From: Dmitry Safonov <dima@arista.com>
To: linux-kernel@vger.kernel.org
Cc: Dmitry Safonov <0x7f454c46@gmail.com>,
Dmitry Safonov <dima@arista.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Guo Ren <guoren@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Ingo Molnar <mingo@redhat.com>, Oleg Nesterov <oleg@redhat.com>,
Russell King <linux@armlinux.org.uk>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Will Deacon <will@kernel.org>,
x86@kernel.org
Subject: [PATCH v3 01/23] x86/elf: Check in_x32_syscall() in compat_arch_setup_additional_pages()
Date: Fri, 11 Jun 2021 19:02:20 +0100 [thread overview]
Message-ID: <20210611180242.711399-2-dima@arista.com> (raw)
In-Reply-To: <20210611180242.711399-1-dima@arista.com>
Partly revert commit 3316ec8ccd34 ("x86/elf: Use e_machine to check for
x32/ia32 in setup_additional_pages()") and commit 9a29a671902c ("elf:
Expose ELF header on arch_setup_additional_pages()".
Both patches did a good thing: removed usage of TIF_X32, but with
a price of additional macros ARCH_SETUP_ADDITIONAL_PAGES() and ifdeffs.
Instead, use in_x32_syscall() - the first thing load_elf_binary() does
after parsing and checking new ELF binary. It's done that early after
exec() that mmap() code already uses it straight away, which is needed
to know which mmap_base to use (see arch_pick_mmap_layout()).
Add comments to describe how it works.
Cc: x86@kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
arch/x86/entry/vdso/vma.c | 4 ++--
arch/x86/include/asm/compat.h | 6 ++++++
arch/x86/include/asm/elf.h | 6 ++----
fs/binfmt_elf.c | 10 +++++++---
fs/compat_binfmt_elf.c | 11 +++--------
include/linux/elf.h | 5 -----
6 files changed, 20 insertions(+), 22 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 235a5794296a..43d42ce82e86 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -396,10 +396,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
#ifdef CONFIG_COMPAT
int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp, bool x32)
+ int uses_interp)
{
#ifdef CONFIG_X86_X32_ABI
- if (x32) {
+ if (in_x32_syscall()) {
if (!vdso64_enabled)
return 0;
return map_vdso_randomized(&vdso_image_x32);
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index be09c7eac89f..58f76665042c 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -186,6 +186,12 @@ static inline bool in_x32_syscall(void)
return false;
}
+/*
+ * Valid all the time on the context of a process that performs syscall.
+ * Just exec()ed process has __X32_SYSCALL_BIT or TS_COMPAT set very
+ * early in load_binary() on setting personality and flags.
+ * See also set_personality_ia32().
+ */
static inline bool in_32bit_syscall(void)
{
return in_ia32_syscall() || in_x32_syscall();
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 7d7500806af8..c0b5733005af 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -383,10 +383,8 @@ struct linux_binprm;
extern int arch_setup_additional_pages(struct linux_binprm *bprm,
int uses_interp);
extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
- int uses_interp, bool x32);
-#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
- compat_arch_setup_additional_pages(bprm, interpreter, \
- (ex->e_machine == EM_X86_64))
+ int uses_interp);
+#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 187b3f2b9202..2347d9067df6 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1002,8 +1002,12 @@ static int load_elf_binary(struct linux_binprm *bprm)
if (retval)
goto out_free_dentry;
- /* Do this immediately, since STACK_TOP as used in setup_arg_pages
- may depend on the personality. */
+ /*
+ * Do this immediately, since STACK_TOP as used in setup_arg_pages
+ * may depend on the personality. At this moment sys_exec()
+ * for loaded compatible application becomes non-native syscall
+ * and in_compat_syscall() starts working.
+ */
SET_PERSONALITY2(*elf_ex, &arch_state);
if (elf_read_implies_exec(*elf_ex, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
@@ -1249,7 +1253,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
set_binfmt(&elf_format);
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
- retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter);
+ retval = arch_setup_additional_pages(bprm, !!interpreter);
if (retval < 0)
goto out;
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index 95e72d271b95..049ba7c011b9 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -110,16 +110,11 @@
#define START_THREAD COMPAT_START_THREAD
#endif
-#ifdef compat_arch_setup_additional_pages
-#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
- compat_arch_setup_additional_pages(bprm, interpreter)
-#endif
-
-#ifdef COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
+#ifdef compat_arch_setup_additional_pages
#undef ARCH_HAS_SETUP_ADDITIONAL_PAGES
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
-#undef ARCH_SETUP_ADDITIONAL_PAGES
-#define ARCH_SETUP_ADDITIONAL_PAGES COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
+#undef arch_setup_additional_pages
+#define arch_setup_additional_pages compat_arch_setup_additional_pages
#endif
#ifdef compat_elf_read_implies_exec
diff --git a/include/linux/elf.h b/include/linux/elf.h
index c9a46c4e183b..6dbcfe7a3fd7 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -27,11 +27,6 @@
start_thread(regs, elf_entry, start_stack)
#endif
-#if defined(ARCH_HAS_SETUP_ADDITIONAL_PAGES) && !defined(ARCH_SETUP_ADDITIONAL_PAGES)
-#define ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
- arch_setup_additional_pages(bprm, interpreter)
-#endif
-
#define ELF32_GNU_PROPERTY_ALIGN 4
#define ELF64_GNU_PROPERTY_ALIGN 8
--
2.31.1
next prev parent reply other threads:[~2021-06-11 18:02 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-11 18:02 [PATCH v3 00/23] Add generic vdso_base tracking Dmitry Safonov
2021-06-11 18:02 ` Dmitry Safonov [this message]
2021-06-19 20:41 ` [PATCH v3 01/23] x86/elf: Check in_x32_syscall() in compat_arch_setup_additional_pages() Thomas Gleixner
2021-06-21 20:59 ` Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 02/23] elf: Move arch_setup_additional_pages() to generic elf.h Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 03/23] arm/elf: Remove needless ifdef CONFIG_MMU Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 04/23] arm64: Use in_compat_task() in arch_setup_additional_pages() Dmitry Safonov
2021-06-15 10:21 ` Will Deacon
2021-06-11 18:02 ` [PATCH v3 05/23] x86: Remove compat_arch_setup_additional_pages() Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 06/23] elf: " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 07/23] vdso: Set mm->context.vdso only on success of _install_special_mapping() Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 08/23] elf/vdso: Modify arch_setup_additional_pages() parameters Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 09/23] elf: Use sysinfo_ehdr in ARCH_DLINFO() Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 10/23] arm/vdso: Remove vdso pointer from mm->context Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 11/23] s390/vdso: Remove vdso_base " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 12/23] sparc/vdso: Remove vdso " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 13/23] mm/mmap: Make vm_special_mapping::mremap return void Dmitry Safonov
2021-06-17 7:20 ` Christophe Leroy
2021-06-21 21:12 ` Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 14/23] x86/signal: Land on &frame->retcode when vdso isn't mapped Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 15/23] x86/signal: Check if vdso_image_32 is mapped before trying to land on it Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 16/23] mm: Add vdso_base in mm_struct Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 17/23] x86/vdso: Migrate to generic vdso_base Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 18/23] arm/vdso: " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 19/23] arm64/vdso: Migrate compat signals " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 20/23] arm64/vdso: Migrate native " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 21/23] mips/vdso: Migrate " Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 22/23] powerpc/vdso: Migrate native signals " Dmitry Safonov
2021-06-15 12:52 ` Michael Ellerman
2021-06-17 6:30 ` Christophe Leroy
2021-06-17 6:36 ` Christophe Leroy
2021-06-17 7:34 ` Christophe Leroy
2021-06-21 21:22 ` Dmitry Safonov
2021-06-11 18:02 ` [PATCH v3 23/23] x86/vdso/selftest: Add a test for unmapping vDSO Dmitry Safonov
2021-06-11 18:21 ` Shuah Khan
2021-06-11 18:37 ` Dmitry Safonov
2021-06-11 18:43 ` Shuah Khan
2021-06-17 9:13 ` [PATCH v3 00/23] Add generic vdso_base tracking Christophe Leroy
2021-06-21 21:57 ` Dmitry Safonov
2022-03-09 15:41 ` Christophe Leroy
2022-03-10 21:17 ` Dmitry Safonov
2022-08-19 9:17 ` Christophe Leroy
2022-08-23 19:13 ` Dmitry Safonov
2023-10-11 10:28 ` Christophe Leroy
2023-10-11 23:20 ` H. Peter Anvin
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