diff options
Diffstat (limited to 'arch/x86/lib/getuser.S')
| -rw-r--r-- | arch/x86/lib/getuser.S | 142 |
1 files changed, 54 insertions, 88 deletions
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index b70d98d79a9d..9d5654b8a72a 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -26,35 +26,44 @@ * as they get called from within inline assembly. */ +#include <linux/export.h> #include <linux/linkage.h> +#include <linux/objtool.h> #include <asm/page_types.h> #include <asm/errno.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> #include <asm/asm.h> #include <asm/smap.h> -#include <asm/export.h> +#include <asm/runtime-const.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 +.macro check_range size:req +.if IS_ENABLED(CONFIG_X86_64) + RUNTIME_CONST_PTR USER_PTR_MAX, rdx + cmp %rdx, %rax + cmova %rdx, %rax +.else + cmp $TASK_SIZE_MAX-\size+1, %eax + jae .Lbad_get_user + sbb %edx, %edx /* array_index_mask_nospec() */ + and %edx, %eax +.endif +.endm + +.macro UACCESS op src dst +1: \op \src,\dst + _ASM_EXTABLE_UA(1b, __get_user_handle_exception) +.endm + .text SYM_FUNC_START(__get_user_1) - 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 + ANNOTATE_NOENDBR + check_range size=1 ASM_STAC -1: movzbl (%_ASM_AX),%edx + UACCESS movzbl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -62,13 +71,10 @@ SYM_FUNC_END(__get_user_1) EXPORT_SYMBOL(__get_user_1) SYM_FUNC_START(__get_user_2) - 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 + ANNOTATE_NOENDBR + check_range size=2 ASM_STAC -2: movzwl (%_ASM_AX),%edx + UACCESS movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -76,13 +82,10 @@ SYM_FUNC_END(__get_user_2) EXPORT_SYMBOL(__get_user_2) SYM_FUNC_START(__get_user_4) - 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 + ANNOTATE_NOENDBR + check_range size=4 ASM_STAC -3: movl (%_ASM_AX),%edx + UACCESS movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -90,38 +93,30 @@ SYM_FUNC_END(__get_user_4) EXPORT_SYMBOL(__get_user_4) SYM_FUNC_START(__get_user_8) -#ifdef CONFIG_X86_64 - 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 + ANNOTATE_NOENDBR +#ifndef CONFIG_X86_64 + xor %ecx,%ecx +#endif + check_range size=8 ASM_STAC -4: movq (%_ASM_AX),%rdx - xor %eax,%eax - ASM_CLAC - RET +#ifdef CONFIG_X86_64 + UACCESS movq (%_ASM_AX),%rdx #else - 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 (%_ASM_AX),%edx -5: movl 4(%_ASM_AX),%ecx + UACCESS movl (%_ASM_AX),%edx + UACCESS movl 4(%_ASM_AX),%ecx +#endif xor %eax,%eax ASM_CLAC RET -#endif 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) + ANNOTATE_NOENDBR ASM_STAC ASM_BARRIER_NOSPEC -6: movzbl (%_ASM_AX),%edx + UACCESS movzbl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -129,9 +124,10 @@ SYM_FUNC_END(__get_user_nocheck_1) EXPORT_SYMBOL(__get_user_nocheck_1) SYM_FUNC_START(__get_user_nocheck_2) + ANNOTATE_NOENDBR ASM_STAC ASM_BARRIER_NOSPEC -7: movzwl (%_ASM_AX),%edx + UACCESS movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -139,9 +135,10 @@ SYM_FUNC_END(__get_user_nocheck_2) EXPORT_SYMBOL(__get_user_nocheck_2) SYM_FUNC_START(__get_user_nocheck_4) + ANNOTATE_NOENDBR ASM_STAC ASM_BARRIER_NOSPEC -8: movl (%_ASM_AX),%edx + UACCESS movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -149,13 +146,15 @@ SYM_FUNC_END(__get_user_nocheck_4) EXPORT_SYMBOL(__get_user_nocheck_4) SYM_FUNC_START(__get_user_nocheck_8) + ANNOTATE_NOENDBR ASM_STAC ASM_BARRIER_NOSPEC #ifdef CONFIG_X86_64 -9: movq (%_ASM_AX),%rdx + UACCESS movq (%_ASM_AX),%rdx #else -9: movl (%_ASM_AX),%edx -10: movl 4(%_ASM_AX),%ecx + xor %ecx,%ecx + UACCESS movl (%_ASM_AX),%edx + UACCESS movl 4(%_ASM_AX),%ecx #endif xor %eax,%eax ASM_CLAC @@ -164,43 +163,10 @@ SYM_FUNC_END(__get_user_nocheck_8) EXPORT_SYMBOL(__get_user_nocheck_8) -SYM_CODE_START_LOCAL(.Lbad_get_user_clac) +SYM_CODE_START_LOCAL(__get_user_handle_exception) ASM_CLAC -bad_get_user: +.Lbad_get_user: xor %edx,%edx mov $(-EFAULT),%_ASM_AX RET -SYM_CODE_END(.Lbad_get_user_clac) - -#ifdef CONFIG_X86_32 -SYM_CODE_START_LOCAL(.Lbad_get_user_8_clac) - ASM_CLAC -bad_get_user_8: - xor %edx,%edx - xor %ecx,%ecx - mov $(-EFAULT),%_ASM_AX - RET -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) -#ifdef CONFIG_X86_64 - _ASM_EXTABLE_UA(4b, .Lbad_get_user_clac) -#else - _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 +SYM_CODE_END(__get_user_handle_exception) |