Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH] x86: Add missing might_fault() from copy_{to,from}_user() | Date | Mon, 16 Nov 2009 15:42:18 +0100 |
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In 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> --- arch/x86/include/asm/uaccess_64.h | 10 +++++++++- arch/x86/lib/copy_user_64.S | 4 ++-- 2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 7adebac..46324c6 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/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 3936998..cf889d4 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) -- 1.6.2.3
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