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authorDan Williams <dan.j.williams@intel.com>2018-05-03 17:06:16 -0700
committerIngo Molnar <mingo@kernel.org>2018-05-15 08:32:42 +0200
commitbd131544aa7e318a5735cbcbad46c4a5ee6b9d42 (patch)
tree48223d5efd96ad0a4dead2ad3ce8657c5185164d /arch/x86/lib
parentda7bc9c57eb0e91e048d05f7dbe5014a8b81ccfa (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 <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539237606.31796.6719743548991782264.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/memcpy_64.S21
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