diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-06-19 14:54:23 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-06-19 19:56:07 +0200 |
| commit | 8a2462df154799129d8259079ec1fecf78703189 (patch) | |
| tree | 1e5785d2855987530f4ebb16240c192d5538f230 | |
| parent | 6ba59ff4227927d3a8530fc2973b80e94b54d58f (diff) | |
x86/uaccess: Improve the 8-byte getuser() case
Streamline the 8-byte case and drop the special handling. Use a macro
which hides the exception handling.
No functional changes.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/CAHk-=whYb2L_atsRk9pBiFiVLGe5wNZLHhRinA69yu6FiKvDsw@mail.gmail.com
| -rw-r--r-- | arch/x86/lib/getuser.S | 69 |
1 files changed, 20 insertions, 49 deletions
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index a1cb3a4e6742..a314622aa093 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -44,21 +44,23 @@ or %rdx, %rax .else cmp $TASK_SIZE_MAX-\size+1, %eax -.if \size != 8 jae .Lbad_get_user -.else - jae .Lbad_get_user_8 -.endif 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) check_range size=1 ASM_STAC -1: movzbl (%_ASM_AX),%edx + UACCESS movzbl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -68,7 +70,7 @@ EXPORT_SYMBOL(__get_user_1) SYM_FUNC_START(__get_user_2) check_range size=2 ASM_STAC -2: movzwl (%_ASM_AX),%edx + UACCESS movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -78,7 +80,7 @@ EXPORT_SYMBOL(__get_user_2) SYM_FUNC_START(__get_user_4) check_range size=4 ASM_STAC -3: movl (%_ASM_AX),%edx + UACCESS movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -89,10 +91,11 @@ SYM_FUNC_START(__get_user_8) check_range size=8 ASM_STAC #ifdef CONFIG_X86_64 -4: movq (%_ASM_AX),%rdx + UACCESS movq (%_ASM_AX),%rdx #else -4: movl (%_ASM_AX),%edx -5: 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 @@ -104,7 +107,7 @@ EXPORT_SYMBOL(__get_user_8) SYM_FUNC_START(__get_user_nocheck_1) ASM_STAC ASM_BARRIER_NOSPEC -6: movzbl (%_ASM_AX),%edx + UACCESS movzbl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -114,7 +117,7 @@ EXPORT_SYMBOL(__get_user_nocheck_1) SYM_FUNC_START(__get_user_nocheck_2) ASM_STAC ASM_BARRIER_NOSPEC -7: movzwl (%_ASM_AX),%edx + UACCESS movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -124,7 +127,7 @@ EXPORT_SYMBOL(__get_user_nocheck_2) SYM_FUNC_START(__get_user_nocheck_4) ASM_STAC ASM_BARRIER_NOSPEC -8: movl (%_ASM_AX),%edx + UACCESS movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC RET @@ -135,10 +138,11 @@ SYM_FUNC_START(__get_user_nocheck_8) 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 @@ -154,36 +158,3 @@ SYM_CODE_START_LOCAL(__get_user_handle_exception) mov $(-EFAULT),%_ASM_AX RET SYM_CODE_END(__get_user_handle_exception) - -#ifdef CONFIG_X86_32 -SYM_CODE_START_LOCAL(__get_user_8_handle_exception) - ASM_CLAC -.Lbad_get_user_8: - xor %edx,%edx - xor %ecx,%ecx - mov $(-EFAULT),%_ASM_AX - RET -SYM_CODE_END(__get_user_8_handle_exception) -#endif - -/* get_user */ - _ASM_EXTABLE_UA(1b, __get_user_handle_exception) - _ASM_EXTABLE_UA(2b, __get_user_handle_exception) - _ASM_EXTABLE_UA(3b, __get_user_handle_exception) -#ifdef CONFIG_X86_64 - _ASM_EXTABLE_UA(4b, __get_user_handle_exception) -#else - _ASM_EXTABLE_UA(4b, __get_user_8_handle_exception) - _ASM_EXTABLE_UA(5b, __get_user_8_handle_exception) -#endif - -/* __get_user */ - _ASM_EXTABLE_UA(6b, __get_user_handle_exception) - _ASM_EXTABLE_UA(7b, __get_user_handle_exception) - _ASM_EXTABLE_UA(8b, __get_user_handle_exception) -#ifdef CONFIG_X86_64 - _ASM_EXTABLE_UA(9b, __get_user_handle_exception) -#else - _ASM_EXTABLE_UA(9b, __get_user_8_handle_exception) - _ASM_EXTABLE_UA(10b, __get_user_8_handle_exception) -#endif |