From: Dmitry Safonov <dsafonov@virtuozzo.com>
To: <linux-kernel@vger.kernel.org>, <mingo@redhat.com>
Cc: <luto@amacapital.net>, <tglx@linutronix.de>, <hpa@zytor.com>,
<x86@kernel.org>, <0x7f454c46@gmail.com>, <oleg@redhat.com>,
<gorcunov@openvz.org>, <xemul@virtuozzo.com>,
<khorenko@virtuozzo.com>, Dmitry Safonov <dsafonov@virtuozzo.com>,
Andy Lutomirski <luto@kernel.org>
Subject: [PATCH 2/6] x86/vdso: introduce do_map_vdso() and vdso_type enum
Date: Wed, 1 Jun 2016 16:11:33 +0300 [thread overview]
Message-ID: <1464786697-20639-3-git-send-email-dsafonov@virtuozzo.com> (raw)
In-Reply-To: <1464786697-20639-1-git-send-email-dsafonov@virtuozzo.com>
Make in-kernel API to map vDSO blobs on x86.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
---
arch/x86/entry/vdso/vma.c | 70 +++++++++++++++++++++++++--------------------
arch/x86/include/asm/vdso.h | 4 +++
2 files changed, 43 insertions(+), 31 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 387028e6755d..4017b60eed33 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -176,11 +176,18 @@ static int vvar_fault(const struct vm_special_mapping *sm,
return VM_FAULT_SIGBUS;
}
-static int map_vdso(const struct vdso_image *image, bool calculate_addr)
+/*
+ * Add vdso and vvar mappings to current process.
+ * @image - blob to map
+ * @addr - request a specific address (zero to map at free addr)
+ * @calculate_addr - turn on aslr (@addr will be ignored)
+ */
+static int map_vdso(const struct vdso_image *image,
+ unsigned long addr, bool calculate_addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- unsigned long addr, text_start;
+ unsigned long text_start;
int ret = 0;
static const struct vm_special_mapping vdso_mapping = {
@@ -193,12 +200,9 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
.fault = vvar_fault,
};
- if (calculate_addr) {
+ if (calculate_addr)
addr = vdso_addr(current->mm->start_stack,
image->size - image->sym_vvar_start);
- } else {
- addr = 0;
- }
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
@@ -249,48 +253,52 @@ up_fail:
return ret;
}
-#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
-static int load_vdso32(void)
+int do_map_vdso(vdso_type type, unsigned long addr, bool randomize_addr)
{
- if (vdso32_enabled != 1) /* Other values all mean "disabled" */
- return 0;
-
- return map_vdso(&vdso_image_32, false);
-}
+ switch (type) {
+#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
+ case VDSO_32:
+ if (vdso32_enabled != 1) /* Other values all mean "disabled" */
+ return 0;
+ /* vDSO aslr turned off for i386 vDSO */
+ return map_vdso(&vdso_image_32, addr, false);
+#endif
+#ifdef CONFIG_X86_64
+ case VDSO_64:
+ if (!vdso64_enabled)
+ return 0;
+ return map_vdso(&vdso_image_64, addr, randomize_addr);
+#endif
+#ifdef CONFIG_X86_X32_ABI
+ case VDSO_X32:
+ if (!vdso64_enabled)
+ return 0;
+ return map_vdso(&vdso_image_x32, addr, randomize_addr);
#endif
+ default:
+ return -EINVAL;
+ }
+}
#ifdef CONFIG_X86_64
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- if (!vdso64_enabled)
- return 0;
-
- return map_vdso(&vdso_image_64, true);
+ return do_map_vdso(VDSO_64, 0, true);
}
#ifdef CONFIG_COMPAT
int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp)
{
-#ifdef CONFIG_X86_X32_ABI
- if (test_thread_flag(TIF_X32)) {
- if (!vdso64_enabled)
- return 0;
-
- return map_vdso(&vdso_image_x32, true);
- }
-#endif
-#ifdef CONFIG_IA32_EMULATION
- return load_vdso32();
-#else
- return 0;
-#endif
+ if (test_thread_flag(TIF_X32))
+ return do_map_vdso(VDSO_X32, 0, true);
+ return do_map_vdso(VDSO_32, 0, false);
}
#endif
#else
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
- return load_vdso32();
+ return do_map_vdso(VDSO_32, 0, false);
}
#endif
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 43dc55be524e..2be137897842 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -41,6 +41,10 @@ extern const struct vdso_image vdso_image_32;
extern void __init init_vdso_image(const struct vdso_image *image);
+typedef enum { VDSO_32, VDSO_64, VDSO_X32 } vdso_type;
+
+extern int do_map_vdso(vdso_type type, unsigned long addr, bool randomize_addr);
+
#endif /* __ASSEMBLER__ */
#endif /* _ASM_X86_VDSO_H */
--
2.8.2
next prev parent reply other threads:[~2016-06-01 13:13 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-01 13:11 [PATCH 0/6] x86: 32-bit compatible C/R on x86_64 Dmitry Safonov
2016-06-01 13:11 ` [PATCH 1/6] x86/vdso: unmap vdso blob on vvar mapping failure Dmitry Safonov
2016-06-01 13:11 ` Dmitry Safonov [this message]
2016-06-03 9:50 ` [PATCH 2/6] x86/vdso: introduce do_map_vdso() and vdso_type enum Cyrill Gorcunov
2016-06-03 10:03 ` Dmitry Safonov
2016-06-01 13:11 ` [PATCH 3/6] x86/arch_prctl/vdso: add ARCH_MAP_VDSO_* Dmitry Safonov
2016-06-01 13:11 ` [PATCH 4/6] x86/coredump: use core regs, rather that TIF_IA32 flag Dmitry Safonov
2016-06-03 9:51 ` Cyrill Gorcunov
2016-06-03 9:56 ` Dmitry Safonov
2016-06-03 10:01 ` Cyrill Gorcunov
2016-06-06 20:45 ` Oleg Nesterov
2016-06-06 22:43 ` Oleg Nesterov
2016-06-08 13:28 ` Dmitry Safonov
2016-06-01 13:11 ` [PATCH 5/6] x86/ptrace: down with test_thread_flag(TIF_IA32) Dmitry Safonov
2016-06-03 9:57 ` Cyrill Gorcunov
2016-06-03 10:27 ` Dmitry Safonov
2016-06-03 10:41 ` Cyrill Gorcunov
2016-06-06 21:19 ` Oleg Nesterov
2016-06-07 11:38 ` Dmitry Safonov
2016-06-09 17:21 ` Andy Lutomirski
2016-06-10 20:07 ` Oleg Nesterov
2016-06-10 20:14 ` Andy Lutomirski
2016-06-13 13:50 ` Oleg Nesterov
2016-06-13 20:40 ` Andy Lutomirski
2016-06-14 14:34 ` Oleg Nesterov
2016-06-14 14:43 ` Dmitry Safonov
2016-06-01 13:11 ` [PATCH 6/6] x86/signal: add SA_{X32,IA32}_ABI sa_flags Dmitry Safonov
2016-06-04 5:08 ` Andy Lutomirski
2016-06-04 15:57 ` Dmitry Safonov
2016-06-01 13:15 ` [PATCH 0/6] x86: 32-bit compatible C/R on x86_64 Dmitry Safonov
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