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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-11-16 15:42:18 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-16 16:09:52 +0100 |
| commit | 3c93ca00eeeb774c7dd666cc7286a9e90c53e998 (patch) | |
| tree | 5f89fe4a22ab1394278e3fc4e9698b0c2327a97b | |
| parent | 14722485830fe6baba738b91d96f06fbd6cf7a18 (diff) | |
| download | linux-3c93ca00eeeb774c7dd666cc7286a9e90c53e998.tar.gz linux-3c93ca00eeeb774c7dd666cc7286a9e90c53e998.tar.bz2 linux-3c93ca00eeeb774c7dd666cc7286a9e90c53e998.zip | |
x86: Add missing might_fault() checks to copy_{to,from}_user()
On x86-64, copy_[to|from]_user() rely on assembly routines that
never call might_fault(), making us missing various lockdep
checks.
This doesn't apply to __copy_from,to_user() that explicitly
handle these calls, neither is it a problem in x86-32 where
copy_to,from_user() rely on the "__" prefixed versions that
also call might_fault().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1258382538-30979-1-git-send-email-fweisbec@gmail.com>
[ v2: fix module export ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/x8664_ksyms_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 4 |
3 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 7adebacaa325..46324c6a4f6e 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -19,7 +19,7 @@ __must_check unsigned long copy_user_generic(void *to, const void *from, unsigned len); __must_check unsigned long -copy_to_user(void __user *to, const void *from, unsigned len); +_copy_to_user(void __user *to, const void *from, unsigned len); __must_check unsigned long _copy_from_user(void *to, const void __user *from, unsigned len); __must_check unsigned long @@ -32,6 +32,7 @@ static inline unsigned long __must_check copy_from_user(void *to, int sz = __compiletime_object_size(to); int ret = -EFAULT; + might_fault(); if (likely(sz == -1 || sz >= n)) ret = _copy_from_user(to, from, n); #ifdef CONFIG_DEBUG_VM @@ -41,6 +42,13 @@ static inline unsigned long __must_check copy_from_user(void *to, return ret; } +static __always_inline __must_check +int copy_to_user(void __user *dst, const void *src, unsigned size) +{ + might_fault(); + + return _copy_to_user(dst, src, size); +} static __always_inline __must_check int __copy_from_user(void *dst, const void __user *src, unsigned size) diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index cd54276b6be8..a1029769b6f2 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -31,7 +31,7 @@ EXPORT_SYMBOL(__put_user_8); EXPORT_SYMBOL(copy_user_generic); EXPORT_SYMBOL(__copy_user_nocache); EXPORT_SYMBOL(_copy_from_user); -EXPORT_SYMBOL(copy_to_user); +EXPORT_SYMBOL(_copy_to_user); EXPORT_SYMBOL(copy_page); EXPORT_SYMBOL(clear_page); diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 39369985f1cb..cf889d4e076a 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -65,7 +65,7 @@ .endm /* Standard copy_to_user with segment limit checking */ -ENTRY(copy_to_user) +ENTRY(_copy_to_user) CFI_STARTPROC GET_THREAD_INFO(%rax) movq %rdi,%rcx @@ -75,7 +75,7 @@ ENTRY(copy_to_user) jae bad_to_user ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string CFI_ENDPROC -ENDPROC(copy_to_user) +ENDPROC(_copy_to_user) /* Standard copy_from_user with segment limit checking */ ENTRY(_copy_from_user) |