diff options
| author | Will Deacon <will.deacon@arm.com> | 2012-09-07 19:24:10 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-09 18:28:48 +0200 |
| commit | ad72907acd2943304c292ae36960bb66e6dc23c9 (patch) | |
| tree | d9f09ddcb8c4bc8d5a3885c89bc28942bd2e33bd /arch | |
| parent | ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS (diff) | |
| download | linux-ad72907acd2943304c292ae36960bb66e6dc23c9.tar.xz linux-ad72907acd2943304c292ae36960bb66e6dc23c9.zip | |
ARM: 7528/1: uaccess: annotate [__]{get,put}_user functions with might_fault()
The user access functions may generate a fault, resulting in invocation
of a handler that may sleep.
This patch annotates the accessors with might_fault() so that we print a
warning if they are invoked from atomic context and help lockdep keep
track of mmap_sem.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/uaccess.h | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 6f83ad6e4d3d..77bd79f2ffdb 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -118,7 +118,7 @@ extern int __get_user_4(void *); : "0" (__p), "r" (__l) \ : __GUP_CLOBBER_##__s) -#define get_user(x,p) \ +#define __get_user_check(x,p) \ ({ \ unsigned long __limit = current_thread_info()->addr_limit - 1; \ register const typeof(*(p)) __user *__p asm("r0") = (p);\ @@ -141,6 +141,12 @@ extern int __get_user_4(void *); __e; \ }) +#define get_user(x,p) \ + ({ \ + might_fault(); \ + __get_user_check(x,p); \ + }) + extern int __put_user_1(void *, unsigned int); extern int __put_user_2(void *, unsigned int); extern int __put_user_4(void *, unsigned int); @@ -155,7 +161,7 @@ extern int __put_user_8(void *, unsigned long long); : "0" (__p), "r" (__r2), "r" (__l) \ : "ip", "lr", "cc") -#define put_user(x,p) \ +#define __put_user_check(x,p) \ ({ \ unsigned long __limit = current_thread_info()->addr_limit - 1; \ register const typeof(*(p)) __r2 asm("r2") = (x); \ @@ -180,6 +186,12 @@ extern int __put_user_8(void *, unsigned long long); __e; \ }) +#define put_user(x,p) \ + ({ \ + might_fault(); \ + __put_user_check(x,p); \ + }) + #else /* CONFIG_MMU */ /* @@ -233,6 +245,7 @@ do { \ unsigned long __gu_addr = (unsigned long)(ptr); \ unsigned long __gu_val; \ __chk_user_ptr(ptr); \ + might_fault(); \ switch (sizeof(*(ptr))) { \ case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ @@ -314,6 +327,7 @@ do { \ unsigned long __pu_addr = (unsigned long)(ptr); \ __typeof__(*(ptr)) __pu_val = (x); \ __chk_user_ptr(ptr); \ + might_fault(); \ switch (sizeof(*(ptr))) { \ case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ |