program startup for the vsyscall page */
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
-{
- struct mm_struct *mm = current->mm;
- unsigned long addr;
- int ret = 0;
- struct vm_area_struct *vma;
- unsigned long vdso32_size = selected_vdso32->size;
-
-#ifdef CONFIG_X86_X32_ABI
- if (test_thread_flag(TIF_X32))
- return x32_setup_additional_pages(bprm, uses_interp);
-#endif
-
- if (vdso32_enabled != 1) /* Other values all mean "disabled" */
- return 0;
-
- down_write(&mm->mmap_sem);
-
- addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
- }
-
- addr += VDSO_OFFSET(VDSO_PREV_PAGES);
-
- current->mm->context.vdso = (void __user *)addr;
-
- /*
- * MAYWRITE to allow gdb to COW and set breakpoints
- */
- ret = install_special_mapping(mm,
- addr,
- vdso32_size,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- selected_vdso32->pages);
-
- if (ret)
- goto up_fail;
-
- vma = _install_special_mapping(mm,
- addr - VDSO_OFFSET(VDSO_PREV_PAGES),
- VDSO_OFFSET(VDSO_PREV_PAGES),
- VM_READ,
- NULL);
-
- if (IS_ERR(vma)) {
- ret = PTR_ERR(vma);
- goto up_fail;
- }
-
- ret = remap_pfn_range(vma,
- addr - VDSO_OFFSET(VDSO_VVAR_PAGE),
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
- PAGE_SIZE,
- PAGE_READONLY);
-
- if (ret)
- goto up_fail;
-
-#ifdef CONFIG_HPET_TIMER
- if (hpet_address) {
- ret = io_remap_pfn_range(vma,
- addr - VDSO_OFFSET(VDSO_HPET_PAGE),
- hpet_address >> PAGE_SHIFT,
- PAGE_SIZE,
- pgprot_noncached(PAGE_READONLY));
-
- if (ret)
- goto up_fail;
- }
-#endif
-
- if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
- current_thread_info()->sysenter_return =
- current->mm->context.vdso +
- selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
-
- up_fail:
- if (ret)
- current->mm->context.vdso = NULL;
-
- up_write(&mm->mmap_sem);
-
- return ret;
-}
-
#ifdef CONFIG_X86_64
subsys_initcall(sysenter_setup);
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index cf21762..e915eae 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -15,6 +15,7 @@
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/page.h>
+#include <asm/hpet.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
@@ -36,7 +37,6 @@ void __init init_vdso_image(const struct vdso_image *image)
image->alt_len));
}
-
#if defined(CONFIG_X86_64)
static int __init init_vdso(void)
{
@@ -49,13 +49,16 @@ static int __init init_vdso(void)
return 0;
}
subsys_initcall(init_vdso);
+#endif
struct linux_binprm;
/* Put the vdso above the (randomized) stack with another randomized offset.
This way there is no hole in the middle of address space.
To save memory make sure it is still in the same PTE as the stack top.
- This doesn't give that many random bits */
+ This doesn't give that many random bits.
+
+ Only used for the 64-bit and x32 vdsos. */
static unsigned long vdso_addr(unsigned long start, unsigned len)
{
unsigned long addr, end;
@@ -81,23 +84,23 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
return addr;
}
-/* Setup a VMA at program startup for the vsyscall page.
- Not called for compat tasks */
-static int setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp,
- struct page **pages,
- unsigned size)
+static int map_vdso(const struct vdso_image *image, bool calculate_addr)
{
struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
unsigned long addr;
- int ret;
+ int ret = 0;
- if (!vdso64_enabled)
- return 0;
+ if (calculate_addr) {
+ addr = vdso_addr(current->mm->start_stack,
+ image->sym_end_mapping);
+ } else {
+ addr = 0;
+ }
down_write(&mm->mmap_sem);
- addr = vdso_addr(mm->start_stack, size);
- addr = get_unmapped_area(NULL, addr, size, 0, 0);
+
+ addr = get_unmapped_area(NULL, addr, image->sym_end_mapping, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
@@ -105,34 +108,115 @@ static int setup_additional_pages(struct linux_binprm *bprm,
current->mm->context.vdso = (void __user *)addr;
- ret = install_special_mapping(mm, addr, size,
+ /*
+ * MAYWRITE to allow gdb to COW and set breakpoints
+ */
+ ret = install_special_mapping(mm,
+ addr,
+ image->size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- pages);
- if (ret) {
- current->mm->context.vdso = NULL;
+ image->pages);
+
+ if (ret)
+ goto up_fail;
+
+ vma = _install_special_mapping(mm,
+ addr + image->size,
+ image->sym_end_mapping - image->size,
+ VM_READ,
+ NULL);
+
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
goto up_fail;
}
+ if (image->sym_vvar_page)
+ ret = remap_pfn_range(vma,
+ addr + image->sym_vvar_page,
+ __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
+ PAGE_SIZE,
+ PAGE_READONLY);
+
+ if (ret)
+ goto up_fail;
+
+#ifdef CONFIG_HPET_TIMER
+ if (hpet_address && image->sym_hpet_page) {
+ ret = io_remap_pfn_range(vma,
+ addr + image->sym_hpet_page,
+ hpet_address >> PAGE_SHIFT,
+ PAGE_SIZE,
+ pgprot_noncached(PAGE_READONLY));
+
+ if (ret)
+ goto up_fail;
+ }
+#endif
+
up_fail:
+ if (ret)
+ current->mm->context.vdso = NULL;
+
up_write(&mm->mmap_sem);
return ret;
}
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+static int load_vdso32(void)
+{
+ int ret;
+
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
+ return 0;
+
+ ret = map_vdso(selected_vdso32, false);
+ if (ret)
+ return ret;
+
+ if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
+ current_thread_info()->sysenter_return =
+ current->mm->context.vdso +
+ selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_X86_64
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_image_64.pages,
- vdso_image_64.size);
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_64, true);
}
+#ifdef CONFIG_COMPAT
+int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp)
+{
#ifdef CONFIG_X86_X32_ABI
-int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+ if (test_thread_flag(TIF_X32)) {
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_x32, true);
+ }
+#endif
+
+ return load_vdso32();
+}
+#endif
+#else
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_image_x32.pages,
- vdso_image_x32.size);
+ return load_vdso32();
}
#endif
+#ifdef CONFIG_X86_64
static __init int vdso_setup(char *s)
{
vdso64_enabled = simple_strtoul(s, NULL, 0);
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 6/7] x86: Move the vvar and hpet mappings next to the 64-bit vDSO
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
` (4 preceding siblings ...)
2014-05-05 19:19 ` [PATCH v5 5/7] x86: Move the 32-bit vdso special pages after the text Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 7/7] x86: Remove vestiges of VDSO_PRELINK and some outdated comments Andy Lutomirski
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
This makes the 64-bit and x32 vdsos use the same mechanism as the
32-bit vdso. Most of the churn is deleting all the old fixmap code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/include/asm/fixmap.h | 11 ++++-------
arch/x86/include/asm/vvar.h | 20 +-------------------
arch/x86/include/uapi/asm/vsyscall.h | 7 +------
arch/x86/kernel/cpu/common.c | 1 +
arch/x86/kernel/hpet.c | 3 ---
arch/x86/kernel/vsyscall_64.c | 15 ++++-----------
arch/x86/mm/fault.c | 5 +++--
arch/x86/mm/init_64.c | 10 +++++-----
arch/x86/vdso/vclock_gettime.c | 22 +++++-----------------
arch/x86/vdso/vdso-layout.lds.S | 2 --
arch/x86/xen/mmu.c | 8 +++-----
11 files changed, 27 insertions(+), 77 deletions(-)
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 43f482a..b0910f9 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -24,7 +24,7 @@
#include <linux/threads.h>
#include <asm/kmap_types.h>
#else
-#include <asm/vsyscall.h>
+#include <uapi/asm/vsyscall.h>
#endif
/*
@@ -41,7 +41,8 @@
extern unsigned long __FIXADDR_TOP;
#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
#else
-#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
+#define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
+ PAGE_SIZE)
#endif
@@ -68,11 +69,7 @@ enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_HOLE,
#else
- VSYSCALL_LAST_PAGE,
- VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
- + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
- VVAR_PAGE,
- VSYSCALL_HPET,
+ VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
#ifdef CONFIG_PARAVIRT_CLOCK
PVCLOCK_FIXMAP_BEGIN,
PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 081d909..5d2b9ad 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -29,31 +29,13 @@
#else
-#ifdef BUILD_VDSO32
+extern char __vvar_page;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name __attribute__((visibility("hidden")));
#define VVAR(name) (vvar_ ## name)
-#else
-
-extern char __vvar_page;
-
-/* Base address of vvars. This is not ABI. */
-#ifdef CONFIG_X86_64
-#define VVAR_ADDRESS (-10*1024*1024 - 4096)
-#else
-#define VVAR_ADDRESS (&__vvar_page)
-#endif
-
-#define DECLARE_VVAR(offset, type, name) \
- static type const * const vvaraddr_ ## name = \
- (void *)(VVAR_ADDRESS + (offset));
-
-#define VVAR(name) (*vvaraddr_ ## name)
-#endif
-
#define DEFINE_VVAR(type, name) \
type name \
__attribute__((section(".vvar_" #name), aligned(16))) __visible
diff --git a/arch/x86/include/uapi/asm/vsyscall.h b/arch/x86/include/uapi/asm/vsyscall.h
index 85dc1b3..b97dd6e 100644
--- a/arch/x86/include/uapi/asm/vsyscall.h
+++ b/arch/x86/include/uapi/asm/vsyscall.h
@@ -7,11 +7,6 @@ enum vsyscall_num {
__NR_vgetcpu,
};
-#define VSYSCALL_START (-10UL << 20)
-#define VSYSCALL_SIZE 1024
-#define VSYSCALL_END (-2UL << 20)
-#define VSYSCALL_MAPPED_PAGES 1
-#define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
-
+#define VSYSCALL_ADDR (-10UL << 20)
#endif /* _UAPI_ASM_X86_VSYSCALL_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7c65b46..2cbbf88 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -20,6 +20,7 @@
#include <asm/processor.h>
#include <asm/debugreg.h>
#include <asm/sections.h>
+#include <asm/vsyscall.h>
#include <linux/topology.h>
#include <linux/cpumask.h>
#include <asm/pgtable.h>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 8d80ae0..bbc15a0 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -74,9 +74,6 @@ static inline void hpet_writel(unsigned int d, unsigned int a)
static inline void hpet_set_mapping(void)
{
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
-#ifdef CONFIG_X86_64
- __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VVAR_NOCACHE);
-#endif
}
static inline void hpet_clear_mapping(void)
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 8b3b3eb..ea5b570 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -91,7 +91,7 @@ static int addr_to_vsyscall_nr(unsigned long addr)
{
int nr;
- if ((addr & ~0xC00UL) != VSYSCALL_START)
+ if ((addr & ~0xC00UL) != VSYSCALL_ADDR)
return -EINVAL;
nr = (addr & 0xC00UL) >> 10;
@@ -330,24 +330,17 @@ void __init map_vsyscall(void)
{
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
- unsigned long physaddr_vvar_page = __pa_symbol(&__vvar_page);
- __set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_vsyscall,
+ __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
- BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_FIRST_PAGE) !=
- (unsigned long)VSYSCALL_START);
-
- __set_fixmap(VVAR_PAGE, physaddr_vvar_page, PAGE_KERNEL_VVAR);
- BUILD_BUG_ON((unsigned long)__fix_to_virt(VVAR_PAGE) !=
- (unsigned long)VVAR_ADDRESS);
+ BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
+ (unsigned long)VSYSCALL_ADDR);
}
static int __init vsyscall_init(void)
{
- BUG_ON(VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE));
-
cpu_notifier_register_begin();
on_each_cpu(cpu_vsyscall_init, NULL, 1);
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8e57229..858b47b 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -18,7 +18,8 @@
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
-#include <asm/fixmap.h> /* VSYSCALL_START */
+#include <asm/fixmap.h> /* VSYSCALL_ADDR */
+#include <asm/vsyscall.h> /* emulate_vsyscall */
#define CREATE_TRACE_POINTS
#include <asm/trace/exceptions.h>
@@ -771,7 +772,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
* emulation.
*/
if (unlikely((error_code & PF_INSTR) &&
- ((address & ~0xfff) == VSYSCALL_START))) {
+ ((address & ~0xfff) == VSYSCALL_ADDR))) {
if (emulate_vsyscall(regs, address))
return;
}
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 5638496..6f88184 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1055,8 +1055,8 @@ void __init mem_init(void)
after_bootmem = 1;
/* Register memory areas for /proc/kcore */
- kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
- VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
+ kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
+ PAGE_SIZE, KCORE_OTHER);
mem_init_print_info(NULL);
}
@@ -1186,8 +1186,8 @@ int kern_addr_valid(unsigned long addr)
* not need special handling anymore:
*/
static struct vm_area_struct gate_vma = {
- .vm_start = VSYSCALL_START,
- .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
+ .vm_start = VSYSCALL_ADDR,
+ .vm_end = VSYSCALL_ADDR + PAGE_SIZE,
.vm_page_prot = PAGE_READONLY_EXEC,
.vm_flags = VM_READ | VM_EXEC
};
@@ -1218,7 +1218,7 @@ int in_gate_area(struct mm_struct *mm, unsigned long addr)
*/
int in_gate_area_no_mm(unsigned long addr)
{
- return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
+ return (addr & PAGE_MASK) == VSYSCALL_ADDR;
}
const char *arch_vma_name(struct vm_area_struct *vma)
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 091554c..b2e4f49 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -30,9 +30,12 @@ extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
extern time_t __vdso_time(time_t *t);
#ifdef CONFIG_HPET_TIMER
-static inline u32 read_hpet_counter(const volatile void *addr)
+extern u8 hpet_page
+ __attribute__((visibility("hidden")));
+
+static notrace cycle_t vread_hpet(void)
{
- return *(const volatile u32 *) (addr + HPET_COUNTER);
+ return *(const volatile u32 *)(&hpet_page + HPET_COUNTER);
}
#endif
@@ -43,11 +46,6 @@ static inline u32 read_hpet_counter(const volatile void *addr)
#include <asm/fixmap.h>
#include <asm/pvclock.h>
-static notrace cycle_t vread_hpet(void)
-{
- return read_hpet_counter((const void *)fix_to_virt(VSYSCALL_HPET));
-}
-
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
@@ -137,16 +135,6 @@ static notrace cycle_t vread_pvclock(int *mode)
#else
-extern u8 hpet_page
- __attribute__((visibility("hidden")));
-
-#ifdef CONFIG_HPET_TIMER
-static notrace cycle_t vread_hpet(void)
-{
- return read_hpet_counter((const void *)(&hpet_page));
-}
-#endif
-
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index e177c08..2ec72f6 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -47,7 +47,6 @@ SECTIONS
.text : { *(.text*) } :text =0x90909090,
-#ifdef BUILD_VDSO32
/*
* The remainder of the vDSO consists of special pages that are
* shared between the kernel and userspace. It needs to be at the
@@ -69,7 +68,6 @@ SECTIONS
hpet_page = .;
. = . + PAGE_SIZE;
-#endif
. = ALIGN(PAGE_SIZE);
end_mapping = .;
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 86e02ea..3060568 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1494,7 +1494,7 @@ static int xen_pgd_alloc(struct mm_struct *mm)
page->private = (unsigned long)user_pgd;
if (user_pgd != NULL) {
- user_pgd[pgd_index(VSYSCALL_START)] =
+ user_pgd[pgd_index(VSYSCALL_ADDR)] =
__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
ret = 0;
}
@@ -2062,8 +2062,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
case FIX_KMAP_BEGIN ... FIX_KMAP_END:
# endif
#else
- case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
- case VVAR_PAGE:
+ case VSYSCALL_PAGE:
#endif
case FIX_TEXT_POKE0:
case FIX_TEXT_POKE1:
@@ -2104,8 +2103,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
#ifdef CONFIG_X86_64
/* Replicate changes to map the vsyscall page into the user
pagetable vsyscall mapping. */
- if ((idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) ||
- idx == VVAR_PAGE) {
+ if (idx == VSYSCALL_PAGE) {
unsigned long vaddr = __fix_to_virt(idx);
set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
}
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v5 7/7] x86: Remove vestiges of VDSO_PRELINK and some outdated comments
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
` (5 preceding siblings ...)
2014-05-05 19:19 ` [PATCH v5 6/7] x86: Move the vvar and hpet mappings next to the 64-bit vDSO Andy Lutomirski
@ 2014-05-05 19:19 ` Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
6 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-05 19:19 UTC (permalink / raw)
To: H. Peter Anvin, x86; +Cc: Stefani Seibold, linux-kernel, Andy Lutomirski
These definitions had no effect.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso.lds.S | 7 +------
arch/x86/vdso/vdso32/vdso32.lds.S | 5 +----
arch/x86/vdso/vdsox32.lds.S | 7 +------
3 files changed, 3 insertions(+), 16 deletions(-)
diff --git a/arch/x86/vdso/vdso.lds.S b/arch/x86/vdso/vdso.lds.S
index b96b267..75e3404 100644
--- a/arch/x86/vdso/vdso.lds.S
+++ b/arch/x86/vdso/vdso.lds.S
@@ -1,14 +1,11 @@
/*
* Linker script for 64-bit vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
-#define VDSO_PRELINK 0xffffffffff700000
#include "vdso-layout.lds.S"
/*
@@ -28,5 +25,3 @@ VERSION {
local: *;
};
}
-
-VDSO64_PRELINK = VDSO_PRELINK;
diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S
index f072095..31056cf 100644
--- a/arch/x86/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/vdso/vdso32/vdso32.lds.S
@@ -1,17 +1,14 @@
/*
* Linker script for 32-bit vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
#include <asm/page.h>
#define BUILD_VDSO32
-#define VDSO_PRELINK 0
#include "../vdso-layout.lds.S"
diff --git a/arch/x86/vdso/vdsox32.lds.S b/arch/x86/vdso/vdsox32.lds.S
index 62272aa..46b991b 100644
--- a/arch/x86/vdso/vdsox32.lds.S
+++ b/arch/x86/vdso/vdsox32.lds.S
@@ -1,14 +1,11 @@
/*
* Linker script for x32 vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
-#define VDSO_PRELINK 0
#include "vdso-layout.lds.S"
/*
@@ -24,5 +21,3 @@ VERSION {
local: *;
};
}
-
-VDSOX32_PRELINK = VDSO_PRELINK;
--
1.9.0
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, mm: Ensure correct alignment of the fixmap
2014-05-05 19:19 ` [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap Andy Lutomirski
@ 2014-05-05 22:24 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:24 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 73159fdcdb9be3eda61b846864352c29371baeb6
Gitweb: http://git.kernel.org/tip/73159fdcdb9be3eda61b846864352c29371baeb6
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:31 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:25 -0700
x86, mm: Ensure correct alignment of the fixmap
The early_ioremap code requires that its buffers not span a PMD
boundary. The logic for ensuring that only works if the fixmap is
aligned, so assert that it's aligned correctly.
To make this work reliably, reserve_top_address needs to be
adjusted.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e59a5f4362661f75dd4841fa74e1f2448045e245.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/mm/ioremap.c | 6 ++++++
arch/x86/mm/pgtable.c | 6 +++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 597ac15..6ef98c5 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -355,6 +355,12 @@ void __init early_ioremap_init(void)
{
pmd_t *pmd;
+#ifdef CONFIG_X86_64
+ BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#else
+ WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
+#endif
+
early_ioremap_setup();
pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index c96314a..5f8bdda 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -449,9 +449,9 @@ void __init reserve_top_address(unsigned long reserve)
{
#ifdef CONFIG_X86_32
BUG_ON(fixmaps_set > 0);
- printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
- (int)-reserve);
- __FIXADDR_TOP = -reserve - PAGE_SIZE;
+ __FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE;
+ printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n",
+ -reserve, __FIXADDR_TOP + PAGE_SIZE);
#endif
}
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Clean up 32-bit vs 64-bit vdso params
2014-05-05 19:19 ` [PATCH v5 2/7] x86: Clean up 32-bit vs 64-bit vdso params Andy Lutomirski
@ 2014-05-05 22:24 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:24 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 3d7ee969bffcc984c8aeaffc6ac6816fd929ace1
Gitweb: http://git.kernel.org/tip/3d7ee969bffcc984c8aeaffc6ac6816fd929ace1
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:32 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:40 -0700
x86, vdso: Clean up 32-bit vs 64-bit vdso params
Rather than using 'vdso_enabled' and an awful #define, just call the
parameters vdso32_enabled and vdso64_enabled.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/87913de56bdcbae3d93917938302fc369b05caee.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/elf.h | 20 +++++++++++++-------
arch/x86/um/vdso/vma.c | 2 +-
arch/x86/vdso/vdso32-setup.c | 19 ++++++++-----------
arch/x86/vdso/vma.c | 6 +++---
kernel/sysctl.c | 5 +++++
5 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 2c71182..e96df2c 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -75,7 +75,12 @@ typedef struct user_fxsr_struct elf_fpxregset_t;
#include <asm/vdso.h>
-extern unsigned int vdso_enabled;
+#ifdef CONFIG_X86_64
+extern unsigned int vdso64_enabled;
+#endif
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+extern unsigned int vdso32_enabled;
+#endif
/*
* This is used to ensure we don't load something for the wrong architecture.
@@ -269,9 +274,9 @@ extern int force_personality32;
struct task_struct;
-#define ARCH_DLINFO_IA32(vdso_enabled) \
+#define ARCH_DLINFO_IA32 \
do { \
- if (vdso_enabled) { \
+ if (vdso32_enabled) { \
NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
} \
@@ -281,7 +286,7 @@ do { \
#define STACK_RND_MASK (0x7ff)
-#define ARCH_DLINFO ARCH_DLINFO_IA32(vdso_enabled)
+#define ARCH_DLINFO ARCH_DLINFO_IA32
/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
@@ -292,14 +297,15 @@ do { \
#define ARCH_DLINFO \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)
+/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
#define ARCH_DLINFO_X32 \
do { \
- if (vdso_enabled) \
+ if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
(unsigned long)current->mm->context.vdso); \
} while (0)
@@ -310,7 +316,7 @@ do { \
if (test_thread_flag(TIF_X32)) \
ARCH_DLINFO_X32; \
else \
- ARCH_DLINFO_IA32(sysctl_vsyscall32)
+ ARCH_DLINFO_IA32
#define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index af91901..916cda4 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -12,7 +12,7 @@
#include <asm/page.h>
#include <linux/init.h>
-unsigned int __read_mostly vdso_enabled = 1;
+static unsigned int __read_mostly vdso_enabled = 1;
unsigned long um_vdso_addr;
extern unsigned long task_size;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0034898..5a657d9 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -37,7 +37,6 @@
#endif
#ifdef CONFIG_X86_64
-#define vdso_enabled sysctl_vsyscall32
#define arch_setup_additional_pages syscall32_setup_pages
#endif
@@ -45,13 +44,13 @@
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
*/
-unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
+unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
-static int __init vdso_setup(char *s)
+static int __init vdso32_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso32_enabled = simple_strtoul(s, NULL, 0);
- if (vdso_enabled > 1)
+ if (vdso32_enabled > 1)
pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
return 1;
@@ -62,12 +61,10 @@ static int __init vdso_setup(char *s)
* behavior on both 64-bit and 32-bit kernels.
* On 32-bit kernels, vdso=[012] means the same thing.
*/
-__setup("vdso32=", vdso_setup);
+__setup("vdso32=", vdso32_setup);
#ifdef CONFIG_X86_32
-__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
-
-EXPORT_SYMBOL_GPL(vdso_enabled);
+__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif
static struct page **vdso32_pages;
@@ -160,7 +157,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
return x32_setup_additional_pages(bprm, uses_interp);
#endif
- if (vdso_enabled != 1) /* Other values all mean "disabled" */
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
down_write(&mm->mmap_sem);
@@ -244,7 +241,7 @@ subsys_initcall(sysenter_setup);
static struct ctl_table abi_table2[] = {
{
.procname = "vsyscall32",
- .data = &sysctl_vsyscall32,
+ .data = &vdso32_enabled,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 1ad1026..8b79039 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -17,7 +17,7 @@
#include <asm/page.h>
#if defined(CONFIG_X86_64)
-unsigned int __read_mostly vdso_enabled = 1;
+unsigned int __read_mostly vdso64_enabled = 1;
DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
@@ -160,7 +160,7 @@ static int setup_additional_pages(struct linux_binprm *bprm,
unsigned long addr;
int ret;
- if (!vdso_enabled)
+ if (!vdso64_enabled)
return 0;
down_write(&mm->mmap_sem);
@@ -203,7 +203,7 @@ int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
static __init int vdso_setup(char *s)
{
- vdso_enabled = simple_strtoul(s, NULL, 0);
+ vdso64_enabled = simple_strtoul(s, NULL, 0);
return 0;
}
__setup("vdso=", vdso_setup);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b58..420d77a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1418,8 +1418,13 @@ static struct ctl_table vm_table[] = {
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
.procname = "vdso_enabled",
+#ifdef CONFIG_X86_32
+ .data = &vdso32_enabled,
+ .maxlen = sizeof(vdso32_enabled),
+#else
.data = &vdso_enabled,
.maxlen = sizeof(vdso_enabled),
+#endif
.mode = 0644,
.proc_handler = proc_dointvec,
.extra1 = &zero,
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
2014-05-05 19:19 ` [PATCH v5 3/7] x86: Move syscall and sysenter setup into kernel/cpu/common.c Andy Lutomirski
@ 2014-05-05 22:24 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:24 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: cfda7bb9ecbf9d96264bb5bade33a842966d1062
Gitweb: http://git.kernel.org/tip/cfda7bb9ecbf9d96264bb5bade33a842966d1062
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:33 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:47 -0700
x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c
This code is used during CPU setup, and it isn't strictly speaking
related to the 32-bit vdso. It's easier to understand how this
works when the code is closer to its callers.
This also lets syscall32_cpu_init be static, which might save some
trivial amount of kernel text.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/4e466987204e232d7b55a53ff6b9739f12237461.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/proto.h | 2 --
arch/x86/kernel/cpu/common.c | 32 ++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso32-setup.c | 30 ------------------------------
3 files changed, 32 insertions(+), 32 deletions(-)
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 6fd3fd7..a90f897 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -12,8 +12,6 @@ void ia32_syscall(void);
void ia32_cstar_target(void);
void ia32_sysenter_target(void);
-void syscall32_cpu_init(void);
-
void x86_configure_nx(void);
void x86_report_nx(void);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index a135239..7c65b46 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -953,6 +953,38 @@ static void vgetcpu_set_mode(void)
else
vgetcpu_mode = VGETCPU_LSL;
}
+
+/* May not be __init: called during resume */
+static void syscall32_cpu_init(void)
+{
+ /* Load these always in case some future AMD CPU supports
+ SYSENTER from compat mode too. */
+ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
+ wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
+ wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
+
+ wrmsrl(MSR_CSTAR, ia32_cstar_target);
+}
+#endif
+
+#ifdef CONFIG_X86_32
+void enable_sep_cpu(void)
+{
+ int cpu = get_cpu();
+ struct tss_struct *tss = &per_cpu(init_tss, cpu);
+
+ if (!boot_cpu_has(X86_FEATURE_SEP)) {
+ put_cpu();
+ return;
+ }
+
+ tss->x86_tss.ss1 = __KERNEL_CS;
+ tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
+ wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+ wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
+ wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
+ put_cpu();
+}
#endif
void __init identify_boot_cpu(void)
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 5a657d9..9c78d5b 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -75,41 +75,11 @@ static unsigned vdso32_size;
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
-/* May not be __init: called during resume */
-void syscall32_cpu_init(void)
-{
- /* Load these always in case some future AMD CPU supports
- SYSENTER from compat mode too. */
- wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
- wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
- wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
-
- wrmsrl(MSR_CSTAR, ia32_cstar_target);
-}
-
#else /* CONFIG_X86_32 */
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
#define vdso32_syscall() (0)
-void enable_sep_cpu(void)
-{
- int cpu = get_cpu();
- struct tss_struct *tss = &per_cpu(init_tss, cpu);
-
- if (!boot_cpu_has(X86_FEATURE_SEP)) {
- put_cpu();
- return;
- }
-
- tss->x86_tss.ss1 = __KERNEL_CS;
- tss->x86_tss.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
- wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
- wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
- wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
- put_cpu();
-}
-
#endif /* CONFIG_X86_64 */
int __init sysenter_setup(void)
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-05 19:19 ` [PATCH v5 4/7] x86: Reimplement vdso.so preparation in build-time C Andy Lutomirski
@ 2014-05-05 22:25 ` tip-bot for Andy Lutomirski
2014-05-29 19:17 ` Paul Gortmaker
0 siblings, 1 reply; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:25 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:34 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:51 -0700
x86, vdso: Reimplement vdso.so preparation in build-time C
Currently, vdso.so files are prepared and analyzed by a combination
of objcopy, nm, some linker script tricks, and some simple ELF
parsers in the kernel. Replace all of that with plain C code that
runs at build time.
All five vdso images now generate .c files that are compiled and
linked in to the kernel image.
This should cause only one userspace-visible change: the loaded vDSO
images are stripped more heavily than they used to be. Everything
outside the loadable segment is dropped. In particular, this causes
the section table and section name strings to be missing. This
should be fine: real dynamic loaders don't load or inspect these
tables anyway. The result is roughly equivalent to eu-strip's
--strip-sections option.
The purpose of this change is to enable the vvar and hpet mappings
to be moved to the page following the vDSO load segment. Currently,
it is possible for the section table to extend into the page after
the load segment, so, if we map it, it risks overlapping the vvar or
hpet page. This happens whenever the load segment is just under a
multiple of PAGE_SIZE.
The only real subtlety here is that the old code had a C file with
inline assembler that did 'call VDSO32_vsyscall' and a linker script
that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most
likely worked by accident: the linker script entry defines a symbol
associated with an address as opposed to an alias for the real
dynamic symbol __kernel_vsyscall. That caused ld to relocate the
reference at link time instead of leaving an interposable dynamic
relocation. Since the VDSO32_vsyscall hack is no longer needed, I
now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
work. vdso2c will generate an error and abort the build if the
resulting image contains any dynamic relocations, so we won't
silently generate bad vdso images.
(Dynamic relocations are a problem because nothing will even attempt
to relocate the vdso.)
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/ia32/ia32_signal.c | 8 +--
arch/x86/include/asm/elf.h | 7 +-
arch/x86/include/asm/mmu.h | 2 +-
arch/x86/include/asm/vdso.h | 70 +++++++------------
arch/x86/kernel/signal.c | 6 +-
arch/x86/mm/init_64.c | 3 +-
arch/x86/vdso/.gitignore | 5 +-
arch/x86/vdso/Makefile | 90 +++++++++---------------
arch/x86/vdso/vclock_gettime.c | 4 +-
arch/x86/vdso/vdso.S | 3 -
arch/x86/vdso/vdso2c.c | 142 ++++++++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso2c.h | 137 ++++++++++++++++++++++++++++++++++++
arch/x86/vdso/vdso32-setup.c | 50 ++++++--------
arch/x86/vdso/vdso32.S | 9 ---
arch/x86/vdso/vdso32/vdso32.lds.S | 10 ---
arch/x86/vdso/vdsox32.S | 3 -
arch/x86/vdso/vma.c | 100 +++++----------------------
arch/x86/xen/setup.c | 11 ++-
18 files changed, 400 insertions(+), 260 deletions(-)
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 2206757..f9e181a 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -383,8 +383,8 @@ int ia32_setup_frame(int sig, struct ksignal *ksig,
} else {
/* Return stub is in 32bit vsyscall page */
if (current->mm->context.vdso)
- restorer = VDSO32_SYMBOL(current->mm->context.vdso,
- sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
}
@@ -462,8 +462,8 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
else
- restorer = VDSO32_SYMBOL(current->mm->context.vdso,
- rt_sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_rt_sigreturn;
put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
/*
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index e96df2c..65b21bc 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -299,7 +299,7 @@ do { \
do { \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
- (unsigned long)current->mm->context.vdso); \
+ (unsigned long __force)current->mm->context.vdso); \
} while (0)
/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
@@ -307,7 +307,7 @@ do { \
do { \
if (vdso64_enabled) \
NEW_AUX_ENT(AT_SYSINFO_EHDR, \
- (unsigned long)current->mm->context.vdso); \
+ (unsigned long __force)current->mm->context.vdso); \
} while (0)
#define AT_SYSINFO 32
@@ -325,7 +325,8 @@ else \
#define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
#define VDSO_ENTRY \
- ((unsigned long)VDSO32_SYMBOL(VDSO_CURRENT_BASE, vsyscall))
+ ((unsigned long)current->mm->context.vdso + \
+ selected_vdso32->sym___kernel_vsyscall)
struct linux_binprm;
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 5f55e69..876e74e 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -18,7 +18,7 @@ typedef struct {
#endif
struct mutex lock;
- void *vdso;
+ void __user *vdso;
} mm_context_t;
#ifdef CONFIG_SMP
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index d1dc554..389fe2c 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -3,63 +3,43 @@
#include <asm/page_types.h>
#include <linux/linkage.h>
+#include <linux/init.h>
-#ifdef __ASSEMBLER__
+#ifndef __ASSEMBLER__
-#define DEFINE_VDSO_IMAGE(symname, filename) \
-__PAGE_ALIGNED_DATA ; \
- .globl symname##_start, symname##_end ; \
- .align PAGE_SIZE ; \
- symname##_start: ; \
- .incbin filename ; \
- symname##_end: ; \
- .align PAGE_SIZE /* extra data here leaks to userspace. */ ; \
- \
-.previous ; \
- \
- .globl symname##_pages ; \
- .bss ; \
- .align 8 ; \
- .type symname##_pages, @object ; \
- symname##_pages: ; \
- .zero (symname##_end - symname##_start + PAGE_SIZE - 1) / PAGE_SIZE * (BITS_PER_LONG / 8) ; \
- .size symname##_pages, .-symname##_pages
+struct vdso_image {
+ void *data;
+ unsigned long size; /* Always a multiple of PAGE_SIZE */
+ struct page **pages; /* Big enough for data/size page pointers */
-#else
+ unsigned long alt, alt_len;
-#define DECLARE_VDSO_IMAGE(symname) \
- extern char symname##_start[], symname##_end[]; \
- extern struct page *symname##_pages[]
+ unsigned long sym_VDSO32_NOTE_MASK;
+ unsigned long sym___kernel_sigreturn;
+ unsigned long sym___kernel_rt_sigreturn;
+ unsigned long sym___kernel_vsyscall;
+ unsigned long sym_VDSO32_SYSENTER_RETURN;
+};
-#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
+#ifdef CONFIG_X86_64
+extern const struct vdso_image vdso_image_64;
+#endif
-#include <asm/vdso32.h>
+#ifdef CONFIG_X86_X32
+extern const struct vdso_image vdso_image_x32;
+#endif
-DECLARE_VDSO_IMAGE(vdso32_int80);
+#if defined CONFIG_X86_32 || defined CONFIG_COMPAT
+extern const struct vdso_image vdso_image_32_int80;
#ifdef CONFIG_COMPAT
-DECLARE_VDSO_IMAGE(vdso32_syscall);
+extern const struct vdso_image vdso_image_32_syscall;
#endif
-DECLARE_VDSO_IMAGE(vdso32_sysenter);
+extern const struct vdso_image vdso_image_32_sysenter;
-/*
- * Given a pointer to the vDSO image, find the pointer to VDSO32_name
- * as that symbol is defined in the vDSO sources or linker script.
- */
-#define VDSO32_SYMBOL(base, name) \
-({ \
- extern const char VDSO32_##name[]; \
- (void __user *)(VDSO32_##name + (unsigned long)(base)); \
-})
+extern const struct vdso_image *selected_vdso32;
#endif
-/*
- * These symbols are defined with the addresses in the vsyscall page.
- * See vsyscall-sigreturn.S.
- */
-extern void __user __kernel_sigreturn;
-extern void __user __kernel_rt_sigreturn;
-
-void __init patch_vdso32(void *vdso, size_t len);
+extern void __init init_vdso_image(const struct vdso_image *image);
#endif /* __ASSEMBLER__ */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 9e5de68..a0da58d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -298,7 +298,8 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
}
if (current->mm->context.vdso)
- restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
else
restorer = &frame->retcode;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
@@ -361,7 +362,8 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
save_altstack_ex(&frame->uc.uc_stack, regs->sp);
/* Set up to return from userspace. */
- restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+ restorer = current->mm->context.vdso +
+ selected_vdso32->sym___kernel_sigreturn;
if (ksig->ka.sa.sa_flags & SA_RESTORER)
restorer = ksig->ka.sa.sa_restorer;
put_user_ex(restorer, &frame->pretcode);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index f35c66c..5638496 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1223,7 +1223,8 @@ int in_gate_area_no_mm(unsigned long addr)
const char *arch_vma_name(struct vm_area_struct *vma)
{
- if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
+ if (vma->vm_mm && vma->vm_start ==
+ (long __force)vma->vm_mm->context.vdso)
return "[vdso]";
if (vma == &gate_vma)
return "[vsyscall]";
diff --git a/arch/x86/vdso/.gitignore b/arch/x86/vdso/.gitignore
index 3282874..aae8ffd 100644
--- a/arch/x86/vdso/.gitignore
+++ b/arch/x86/vdso/.gitignore
@@ -1,8 +1,7 @@
vdso.lds
-vdso-syms.lds
vdsox32.lds
-vdsox32-syms.lds
-vdso32-syms.lds
vdso32-syscall-syms.lds
vdso32-sysenter-syms.lds
vdso32-int80-syms.lds
+vdso-image-*.c
+vdso2c
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index c580d12..895d4b1 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -24,15 +24,30 @@ vobj64s := $(filter-out $(vobjx32s-compat),$(vobjs-y))
# files to link into kernel
obj-y += vma.o
-obj-$(VDSO64-y) += vdso.o
-obj-$(VDSOX32-y) += vdsox32.o
-obj-$(VDSO32-y) += vdso32.o vdso32-setup.o
+
+# vDSO images to build
+vdso_img-$(VDSO64-y) += 64
+vdso_img-$(VDSOX32-y) += x32
+vdso_img-$(VDSO32-y) += 32-int80
+vdso_img-$(CONFIG_COMPAT) += 32-syscall
+vdso_img-$(VDSO32-y) += 32-sysenter
+
+obj-$(VDSO32-y) += vdso32-setup.o
vobjs := $(foreach F,$(vobj64s),$(obj)/$F)
$(obj)/vdso.o: $(obj)/vdso.so
-targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
+targets += vdso.lds $(vobjs-y)
+
+# Build the vDSO image C files and link them in.
+vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
+vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
+vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
+obj-y += $(vdso_img_objs)
+targets += $(vdso_img_cfiles)
+targets += $(vdso_img_sodbg)
+.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c)
export CPPFLAGS_vdso.lds += -P -C
@@ -41,14 +56,18 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
-Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 \
$(DISABLE_LTO)
-$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
-
-$(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
+$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
$(call if_changed,vdso)
-$(obj)/%.so: OBJCOPYFLAGS := -S
-$(obj)/%.so: $(obj)/%.so.dbg FORCE
- $(call if_changed,objcopy)
+hostprogs-y += vdso2c
+
+quiet_cmd_vdso2c = VDSO2C $@
+define cmd_vdso2c
+ $(obj)/vdso2c $< $@
+endef
+
+$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso2c FORCE
+ $(call if_changed,vdso2c)
#
# Don't omit frame pointers for ease of userspace debugging, but do
@@ -68,22 +87,6 @@ CFLAGS_REMOVE_vclock_gettime.o = -pg
CFLAGS_REMOVE_vgetcpu.o = -pg
CFLAGS_REMOVE_vvar.o = -pg
-targets += vdso-syms.lds
-obj-$(VDSO64-y) += vdso-syms.lds
-
-#
-# Match symbols in the DSO that look like VDSO*; produce a file of constants.
-#
-sed-vdsosym := -e 's/^00*/0/' \
- -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
-quiet_cmd_vdsosym = VDSOSYM $@
-define cmd_vdsosym
- $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
-endef
-
-$(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
- $(call if_changed,vdsosym)
-
#
# X32 processes use x32 vDSO to access 64bit kernel data.
#
@@ -94,9 +97,6 @@ $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
# so that it can reach 64bit address space with 64bit pointers.
#
-targets += vdsox32-syms.lds
-obj-$(VDSOX32-y) += vdsox32-syms.lds
-
CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdsox32.lds = -Wl,-m,elf32_x86_64 \
-Wl,-soname=linux-vdso.so.1 \
@@ -113,9 +113,7 @@ quiet_cmd_x32 = X32 $@
$(obj)/%-x32.o: $(obj)/%.o FORCE
$(call if_changed,x32)
-targets += vdsox32.so vdsox32.so.dbg vdsox32.lds $(vobjx32s-y)
-
-$(obj)/vdsox32.o: $(src)/vdsox32.S $(obj)/vdsox32.so
+targets += vdsox32.lds $(vobjx32s-y)
$(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
$(call if_changed,vdso)
@@ -123,7 +121,6 @@ $(obj)/vdsox32.so.dbg: $(src)/vdsox32.lds $(vobjx32s) FORCE
#
# Build multiple 32-bit vDSO images to choose from at boot time.
#
-obj-$(VDSO32-y) += vdso32-syms.lds
vdso32.so-$(VDSO32-y) += int80
vdso32.so-$(CONFIG_COMPAT) += syscall
vdso32.so-$(VDSO32-y) += sysenter
@@ -138,10 +135,8 @@ VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-m,elf_i386 -Wl,-soname=linux-gate.so.1
override obj-dirs = $(dir $(obj)) $(obj)/vdso32/
targets += vdso32/vdso32.lds
-targets += $(vdso32-images) $(vdso32-images:=.dbg)
targets += vdso32/note.o vdso32/vclock_gettime.o $(vdso32.so-y:%=vdso32/%.o)
-
-extra-y += $(vdso32-images)
+targets += vdso32/vclock_gettime.o
$(obj)/vdso32.o: $(vdso32-images:%=$(obj)/%)
@@ -166,27 +161,6 @@ $(vdso32-images:%=$(obj)/%.dbg): $(obj)/vdso32-%.so.dbg: FORCE \
$(obj)/vdso32/%.o
$(call if_changed,vdso)
-# Make vdso32-*-syms.lds from each image, and then make sure they match.
-# The only difference should be that some do not define VDSO32_SYSENTER_RETURN.
-
-targets += vdso32-syms.lds $(vdso32.so-y:%=vdso32-%-syms.lds)
-
-quiet_cmd_vdso32sym = VDSOSYM $@
-define cmd_vdso32sym
- if LC_ALL=C sort -u $(filter-out FORCE,$^) > $(@D)/.tmp_$(@F) && \
- $(foreach H,$(filter-out FORCE,$^),\
- if grep -q VDSO32_SYSENTER_RETURN $H; \
- then diff -u $(@D)/.tmp_$(@F) $H; \
- else sed /VDSO32_SYSENTER_RETURN/d $(@D)/.tmp_$(@F) | \
- diff -u - $H; fi &&) : ;\
- then mv -f $(@D)/.tmp_$(@F) $@; \
- else rm -f $(@D)/.tmp_$(@F); exit 1; \
- fi
-endef
-
-$(obj)/vdso32-syms.lds: $(vdso32.so-y:%=$(obj)/vdso32-%-syms.lds) FORCE
- $(call if_changed,vdso32sym)
-
#
# The DSO images are built using a special linker script.
#
@@ -197,7 +171,7 @@ quiet_cmd_vdso = VDSO $@
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) \
- $(LTO_CFLAGS)
+ -Wl,-Bsymbolic $(LTO_CFLAGS)
GCOV_PROFILE := n
#
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 16d6861..091554c 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -154,7 +154,7 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
- "call VDSO32_vsyscall \n"
+ "call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
@@ -169,7 +169,7 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
asm(
"mov %%ebx, %%edx \n"
"mov %2, %%ebx \n"
- "call VDSO32_vsyscall \n"
+ "call __kernel_vsyscall \n"
"mov %%edx, %%ebx \n"
: "=a" (ret)
: "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
diff --git a/arch/x86/vdso/vdso.S b/arch/x86/vdso/vdso.S
deleted file mode 100644
index be3f23b..0000000
--- a/arch/x86/vdso/vdso.S
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdso, "arch/x86/vdso/vdso.so")
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
new file mode 100644
index 0000000..976e8e4
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.c
@@ -0,0 +1,142 @@
+#include <inttypes.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <err.h>
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <linux/elf.h>
+#include <linux/types.h>
+
+/* Symbols that we need in vdso2c. */
+char const * const required_syms[] = {
+ "VDSO32_NOTE_MASK",
+ "VDSO32_SYSENTER_RETURN",
+ "__kernel_vsyscall",
+ "__kernel_sigreturn",
+ "__kernel_rt_sigreturn",
+};
+
+__attribute__((format(printf, 1, 2))) __attribute__((noreturn))
+static void fail(const char *format, ...)
+{
+ va_list ap;
+ va_start(ap, format);
+ fprintf(stderr, "Error: ");
+ vfprintf(stderr, format, ap);
+ exit(1);
+ va_end(ap);
+}
+
+#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
+
+#define BITS 64
+#define GOFUNC go64
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Phdr Elf64_Phdr
+#define Elf_Sym Elf64_Sym
+#define Elf_Dyn Elf64_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+#define BITS 32
+#define GOFUNC go32
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Phdr Elf32_Phdr
+#define Elf_Sym Elf32_Sym
+#define Elf_Dyn Elf32_Dyn
+#include "vdso2c.h"
+#undef BITS
+#undef GOFUNC
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Phdr
+#undef Elf_Sym
+#undef Elf_Dyn
+
+static int go(void *addr, size_t len, FILE *outfile, const char *name)
+{
+ Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
+
+ if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
+ return go64(addr, len, outfile, name);
+ } else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
+ return go32(addr, len, outfile, name);
+ } else {
+ fprintf(stderr, "Error: unknown ELF class\n");
+ return 1;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int fd;
+ off_t len;
+ void *addr;
+ FILE *outfile;
+ int ret;
+ char *name, *tmp;
+ int namelen;
+
+ if (argc != 3) {
+ printf("Usage: vdso2c INPUT OUTPUT\n");
+ return 1;
+ }
+
+ /*
+ * Figure out the struct name. If we're writing to a .so file,
+ * generate raw output insted.
+ */
+ name = strdup(argv[2]);
+ namelen = strlen(name);
+ if (namelen >= 3 && !strcmp(name + namelen - 3, ".so")) {
+ name = NULL;
+ } else {
+ tmp = strrchr(name, '/');
+ if (tmp)
+ name = tmp + 1;
+ tmp = strchr(name, '.');
+ if (tmp)
+ *tmp = '\0';
+ for (tmp = name; *tmp; tmp++)
+ if (*tmp == '-')
+ *tmp = '_';
+ }
+
+ fd = open(argv[1], O_RDONLY);
+ if (fd == -1)
+ err(1, "%s", argv[1]);
+
+ len = lseek(fd, 0, SEEK_END);
+ if (len == (off_t)-1)
+ err(1, "lseek");
+
+ addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ if (addr == MAP_FAILED)
+ err(1, "mmap");
+
+ outfile = fopen(argv[2], "w");
+ if (!outfile)
+ err(1, "%s", argv[2]);
+
+ ret = go(addr, (size_t)len, outfile, name);
+
+ munmap(addr, len);
+ fclose(outfile);
+
+ return ret;
+}
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
new file mode 100644
index 0000000..9276e52
--- /dev/null
+++ b/arch/x86/vdso/vdso2c.h
@@ -0,0 +1,137 @@
+/*
+ * This file is included twice from vdso2c.c. It generates code for 32-bit
+ * and 64-bit vDSOs. We need both for 64-bit builds, since 32-bit vDSOs
+ * are built for 32-bit userspace.
+ */
+
+static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+{
+ int found_load = 0;
+ unsigned long load_size = -1; /* Work around bogus warning */
+ unsigned long data_size;
+ Elf_Ehdr *hdr = (Elf_Ehdr *)addr;
+ int i;
+ unsigned long j;
+ Elf_Shdr *symtab_hdr = NULL, *strtab_hdr, *secstrings_hdr,
+ *alt_sec = NULL;
+ Elf_Dyn *dyn = 0, *dyn_end = 0;
+ const char *secstrings;
+ uint64_t syms[NSYMS] = {};
+
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
+
+ /* Walk the segment table. */
+ for (i = 0; i < hdr->e_phnum; i++) {
+ if (pt[i].p_type == PT_LOAD) {
+ if (found_load)
+ fail("multiple PT_LOAD segs\n");
+
+ if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
+ fail("PT_LOAD in wrong place\n");
+
+ if (pt[i].p_memsz != pt[i].p_filesz)
+ fail("cannot handle memsz != filesz\n");
+
+ load_size = pt[i].p_memsz;
+ found_load = 1;
+ } else if (pt[i].p_type == PT_DYNAMIC) {
+ dyn = addr + pt[i].p_offset;
+ dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
+ }
+ }
+ if (!found_load)
+ fail("no PT_LOAD seg\n");
+ data_size = (load_size + 4095) / 4096 * 4096;
+
+ /* Walk the dynamic table */
+ for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
+ if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
+ dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
+ fail("vdso image contains dynamic relocations\n");
+ }
+
+ /* Walk the section table */
+ secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
+ secstrings = addr + secstrings_hdr->sh_offset;
+ for (i = 0; i < hdr->e_shnum; i++) {
+ Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
+ if (sh->sh_type == SHT_SYMTAB)
+ symtab_hdr = sh;
+
+ if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
+ alt_sec = sh;
+ }
+
+ if (!symtab_hdr) {
+ fail("no symbol table\n");
+ return 1;
+ }
+
+ strtab_hdr = addr + hdr->e_shoff +
+ hdr->e_shentsize * symtab_hdr->sh_link;
+
+ /* Walk the symbol table */
+ for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
+ int k;
+ Elf_Sym *sym = addr + symtab_hdr->sh_offset +
+ symtab_hdr->sh_entsize * i;
+ const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
+ for (k = 0; k < NSYMS; k++) {
+ if (!strcmp(name, required_syms[k])) {
+ if (syms[k]) {
+ fail("duplicate symbol %s\n",
+ required_syms[k]);
+ }
+ syms[k] = sym->st_value;
+ }
+ }
+ }
+
+ /* Remove sections. */
+ hdr->e_shoff = 0;
+ hdr->e_shentsize = 0;
+ hdr->e_shnum = 0;
+ hdr->e_shstrndx = SHN_UNDEF;
+
+ if (!name) {
+ fwrite(addr, load_size, 1, outfile);
+ return 0;
+ }
+
+ fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
+ fprintf(outfile, "#include <linux/linkage.h>\n");
+ fprintf(outfile, "#include <asm/page_types.h>\n");
+ fprintf(outfile, "#include <asm/vdso.h>\n");
+ fprintf(outfile, "\n");
+ fprintf(outfile,
+ "static unsigned char raw_data[%lu] __page_aligned_data = {",
+ data_size);
+ for (j = 0; j < load_size; j++) {
+ if (j % 10 == 0)
+ fprintf(outfile, "\n\t");
+ fprintf(outfile, "0x%02X, ", (int)((unsigned char *)addr)[j]);
+ }
+ fprintf(outfile, "\n};\n\n");
+
+ fprintf(outfile, "static struct page *pages[%lu];\n\n",
+ data_size / 4096);
+
+ fprintf(outfile, "const struct vdso_image %s = {\n", name);
+ fprintf(outfile, "\t.data = raw_data,\n");
+ fprintf(outfile, "\t.size = %lu,\n", data_size);
+ fprintf(outfile, "\t.pages = pages,\n");
+ if (alt_sec) {
+ fprintf(outfile, "\t.alt = %lu,\n",
+ (unsigned long)alt_sec->sh_offset);
+ fprintf(outfile, "\t.alt_len = %lu,\n",
+ (unsigned long)alt_sec->sh_size);
+ }
+ for (i = 0; i < NSYMS; i++) {
+ if (syms[i])
+ fprintf(outfile, "\t.sym_%s = 0x%" PRIx64 ",\n",
+ required_syms[i], syms[i]);
+ }
+ fprintf(outfile, "};\n");
+
+ return 0;
+}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 9c78d5b..d414601 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -29,6 +29,7 @@
#include <asm/fixmap.h>
#include <asm/hpet.h>
#include <asm/vvar.h>
+#include <asm/vdso32.h>
#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT 0
@@ -67,9 +68,6 @@ __setup("vdso32=", vdso32_setup);
__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif
-static struct page **vdso32_pages;
-static unsigned vdso32_size;
-
#ifdef CONFIG_X86_64
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
@@ -82,34 +80,23 @@ static unsigned vdso32_size;
#endif /* CONFIG_X86_64 */
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+const struct vdso_image *selected_vdso32;
+#endif
+
int __init sysenter_setup(void)
{
- char *vdso32_start, *vdso32_end;
- int npages, i;
-
#ifdef CONFIG_COMPAT
- if (vdso32_syscall()) {
- vdso32_start = vdso32_syscall_start;
- vdso32_end = vdso32_syscall_end;
- vdso32_pages = vdso32_syscall_pages;
- } else
+ if (vdso32_syscall())
+ selected_vdso32 = &vdso_image_32_syscall;
+ else
#endif
- if (vdso32_sysenter()) {
- vdso32_start = vdso32_sysenter_start;
- vdso32_end = vdso32_sysenter_end;
- vdso32_pages = vdso32_sysenter_pages;
- } else {
- vdso32_start = vdso32_int80_start;
- vdso32_end = vdso32_int80_end;
- vdso32_pages = vdso32_int80_pages;
- }
-
- npages = ((vdso32_end - vdso32_start) + PAGE_SIZE - 1) / PAGE_SIZE;
- vdso32_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdso32_pages[i] = virt_to_page(vdso32_start + i*PAGE_SIZE);
+ if (vdso32_sysenter())
+ selected_vdso32 = &vdso_image_32_sysenter;
+ else
+ selected_vdso32 = &vdso_image_32_int80;
- patch_vdso32(vdso32_start, vdso32_size);
+ init_vdso_image(selected_vdso32);
return 0;
}
@@ -121,6 +108,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
unsigned long addr;
int ret = 0;
struct vm_area_struct *vma;
+ unsigned long vdso32_size = selected_vdso32->size;
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
@@ -140,7 +128,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
addr += VDSO_OFFSET(VDSO_PREV_PAGES);
- current->mm->context.vdso = (void *)addr;
+ current->mm->context.vdso = (void __user *)addr;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
@@ -150,7 +138,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
vdso32_size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso32_pages);
+ selected_vdso32->pages);
if (ret)
goto up_fail;
@@ -188,8 +176,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
}
#endif
- current_thread_info()->sysenter_return =
- VDSO32_SYMBOL(addr, SYSENTER_RETURN);
+ if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
+ current_thread_info()->sysenter_return =
+ current->mm->context.vdso +
+ selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
up_fail:
if (ret)
diff --git a/arch/x86/vdso/vdso32.S b/arch/x86/vdso/vdso32.S
deleted file mode 100644
index 018bcd9..0000000
--- a/arch/x86/vdso/vdso32.S
+++ /dev/null
@@ -1,9 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdso32_int80, "arch/x86/vdso/vdso32-int80.so")
-
-#ifdef CONFIG_COMPAT
-DEFINE_VDSO_IMAGE(vdso32_syscall, "arch/x86/vdso/vdso32-syscall.so")
-#endif
-
-DEFINE_VDSO_IMAGE(vdso32_sysenter, "arch/x86/vdso/vdso32-sysenter.so")
diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S
index aadb8b9..f072095 100644
--- a/arch/x86/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/vdso/vdso32/vdso32.lds.S
@@ -38,13 +38,3 @@ VERSION
local: *;
};
}
-
-/*
- * Symbols we define here called VDSO* get their values into vdso32-syms.h.
- */
-VDSO32_vsyscall = __kernel_vsyscall;
-VDSO32_sigreturn = __kernel_sigreturn;
-VDSO32_rt_sigreturn = __kernel_rt_sigreturn;
-VDSO32_clock_gettime = clock_gettime;
-VDSO32_gettimeofday = gettimeofday;
-VDSO32_time = time;
diff --git a/arch/x86/vdso/vdsox32.S b/arch/x86/vdso/vdsox32.S
deleted file mode 100644
index f4aa34e..0000000
--- a/arch/x86/vdso/vdsox32.S
+++ /dev/null
@@ -1,3 +0,0 @@
-#include <asm/vdso.h>
-
-DEFINE_VDSO_IMAGE(vdsox32, "arch/x86/vdso/vdsox32.so")
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 8b79039..cf21762 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -19,99 +19,31 @@
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
-DECLARE_VDSO_IMAGE(vdso);
extern unsigned short vdso_sync_cpuid;
-static unsigned vdso_size;
-
-#ifdef CONFIG_X86_X32_ABI
-DECLARE_VDSO_IMAGE(vdsox32);
-static unsigned vdsox32_size;
-#endif
#endif
-#if defined(CONFIG_X86_32) || defined(CONFIG_X86_X32_ABI) || \
- defined(CONFIG_COMPAT)
-void __init patch_vdso32(void *vdso, size_t len)
+void __init init_vdso_image(const struct vdso_image *image)
{
- Elf32_Ehdr *hdr = vdso;
- Elf32_Shdr *sechdrs, *alt_sec = 0;
- char *secstrings;
- void *alt_data;
int i;
+ int npages = (image->size) / PAGE_SIZE;
- BUG_ON(len < sizeof(Elf32_Ehdr));
- BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
-
- sechdrs = (void *)hdr + hdr->e_shoff;
- secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-
- for (i = 1; i < hdr->e_shnum; i++) {
- Elf32_Shdr *shdr = &sechdrs[i];
- if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
- alt_sec = shdr;
- goto found;
- }
- }
-
- /* If we get here, it's probably a bug. */
- pr_warning("patch_vdso32: .altinstructions not found\n");
- return; /* nothing to patch */
+ BUG_ON(image->size % PAGE_SIZE != 0);
+ for (i = 0; i < npages; i++)
+ image->pages[i] = virt_to_page(image->data + i*PAGE_SIZE);
-found:
- alt_data = (void *)hdr + alt_sec->sh_offset;
- apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
+ apply_alternatives((struct alt_instr *)(image->data + image->alt),
+ (struct alt_instr *)(image->data + image->alt +
+ image->alt_len));
}
-#endif
-
-#if defined(CONFIG_X86_64)
-static void __init patch_vdso64(void *vdso, size_t len)
-{
- Elf64_Ehdr *hdr = vdso;
- Elf64_Shdr *sechdrs, *alt_sec = 0;
- char *secstrings;
- void *alt_data;
- int i;
- BUG_ON(len < sizeof(Elf64_Ehdr));
- BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0);
-
- sechdrs = (void *)hdr + hdr->e_shoff;
- secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-
- for (i = 1; i < hdr->e_shnum; i++) {
- Elf64_Shdr *shdr = &sechdrs[i];
- if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) {
- alt_sec = shdr;
- goto found;
- }
- }
-
- /* If we get here, it's probably a bug. */
- pr_warning("patch_vdso64: .altinstructions not found\n");
- return; /* nothing to patch */
-
-found:
- alt_data = (void *)hdr + alt_sec->sh_offset;
- apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
-}
+#if defined(CONFIG_X86_64)
static int __init init_vdso(void)
{
- int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE;
- int i;
-
- patch_vdso64(vdso_start, vdso_end - vdso_start);
-
- vdso_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE);
+ init_vdso_image(&vdso_image_64);
#ifdef CONFIG_X86_X32_ABI
- patch_vdso32(vdsox32_start, vdsox32_end - vdsox32_start);
- npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE;
- vdsox32_size = npages << PAGE_SHIFT;
- for (i = 0; i < npages; i++)
- vdsox32_pages[i] = virt_to_page(vdsox32_start + i*PAGE_SIZE);
+ init_vdso_image(&vdso_image_x32);
#endif
return 0;
@@ -171,7 +103,7 @@ static int setup_additional_pages(struct linux_binprm *bprm,
goto up_fail;
}
- current->mm->context.vdso = (void *)addr;
+ current->mm->context.vdso = (void __user *)addr;
ret = install_special_mapping(mm, addr, size,
VM_READ|VM_EXEC|
@@ -189,15 +121,15 @@ up_fail:
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_pages,
- vdso_size);
+ return setup_additional_pages(bprm, uses_interp, vdso_image_64.pages,
+ vdso_image_64.size);
}
#ifdef CONFIG_X86_X32_ABI
int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdsox32_pages,
- vdsox32_size);
+ return setup_additional_pages(bprm, uses_interp, vdso_image_x32.pages,
+ vdso_image_x32.size);
}
#endif
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 0982233..7225a95 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -516,10 +516,17 @@ char * __init xen_memory_setup(void)
static void __init fiddle_vdso(void)
{
#ifdef CONFIG_X86_32
+ /*
+ * This could be called before selected_vdso32 is initialized, so
+ * just fiddle with both possible images. vdso_image_32_syscall
+ * can't be selected, since it only exists on 64-bit systems.
+ */
u32 *mask;
- mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
+ mask = vdso_image_32_int80.data +
+ vdso_image_32_int80.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
- mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
+ mask = vdso_image_32_sysenter.data +
+ vdso_image_32_sysenter.sym_VDSO32_NOTE_MASK;
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
#endif
}
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Move the 32-bit vdso special pages after the text
2014-05-05 19:19 ` [PATCH v5 5/7] x86: Move the 32-bit vdso special pages after the text Andy Lutomirski
@ 2014-05-05 22:25 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:25 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 18d0a6fd227177fd243993179c90e454d0638b06
Gitweb: http://git.kernel.org/tip/18d0a6fd227177fd243993179c90e454d0638b06
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:35 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:18:56 -0700
x86, vdso: Move the 32-bit vdso special pages after the text
This unifies the vdso mapping code and teaches it how to map special
pages at addresses corresponding to symbols in the vdso image. The
new code is used for all vdso variants, but so far only the 32-bit
variants use the new vvar page position.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/b6d7858ad7b5ac3fd3c29cab6d6d769bc45d195e.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/elf.h | 8 +--
arch/x86/include/asm/vdso.h | 4 ++
arch/x86/include/asm/vdso32.h | 11 ----
arch/x86/vdso/vdso-layout.lds.S | 42 ++++++++-----
arch/x86/vdso/vdso2c.c | 14 +++++
arch/x86/vdso/vdso2c.h | 17 ++++++
arch/x86/vdso/vdso32-setup.c | 115 +-----------------------------------
arch/x86/vdso/vma.c | 128 +++++++++++++++++++++++++++++++++-------
8 files changed, 173 insertions(+), 166 deletions(-)
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 65b21bc..1a055c8 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -333,11 +333,9 @@ struct linux_binprm;
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
-extern int x32_setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp);
-
-extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
-#define compat_arch_setup_additional_pages syscall32_setup_pages
+extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp);
+#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 389fe2c..d0a2c90 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -14,6 +14,10 @@ struct vdso_image {
unsigned long alt, alt_len;
+ unsigned long sym_end_mapping; /* Total size of the mapping */
+
+ unsigned long sym_vvar_page;
+ unsigned long sym_hpet_page;
unsigned long sym_VDSO32_NOTE_MASK;
unsigned long sym___kernel_sigreturn;
unsigned long sym___kernel_rt_sigreturn;
diff --git a/arch/x86/include/asm/vdso32.h b/arch/x86/include/asm/vdso32.h
deleted file mode 100644
index 7efb701..0000000
--- a/arch/x86/include/asm/vdso32.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef _ASM_X86_VDSO32_H
-#define _ASM_X86_VDSO32_H
-
-#define VDSO_BASE_PAGE 0
-#define VDSO_VVAR_PAGE 1
-#define VDSO_HPET_PAGE 2
-#define VDSO_PAGES 3
-#define VDSO_PREV_PAGES 2
-#define VDSO_OFFSET(x) ((x) * PAGE_SIZE)
-
-#endif
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index 9df017a..e177c08 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -1,3 +1,5 @@
+#include <asm/vdso.h>
+
/*
* Linker script for vDSO. This is an ELF shared object prelinked to
* its virtual address, and with only one read-only segment.
@@ -6,20 +8,6 @@
SECTIONS
{
-#ifdef BUILD_VDSO32
-#include <asm/vdso32.h>
-
- hpet_page = . - VDSO_OFFSET(VDSO_HPET_PAGE);
-
- vvar = . - VDSO_OFFSET(VDSO_VVAR_PAGE);
-
- /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar + offset;
-#define __VVAR_KERNEL_LDS
-#include <asm/vvar.h>
-#undef __VVAR_KERNEL_LDS
-#undef EMIT_VVAR
-#endif
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
@@ -59,11 +47,33 @@ SECTIONS
.text : { *(.text*) } :text =0x90909090,
+#ifdef BUILD_VDSO32
/*
- * The comma above works around a bug in gold:
- * https://sourceware.org/bugzilla/show_bug.cgi?id=16804
+ * The remainder of the vDSO consists of special pages that are
+ * shared between the kernel and userspace. It needs to be at the
+ * end so that it doesn't overlap the mapping of the actual
+ * vDSO image.
*/
+ . = ALIGN(PAGE_SIZE);
+ vvar_page = .;
+
+ /* Place all vvars at the offsets in asm/vvar.h. */
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define __VVAR_KERNEL_LDS
+#include <asm/vvar.h>
+#undef __VVAR_KERNEL_LDS
+#undef EMIT_VVAR
+
+ . = vvar_page + PAGE_SIZE;
+
+ hpet_page = .;
+ . = . + PAGE_SIZE;
+#endif
+
+ . = ALIGN(PAGE_SIZE);
+ end_mapping = .;
+
/DISCARD/ : {
*(.discard)
*(.discard.*)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 976e8e4..81edd1e 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -15,7 +15,21 @@
#include <linux/types.h>
/* Symbols that we need in vdso2c. */
+enum {
+ sym_vvar_page,
+ sym_hpet_page,
+ sym_end_mapping,
+};
+
+const int special_pages[] = {
+ sym_vvar_page,
+ sym_hpet_page,
+};
+
char const * const required_syms[] = {
+ [sym_vvar_page] = "vvar_page",
+ [sym_hpet_page] = "hpet_page",
+ [sym_end_mapping] = "end_mapping",
"VDSO32_NOTE_MASK",
"VDSO32_SYSENTER_RETURN",
"__kernel_vsyscall",
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 9276e52..ed2e894 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -87,6 +87,23 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
}
}
+ /* Validate mapping addresses. */
+ for (i = 0; i < sizeof(special_pages) / sizeof(special_pages[0]); i++) {
+ if (!syms[i])
+ continue; /* The mapping isn't used; ignore it. */
+
+ if (syms[i] % 4096)
+ fail("%s must be a multiple of 4096\n",
+ required_syms[i]);
+ if (syms[i] < data_size)
+ fail("%s must be after the text mapping\n",
+ required_syms[i]);
+ if (syms[sym_end_mapping] < syms[i] + 4096)
+ fail("%s overruns end_mapping\n", required_syms[i]);
+ }
+ if (syms[sym_end_mapping] % 4096)
+ fail("end_mapping must be a multiple of 4096\n");
+
/* Remove sections. */
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index d414601..c3ed708 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -8,28 +8,12 @@
#include <linux/init.h>
#include <linux/smp.h>
-#include <linux/thread_info.h>
-#include <linux/sched.h>
-#include <linux/gfp.h>
-#include <linux/string.h>
-#include <linux/elf.h>
-#include <linux/mm.h>
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/mm_types.h>
#include <asm/cpufeature.h>
-#include <asm/msr.h>
-#include <asm/pgtable.h>
-#include <asm/unistd.h>
-#include <asm/elf.h>
-#include <asm/tlbflush.h>
+#include <asm/processor.h>
#include <asm/vdso.h>
-#include <asm/proto.h>
-#include <asm/fixmap.h>
-#include <asm/hpet.h>
-#include <asm/vvar.h>
-#include <asm/vdso32.h>
#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT 0
@@ -37,10 +21,6 @@
#define VDSO_DEFAULT 1
#endif
-#ifdef CONFIG_X86_64
-#define arch_setup_additional_pages syscall32_setup_pages
-#endif
-
/*
* Should the kernel map a VDSO page into processes and pass its
* address down to glibc upon exec()?
@@ -101,95 +81,6 @@ int __init sysenter_setup(void)
return 0;
}
-/* Setup a VMA at program startup for the vsyscall page */
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
-{
- struct mm_struct *mm = current->mm;
- unsigned long addr;
- int ret = 0;
- struct vm_area_struct *vma;
- unsigned long vdso32_size = selected_vdso32->size;
-
-#ifdef CONFIG_X86_X32_ABI
- if (test_thread_flag(TIF_X32))
- return x32_setup_additional_pages(bprm, uses_interp);
-#endif
-
- if (vdso32_enabled != 1) /* Other values all mean "disabled" */
- return 0;
-
- down_write(&mm->mmap_sem);
-
- addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
- }
-
- addr += VDSO_OFFSET(VDSO_PREV_PAGES);
-
- current->mm->context.vdso = (void __user *)addr;
-
- /*
- * MAYWRITE to allow gdb to COW and set breakpoints
- */
- ret = install_special_mapping(mm,
- addr,
- vdso32_size,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- selected_vdso32->pages);
-
- if (ret)
- goto up_fail;
-
- vma = _install_special_mapping(mm,
- addr - VDSO_OFFSET(VDSO_PREV_PAGES),
- VDSO_OFFSET(VDSO_PREV_PAGES),
- VM_READ,
- NULL);
-
- if (IS_ERR(vma)) {
- ret = PTR_ERR(vma);
- goto up_fail;
- }
-
- ret = remap_pfn_range(vma,
- addr - VDSO_OFFSET(VDSO_VVAR_PAGE),
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
- PAGE_SIZE,
- PAGE_READONLY);
-
- if (ret)
- goto up_fail;
-
-#ifdef CONFIG_HPET_TIMER
- if (hpet_address) {
- ret = io_remap_pfn_range(vma,
- addr - VDSO_OFFSET(VDSO_HPET_PAGE),
- hpet_address >> PAGE_SHIFT,
- PAGE_SIZE,
- pgprot_noncached(PAGE_READONLY));
-
- if (ret)
- goto up_fail;
- }
-#endif
-
- if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
- current_thread_info()->sysenter_return =
- current->mm->context.vdso +
- selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
-
- up_fail:
- if (ret)
- current->mm->context.vdso = NULL;
-
- up_write(&mm->mmap_sem);
-
- return ret;
-}
-
#ifdef CONFIG_X86_64
subsys_initcall(sysenter_setup);
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index cf21762..e915eae 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -15,6 +15,7 @@
#include <asm/proto.h>
#include <asm/vdso.h>
#include <asm/page.h>
+#include <asm/hpet.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
@@ -36,7 +37,6 @@ void __init init_vdso_image(const struct vdso_image *image)
image->alt_len));
}
-
#if defined(CONFIG_X86_64)
static int __init init_vdso(void)
{
@@ -49,13 +49,16 @@ static int __init init_vdso(void)
return 0;
}
subsys_initcall(init_vdso);
+#endif
struct linux_binprm;
/* Put the vdso above the (randomized) stack with another randomized offset.
This way there is no hole in the middle of address space.
To save memory make sure it is still in the same PTE as the stack top.
- This doesn't give that many random bits */
+ This doesn't give that many random bits.
+
+ Only used for the 64-bit and x32 vdsos. */
static unsigned long vdso_addr(unsigned long start, unsigned len)
{
unsigned long addr, end;
@@ -81,23 +84,23 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
return addr;
}
-/* Setup a VMA at program startup for the vsyscall page.
- Not called for compat tasks */
-static int setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp,
- struct page **pages,
- unsigned size)
+static int map_vdso(const struct vdso_image *image, bool calculate_addr)
{
struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
unsigned long addr;
- int ret;
+ int ret = 0;
- if (!vdso64_enabled)
- return 0;
+ if (calculate_addr) {
+ addr = vdso_addr(current->mm->start_stack,
+ image->sym_end_mapping);
+ } else {
+ addr = 0;
+ }
down_write(&mm->mmap_sem);
- addr = vdso_addr(mm->start_stack, size);
- addr = get_unmapped_area(NULL, addr, size, 0, 0);
+
+ addr = get_unmapped_area(NULL, addr, image->sym_end_mapping, 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
@@ -105,34 +108,115 @@ static int setup_additional_pages(struct linux_binprm *bprm,
current->mm->context.vdso = (void __user *)addr;
- ret = install_special_mapping(mm, addr, size,
+ /*
+ * MAYWRITE to allow gdb to COW and set breakpoints
+ */
+ ret = install_special_mapping(mm,
+ addr,
+ image->size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- pages);
- if (ret) {
- current->mm->context.vdso = NULL;
+ image->pages);
+
+ if (ret)
+ goto up_fail;
+
+ vma = _install_special_mapping(mm,
+ addr + image->size,
+ image->sym_end_mapping - image->size,
+ VM_READ,
+ NULL);
+
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
goto up_fail;
}
+ if (image->sym_vvar_page)
+ ret = remap_pfn_range(vma,
+ addr + image->sym_vvar_page,
+ __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
+ PAGE_SIZE,
+ PAGE_READONLY);
+
+ if (ret)
+ goto up_fail;
+
+#ifdef CONFIG_HPET_TIMER
+ if (hpet_address && image->sym_hpet_page) {
+ ret = io_remap_pfn_range(vma,
+ addr + image->sym_hpet_page,
+ hpet_address >> PAGE_SHIFT,
+ PAGE_SIZE,
+ pgprot_noncached(PAGE_READONLY));
+
+ if (ret)
+ goto up_fail;
+ }
+#endif
+
up_fail:
+ if (ret)
+ current->mm->context.vdso = NULL;
+
up_write(&mm->mmap_sem);
return ret;
}
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+static int load_vdso32(void)
+{
+ int ret;
+
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
+ return 0;
+
+ ret = map_vdso(selected_vdso32, false);
+ if (ret)
+ return ret;
+
+ if (selected_vdso32->sym_VDSO32_SYSENTER_RETURN)
+ current_thread_info()->sysenter_return =
+ current->mm->context.vdso +
+ selected_vdso32->sym_VDSO32_SYSENTER_RETURN;
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_X86_64
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_image_64.pages,
- vdso_image_64.size);
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_64, true);
}
+#ifdef CONFIG_COMPAT
+int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp)
+{
#ifdef CONFIG_X86_X32_ABI
-int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+ if (test_thread_flag(TIF_X32)) {
+ if (!vdso64_enabled)
+ return 0;
+
+ return map_vdso(&vdso_image_x32, true);
+ }
+#endif
+
+ return load_vdso32();
+}
+#endif
+#else
+int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return setup_additional_pages(bprm, uses_interp, vdso_image_x32.pages,
- vdso_image_x32.size);
+ return load_vdso32();
}
#endif
+#ifdef CONFIG_X86_64
static __init int vdso_setup(char *s)
{
vdso64_enabled = simple_strtoul(s, NULL, 0);
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
2014-05-05 19:19 ` [PATCH v5 6/7] x86: Move the vvar and hpet mappings next to the 64-bit vDSO Andy Lutomirski
@ 2014-05-05 22:25 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:25 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: f40c330091c7aa9956ab66f97a3abc8a68b67240
Gitweb: http://git.kernel.org/tip/f40c330091c7aa9956ab66f97a3abc8a68b67240
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:36 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:19:01 -0700
x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO
This makes the 64-bit and x32 vdsos use the same mechanism as the
32-bit vdso. Most of the churn is deleting all the old fixmap code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/8af87023f57f6bb96ec8d17fce3f88018195b49b.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/fixmap.h | 11 ++++-------
arch/x86/include/asm/vvar.h | 20 +-------------------
arch/x86/include/uapi/asm/vsyscall.h | 7 +------
arch/x86/kernel/cpu/common.c | 1 +
arch/x86/kernel/hpet.c | 3 ---
arch/x86/kernel/vsyscall_64.c | 15 ++++-----------
arch/x86/mm/fault.c | 5 +++--
arch/x86/mm/init_64.c | 10 +++++-----
arch/x86/vdso/vclock_gettime.c | 22 +++++-----------------
arch/x86/vdso/vdso-layout.lds.S | 2 --
arch/x86/xen/mmu.c | 8 +++-----
11 files changed, 27 insertions(+), 77 deletions(-)
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 43f482a..b0910f9 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -24,7 +24,7 @@
#include <linux/threads.h>
#include <asm/kmap_types.h>
#else
-#include <asm/vsyscall.h>
+#include <uapi/asm/vsyscall.h>
#endif
/*
@@ -41,7 +41,8 @@
extern unsigned long __FIXADDR_TOP;
#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
#else
-#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
+#define FIXADDR_TOP (round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
+ PAGE_SIZE)
#endif
@@ -68,11 +69,7 @@ enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_HOLE,
#else
- VSYSCALL_LAST_PAGE,
- VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
- + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
- VVAR_PAGE,
- VSYSCALL_HPET,
+ VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
#ifdef CONFIG_PARAVIRT_CLOCK
PVCLOCK_FIXMAP_BEGIN,
PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 081d909..5d2b9ad 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -29,31 +29,13 @@
#else
-#ifdef BUILD_VDSO32
+extern char __vvar_page;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name __attribute__((visibility("hidden")));
#define VVAR(name) (vvar_ ## name)
-#else
-
-extern char __vvar_page;
-
-/* Base address of vvars. This is not ABI. */
-#ifdef CONFIG_X86_64
-#define VVAR_ADDRESS (-10*1024*1024 - 4096)
-#else
-#define VVAR_ADDRESS (&__vvar_page)
-#endif
-
-#define DECLARE_VVAR(offset, type, name) \
- static type const * const vvaraddr_ ## name = \
- (void *)(VVAR_ADDRESS + (offset));
-
-#define VVAR(name) (*vvaraddr_ ## name)
-#endif
-
#define DEFINE_VVAR(type, name) \
type name \
__attribute__((section(".vvar_" #name), aligned(16))) __visible
diff --git a/arch/x86/include/uapi/asm/vsyscall.h b/arch/x86/include/uapi/asm/vsyscall.h
index 85dc1b3..b97dd6e 100644
--- a/arch/x86/include/uapi/asm/vsyscall.h
+++ b/arch/x86/include/uapi/asm/vsyscall.h
@@ -7,11 +7,6 @@ enum vsyscall_num {
__NR_vgetcpu,
};
-#define VSYSCALL_START (-10UL << 20)
-#define VSYSCALL_SIZE 1024
-#define VSYSCALL_END (-2UL << 20)
-#define VSYSCALL_MAPPED_PAGES 1
-#define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr))
-
+#define VSYSCALL_ADDR (-10UL << 20)
#endif /* _UAPI_ASM_X86_VSYSCALL_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7c65b46..2cbbf88 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -20,6 +20,7 @@
#include <asm/processor.h>
#include <asm/debugreg.h>
#include <asm/sections.h>
+#include <asm/vsyscall.h>
#include <linux/topology.h>
#include <linux/cpumask.h>
#include <asm/pgtable.h>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 8d80ae0..bbc15a0 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -74,9 +74,6 @@ static inline void hpet_writel(unsigned int d, unsigned int a)
static inline void hpet_set_mapping(void)
{
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
-#ifdef CONFIG_X86_64
- __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VVAR_NOCACHE);
-#endif
}
static inline void hpet_clear_mapping(void)
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 8b3b3eb..ea5b570 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -91,7 +91,7 @@ static int addr_to_vsyscall_nr(unsigned long addr)
{
int nr;
- if ((addr & ~0xC00UL) != VSYSCALL_START)
+ if ((addr & ~0xC00UL) != VSYSCALL_ADDR)
return -EINVAL;
nr = (addr & 0xC00UL) >> 10;
@@ -330,24 +330,17 @@ void __init map_vsyscall(void)
{
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
- unsigned long physaddr_vvar_page = __pa_symbol(&__vvar_page);
- __set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_vsyscall,
+ __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
vsyscall_mode == NATIVE
? PAGE_KERNEL_VSYSCALL
: PAGE_KERNEL_VVAR);
- BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_FIRST_PAGE) !=
- (unsigned long)VSYSCALL_START);
-
- __set_fixmap(VVAR_PAGE, physaddr_vvar_page, PAGE_KERNEL_VVAR);
- BUILD_BUG_ON((unsigned long)__fix_to_virt(VVAR_PAGE) !=
- (unsigned long)VVAR_ADDRESS);
+ BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
+ (unsigned long)VSYSCALL_ADDR);
}
static int __init vsyscall_init(void)
{
- BUG_ON(VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE));
-
cpu_notifier_register_begin();
on_each_cpu(cpu_vsyscall_init, NULL, 1);
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8e57229..858b47b 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -18,7 +18,8 @@
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
-#include <asm/fixmap.h> /* VSYSCALL_START */
+#include <asm/fixmap.h> /* VSYSCALL_ADDR */
+#include <asm/vsyscall.h> /* emulate_vsyscall */
#define CREATE_TRACE_POINTS
#include <asm/trace/exceptions.h>
@@ -771,7 +772,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
* emulation.
*/
if (unlikely((error_code & PF_INSTR) &&
- ((address & ~0xfff) == VSYSCALL_START))) {
+ ((address & ~0xfff) == VSYSCALL_ADDR))) {
if (emulate_vsyscall(regs, address))
return;
}
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 5638496..6f88184 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1055,8 +1055,8 @@ void __init mem_init(void)
after_bootmem = 1;
/* Register memory areas for /proc/kcore */
- kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
- VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
+ kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
+ PAGE_SIZE, KCORE_OTHER);
mem_init_print_info(NULL);
}
@@ -1186,8 +1186,8 @@ int kern_addr_valid(unsigned long addr)
* not need special handling anymore:
*/
static struct vm_area_struct gate_vma = {
- .vm_start = VSYSCALL_START,
- .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
+ .vm_start = VSYSCALL_ADDR,
+ .vm_end = VSYSCALL_ADDR + PAGE_SIZE,
.vm_page_prot = PAGE_READONLY_EXEC,
.vm_flags = VM_READ | VM_EXEC
};
@@ -1218,7 +1218,7 @@ int in_gate_area(struct mm_struct *mm, unsigned long addr)
*/
int in_gate_area_no_mm(unsigned long addr)
{
- return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
+ return (addr & PAGE_MASK) == VSYSCALL_ADDR;
}
const char *arch_vma_name(struct vm_area_struct *vma)
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 091554c..b2e4f49 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -30,9 +30,12 @@ extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz);
extern time_t __vdso_time(time_t *t);
#ifdef CONFIG_HPET_TIMER
-static inline u32 read_hpet_counter(const volatile void *addr)
+extern u8 hpet_page
+ __attribute__((visibility("hidden")));
+
+static notrace cycle_t vread_hpet(void)
{
- return *(const volatile u32 *) (addr + HPET_COUNTER);
+ return *(const volatile u32 *)(&hpet_page + HPET_COUNTER);
}
#endif
@@ -43,11 +46,6 @@ static inline u32 read_hpet_counter(const volatile void *addr)
#include <asm/fixmap.h>
#include <asm/pvclock.h>
-static notrace cycle_t vread_hpet(void)
-{
- return read_hpet_counter((const void *)fix_to_virt(VSYSCALL_HPET));
-}
-
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
@@ -137,16 +135,6 @@ static notrace cycle_t vread_pvclock(int *mode)
#else
-extern u8 hpet_page
- __attribute__((visibility("hidden")));
-
-#ifdef CONFIG_HPET_TIMER
-static notrace cycle_t vread_hpet(void)
-{
- return read_hpet_counter((const void *)(&hpet_page));
-}
-#endif
-
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index e177c08..2ec72f6 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -47,7 +47,6 @@ SECTIONS
.text : { *(.text*) } :text =0x90909090,
-#ifdef BUILD_VDSO32
/*
* The remainder of the vDSO consists of special pages that are
* shared between the kernel and userspace. It needs to be at the
@@ -69,7 +68,6 @@ SECTIONS
hpet_page = .;
. = . + PAGE_SIZE;
-#endif
. = ALIGN(PAGE_SIZE);
end_mapping = .;
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 86e02ea..3060568 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1494,7 +1494,7 @@ static int xen_pgd_alloc(struct mm_struct *mm)
page->private = (unsigned long)user_pgd;
if (user_pgd != NULL) {
- user_pgd[pgd_index(VSYSCALL_START)] =
+ user_pgd[pgd_index(VSYSCALL_ADDR)] =
__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
ret = 0;
}
@@ -2062,8 +2062,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
case FIX_KMAP_BEGIN ... FIX_KMAP_END:
# endif
#else
- case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
- case VVAR_PAGE:
+ case VSYSCALL_PAGE:
#endif
case FIX_TEXT_POKE0:
case FIX_TEXT_POKE1:
@@ -2104,8 +2103,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
#ifdef CONFIG_X86_64
/* Replicate changes to map the vsyscall page into the user
pagetable vsyscall mapping. */
- if ((idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) ||
- idx == VVAR_PAGE) {
+ if (idx == VSYSCALL_PAGE) {
unsigned long vaddr = __fix_to_virt(idx);
set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
}
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
2014-05-05 19:19 ` [PATCH v5 7/7] x86: Remove vestiges of VDSO_PRELINK and some outdated comments Andy Lutomirski
@ 2014-05-05 22:25 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-05 22:25 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 2b6f2e649f7376d9871df63a9aa0b41efd464d74
Gitweb: http://git.kernel.org/tip/2b6f2e649f7376d9871df63a9aa0b41efd464d74
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Mon, 5 May 2014 12:19:37 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 5 May 2014 13:19:07 -0700
x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments
These definitions had no effect.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/946c104e40c47319f8ab406e54118799cb55bd99.1399317206.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/vdso/vdso.lds.S | 7 +------
arch/x86/vdso/vdso32/vdso32.lds.S | 5 +----
arch/x86/vdso/vdsox32.lds.S | 7 +------
3 files changed, 3 insertions(+), 16 deletions(-)
diff --git a/arch/x86/vdso/vdso.lds.S b/arch/x86/vdso/vdso.lds.S
index b96b267..75e3404 100644
--- a/arch/x86/vdso/vdso.lds.S
+++ b/arch/x86/vdso/vdso.lds.S
@@ -1,14 +1,11 @@
/*
* Linker script for 64-bit vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
-#define VDSO_PRELINK 0xffffffffff700000
#include "vdso-layout.lds.S"
/*
@@ -28,5 +25,3 @@ VERSION {
local: *;
};
}
-
-VDSO64_PRELINK = VDSO_PRELINK;
diff --git a/arch/x86/vdso/vdso32/vdso32.lds.S b/arch/x86/vdso/vdso32/vdso32.lds.S
index f072095..31056cf 100644
--- a/arch/x86/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/vdso/vdso32/vdso32.lds.S
@@ -1,17 +1,14 @@
/*
* Linker script for 32-bit vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
#include <asm/page.h>
#define BUILD_VDSO32
-#define VDSO_PRELINK 0
#include "../vdso-layout.lds.S"
diff --git a/arch/x86/vdso/vdsox32.lds.S b/arch/x86/vdso/vdsox32.lds.S
index 62272aa..46b991b 100644
--- a/arch/x86/vdso/vdsox32.lds.S
+++ b/arch/x86/vdso/vdsox32.lds.S
@@ -1,14 +1,11 @@
/*
* Linker script for x32 vDSO.
* We #include the file to define the layout details.
- * Here we only choose the prelinked virtual address.
*
* This file defines the version script giving the user-exported symbols in
- * the DSO. We can define local symbols here called VDSO* to make their
- * values visible using the asm-x86/vdso.h macros from the kernel proper.
+ * the DSO.
*/
-#define VDSO_PRELINK 0
#include "vdso-layout.lds.S"
/*
@@ -24,5 +21,3 @@ VERSION {
local: *;
};
}
-
-VDSOX32_PRELINK = VDSO_PRELINK;
^ permalink raw reply related [flat|nested] 39+ messages in thread
* Re: [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
@ 2014-05-29 19:17 ` Paul Gortmaker
2014-05-29 19:32 ` Andy Lutomirski
0 siblings, 1 reply; 39+ messages in thread
From: Paul Gortmaker @ 2014-05-29 19:17 UTC (permalink / raw)
To: mingo, H. Peter Anvin, luto, LKML, tglx, hpa
Cc: linux-tip-commits, linux-next
On Mon, May 5, 2014 at 6:25 PM, tip-bot for Andy Lutomirski
<tipbot@zytor.com> wrote:
> Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
> Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
> Author: Andy Lutomirski <luto@amacapital.net>
> AuthorDate: Mon, 5 May 2014 12:19:34 -0700
> Committer: H. Peter Anvin <hpa@linux.intel.com>
> CommitDate: Mon, 5 May 2014 13:18:51 -0700
>
> x86, vdso: Reimplement vdso.so preparation in build-time C
Just a heads up in case it hasn't been mentioned already;
the x86 builds in linux-next which IIRC are done as cross
compile on a powerpc box are failing as follows:
VDSO2C arch/x86/vdso/vdso-image-64.c
/bin/sh: line 1: 15995 Segmentation fault arch/x86/vdso/vdso2c
arch/x86/vdso/vdso64.so.dbg arch/x86/vdso/vdso-image-64.c
make[3]: *** [arch/x86/vdso/vdso-image-64.c] Error 139
http://kisskb.ellerman.id.au/kisskb/buildresult/11265454/
Paul.
--
>
> Currently, vdso.so files are prepared and analyzed by a combination
> of objcopy, nm, some linker script tricks, and some simple ELF
> parsers in the kernel. Replace all of that with plain C code that
> runs at build time.
>
> All five vdso images now generate .c files that are compiled and
> linked in to the kernel image.
>
> This should cause only one userspace-visible change: the loaded vDSO
> images are stripped more heavily than they used to be. Everything
> outside the loadable segment is dropped. In particular, this causes
> the section table and section name strings to be missing. This
> should be fine: real dynamic loaders don't load or inspect these
> tables anyway. The result is roughly equivalent to eu-strip's
> --strip-sections option.
>
> The purpose of this change is to enable the vvar and hpet mappings
> to be moved to the page following the vDSO load segment. Currently,
> it is possible for the section table to extend into the page after
> the load segment, so, if we map it, it risks overlapping the vvar or
> hpet page. This happens whenever the load segment is just under a
> multiple of PAGE_SIZE.
>
> The only real subtlety here is that the old code had a C file with
> inline assembler that did 'call VDSO32_vsyscall' and a linker script
> that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most
> likely worked by accident: the linker script entry defines a symbol
> associated with an address as opposed to an alias for the real
> dynamic symbol __kernel_vsyscall. That caused ld to relocate the
> reference at link time instead of leaving an interposable dynamic
> relocation. Since the VDSO32_vsyscall hack is no longer needed, I
> now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it
> work. vdso2c will generate an error and abort the build if the
> resulting image contains any dynamic relocations, so we won't
> silently generate bad vdso images.
>
> (Dynamic relocations are a problem because nothing will even attempt
> to relocate the vdso.)
>
> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
> Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net
> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> ---
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-29 19:17 ` Paul Gortmaker
@ 2014-05-29 19:32 ` Andy Lutomirski
2014-05-29 19:43 ` H. Peter Anvin
2014-05-29 19:43 ` [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C Josh Boyer
0 siblings, 2 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 19:32 UTC (permalink / raw)
To: Paul Gortmaker
Cc: Ingo Molnar, H. Peter Anvin, LKML, tglx, H. Peter Anvin,
linux-tip-commits, linux-next
On Thu, May 29, 2014 at 12:17 PM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> On Mon, May 5, 2014 at 6:25 PM, tip-bot for Andy Lutomirski
> <tipbot@zytor.com> wrote:
>> Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
>> Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
>> Author: Andy Lutomirski <luto@amacapital.net>
>> AuthorDate: Mon, 5 May 2014 12:19:34 -0700
>> Committer: H. Peter Anvin <hpa@linux.intel.com>
>> CommitDate: Mon, 5 May 2014 13:18:51 -0700
>>
>> x86, vdso: Reimplement vdso.so preparation in build-time C
>
> Just a heads up in case it hasn't been mentioned already;
> the x86 builds in linux-next which IIRC are done as cross
> compile on a powerpc box are failing as follows:
>
> VDSO2C arch/x86/vdso/vdso-image-64.c
> /bin/sh: line 1: 15995 Segmentation fault arch/x86/vdso/vdso2c
> arch/x86/vdso/vdso64.so.dbg arch/x86/vdso/vdso-image-64.c
> make[3]: *** [arch/x86/vdso/vdso-image-64.c] Error 139
>
> http://kisskb.ellerman.id.au/kisskb/buildresult/11265454/
>
Egads. This wouldn't be a big-endian host by any chance?
--Andy
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-29 19:32 ` Andy Lutomirski
@ 2014-05-29 19:43 ` H. Peter Anvin
2014-05-29 19:46 ` Andy Lutomirski
2014-05-29 19:43 ` [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C Josh Boyer
1 sibling, 1 reply; 39+ messages in thread
From: H. Peter Anvin @ 2014-05-29 19:43 UTC (permalink / raw)
To: Andy Lutomirski, Paul Gortmaker
Cc: Ingo Molnar, LKML, tglx, H. Peter Anvin, linux-tip-commits, linux-next
On 05/29/2014 12:32 PM, Andy Lutomirski wrote:
> On Thu, May 29, 2014 at 12:17 PM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
>> On Mon, May 5, 2014 at 6:25 PM, tip-bot for Andy Lutomirski
>> <tipbot@zytor.com> wrote:
>>> Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
>>> Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
>>> Author: Andy Lutomirski <luto@amacapital.net>
>>> AuthorDate: Mon, 5 May 2014 12:19:34 -0700
>>> Committer: H. Peter Anvin <hpa@linux.intel.com>
>>> CommitDate: Mon, 5 May 2014 13:18:51 -0700
>>>
>>> x86, vdso: Reimplement vdso.so preparation in build-time C
>>
>> Just a heads up in case it hasn't been mentioned already;
>> the x86 builds in linux-next which IIRC are done as cross
>> compile on a powerpc box are failing as follows:
>>
>> VDSO2C arch/x86/vdso/vdso-image-64.c
>> /bin/sh: line 1: 15995 Segmentation fault arch/x86/vdso/vdso2c
>> arch/x86/vdso/vdso64.so.dbg arch/x86/vdso/vdso-image-64.c
>> make[3]: *** [arch/x86/vdso/vdso-image-64.c] Error 139
>>
>> http://kisskb.ellerman.id.au/kisskb/buildresult/11265454/
>>
>
> Egads. This wouldn't be a big-endian host by any chance?
>
He said PowerPC; most but not all PowerPC systems are bigendian. Seems
like a fair assumption to make.
-hpa
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-29 19:32 ` Andy Lutomirski
2014-05-29 19:43 ` H. Peter Anvin
@ 2014-05-29 19:43 ` Josh Boyer
1 sibling, 0 replies; 39+ messages in thread
From: Josh Boyer @ 2014-05-29 19:43 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Paul Gortmaker, Ingo Molnar, H. Peter Anvin, LKML, tglx,
H. Peter Anvin, linux-tip-commits, linux-next
On Thu, May 29, 2014 at 3:32 PM, Andy Lutomirski <luto@amacapital.net> wrote:
> On Thu, May 29, 2014 at 12:17 PM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
>> On Mon, May 5, 2014 at 6:25 PM, tip-bot for Andy Lutomirski
>> <tipbot@zytor.com> wrote:
>>> Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
>>> Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
>>> Author: Andy Lutomirski <luto@amacapital.net>
>>> AuthorDate: Mon, 5 May 2014 12:19:34 -0700
>>> Committer: H. Peter Anvin <hpa@linux.intel.com>
>>> CommitDate: Mon, 5 May 2014 13:18:51 -0700
>>>
>>> x86, vdso: Reimplement vdso.so preparation in build-time C
>>
>> Just a heads up in case it hasn't been mentioned already;
>> the x86 builds in linux-next which IIRC are done as cross
>> compile on a powerpc box are failing as follows:
>>
>> VDSO2C arch/x86/vdso/vdso-image-64.c
>> /bin/sh: line 1: 15995 Segmentation fault arch/x86/vdso/vdso2c
>> arch/x86/vdso/vdso64.so.dbg arch/x86/vdso/vdso-image-64.c
>> make[3]: *** [arch/x86/vdso/vdso-image-64.c] Error 139
>>
>> http://kisskb.ellerman.id.au/kisskb/buildresult/11265454/
>>
>
> Egads. This wouldn't be a big-endian host by any chance?
Likely if it's really a cross compile on a powerpc machine. Virtually
all existing powerpc machines are big-endian.
josh
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C
2014-05-29 19:43 ` H. Peter Anvin
@ 2014-05-29 19:46 ` Andy Lutomirski
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 " Andy Lutomirski
0 siblings, 2 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 19:46 UTC (permalink / raw)
To: H. Peter Anvin
Cc: Paul Gortmaker, Ingo Molnar, LKML, tglx, H. Peter Anvin,
linux-tip-commits, linux-next
On Thu, May 29, 2014 at 12:43 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 05/29/2014 12:32 PM, Andy Lutomirski wrote:
>> On Thu, May 29, 2014 at 12:17 PM, Paul Gortmaker
>> <paul.gortmaker@windriver.com> wrote:
>>> On Mon, May 5, 2014 at 6:25 PM, tip-bot for Andy Lutomirski
>>> <tipbot@zytor.com> wrote:
>>>> Commit-ID: 6f121e548f83674ab4920a4e60afb58d4f61b829
>>>> Gitweb: http://git.kernel.org/tip/6f121e548f83674ab4920a4e60afb58d4f61b829
>>>> Author: Andy Lutomirski <luto@amacapital.net>
>>>> AuthorDate: Mon, 5 May 2014 12:19:34 -0700
>>>> Committer: H. Peter Anvin <hpa@linux.intel.com>
>>>> CommitDate: Mon, 5 May 2014 13:18:51 -0700
>>>>
>>>> x86, vdso: Reimplement vdso.so preparation in build-time C
>>>
>>> Just a heads up in case it hasn't been mentioned already;
>>> the x86 builds in linux-next which IIRC are done as cross
>>> compile on a powerpc box are failing as follows:
>>>
>>> VDSO2C arch/x86/vdso/vdso-image-64.c
>>> /bin/sh: line 1: 15995 Segmentation fault arch/x86/vdso/vdso2c
>>> arch/x86/vdso/vdso64.so.dbg arch/x86/vdso/vdso-image-64.c
>>> make[3]: *** [arch/x86/vdso/vdso-image-64.c] Error 139
>>>
>>> http://kisskb.ellerman.id.au/kisskb/buildresult/11265454/
>>>
>>
>> Egads. This wouldn't be a big-endian host by any chance?
>>
>
> He said PowerPC; most but not all PowerPC systems are bigendian. Seems
> like a fair assumption to make.
>
I suppose I shouldn't have assumed that code in arch/x86 would always
run on little-endian machines. I'll fix it.
--Andy
^ permalink raw reply [flat|nested] 39+ messages in thread
* [PATCH 0/2] x86,vdso: vdso build fixes and improvements
2014-05-29 19:46 ` Andy Lutomirski
@ 2014-05-29 21:57 ` Andy Lutomirski
2014-05-29 21:57 ` [PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
` (2 more replies)
2014-05-30 15:48 ` [PATCH v2 " Andy Lutomirski
1 sibling, 3 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 21:57 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
Patch 1 causes make;make to behave similarly to make if vdso2c fails.
Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
have a big-endian machine to test on, though.
Andy Lutomirski (2):
x86,vdso: When vdso2c fails, unlink the output
x86,vdso: Fix cross-compilation from big-endian architectures
arch/x86/vdso/vdso2c.c | 35 ++++++++++++++++++-------
arch/x86/vdso/vdso2c.h | 69 ++++++++++++++++++++++++++------------------------
2 files changed, 62 insertions(+), 42 deletions(-)
--
1.9.3
^ permalink raw reply [flat|nested] 39+ messages in thread
* [PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
@ 2014-05-29 21:57 ` Andy Lutomirski
2014-05-29 21:57 ` [PATCH 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
2014-05-29 22:41 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Paul Gortmaker
2 siblings, 0 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 21:57 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
This avoids bizarre failures if make is run again.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso2c.c | 20 +++++++++++---------
arch/x86/vdso/vdso2c.h | 10 +++-------
2 files changed, 14 insertions(+), 16 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 81edd1e..fe8bfbf 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -14,6 +14,8 @@
#include <linux/elf.h>
#include <linux/types.h>
+const char *outfilename;
+
/* Symbols that we need in vdso2c. */
enum {
sym_vvar_page,
@@ -44,6 +46,7 @@ static void fail(const char *format, ...)
va_start(ap, format);
fprintf(stderr, "Error: ");
vfprintf(stderr, format, ap);
+ unlink(outfilename);
exit(1);
va_end(ap);
}
@@ -82,17 +85,16 @@ static void fail(const char *format, ...)
#undef Elf_Sym
#undef Elf_Dyn
-static int go(void *addr, size_t len, FILE *outfile, const char *name)
+static void go(void *addr, size_t len, FILE *outfile, const char *name)
{
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
- return go64(addr, len, outfile, name);
+ go64(addr, len, outfile, name);
} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
- return go32(addr, len, outfile, name);
+ go32(addr, len, outfile, name);
} else {
- fprintf(stderr, "Error: unknown ELF class\n");
- return 1;
+ fail("unknown ELF class\n");
}
}
@@ -102,7 +104,6 @@ int main(int argc, char **argv)
off_t len;
void *addr;
FILE *outfile;
- int ret;
char *name, *tmp;
int namelen;
@@ -143,14 +144,15 @@ int main(int argc, char **argv)
if (addr == MAP_FAILED)
err(1, "mmap");
- outfile = fopen(argv[2], "w");
+ outfilename = argv[2];
+ outfile = fopen(outfilename, "w");
if (!outfile)
err(1, "%s", argv[2]);
- ret = go(addr, (size_t)len, outfile, name);
+ go(addr, (size_t)len, outfile, name);
munmap(addr, len);
fclose(outfile);
- return ret;
+ return 0;
}
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 3dcc61e..26a7c1f 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -4,7 +4,7 @@
* are built for 32-bit userspace.
*/
-static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
{
int found_load = 0;
unsigned long load_size = -1; /* Work around bogus warning */
@@ -62,10 +62,8 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
alt_sec = sh;
}
- if (!symtab_hdr) {
+ if (!symtab_hdr)
fail("no symbol table\n");
- return 1;
- }
strtab_hdr = addr + hdr->e_shoff +
hdr->e_shentsize * symtab_hdr->sh_link;
@@ -112,7 +110,7 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
if (!name) {
fwrite(addr, load_size, 1, outfile);
- return 0;
+ return;
}
fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
@@ -152,6 +150,4 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
required_syms[i], syms[i]);
}
fprintf(outfile, "};\n");
-
- return 0;
}
--
1.9.3
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
2014-05-29 21:57 ` [PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
@ 2014-05-29 21:57 ` Andy Lutomirski
2014-05-29 22:41 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Paul Gortmaker
2 siblings, 0 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 21:57 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
This adds a macro GET(x) to convert x from big-endian to
little-endian. Hopefully I put it everywhere it needs to go and got
all the cases needed for everyone's linux/elf.h.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso2c.c | 15 +++++++++++++
arch/x86/vdso/vdso2c.h | 59 ++++++++++++++++++++++++++++----------------------
2 files changed, 48 insertions(+), 26 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index fe8bfbf..de19ced 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -51,6 +51,21 @@ static void fail(const char *format, ...)
va_end(ap);
}
+/*
+ * Evil macros to do a little-endian read.
+ */
+#define __GET_TYPE(x, type, bits, ifnot) \
+ __builtin_choose_expr( \
+ __builtin_types_compatible_p(typeof(x), type), \
+ le##bits##toh((x)), ifnot)
+
+extern void bad_get(uint64_t);
+
+#define GET(x) \
+ __GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
+ __GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
+ __GET_TYPE((x), __u16, 16, bad_get(x))))))
+
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
#define BITS 64
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 26a7c1f..dadecb9 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -18,25 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
const char *secstrings;
uint64_t syms[NSYMS] = {};
- Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
/* Walk the segment table. */
- for (i = 0; i < hdr->e_phnum; i++) {
- if (pt[i].p_type == PT_LOAD) {
+ for (i = 0; i < GET(hdr->e_phnum); i++) {
+ if (GET(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
- if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
+ if (GET(pt[i].p_offset) != 0 ||
+ GET(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
- if (pt[i].p_memsz != pt[i].p_filesz)
+ if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
- load_size = pt[i].p_memsz;
+ load_size = GET(pt[i].p_memsz);
found_load = 1;
- } else if (pt[i].p_type == PT_DYNAMIC) {
- dyn = addr + pt[i].p_offset;
- dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
+ } else if (GET(pt[i].p_type) == PT_DYNAMIC) {
+ dyn = addr + GET(pt[i].p_offset);
+ dyn_end = addr + GET(pt[i].p_offset) +
+ GET(pt[i].p_memsz);
}
}
if (!found_load)
@@ -44,43 +46,48 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
- if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
- dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
+ for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET(dyn[i].d_tag);
+ if (tag == DT_REL || tag == DT_RELSZ ||
+ tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
- secstrings = addr + secstrings_hdr->sh_offset;
- for (i = 0; i < hdr->e_shnum; i++) {
- Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
- if (sh->sh_type == SHT_SYMTAB)
+ secstrings_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
+ secstrings = addr + GET(secstrings_hdr->sh_offset);
+ for (i = 0; i < GET(hdr->e_shnum); i++) {
+ Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * i;
+ if (GET(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
- if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
+ if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + hdr->e_shoff +
- hdr->e_shentsize * symtab_hdr->sh_link;
+ strtab_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
/* Walk the symbol table */
- for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
+ for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
+ i++) {
int k;
- Elf_Sym *sym = addr + symtab_hdr->sh_offset +
- symtab_hdr->sh_entsize * i;
- const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
+ Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
+ GET(symtab_hdr->sh_entsize) * i;
+ const char *name = addr + GET(strtab_hdr->sh_offset) +
+ GET(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
- syms[k] = sym->st_value;
+ syms[k] = GET(sym->st_value);
}
}
}
@@ -106,7 +113,7 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
hdr->e_shnum = 0;
- hdr->e_shstrndx = SHN_UNDEF;
+ hdr->e_shstrndx = htole16(SHN_UNDEF);
if (!name) {
fwrite(addr, load_size, 1, outfile);
--
1.9.3
^ permalink raw reply related [flat|nested] 39+ messages in thread
* Re: [PATCH 0/2] x86,vdso: vdso build fixes and improvements
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
2014-05-29 21:57 ` [PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
2014-05-29 21:57 ` [PATCH 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
@ 2014-05-29 22:41 ` Paul Gortmaker
2014-05-29 22:49 ` Andy Lutomirski
2 siblings, 1 reply; 39+ messages in thread
From: Paul Gortmaker @ 2014-05-29 22:41 UTC (permalink / raw)
To: Andy Lutomirski, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Stephen Rothwell
On 14-05-29 05:57 PM, Andy Lutomirski wrote:
> Patch 1 causes make;make to behave similarly to make if vdso2c fails.
> Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
> have a big-endian machine to test on, though.
Since the x86 builds are unconditionally failing as-is now in
linux-next, perhaps Stephen [Cc'd] can layer these on the top of
the tree he'll be making within the next couple of hours to give
them a big-endian test.
Paul.
--
>
> Andy Lutomirski (2):
> x86,vdso: When vdso2c fails, unlink the output
> x86,vdso: Fix cross-compilation from big-endian architectures
>
> arch/x86/vdso/vdso2c.c | 35 ++++++++++++++++++-------
> arch/x86/vdso/vdso2c.h | 69 ++++++++++++++++++++++++++------------------------
> 2 files changed, 62 insertions(+), 42 deletions(-)
>
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH 0/2] x86,vdso: vdso build fixes and improvements
2014-05-29 22:41 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Paul Gortmaker
@ 2014-05-29 22:49 ` Andy Lutomirski
2014-05-30 5:42 ` Stephen Rothwell
0 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-29 22:49 UTC (permalink / raw)
To: Paul Gortmaker
Cc: H. Peter Anvin, Josh Boyer, Ingo Molnar, LKML, tglx,
linux-tip-commits, linux-next, Stephen Rothwell
On Thu, May 29, 2014 at 3:41 PM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> On 14-05-29 05:57 PM, Andy Lutomirski wrote:
>> Patch 1 causes make;make to behave similarly to make if vdso2c fails.
>> Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
>> have a big-endian machine to test on, though.
>
> Since the x86 builds are unconditionally failing as-is now in
> linux-next, perhaps Stephen [Cc'd] can layer these on the top of
> the tree he'll be making within the next couple of hours to give
> them a big-endian test.
Stephen, if you do this, could you also send me some of the build outputs:
arch/x86/vdso/*.so.dbg
arch/x86/vdso/*-image-*.c
I'd like to verify that the output is correct. It would be
unfortunate if the cross-built kernel had some subtle error.
Thanks,
Andy
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH 0/2] x86,vdso: vdso build fixes and improvements
2014-05-29 22:49 ` Andy Lutomirski
@ 2014-05-30 5:42 ` Stephen Rothwell
2014-05-30 15:40 ` Andy Lutomirski
0 siblings, 1 reply; 39+ messages in thread
From: Stephen Rothwell @ 2014-05-30 5:42 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Paul Gortmaker, H. Peter Anvin, Josh Boyer, Ingo Molnar, LKML,
tglx, linux-tip-commits, linux-next
[-- Attachment #1: Type: text/plain, Size: 1220 bytes --]
Hi Andy,
On Thu, 29 May 2014 15:49:52 -0700 Andy Lutomirski <luto@amacapital.net> wrote:
>
> On Thu, May 29, 2014 at 3:41 PM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > On 14-05-29 05:57 PM, Andy Lutomirski wrote:
> >> Patch 1 causes make;make to behave similarly to make if vdso2c fails.
> >> Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
> >> have a big-endian machine to test on, though.
> >
> > Since the x86 builds are unconditionally failing as-is now in
> > linux-next, perhaps Stephen [Cc'd] can layer these on the top of
> > the tree he'll be making within the next couple of hours to give
> > them a big-endian test.
I added them just after the merge of the tip tree today and will keep
them there until they (or somo other solution) turn up some other way.
> Stephen, if you do this, could you also send me some of the build outputs:
>
> arch/x86/vdso/*.so.dbg
> arch/x86/vdso/*-image-*.c
>
> I'd like to verify that the output is correct. It would be
> unfortunate if the cross-built kernel had some subtle error.
OK, I will send them in a separate email.
--
Cheers,
Stephen Rothwell sfr@canb.auug.org.au
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 836 bytes --]
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH 0/2] x86,vdso: vdso build fixes and improvements
2014-05-30 5:42 ` Stephen Rothwell
@ 2014-05-30 15:40 ` Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 15:40 UTC (permalink / raw)
To: Stephen Rothwell
Cc: Paul Gortmaker, H. Peter Anvin, Josh Boyer, Ingo Molnar, LKML,
tglx, linux-tip-commits, linux-next
On Thu, May 29, 2014 at 10:42 PM, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> Hi Andy,
>
> On Thu, 29 May 2014 15:49:52 -0700 Andy Lutomirski <luto@amacapital.net> wrote:
>>
>> On Thu, May 29, 2014 at 3:41 PM, Paul Gortmaker
>> <paul.gortmaker@windriver.com> wrote:
>> > On 14-05-29 05:57 PM, Andy Lutomirski wrote:
>> >> Patch 1 causes make;make to behave similarly to make if vdso2c fails.
>> >> Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
>> >> have a big-endian machine to test on, though.
>> >
>> > Since the x86 builds are unconditionally failing as-is now in
>> > linux-next, perhaps Stephen [Cc'd] can layer these on the top of
>> > the tree he'll be making within the next couple of hours to give
>> > them a big-endian test.
>
> I added them just after the merge of the tip tree today and will keep
> them there until they (or somo other solution) turn up some other way.
>
>> Stephen, if you do this, could you also send me some of the build outputs:
>>
>> arch/x86/vdso/*.so.dbg
>> arch/x86/vdso/*-image-*.c
>>
>> I'd like to verify that the output is correct. It would be
>> unfortunate if the cross-built kernel had some subtle error.
>
> OK, I will send them in a separate email.
For the benefit of the archives: the patches are bad. New ones coming.
--Andy
>
> --
> Cheers,
> Stephen Rothwell sfr@canb.auug.org.au
--
Andy Lutomirski
AMA Capital Management, LLC
^ permalink raw reply [flat|nested] 39+ messages in thread
* [PATCH v2 0/2] x86,vdso: vdso build fixes and improvements
2014-05-29 19:46 ` Andy Lutomirski
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
@ 2014-05-30 15:48 ` Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
1 sibling, 2 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 15:48 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
Patch 1 causes make;make to behave similarly to make if vdso2c fails.
Patch 2 hopefully fixes x86 crossbuilds on big-endian machines. I don't
have a big-endian machine to test on, though.
Changes from v1: Add two missing endian fixes
Andy Lutomirski (2):
x86,vdso: When vdso2c fails, unlink the output
x86,vdso: Fix cross-compilation from big-endian architectures
arch/x86/vdso/vdso2c.c | 35 +++++++++++++++++-------
arch/x86/vdso/vdso2c.h | 73 ++++++++++++++++++++++++++------------------------
2 files changed, 64 insertions(+), 44 deletions(-)
--
1.9.3
^ permalink raw reply [flat|nested] 39+ messages in thread
* [PATCH v2 1/2] x86,vdso: When vdso2c fails, unlink the output
2014-05-30 15:48 ` [PATCH v2 " Andy Lutomirski
@ 2014-05-30 15:48 ` Andy Lutomirski
2014-05-31 3:09 ` [tip:x86/vdso] x86/vdso, build: " tip-bot for Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
1 sibling, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 15:48 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
This avoids bizarre failures if make is run again.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso2c.c | 20 +++++++++++---------
arch/x86/vdso/vdso2c.h | 10 +++-------
2 files changed, 14 insertions(+), 16 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 81edd1e..fe8bfbf 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -14,6 +14,8 @@
#include <linux/elf.h>
#include <linux/types.h>
+const char *outfilename;
+
/* Symbols that we need in vdso2c. */
enum {
sym_vvar_page,
@@ -44,6 +46,7 @@ static void fail(const char *format, ...)
va_start(ap, format);
fprintf(stderr, "Error: ");
vfprintf(stderr, format, ap);
+ unlink(outfilename);
exit(1);
va_end(ap);
}
@@ -82,17 +85,16 @@ static void fail(const char *format, ...)
#undef Elf_Sym
#undef Elf_Dyn
-static int go(void *addr, size_t len, FILE *outfile, const char *name)
+static void go(void *addr, size_t len, FILE *outfile, const char *name)
{
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
- return go64(addr, len, outfile, name);
+ go64(addr, len, outfile, name);
} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
- return go32(addr, len, outfile, name);
+ go32(addr, len, outfile, name);
} else {
- fprintf(stderr, "Error: unknown ELF class\n");
- return 1;
+ fail("unknown ELF class\n");
}
}
@@ -102,7 +104,6 @@ int main(int argc, char **argv)
off_t len;
void *addr;
FILE *outfile;
- int ret;
char *name, *tmp;
int namelen;
@@ -143,14 +144,15 @@ int main(int argc, char **argv)
if (addr == MAP_FAILED)
err(1, "mmap");
- outfile = fopen(argv[2], "w");
+ outfilename = argv[2];
+ outfile = fopen(outfilename, "w");
if (!outfile)
err(1, "%s", argv[2]);
- ret = go(addr, (size_t)len, outfile, name);
+ go(addr, (size_t)len, outfile, name);
munmap(addr, len);
fclose(outfile);
- return ret;
+ return 0;
}
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 3dcc61e..26a7c1f 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -4,7 +4,7 @@
* are built for 32-bit userspace.
*/
-static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
{
int found_load = 0;
unsigned long load_size = -1; /* Work around bogus warning */
@@ -62,10 +62,8 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
alt_sec = sh;
}
- if (!symtab_hdr) {
+ if (!symtab_hdr)
fail("no symbol table\n");
- return 1;
- }
strtab_hdr = addr + hdr->e_shoff +
hdr->e_shentsize * symtab_hdr->sh_link;
@@ -112,7 +110,7 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
if (!name) {
fwrite(addr, load_size, 1, outfile);
- return 0;
+ return;
}
fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
@@ -152,6 +150,4 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
required_syms[i], syms[i]);
}
fprintf(outfile, "};\n");
-
- return 0;
}
--
1.9.3
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 15:48 ` [PATCH v2 " Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
@ 2014-05-30 15:48 ` Andy Lutomirski
2014-05-30 20:02 ` H. Peter Anvin
` (3 more replies)
1 sibling, 4 replies; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 15:48 UTC (permalink / raw)
To: Paul Gortmaker, H. Peter Anvin
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits,
linux-next, Andy Lutomirski
This adds a macro GET(x) to convert x from big-endian to
little-endian. Hopefully I put it everywhere it needs to go and got
all the cases needed for everyone's linux/elf.h.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
arch/x86/vdso/vdso2c.c | 15 ++++++++++++
arch/x86/vdso/vdso2c.h | 63 ++++++++++++++++++++++++++++----------------------
2 files changed, 50 insertions(+), 28 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index fe8bfbf..de19ced 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -51,6 +51,21 @@ static void fail(const char *format, ...)
va_end(ap);
}
+/*
+ * Evil macros to do a little-endian read.
+ */
+#define __GET_TYPE(x, type, bits, ifnot) \
+ __builtin_choose_expr( \
+ __builtin_types_compatible_p(typeof(x), type), \
+ le##bits##toh((x)), ifnot)
+
+extern void bad_get(uint64_t);
+
+#define GET(x) \
+ __GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
+ __GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
+ __GET_TYPE((x), __u16, 16, bad_get(x))))))
+
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
#define BITS 64
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 26a7c1f..f0475da 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -18,25 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
const char *secstrings;
uint64_t syms[NSYMS] = {};
- Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
/* Walk the segment table. */
- for (i = 0; i < hdr->e_phnum; i++) {
- if (pt[i].p_type == PT_LOAD) {
+ for (i = 0; i < GET(hdr->e_phnum); i++) {
+ if (GET(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
- if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
+ if (GET(pt[i].p_offset) != 0 ||
+ GET(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
- if (pt[i].p_memsz != pt[i].p_filesz)
+ if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
- load_size = pt[i].p_memsz;
+ load_size = GET(pt[i].p_memsz);
found_load = 1;
- } else if (pt[i].p_type == PT_DYNAMIC) {
- dyn = addr + pt[i].p_offset;
- dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
+ } else if (GET(pt[i].p_type) == PT_DYNAMIC) {
+ dyn = addr + GET(pt[i].p_offset);
+ dyn_end = addr + GET(pt[i].p_offset) +
+ GET(pt[i].p_memsz);
}
}
if (!found_load)
@@ -44,43 +46,48 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
- if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
- dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
+ for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET(dyn[i].d_tag);
+ if (tag == DT_REL || tag == DT_RELSZ ||
+ tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
- secstrings = addr + secstrings_hdr->sh_offset;
- for (i = 0; i < hdr->e_shnum; i++) {
- Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
- if (sh->sh_type == SHT_SYMTAB)
+ secstrings_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
+ secstrings = addr + GET(secstrings_hdr->sh_offset);
+ for (i = 0; i < GET(hdr->e_shnum); i++) {
+ Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * i;
+ if (GET(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
- if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
+ if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + hdr->e_shoff +
- hdr->e_shentsize * symtab_hdr->sh_link;
+ strtab_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
/* Walk the symbol table */
- for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
+ for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
+ i++) {
int k;
- Elf_Sym *sym = addr + symtab_hdr->sh_offset +
- symtab_hdr->sh_entsize * i;
- const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
+ Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
+ GET(symtab_hdr->sh_entsize) * i;
+ const char *name = addr + GET(strtab_hdr->sh_offset) +
+ GET(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
- syms[k] = sym->st_value;
+ syms[k] = GET(sym->st_value);
}
}
}
@@ -106,7 +113,7 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
hdr->e_shnum = 0;
- hdr->e_shstrndx = SHN_UNDEF;
+ hdr->e_shstrndx = htole16(SHN_UNDEF);
if (!name) {
fwrite(addr, load_size, 1, outfile);
@@ -140,9 +147,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
fprintf(outfile, "\t},\n");
if (alt_sec) {
fprintf(outfile, "\t.alt = %lu,\n",
- (unsigned long)alt_sec->sh_offset);
+ (unsigned long)GET(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
- (unsigned long)alt_sec->sh_size);
+ (unsigned long)GET(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])
--
1.9.3
^ permalink raw reply related [flat|nested] 39+ messages in thread
* Re: [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
@ 2014-05-30 20:02 ` H. Peter Anvin
2014-05-30 20:09 ` Andy Lutomirski
2014-05-31 3:09 ` [tip:x86/vdso] x86/vdso, build: " tip-bot for Andy Lutomirski
` (2 subsequent siblings)
3 siblings, 1 reply; 39+ messages in thread
From: H. Peter Anvin @ 2014-05-30 20:02 UTC (permalink / raw)
To: Andy Lutomirski, Paul Gortmaker
Cc: Josh Boyer, Ingo Molnar, LKML, tglx, linux-tip-commits, linux-next
On 05/30/2014 08:48 AM, Andy Lutomirski wrote:
> This adds a macro GET(x) to convert x from big-endian to
> little-endian. Hopefully I put it everywhere it needs to go and got
> all the cases needed for everyone's linux/elf.h.
>
> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
> ---
> arch/x86/vdso/vdso2c.c | 15 ++++++++++++
> arch/x86/vdso/vdso2c.h | 63 ++++++++++++++++++++++++++++----------------------
> 2 files changed, 50 insertions(+), 28 deletions(-)
A couple of observations:
1. We shouldn't use double-underscore in host C code.
2. It would be nice if we can take these sort of things (host-build
helper macros) and move them to some common file in the Linux kernel
eventually, so it would be a good thing to make the naming a little
less general.
3. Even though it isn't necessary, making it work on 8-bit values so
one doesn't have to worry about the type would seem like a good
thing.
I came up with the following, it seems like a reasonable simplification:
> #define _LE(x, bits, ifnot) \
> __builtin_choose_expr( \
> (sizeof(x) == bits/8), \
> (__typeof__(x))le##bits##toh(x), ifnot)
>
> extern void bad_le(uint64_t);
> #define _LAST_LE(x) \
> __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x))
>
> #define LE(x) \
> _LE(x, 64, _LE(x, 32, _LE(x, 16, _LAST_LE(x))))
What do you think?
-hpa
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 20:02 ` H. Peter Anvin
@ 2014-05-30 20:09 ` Andy Lutomirski
2014-05-30 20:21 ` H. Peter Anvin
0 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 20:09 UTC (permalink / raw)
To: H. Peter Anvin
Cc: Paul Gortmaker, Josh Boyer, Ingo Molnar, LKML, tglx,
linux-tip-commits, linux-next
On Fri, May 30, 2014 at 1:02 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 05/30/2014 08:48 AM, Andy Lutomirski wrote:
>> This adds a macro GET(x) to convert x from big-endian to
>> little-endian. Hopefully I put it everywhere it needs to go and got
>> all the cases needed for everyone's linux/elf.h.
>>
>> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
>> ---
>> arch/x86/vdso/vdso2c.c | 15 ++++++++++++
>> arch/x86/vdso/vdso2c.h | 63 ++++++++++++++++++++++++++++----------------------
>> 2 files changed, 50 insertions(+), 28 deletions(-)
>
> A couple of observations:
>
> 1. We shouldn't use double-underscore in host C code.
>
> 2. It would be nice if we can take these sort of things (host-build
> helper macros) and move them to some common file in the Linux kernel
> eventually, so it would be a good thing to make the naming a little
> less general.
>
> 3. Even though it isn't necessary, making it work on 8-bit values so
> one doesn't have to worry about the type would seem like a good
> thing.
>
> I came up with the following, it seems like a reasonable simplification:
>
>> #define _LE(x, bits, ifnot) \
>> __builtin_choose_expr( \
>> (sizeof(x) == bits/8), \
>> (__typeof__(x))le##bits##toh(x), ifnot)
This will do awful things if x is a floating-point type, and, for
integers, the cast is probably unnecessary. But it should be okay.
>>
>> extern void bad_le(uint64_t);
If this ever goes in a common header, then we should do the
__attribute__((error)) thing. I wonder if it would ever make sense to
have __LINUX_HOSTPROG__ and make some of the basic headers work. Hmm.
>> #define _LAST_LE(x) \
>> __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x))
>>
>> #define LE(x) \
>> _LE(x, 64, _LE(x, 32, _LE(x, 16, _LAST_LE(x))))
>
> What do you think?
My only real real objection is that _LE sounds like converting *to*
little-endian to me. Admittedly, that's the same thing on any
remotely sane architecture, but still.
--Andy
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 20:09 ` Andy Lutomirski
@ 2014-05-30 20:21 ` H. Peter Anvin
2014-05-30 20:34 ` Andy Lutomirski
0 siblings, 1 reply; 39+ messages in thread
From: H. Peter Anvin @ 2014-05-30 20:21 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Paul Gortmaker, Josh Boyer, Ingo Molnar, LKML, tglx,
linux-tip-commits, linux-next
On 05/30/2014 01:09 PM, Andy Lutomirski wrote:
>>
>> I came up with the following, it seems like a reasonable simplification:
>>
>>> #define _LE(x, bits, ifnot) \
>>> __builtin_choose_expr( \
>>> (sizeof(x) == bits/8), \
>>> (__typeof__(x))le##bits##toh(x), ifnot)
>
> This will do awful things if x is a floating-point type, and, for
> integers, the cast is probably unnecessary. But it should be okay.
>
I mostly wanted to preserve the signedness. Yes, if we care about
floating-point it gets trickier.
At some point hopefully there will be a native C feature to handle this
crap.
>>> extern void bad_le(uint64_t);
>
> If this ever goes in a common header, then we should do the
> __attribute__((error)) thing. I wonder if it would ever make sense to
> have __LINUX_HOSTPROG__ and make some of the basic headers work. Hmm.
>
>>> #define _LAST_LE(x) \
>>> __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x))
>>>
>>> #define LE(x) \
>>> _LE(x, 64, _LE(x, 32, _LE(x, 16, _LAST_LE(x))))
>>
>> What do you think?
>
> My only real real objection is that _LE sounds like converting *to*
> little-endian to me. Admittedly, that's the same thing on any
> remotely sane architecture, but still.
GET_LE() then?
-hpa
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 20:21 ` H. Peter Anvin
@ 2014-05-30 20:34 ` Andy Lutomirski
2014-05-31 0:14 ` H. Peter Anvin
0 siblings, 1 reply; 39+ messages in thread
From: Andy Lutomirski @ 2014-05-30 20:34 UTC (permalink / raw)
To: H. Peter Anvin
Cc: Paul Gortmaker, Josh Boyer, Ingo Molnar, LKML, tglx,
linux-tip-commits, linux-next
On Fri, May 30, 2014 at 1:21 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 05/30/2014 01:09 PM, Andy Lutomirski wrote:
>>>
>>> I came up with the following, it seems like a reasonable simplification:
>>>
>>>> #define _LE(x, bits, ifnot) \
>>>> __builtin_choose_expr( \
>>>> (sizeof(x) == bits/8), \
>>>> (__typeof__(x))le##bits##toh(x), ifnot)
>>
>> This will do awful things if x is a floating-point type, and, for
>> integers, the cast is probably unnecessary. But it should be okay.
>>
>
> I mostly wanted to preserve the signedness. Yes, if we care about
> floating-point it gets trickier.
>
> At some point hopefully there will be a native C feature to handle this
> crap.
>
>>>> extern void bad_le(uint64_t);
>>
>> If this ever goes in a common header, then we should do the
>> __attribute__((error)) thing. I wonder if it would ever make sense to
>> have __LINUX_HOSTPROG__ and make some of the basic headers work. Hmm.
>>
>>>> #define _LAST_LE(x) \
>>>> __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x))
>>>>
>>>> #define LE(x) \
>>>> _LE(x, 64, _LE(x, 32, _LE(x, 16, _LAST_LE(x))))
>>>
>>> What do you think?
>>
>> My only real real objection is that _LE sounds like converting *to*
>> little-endian to me. Admittedly, that's the same thing on any
>> remotely sane architecture, but still.
>
> GET_LE() then?
Sounds good.
Are you planning on writing the patch?
I think my v2 is good -- the only diff I could find in my image.c
files and Stephen's was in the alt_xyz output, and I think I fixed
that in v2.
--Andy
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures
2014-05-30 20:34 ` Andy Lutomirski
@ 2014-05-31 0:14 ` H. Peter Anvin
0 siblings, 0 replies; 39+ messages in thread
From: H. Peter Anvin @ 2014-05-31 0:14 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Paul Gortmaker, Josh Boyer, Ingo Molnar, LKML, tglx,
linux-tip-commits, linux-next
On 05/30/2014 01:34 PM, Andy Lutomirski wrote:
>>
>> GET_LE() then?
>
> Sounds good.
>
> Are you planning on writing the patch?
>
> I think my v2 is good -- the only diff I could find in my image.c
> files and Stephen's was in the alt_xyz output, and I think I fixed
> that in v2.
>
Build testing one now.
-hpa
^ permalink raw reply [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86/vdso, build: When vdso2c fails, unlink the output
2014-05-30 15:48 ` [PATCH v2 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
@ 2014-05-31 3:09 ` tip-bot for Andy Lutomirski
0 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-31 3:09 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: 011561837dad082a92c0537db2d134e66419c6ad
Gitweb: http://git.kernel.org/tip/011561837dad082a92c0537db2d134e66419c6ad
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Fri, 30 May 2014 08:48:48 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Fri, 30 May 2014 16:58:39 -0700
x86/vdso, build: When vdso2c fails, unlink the output
This avoids bizarre failures if make is run again.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1764385fe9931e8940b9d001132515448ea89523.1401464755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/vdso/vdso2c.c | 20 +++++++++++---------
arch/x86/vdso/vdso2c.h | 10 +++-------
2 files changed, 14 insertions(+), 16 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 81edd1e..fe8bfbf 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -14,6 +14,8 @@
#include <linux/elf.h>
#include <linux/types.h>
+const char *outfilename;
+
/* Symbols that we need in vdso2c. */
enum {
sym_vvar_page,
@@ -44,6 +46,7 @@ static void fail(const char *format, ...)
va_start(ap, format);
fprintf(stderr, "Error: ");
vfprintf(stderr, format, ap);
+ unlink(outfilename);
exit(1);
va_end(ap);
}
@@ -82,17 +85,16 @@ static void fail(const char *format, ...)
#undef Elf_Sym
#undef Elf_Dyn
-static int go(void *addr, size_t len, FILE *outfile, const char *name)
+static void go(void *addr, size_t len, FILE *outfile, const char *name)
{
Elf64_Ehdr *hdr = (Elf64_Ehdr *)addr;
if (hdr->e_ident[EI_CLASS] == ELFCLASS64) {
- return go64(addr, len, outfile, name);
+ go64(addr, len, outfile, name);
} else if (hdr->e_ident[EI_CLASS] == ELFCLASS32) {
- return go32(addr, len, outfile, name);
+ go32(addr, len, outfile, name);
} else {
- fprintf(stderr, "Error: unknown ELF class\n");
- return 1;
+ fail("unknown ELF class\n");
}
}
@@ -102,7 +104,6 @@ int main(int argc, char **argv)
off_t len;
void *addr;
FILE *outfile;
- int ret;
char *name, *tmp;
int namelen;
@@ -143,14 +144,15 @@ int main(int argc, char **argv)
if (addr == MAP_FAILED)
err(1, "mmap");
- outfile = fopen(argv[2], "w");
+ outfilename = argv[2];
+ outfile = fopen(outfilename, "w");
if (!outfile)
err(1, "%s", argv[2]);
- ret = go(addr, (size_t)len, outfile, name);
+ go(addr, (size_t)len, outfile, name);
munmap(addr, len);
fclose(outfile);
- return ret;
+ return 0;
}
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 3dcc61e..26a7c1f 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -4,7 +4,7 @@
* are built for 32-bit userspace.
*/
-static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
+static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
{
int found_load = 0;
unsigned long load_size = -1; /* Work around bogus warning */
@@ -62,10 +62,8 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
alt_sec = sh;
}
- if (!symtab_hdr) {
+ if (!symtab_hdr)
fail("no symbol table\n");
- return 1;
- }
strtab_hdr = addr + hdr->e_shoff +
hdr->e_shentsize * symtab_hdr->sh_link;
@@ -112,7 +110,7 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
if (!name) {
fwrite(addr, load_size, 1, outfile);
- return 0;
+ return;
}
fprintf(outfile, "/* AUTOMATICALLY GENERATED -- DO NOT EDIT */\n\n");
@@ -152,6 +150,4 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
required_syms[i], syms[i]);
}
fprintf(outfile, "};\n");
-
- return 0;
}
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86/vdso, build: Fix cross-compilation from big-endian architectures
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
2014-05-30 20:02 ` H. Peter Anvin
@ 2014-05-31 3:09 ` tip-bot for Andy Lutomirski
2014-05-31 3:10 ` [tip:x86/vdso] x86/vdso, build: Make LE access macros clearer, host-safe tip-bot for H. Peter Anvin
2014-05-31 10:40 ` tip-bot for H. Peter Anvin
3 siblings, 0 replies; 39+ messages in thread
From: tip-bot for Andy Lutomirski @ 2014-05-31 3:09 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: add4eed0a2abea3951206f504330ee5daf8c178a
Gitweb: http://git.kernel.org/tip/add4eed0a2abea3951206f504330ee5daf8c178a
Author: Andy Lutomirski <luto@amacapital.net>
AuthorDate: Fri, 30 May 2014 08:48:49 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Fri, 30 May 2014 16:58:43 -0700
x86/vdso, build: Fix cross-compilation from big-endian architectures
This adds a macro GET(x) to convert x from big-endian to
little-endian. Hopefully I put it everywhere it needs to go and got
all the cases needed for everyone's linux/elf.h.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/vdso/vdso2c.c | 15 ++++++++++++
arch/x86/vdso/vdso2c.h | 63 ++++++++++++++++++++++++++++----------------------
2 files changed, 50 insertions(+), 28 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index fe8bfbf..de19ced 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -51,6 +51,21 @@ static void fail(const char *format, ...)
va_end(ap);
}
+/*
+ * Evil macros to do a little-endian read.
+ */
+#define __GET_TYPE(x, type, bits, ifnot) \
+ __builtin_choose_expr( \
+ __builtin_types_compatible_p(typeof(x), type), \
+ le##bits##toh((x)), ifnot)
+
+extern void bad_get(uint64_t);
+
+#define GET(x) \
+ __GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
+ __GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
+ __GET_TYPE((x), __u16, 16, bad_get(x))))))
+
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
#define BITS 64
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index 26a7c1f..f0475da 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -18,25 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
const char *secstrings;
uint64_t syms[NSYMS] = {};
- Elf_Phdr *pt = (Elf_Phdr *)(addr + hdr->e_phoff);
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
/* Walk the segment table. */
- for (i = 0; i < hdr->e_phnum; i++) {
- if (pt[i].p_type == PT_LOAD) {
+ for (i = 0; i < GET(hdr->e_phnum); i++) {
+ if (GET(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
- if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
+ if (GET(pt[i].p_offset) != 0 ||
+ GET(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
- if (pt[i].p_memsz != pt[i].p_filesz)
+ if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
- load_size = pt[i].p_memsz;
+ load_size = GET(pt[i].p_memsz);
found_load = 1;
- } else if (pt[i].p_type == PT_DYNAMIC) {
- dyn = addr + pt[i].p_offset;
- dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
+ } else if (GET(pt[i].p_type) == PT_DYNAMIC) {
+ dyn = addr + GET(pt[i].p_offset);
+ dyn_end = addr + GET(pt[i].p_offset) +
+ GET(pt[i].p_memsz);
}
}
if (!found_load)
@@ -44,43 +46,48 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
- if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
- dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
+ for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET(dyn[i].d_tag);
+ if (tag == DT_REL || tag == DT_RELSZ ||
+ tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
- secstrings = addr + secstrings_hdr->sh_offset;
- for (i = 0; i < hdr->e_shnum; i++) {
- Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
- if (sh->sh_type == SHT_SYMTAB)
+ secstrings_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
+ secstrings = addr + GET(secstrings_hdr->sh_offset);
+ for (i = 0; i < GET(hdr->e_shnum); i++) {
+ Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * i;
+ if (GET(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
- if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
+ if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + hdr->e_shoff +
- hdr->e_shentsize * symtab_hdr->sh_link;
+ strtab_hdr = addr + GET(hdr->e_shoff) +
+ GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
/* Walk the symbol table */
- for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
+ for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
+ i++) {
int k;
- Elf_Sym *sym = addr + symtab_hdr->sh_offset +
- symtab_hdr->sh_entsize * i;
- const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
+ Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
+ GET(symtab_hdr->sh_entsize) * i;
+ const char *name = addr + GET(strtab_hdr->sh_offset) +
+ GET(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
- syms[k] = sym->st_value;
+ syms[k] = GET(sym->st_value);
}
}
}
@@ -106,7 +113,7 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
hdr->e_shnum = 0;
- hdr->e_shstrndx = SHN_UNDEF;
+ hdr->e_shstrndx = htole16(SHN_UNDEF);
if (!name) {
fwrite(addr, load_size, 1, outfile);
@@ -140,9 +147,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
fprintf(outfile, "\t},\n");
if (alt_sec) {
fprintf(outfile, "\t.alt = %lu,\n",
- (unsigned long)alt_sec->sh_offset);
+ (unsigned long)GET(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
- (unsigned long)alt_sec->sh_size);
+ (unsigned long)GET(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86/vdso, build: Make LE access macros clearer, host-safe
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
2014-05-30 20:02 ` H. Peter Anvin
2014-05-31 3:09 ` [tip:x86/vdso] x86/vdso, build: " tip-bot for Andy Lutomirski
@ 2014-05-31 3:10 ` tip-bot for H. Peter Anvin
2014-05-31 10:40 ` tip-bot for H. Peter Anvin
3 siblings, 0 replies; 39+ messages in thread
From: tip-bot for H. Peter Anvin @ 2014-05-31 3:10 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: e002e99ea4b07c8446d8e1ca892c60f44630643e
Gitweb: http://git.kernel.org/tip/e002e99ea4b07c8446d8e1ca892c60f44630643e
Author: H. Peter Anvin <hpa@linux.intel.com>
AuthorDate: Fri, 30 May 2014 17:03:22 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Fri, 30 May 2014 17:03:22 -0700
x86/vdso, build: Make LE access macros clearer, host-safe
Make it a little clearer what the littleendian access macros in
vdso2c.[ch] actually do. This way they can probably also be moved to
a central location (e.g. tools/include) for the benefit of other host
tools.
We should avoid implementation namespace symbols when writing code
that is compiling for the compiler host, so avoid names starting with
double underscore or underscore-capital.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net
---
arch/x86/vdso/vdso2c.c | 16 ++++++-------
arch/x86/vdso/vdso2c.h | 65 ++++++++++++++++++++++++++------------------------
2 files changed, 42 insertions(+), 39 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index de19ced..a09d5a8 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -54,17 +54,17 @@ static void fail(const char *format, ...)
/*
* Evil macros to do a little-endian read.
*/
-#define __GET_TYPE(x, type, bits, ifnot) \
+#define GLE(x, bits, ifnot) \
__builtin_choose_expr( \
- __builtin_types_compatible_p(typeof(x), type), \
- le##bits##toh((x)), ifnot)
+ (sizeof(x) == bits/8), \
+ (__typeof__(x))le##bits##toh(x), ifnot)
-extern void bad_get(uint64_t);
+extern void bad_get_le(uint64_t);
+#define LAST_LE(x) \
+ __builtin_choose_expr(sizeof(x) == 1, (x), bad_le(x))
-#define GET(x) \
- __GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
- __GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
- __GET_TYPE((x), __u16, 16, bad_get(x))))))
+#define GET_LE(x) \
+ GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x))))
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index f0475da..d1e99e1 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -18,27 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
const char *secstrings;
uint64_t syms[NSYMS] = {};
- Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff));
/* Walk the segment table. */
- for (i = 0; i < GET(hdr->e_phnum); i++) {
- if (GET(pt[i].p_type) == PT_LOAD) {
+ for (i = 0; i < GET_LE(hdr->e_phnum); i++) {
+ if (GET_LE(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
- if (GET(pt[i].p_offset) != 0 ||
- GET(pt[i].p_vaddr) != 0)
+ if (GET_LE(pt[i].p_offset) != 0 ||
+ GET_LE(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
- if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
+ if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
- load_size = GET(pt[i].p_memsz);
+ load_size = GET_LE(pt[i].p_memsz);
found_load = 1;
- } else if (GET(pt[i].p_type) == PT_DYNAMIC) {
- dyn = addr + GET(pt[i].p_offset);
- dyn_end = addr + GET(pt[i].p_offset) +
- GET(pt[i].p_memsz);
+ } else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) {
+ dyn = addr + GET_LE(pt[i].p_offset);
+ dyn_end = addr + GET_LE(pt[i].p_offset) +
+ GET_LE(pt[i].p_memsz);
}
}
if (!found_load)
@@ -46,48 +46,51 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
- typeof(dyn[i].d_tag) tag = GET(dyn[i].d_tag);
+ for (i = 0; dyn + i < dyn_end &&
+ GET_LE(dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag);
if (tag == DT_REL || tag == DT_RELSZ ||
tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
- secstrings = addr + GET(secstrings_hdr->sh_offset);
- for (i = 0; i < GET(hdr->e_shnum); i++) {
- Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize) * i;
- if (GET(sh->sh_type) == SHT_SYMTAB)
+ secstrings_hdr = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx);
+ secstrings = addr + GET_LE(secstrings_hdr->sh_offset);
+ for (i = 0; i < GET_LE(hdr->e_shnum); i++) {
+ Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize) * i;
+ if (GET_LE(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
- if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
+ if (!strcmp(secstrings + GET_LE(sh->sh_name),
+ ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
+ strtab_hdr = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link);
/* Walk the symbol table */
- for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
+ for (i = 0;
+ i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize);
i++) {
int k;
- Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
- GET(symtab_hdr->sh_entsize) * i;
- const char *name = addr + GET(strtab_hdr->sh_offset) +
- GET(sym->st_name);
+ Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) +
+ GET_LE(symtab_hdr->sh_entsize) * i;
+ const char *name = addr + GET_LE(strtab_hdr->sh_offset) +
+ GET_LE(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
- syms[k] = GET(sym->st_value);
+ syms[k] = GET_LE(sym->st_value);
}
}
}
@@ -147,9 +150,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
fprintf(outfile, "\t},\n");
if (alt_sec) {
fprintf(outfile, "\t.alt = %lu,\n",
- (unsigned long)GET(alt_sec->sh_offset));
+ (unsigned long)GET_LE(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
- (unsigned long)GET(alt_sec->sh_size));
+ (unsigned long)GET_LE(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [tip:x86/vdso] x86/vdso, build: Make LE access macros clearer, host-safe
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
` (2 preceding siblings ...)
2014-05-31 3:10 ` [tip:x86/vdso] x86/vdso, build: Make LE access macros clearer, host-safe tip-bot for H. Peter Anvin
@ 2014-05-31 10:40 ` tip-bot for H. Peter Anvin
3 siblings, 0 replies; 39+ messages in thread
From: tip-bot for H. Peter Anvin @ 2014-05-31 10:40 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, luto, hpa, mingo, tglx, hpa
Commit-ID: c191920f737a09a7252088f018f6747f0d2f484d
Gitweb: http://git.kernel.org/tip/c191920f737a09a7252088f018f6747f0d2f484d
Author: H. Peter Anvin <hpa@linux.intel.com>
AuthorDate: Fri, 30 May 2014 17:03:22 -0700
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Sat, 31 May 2014 03:35:27 -0700
x86/vdso, build: Make LE access macros clearer, host-safe
Make it a little clearer what the littleendian access macros in
vdso2c.[ch] actually do. This way they can probably also be moved to
a central location (e.g. tools/include) for the benefit of other host
tools.
We should avoid implementation namespace symbols when writing code
that is compiling for the compiler host, so avoid names starting with
double underscore or underscore-capital.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net
---
arch/x86/vdso/vdso2c.c | 16 ++++++-------
arch/x86/vdso/vdso2c.h | 65 ++++++++++++++++++++++++++------------------------
2 files changed, 42 insertions(+), 39 deletions(-)
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index de19ced..deabaf5 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -54,17 +54,17 @@ static void fail(const char *format, ...)
/*
* Evil macros to do a little-endian read.
*/
-#define __GET_TYPE(x, type, bits, ifnot) \
+#define GLE(x, bits, ifnot) \
__builtin_choose_expr( \
- __builtin_types_compatible_p(typeof(x), type), \
- le##bits##toh((x)), ifnot)
+ (sizeof(x) == bits/8), \
+ (__typeof__(x))le##bits##toh(x), ifnot)
-extern void bad_get(uint64_t);
+extern void bad_get_le(uint64_t);
+#define LAST_LE(x) \
+ __builtin_choose_expr(sizeof(x) == 1, (x), bad_get_le(x))
-#define GET(x) \
- __GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
- __GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
- __GET_TYPE((x), __u16, 16, bad_get(x))))))
+#define GET_LE(x) \
+ GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x))))
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index f0475da..d1e99e1 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -18,27 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
const char *secstrings;
uint64_t syms[NSYMS] = {};
- Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
+ Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff));
/* Walk the segment table. */
- for (i = 0; i < GET(hdr->e_phnum); i++) {
- if (GET(pt[i].p_type) == PT_LOAD) {
+ for (i = 0; i < GET_LE(hdr->e_phnum); i++) {
+ if (GET_LE(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
- if (GET(pt[i].p_offset) != 0 ||
- GET(pt[i].p_vaddr) != 0)
+ if (GET_LE(pt[i].p_offset) != 0 ||
+ GET_LE(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
- if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
+ if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
- load_size = GET(pt[i].p_memsz);
+ load_size = GET_LE(pt[i].p_memsz);
found_load = 1;
- } else if (GET(pt[i].p_type) == PT_DYNAMIC) {
- dyn = addr + GET(pt[i].p_offset);
- dyn_end = addr + GET(pt[i].p_offset) +
- GET(pt[i].p_memsz);
+ } else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) {
+ dyn = addr + GET_LE(pt[i].p_offset);
+ dyn_end = addr + GET_LE(pt[i].p_offset) +
+ GET_LE(pt[i].p_memsz);
}
}
if (!found_load)
@@ -46,48 +46,51 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
- for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
- typeof(dyn[i].d_tag) tag = GET(dyn[i].d_tag);
+ for (i = 0; dyn + i < dyn_end &&
+ GET_LE(dyn[i].d_tag) != DT_NULL; i++) {
+ typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag);
if (tag == DT_REL || tag == DT_RELSZ ||
tag == DT_RELENT || tag == DT_TEXTREL)
fail("vdso image contains dynamic relocations\n");
}
/* Walk the section table */
- secstrings_hdr = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
- secstrings = addr + GET(secstrings_hdr->sh_offset);
- for (i = 0; i < GET(hdr->e_shnum); i++) {
- Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize) * i;
- if (GET(sh->sh_type) == SHT_SYMTAB)
+ secstrings_hdr = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx);
+ secstrings = addr + GET_LE(secstrings_hdr->sh_offset);
+ for (i = 0; i < GET_LE(hdr->e_shnum); i++) {
+ Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize) * i;
+ if (GET_LE(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
- if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
+ if (!strcmp(secstrings + GET_LE(sh->sh_name),
+ ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
- strtab_hdr = addr + GET(hdr->e_shoff) +
- GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
+ strtab_hdr = addr + GET_LE(hdr->e_shoff) +
+ GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link);
/* Walk the symbol table */
- for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
+ for (i = 0;
+ i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize);
i++) {
int k;
- Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
- GET(symtab_hdr->sh_entsize) * i;
- const char *name = addr + GET(strtab_hdr->sh_offset) +
- GET(sym->st_name);
+ Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) +
+ GET_LE(symtab_hdr->sh_entsize) * i;
+ const char *name = addr + GET_LE(strtab_hdr->sh_offset) +
+ GET_LE(sym->st_name);
for (k = 0; k < NSYMS; k++) {
if (!strcmp(name, required_syms[k])) {
if (syms[k]) {
fail("duplicate symbol %s\n",
required_syms[k]);
}
- syms[k] = GET(sym->st_value);
+ syms[k] = GET_LE(sym->st_value);
}
}
}
@@ -147,9 +150,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
fprintf(outfile, "\t},\n");
if (alt_sec) {
fprintf(outfile, "\t.alt = %lu,\n",
- (unsigned long)GET(alt_sec->sh_offset));
+ (unsigned long)GET_LE(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
- (unsigned long)GET(alt_sec->sh_size));
+ (unsigned long)GET_LE(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])
^ permalink raw reply related [flat|nested] 39+ messages in thread
end of thread, other threads:[~2014-05-31 10:40 UTC | newest]
Thread overview: 39+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-05-05 19:19 [PATCH v5 0/7] Clean up and unify the vDSO Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, mm: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 2/7] x86: Clean up 32-bit vs 64-bit vdso params Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 3/7] x86: Move syscall and sysenter setup into kernel/cpu/common.c Andy Lutomirski
2014-05-05 22:24 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 4/7] x86: Reimplement vdso.so preparation in build-time C Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-29 19:17 ` Paul Gortmaker
2014-05-29 19:32 ` Andy Lutomirski
2014-05-29 19:43 ` H. Peter Anvin
2014-05-29 19:46 ` Andy Lutomirski
2014-05-29 21:57 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Andy Lutomirski
2014-05-29 21:57 ` [PATCH 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
2014-05-29 21:57 ` [PATCH 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
2014-05-29 22:41 ` [PATCH 0/2] x86,vdso: vdso build fixes and improvements Paul Gortmaker
2014-05-29 22:49 ` Andy Lutomirski
2014-05-30 5:42 ` Stephen Rothwell
2014-05-30 15:40 ` Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 " Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 1/2] x86,vdso: When vdso2c fails, unlink the output Andy Lutomirski
2014-05-31 3:09 ` [tip:x86/vdso] x86/vdso, build: " tip-bot for Andy Lutomirski
2014-05-30 15:48 ` [PATCH v2 2/2] x86,vdso: Fix cross-compilation from big-endian architectures Andy Lutomirski
2014-05-30 20:02 ` H. Peter Anvin
2014-05-30 20:09 ` Andy Lutomirski
2014-05-30 20:21 ` H. Peter Anvin
2014-05-30 20:34 ` Andy Lutomirski
2014-05-31 0:14 ` H. Peter Anvin
2014-05-31 3:09 ` [tip:x86/vdso] x86/vdso, build: " tip-bot for Andy Lutomirski
2014-05-31 3:10 ` [tip:x86/vdso] x86/vdso, build: Make LE access macros clearer, host-safe tip-bot for H. Peter Anvin
2014-05-31 10:40 ` tip-bot for H. Peter Anvin
2014-05-29 19:43 ` [tip:x86/vdso] x86, vdso: Reimplement vdso.so preparation in build-time C Josh Boyer
2014-05-05 19:19 ` [PATCH v5 5/7] x86: Move the 32-bit vdso special pages after the text Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 6/7] x86: Move the vvar and hpet mappings next to the 64-bit vDSO Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-05-05 19:19 ` [PATCH v5 7/7] x86: Remove vestiges of VDSO_PRELINK and some outdated comments Andy Lutomirski
2014-05-05 22:25 ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
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