diff options
| author | Dan Williams <[email protected]> | 2018-05-03 17:06:16 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2018-05-15 08:32:42 +0200 |
| commit | bd131544aa7e318a5735cbcbad46c4a5ee6b9d42 (patch) | |
| tree | 48223d5efd96ad0a4dead2ad3ce8657c5185164d | |
| parent | da7bc9c57eb0e91e048d05f7dbe5014a8b81ccfa (diff) | |
x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling
The memcpy_mcsafe() implementation handles CPU exceptions when reading
from the source address. Before it can be used for user copies it needs
to grow support for handling write faults. In preparation for adding
that exception handling update the labels for the read cache word X case
(.L_cache_rX) and write cache word X case (.L_cache_wX).
Reported-by: Tony Luck <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/152539237606.31796.6719743548991782264.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/lib/memcpy_64.S | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S index 54c971892db5..5709f3ec22a4 100644 --- a/arch/x86/lib/memcpy_64.S +++ b/arch/x86/lib/memcpy_64.S @@ -204,13 +204,14 @@ ENTRY(__memcpy_mcsafe) subl $8, %ecx negl %ecx subl %ecx, %edx -.L_copy_leading_bytes: +.L_read_leading_bytes: movb (%rsi), %al +.L_write_leading_bytes: movb %al, (%rdi) incq %rsi incq %rdi decl %ecx - jnz .L_copy_leading_bytes + jnz .L_read_leading_bytes .L_8byte_aligned: movl %edx, %ecx @@ -218,13 +219,14 @@ ENTRY(__memcpy_mcsafe) shrl $3, %ecx jz .L_no_whole_words -.L_copy_words: +.L_read_words: movq (%rsi), %r8 +.L_write_words: movq %r8, (%rdi) addq $8, %rsi addq $8, %rdi decl %ecx - jnz .L_copy_words + jnz .L_read_words /* Any trailing bytes? */ .L_no_whole_words: @@ -233,13 +235,14 @@ ENTRY(__memcpy_mcsafe) /* Copy trailing bytes */ movl %edx, %ecx -.L_copy_trailing_bytes: +.L_read_trailing_bytes: movb (%rsi), %al +.L_write_trailing_bytes: movb %al, (%rdi) incq %rsi incq %rdi decl %ecx - jnz .L_copy_trailing_bytes + jnz .L_read_trailing_bytes /* Copy successful. Return zero */ .L_done_memcpy_trap: @@ -256,7 +259,7 @@ EXPORT_SYMBOL_GPL(__memcpy_mcsafe) .previous - _ASM_EXTABLE_FAULT(.L_copy_leading_bytes, .L_memcpy_mcsafe_fail) - _ASM_EXTABLE_FAULT(.L_copy_words, .L_memcpy_mcsafe_fail) - _ASM_EXTABLE_FAULT(.L_copy_trailing_bytes, .L_memcpy_mcsafe_fail) + _ASM_EXTABLE_FAULT(.L_read_leading_bytes, .L_memcpy_mcsafe_fail) + _ASM_EXTABLE_FAULT(.L_read_words, .L_memcpy_mcsafe_fail) + _ASM_EXTABLE_FAULT(.L_read_trailing_bytes, .L_memcpy_mcsafe_fail) #endif |