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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-07 21:22:28 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-09 20:28:47 +0400 |
| commit | 8404663f81d212918ff85f493649a7991209fa04 (patch) | |
| tree | b695686fd2764914da245ef31649b1deb91ddafa /arch/arm/include/asm | |
| parent | 2b2040af0b64cd93e5d4df2494c4486cf604090d (diff) | |
| download | linux-8404663f81d212918ff85f493649a7991209fa04.tar.xz | |
ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm')
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 8 | ||||
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 40 |
2 files changed, 35 insertions, 13 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 03fb93621d0d..5c8b3bf4d825 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -320,4 +320,12 @@ .size \name , . - \name .endm + .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req +#ifndef CONFIG_CPU_USE_DOMAINS + adds \tmp, \addr, #\size - 1 + sbcccs \tmp, \tmp, \limit + bcs \bad +#endif + .endm + #endif /* __ASM_ASSEMBLER_H__ */ diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 479a6352e0b5..6f83ad6e4d3d 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -101,28 +101,39 @@ extern int __get_user_1(void *); extern int __get_user_2(void *); extern int __get_user_4(void *); -#define __get_user_x(__r2,__p,__e,__s,__i...) \ +#define __GUP_CLOBBER_1 "lr", "cc" +#ifdef CONFIG_CPU_USE_DOMAINS +#define __GUP_CLOBBER_2 "ip", "lr", "cc" +#else +#define __GUP_CLOBBER_2 "lr", "cc" +#endif +#define __GUP_CLOBBER_4 "lr", "cc" + +#define __get_user_x(__r2,__p,__e,__l,__s) \ __asm__ __volatile__ ( \ __asmeq("%0", "r0") __asmeq("%1", "r2") \ + __asmeq("%3", "r1") \ "bl __get_user_" #__s \ : "=&r" (__e), "=r" (__r2) \ - : "0" (__p) \ - : __i, "cc") + : "0" (__p), "r" (__l) \ + : __GUP_CLOBBER_##__s) #define get_user(x,p) \ ({ \ + unsigned long __limit = current_thread_info()->addr_limit - 1; \ register const typeof(*(p)) __user *__p asm("r0") = (p);\ register unsigned long __r2 asm("r2"); \ + register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ switch (sizeof(*(__p))) { \ case 1: \ - __get_user_x(__r2, __p, __e, 1, "lr"); \ - break; \ + __get_user_x(__r2, __p, __e, __l, 1); \ + break; \ case 2: \ - __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \ + __get_user_x(__r2, __p, __e, __l, 2); \ break; \ case 4: \ - __get_user_x(__r2, __p, __e, 4, "lr"); \ + __get_user_x(__r2, __p, __e, __l, 4); \ break; \ default: __e = __get_user_bad(); break; \ } \ @@ -135,31 +146,34 @@ extern int __put_user_2(void *, unsigned int); extern int __put_user_4(void *, unsigned int); extern int __put_user_8(void *, unsigned long long); -#define __put_user_x(__r2,__p,__e,__s) \ +#define __put_user_x(__r2,__p,__e,__l,__s) \ __asm__ __volatile__ ( \ __asmeq("%0", "r0") __asmeq("%2", "r2") \ + __asmeq("%3", "r1") \ "bl __put_user_" #__s \ : "=&r" (__e) \ - : "0" (__p), "r" (__r2) \ + : "0" (__p), "r" (__r2), "r" (__l) \ : "ip", "lr", "cc") #define put_user(x,p) \ ({ \ + unsigned long __limit = current_thread_info()->addr_limit - 1; \ register const typeof(*(p)) __r2 asm("r2") = (x); \ register const typeof(*(p)) __user *__p asm("r0") = (p);\ + register unsigned long __l asm("r1") = __limit; \ register int __e asm("r0"); \ switch (sizeof(*(__p))) { \ case 1: \ - __put_user_x(__r2, __p, __e, 1); \ + __put_user_x(__r2, __p, __e, __l, 1); \ break; \ case 2: \ - __put_user_x(__r2, __p, __e, 2); \ + __put_user_x(__r2, __p, __e, __l, 2); \ break; \ case 4: \ - __put_user_x(__r2, __p, __e, 4); \ + __put_user_x(__r2, __p, __e, __l, 4); \ break; \ case 8: \ - __put_user_x(__r2, __p, __e, 8); \ + __put_user_x(__r2, __p, __e, __l, 8); \ break; \ default: __e = __put_user_bad(); break; \ } \ |