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author | Victor Kamensky <victor.kamensky@linaro.org> | 2014-09-04 07:07:33 +0200 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-09-12 18:38:59 +0200 |
commit | d9981380b49b839ecaffbbe131908a342db68980 (patch) | |
tree | bd39bf86b001180366029db52f5a3c7e9e5bd7e3 /arch | |
parent | ARM: 8135/1: Fix in-correct barrier usage in SWP{B} emulation (diff) | |
download | linux-d9981380b49b839ecaffbbe131908a342db68980.tar.xz linux-d9981380b49b839ecaffbbe131908a342db68980.zip |
ARM: 8137/1: fix get_user BE behavior for target variable with size of 8 bytes
e38361d 'ARM: 8091/2: add get_user() support for 8 byte types' commit
broke V7 BE get_user call when target var size is 64 bit, but '*ptr' size
is 32 bit or smaller. e38361d changed type of __r2 from 'register
unsigned long' to 'register typeof(x) __r2 asm("r2")' i.e before the change
even when target variable size was 64 bit, __r2 was still 32 bit.
But after e38361d commit, for target var of 64 bit size, __r2 became 64
bit and now it should occupy 2 registers r2, and r3. The issue in BE case
that r3 register is least significant word of __r2 and r2 register is most
significant word of __r2. But __get_user_4 still copies result into r2 (most
significant word of __r2). Subsequent code copies from __r2 into x, but
for situation described it will pick up only garbage from r3 register.
Special __get_user_64t_(124) functions are introduced. They are similar to
corresponding __get_user_(124) function but result stored in r3 register
(lsw in case of 64 bit __r2 in BE image). Those function are used by
get_user macro in case of BE and target var size is 64bit.
Also changed __get_user_lo8 name into __get_user_32t_8 to get consistent
naming accross all cases.
Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/include/asm/uaccess.h | 48 | ||||
-rw-r--r-- | arch/arm/lib/getuser.S | 38 |
2 files changed, 75 insertions, 11 deletions
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index a4cd7af475e9..4767eb9caa78 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -107,8 +107,11 @@ static inline void set_fs(mm_segment_t fs) extern int __get_user_1(void *); extern int __get_user_2(void *); extern int __get_user_4(void *); -extern int __get_user_lo8(void *); +extern int __get_user_32t_8(void *); extern int __get_user_8(void *); +extern int __get_user_64t_1(void *); +extern int __get_user_64t_2(void *); +extern int __get_user_64t_4(void *); #define __GUP_CLOBBER_1 "lr", "cc" #ifdef CONFIG_CPU_USE_DOMAINS @@ -117,7 +120,7 @@ extern int __get_user_8(void *); #define __GUP_CLOBBER_2 "lr", "cc" #endif #define __GUP_CLOBBER_4 "lr", "cc" -#define __GUP_CLOBBER_lo8 "lr", "cc" +#define __GUP_CLOBBER_32t_8 "lr", "cc" #define __GUP_CLOBBER_8 "lr", "cc" #define __get_user_x(__r2,__p,__e,__l,__s) \ @@ -131,12 +134,30 @@ extern int __get_user_8(void *); /* narrowing a double-word get into a single 32bit word register: */ #ifdef __ARMEB__ -#define __get_user_xb(__r2, __p, __e, __l, __s) \ - __get_user_x(__r2, __p, __e, __l, lo8) +#define __get_user_x_32t(__r2, __p, __e, __l, __s) \ + __get_user_x(__r2, __p, __e, __l, 32t_8) #else -#define __get_user_xb __get_user_x +#define __get_user_x_32t __get_user_x #endif +/* + * storing result into proper least significant word of 64bit target var, + * different only for big endian case where 64 bit __r2 lsw is r3: + */ +#ifdef __ARMEB__ +#define __get_user_x_64t(__r2, __p, __e, __l, __s) \ + __asm__ __volatile__ ( \ + __asmeq("%0", "r0") __asmeq("%1", "r2") \ + __asmeq("%3", "r1") \ + "bl __get_user_64t_" #__s \ + : "=&r" (__e), "=r" (__r2) \ + : "0" (__p), "r" (__l) \ + : __GUP_CLOBBER_##__s) +#else +#define __get_user_x_64t __get_user_x +#endif + + #define __get_user_check(x,p) \ ({ \ unsigned long __limit = current_thread_info()->addr_limit - 1; \ @@ -146,17 +167,26 @@ extern int __get_user_8(void *); register int __e asm("r0"); \ switch (sizeof(*(__p))) { \ case 1: \ - __get_user_x(__r2, __p, __e, __l, 1); \ + if (sizeof((x)) >= 8) \ + __get_user_x_64t(__r2, __p, __e, __l, 1); \ + else \ + __get_user_x(__r2, __p, __e, __l, 1); \ break; \ case 2: \ - __get_user_x(__r2, __p, __e, __l, 2); \ + if (sizeof((x)) >= 8) \ + __get_user_x_64t(__r2, __p, __e, __l, 2); \ + else \ + __get_user_x(__r2, __p, __e, __l, 2); \ break; \ case 4: \ - __get_user_x(__r2, __p, __e, __l, 4); \ + if (sizeof((x)) >= 8) \ + __get_user_x_64t(__r2, __p, __e, __l, 4); \ + else \ + __get_user_x(__r2, __p, __e, __l, 4); \ break; \ case 8: \ if (sizeof((x)) < 8) \ - __get_user_xb(__r2, __p, __e, __l, 4); \ + __get_user_x_32t(__r2, __p, __e, __l, 4); \ else \ __get_user_x(__r2, __p, __e, __l, 8); \ break; \ diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S index 938600098b88..8ecfd15c3a02 100644 --- a/arch/arm/lib/getuser.S +++ b/arch/arm/lib/getuser.S @@ -80,7 +80,7 @@ ENTRY(__get_user_8) ENDPROC(__get_user_8) #ifdef __ARMEB__ -ENTRY(__get_user_lo8) +ENTRY(__get_user_32t_8) check_uaccess r0, 8, r1, r2, __get_user_bad #ifdef CONFIG_CPU_USE_DOMAINS add r0, r0, #4 @@ -90,7 +90,37 @@ ENTRY(__get_user_lo8) #endif mov r0, #0 ret lr -ENDPROC(__get_user_lo8) +ENDPROC(__get_user_32t_8) + +ENTRY(__get_user_64t_1) + check_uaccess r0, 1, r1, r2, __get_user_bad8 +8: TUSER(ldrb) r3, [r0] + mov r0, #0 + ret lr +ENDPROC(__get_user_64t_1) + +ENTRY(__get_user_64t_2) + check_uaccess r0, 2, r1, r2, __get_user_bad8 +#ifdef CONFIG_CPU_USE_DOMAINS +rb .req ip +9: ldrbt r3, [r0], #1 +10: ldrbt rb, [r0], #0 +#else +rb .req r0 +9: ldrb r3, [r0] +10: ldrb rb, [r0, #1] +#endif + orr r3, rb, r3, lsl #8 + mov r0, #0 + ret lr +ENDPROC(__get_user_64t_2) + +ENTRY(__get_user_64t_4) + check_uaccess r0, 4, r1, r2, __get_user_bad8 +11: TUSER(ldr) r3, [r0] + mov r0, #0 + ret lr +ENDPROC(__get_user_64t_4) #endif __get_user_bad8: @@ -111,5 +141,9 @@ ENDPROC(__get_user_bad8) .long 6b, __get_user_bad8 #ifdef __ARMEB__ .long 7b, __get_user_bad + .long 8b, __get_user_bad8 + .long 9b, __get_user_bad8 + .long 10b, __get_user_bad8 + .long 11b, __get_user_bad8 #endif .popsection |