diff options
Diffstat (limited to 'arch/x86/lib/copy_user_64.S')
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 111 |
1 files changed, 63 insertions, 48 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 86976b55ae74..a73f88dae9a0 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -15,6 +15,7 @@ #include <asm/asm.h> #include <asm/smap.h> #include <asm/export.h> +#include <asm/trapnr.h> .macro ALIGN_DESTINATION /* check for bad alignment of destination */ @@ -36,8 +37,8 @@ jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(100b, 103b) - _ASM_EXTABLE_UA(101b, 103b) + _ASM_EXTABLE_CPY(100b, 103b) + _ASM_EXTABLE_CPY(101b, 103b) .endm /* @@ -116,26 +117,26 @@ ENTRY(copy_user_generic_unrolled) 60: jmp .Lcopy_user_handle_tail /* ecx is zerorest also */ .previous - _ASM_EXTABLE_UA(1b, 30b) - _ASM_EXTABLE_UA(2b, 30b) - _ASM_EXTABLE_UA(3b, 30b) - _ASM_EXTABLE_UA(4b, 30b) - _ASM_EXTABLE_UA(5b, 30b) - _ASM_EXTABLE_UA(6b, 30b) - _ASM_EXTABLE_UA(7b, 30b) - _ASM_EXTABLE_UA(8b, 30b) - _ASM_EXTABLE_UA(9b, 30b) - _ASM_EXTABLE_UA(10b, 30b) - _ASM_EXTABLE_UA(11b, 30b) - _ASM_EXTABLE_UA(12b, 30b) - _ASM_EXTABLE_UA(13b, 30b) - _ASM_EXTABLE_UA(14b, 30b) - _ASM_EXTABLE_UA(15b, 30b) - _ASM_EXTABLE_UA(16b, 30b) - _ASM_EXTABLE_UA(18b, 40b) - _ASM_EXTABLE_UA(19b, 40b) - _ASM_EXTABLE_UA(21b, 50b) - _ASM_EXTABLE_UA(22b, 50b) + _ASM_EXTABLE_CPY(1b, 30b) + _ASM_EXTABLE_CPY(2b, 30b) + _ASM_EXTABLE_CPY(3b, 30b) + _ASM_EXTABLE_CPY(4b, 30b) + _ASM_EXTABLE_CPY(5b, 30b) + _ASM_EXTABLE_CPY(6b, 30b) + _ASM_EXTABLE_CPY(7b, 30b) + _ASM_EXTABLE_CPY(8b, 30b) + _ASM_EXTABLE_CPY(9b, 30b) + _ASM_EXTABLE_CPY(10b, 30b) + _ASM_EXTABLE_CPY(11b, 30b) + _ASM_EXTABLE_CPY(12b, 30b) + _ASM_EXTABLE_CPY(13b, 30b) + _ASM_EXTABLE_CPY(14b, 30b) + _ASM_EXTABLE_CPY(15b, 30b) + _ASM_EXTABLE_CPY(16b, 30b) + _ASM_EXTABLE_CPY(18b, 40b) + _ASM_EXTABLE_CPY(19b, 40b) + _ASM_EXTABLE_CPY(21b, 50b) + _ASM_EXTABLE_CPY(22b, 50b) ENDPROC(copy_user_generic_unrolled) EXPORT_SYMBOL(copy_user_generic_unrolled) @@ -180,8 +181,8 @@ ENTRY(copy_user_generic_string) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, 11b) - _ASM_EXTABLE_UA(3b, 12b) + _ASM_EXTABLE_CPY(1b, 11b) + _ASM_EXTABLE_CPY(3b, 12b) ENDPROC(copy_user_generic_string) EXPORT_SYMBOL(copy_user_generic_string) @@ -213,7 +214,7 @@ ENTRY(copy_user_enhanced_fast_string) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, 12b) + _ASM_EXTABLE_CPY(1b, 12b) ENDPROC(copy_user_enhanced_fast_string) EXPORT_SYMBOL(copy_user_enhanced_fast_string) @@ -221,6 +222,7 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string) * Try to copy last bytes and clear the rest if needed. * Since protection fault in copy_from/to_user is not a normal situation, * it is not necessary to optimize tail handling. + * Don't try to copy the tail if machine check happened * * Input: * rdi destination @@ -233,12 +235,25 @@ EXPORT_SYMBOL(copy_user_enhanced_fast_string) ALIGN; .Lcopy_user_handle_tail: movl %edx,%ecx + cmp $X86_TRAP_MC,%eax /* check if X86_TRAP_MC */ + je 3f 1: rep movsb 2: mov %ecx,%eax ASM_CLAC ret - _ASM_EXTABLE_UA(1b, 2b) + /* + * Return zero to pretend that this copy succeeded. This + * is counter-intuitive, but needed to prevent the code + * in lib/iov_iter.c from retrying and running back into + * the poison cache line again. The machine check handler + * will ensure that a SIGBUS is sent to the task. + */ +3: xorl %eax,%eax + ASM_CLAC + ret + + _ASM_EXTABLE_CPY(1b, 2b) END(.Lcopy_user_handle_tail) /* @@ -367,27 +382,27 @@ ENTRY(__copy_user_nocache) jmp .Lcopy_user_handle_tail .previous - _ASM_EXTABLE_UA(1b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(2b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(3b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(4b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(5b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(6b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(7b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(8b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(9b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(10b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(11b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(12b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(13b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(14b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(15b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(16b, .L_fixup_4x8b_copy) - _ASM_EXTABLE_UA(20b, .L_fixup_8b_copy) - _ASM_EXTABLE_UA(21b, .L_fixup_8b_copy) - _ASM_EXTABLE_UA(30b, .L_fixup_4b_copy) - _ASM_EXTABLE_UA(31b, .L_fixup_4b_copy) - _ASM_EXTABLE_UA(40b, .L_fixup_1b_copy) - _ASM_EXTABLE_UA(41b, .L_fixup_1b_copy) + _ASM_EXTABLE_CPY(1b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(2b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(3b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(4b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(5b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(6b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(7b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(8b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(9b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(10b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(11b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(12b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(13b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(14b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(15b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(16b, .L_fixup_4x8b_copy) + _ASM_EXTABLE_CPY(20b, .L_fixup_8b_copy) + _ASM_EXTABLE_CPY(21b, .L_fixup_8b_copy) + _ASM_EXTABLE_CPY(30b, .L_fixup_4b_copy) + _ASM_EXTABLE_CPY(31b, .L_fixup_4b_copy) + _ASM_EXTABLE_CPY(40b, .L_fixup_1b_copy) + _ASM_EXTABLE_CPY(41b, .L_fixup_1b_copy) ENDPROC(__copy_user_nocache) EXPORT_SYMBOL(__copy_user_nocache) |