diff options
| -rw-r--r-- | arch/x86/include/asm/uaccess_32.h | 12 | ||||
| -rw-r--r-- | arch/x86/lib/usercopy_32.c | 6 | ||||
| -rw-r--r-- | include/linux/compiler-gcc4.h | 3 | ||||
| -rw-r--r-- | include/linux/compiler.h | 4 |
4 files changed, 22 insertions, 3 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 582d6aef741..952f9e793c3 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -191,6 +191,13 @@ unsigned long __must_check _copy_from_user(void *to, const void __user *from, unsigned long n); + +extern void copy_from_user_overflow(void) +#ifdef CONFIG_DEBUG_STACKOVERFLOW + __compiletime_warning("copy_from_user() buffer size is not provably correct") +#endif +; + static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) @@ -200,10 +207,9 @@ static inline unsigned long __must_check copy_from_user(void *to, if (likely(sz == -1 || sz >= n)) ret = _copy_from_user(to, from, n); -#ifdef CONFIG_DEBUG_VM else - WARN(1, "Buffer overflow detected!\n"); -#endif + copy_from_user_overflow(); + return ret; } diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index 8498684e45b..e218d5df85f 100644 --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -883,3 +883,9 @@ _copy_from_user(void *to, const void __user *from, unsigned long n) return n; } EXPORT_SYMBOL(_copy_from_user); + +void copy_from_user_overflow(void) +{ + WARN(1, "Buffer overflow detected!\n"); +} +EXPORT_SYMBOL(copy_from_user_overflow); diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index a3aef5d55db..f1709c1f9ea 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -39,3 +39,6 @@ #endif #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) +#if __GNUC_MINOR__ >= 4 +#define __compiletime_warning(message) __attribute__((warning(message))) +#endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 8e54108688f..950356311f1 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -270,6 +270,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #ifndef __compiletime_object_size # define __compiletime_object_size(obj) -1 #endif +#ifndef __compiletime_warning +# define __compiletime_warning(message) +#endif + /* * Prevent the compiler from merging or refetching accesses. The compiler * is also forbidden from reordering successive instances of ACCESS_ONCE(), |