diff options
Diffstat (limited to 'arch/x86/lib/getuser.S')
| -rw-r--r-- | arch/x86/lib/getuser.S | 107 |
1 files changed, 84 insertions, 23 deletions
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index c8a85b512796..fa1bc2104b32 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -35,10 +35,21 @@ #include <asm/smap.h> #include <asm/export.h> +#define ASM_BARRIER_NOSPEC ALTERNATIVE "", "lfence", X86_FEATURE_LFENCE_RDTSC + +#ifdef CONFIG_X86_5LEVEL +#define LOAD_TASK_SIZE_MINUS_N(n) \ + ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rdx), \ + __stringify(mov $((1 << 56) - 4096 - (n)),%rdx), X86_FEATURE_LA57 +#else +#define LOAD_TASK_SIZE_MINUS_N(n) \ + mov $(TASK_SIZE_MAX - (n)),%_ASM_DX +#endif + .text SYM_FUNC_START(__get_user_1) - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(0) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX @@ -51,15 +62,13 @@ SYM_FUNC_END(__get_user_1) EXPORT_SYMBOL(__get_user_1) SYM_FUNC_START(__get_user_2) - add $1,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(1) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -2: movzwl -1(%_ASM_AX),%edx +2: movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC ret @@ -67,15 +76,13 @@ SYM_FUNC_END(__get_user_2) EXPORT_SYMBOL(__get_user_2) SYM_FUNC_START(__get_user_4) - add $3,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(3) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -3: movl -3(%_ASM_AX),%edx +3: movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC ret @@ -84,29 +91,25 @@ EXPORT_SYMBOL(__get_user_4) SYM_FUNC_START(__get_user_8) #ifdef CONFIG_X86_64 - add $7,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(7) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -4: movq -7(%_ASM_AX),%rdx +4: movq (%_ASM_AX),%rdx xor %eax,%eax ASM_CLAC ret #else - add $7,%_ASM_AX - jc bad_get_user_8 - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(7) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user_8 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -4: movl -7(%_ASM_AX),%edx -5: movl -3(%_ASM_AX),%ecx +4: movl (%_ASM_AX),%edx +5: movl 4(%_ASM_AX),%ecx xor %eax,%eax ASM_CLAC ret @@ -114,6 +117,52 @@ SYM_FUNC_START(__get_user_8) SYM_FUNC_END(__get_user_8) EXPORT_SYMBOL(__get_user_8) +/* .. and the same for __get_user, just without the range checks */ +SYM_FUNC_START(__get_user_nocheck_1) + ASM_STAC + ASM_BARRIER_NOSPEC +6: movzbl (%_ASM_AX),%edx + xor %eax,%eax + ASM_CLAC + ret +SYM_FUNC_END(__get_user_nocheck_1) +EXPORT_SYMBOL(__get_user_nocheck_1) + +SYM_FUNC_START(__get_user_nocheck_2) + ASM_STAC + ASM_BARRIER_NOSPEC +7: movzwl (%_ASM_AX),%edx + xor %eax,%eax + ASM_CLAC + ret +SYM_FUNC_END(__get_user_nocheck_2) +EXPORT_SYMBOL(__get_user_nocheck_2) + +SYM_FUNC_START(__get_user_nocheck_4) + ASM_STAC + ASM_BARRIER_NOSPEC +8: movl (%_ASM_AX),%edx + xor %eax,%eax + ASM_CLAC + ret +SYM_FUNC_END(__get_user_nocheck_4) +EXPORT_SYMBOL(__get_user_nocheck_4) + +SYM_FUNC_START(__get_user_nocheck_8) + ASM_STAC + ASM_BARRIER_NOSPEC +#ifdef CONFIG_X86_64 +9: movq (%_ASM_AX),%rdx +#else +9: movl (%_ASM_AX),%edx +10: movl 4(%_ASM_AX),%ecx +#endif + xor %eax,%eax + ASM_CLAC + ret +SYM_FUNC_END(__get_user_nocheck_8) +EXPORT_SYMBOL(__get_user_nocheck_8) + SYM_CODE_START_LOCAL(.Lbad_get_user_clac) ASM_CLAC @@ -134,6 +183,7 @@ bad_get_user_8: SYM_CODE_END(.Lbad_get_user_8_clac) #endif +/* get_user */ _ASM_EXTABLE_UA(1b, .Lbad_get_user_clac) _ASM_EXTABLE_UA(2b, .Lbad_get_user_clac) _ASM_EXTABLE_UA(3b, .Lbad_get_user_clac) @@ -143,3 +193,14 @@ SYM_CODE_END(.Lbad_get_user_8_clac) _ASM_EXTABLE_UA(4b, .Lbad_get_user_8_clac) _ASM_EXTABLE_UA(5b, .Lbad_get_user_8_clac) #endif + +/* __get_user */ + _ASM_EXTABLE_UA(6b, .Lbad_get_user_clac) + _ASM_EXTABLE_UA(7b, .Lbad_get_user_clac) + _ASM_EXTABLE_UA(8b, .Lbad_get_user_clac) +#ifdef CONFIG_X86_64 + _ASM_EXTABLE_UA(9b, .Lbad_get_user_clac) +#else + _ASM_EXTABLE_UA(9b, .Lbad_get_user_8_clac) + _ASM_EXTABLE_UA(10b, .Lbad_get_user_8_clac) +#endif |