linux_dsm_epyc7002/arch/x86/lib/memset_64.S
Andrey Ryabinin 393f203f5f x86_64: kasan: add interceptors for memset/memmove/memcpy functions
Recently instrumentation of builtin functions calls was removed from GCC
5.0.  To check the memory accessed by such functions, userspace asan
always uses interceptors for them.

So now we should do this as well.  This patch declares
memset/memmove/memcpy as weak symbols.  In mm/kasan/kasan.c we have our
own implementation of those functions which checks memory before accessing
it.

Default memset/memmove/memcpy now now always have aliases with '__'
prefix.  For files that built without kasan instrumentation (e.g.
mm/slub.c) original mem* replaced (via #define) with prefixed variants,
cause we don't want to check memory accesses there.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:41 -08:00

157 lines
3.1 KiB
ArmAsm

/* Copyright 2002 Andi Kleen, SuSE Labs */
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/cpufeature.h>
#include <asm/alternative-asm.h>
/*
* ISO C memset - set a memory block to a byte value. This function uses fast
* string to get better performance than the original function. The code is
* simpler and shorter than the orignal function as well.
*
* rdi destination
* rsi value (char)
* rdx count (bytes)
*
* rax original destination
*/
.section .altinstr_replacement, "ax", @progbits
.Lmemset_c:
movq %rdi,%r9
movq %rdx,%rcx
andl $7,%edx
shrq $3,%rcx
/* expand byte value */
movzbl %sil,%esi
movabs $0x0101010101010101,%rax
imulq %rsi,%rax
rep stosq
movl %edx,%ecx
rep stosb
movq %r9,%rax
ret
.Lmemset_e:
.previous
/*
* ISO C memset - set a memory block to a byte value. This function uses
* enhanced rep stosb to override the fast string function.
* The code is simpler and shorter than the fast string function as well.
*
* rdi destination
* rsi value (char)
* rdx count (bytes)
*
* rax original destination
*/
.section .altinstr_replacement, "ax", @progbits
.Lmemset_c_e:
movq %rdi,%r9
movb %sil,%al
movq %rdx,%rcx
rep stosb
movq %r9,%rax
ret
.Lmemset_e_e:
.previous
.weak memset
ENTRY(memset)
ENTRY(__memset)
CFI_STARTPROC
movq %rdi,%r10
/* expand byte value */
movzbl %sil,%ecx
movabs $0x0101010101010101,%rax
imulq %rcx,%rax
/* align dst */
movl %edi,%r9d
andl $7,%r9d
jnz .Lbad_alignment
CFI_REMEMBER_STATE
.Lafter_bad_alignment:
movq %rdx,%rcx
shrq $6,%rcx
jz .Lhandle_tail
.p2align 4
.Lloop_64:
decq %rcx
movq %rax,(%rdi)
movq %rax,8(%rdi)
movq %rax,16(%rdi)
movq %rax,24(%rdi)
movq %rax,32(%rdi)
movq %rax,40(%rdi)
movq %rax,48(%rdi)
movq %rax,56(%rdi)
leaq 64(%rdi),%rdi
jnz .Lloop_64
/* Handle tail in loops. The loops should be faster than hard
to predict jump tables. */
.p2align 4
.Lhandle_tail:
movl %edx,%ecx
andl $63&(~7),%ecx
jz .Lhandle_7
shrl $3,%ecx
.p2align 4
.Lloop_8:
decl %ecx
movq %rax,(%rdi)
leaq 8(%rdi),%rdi
jnz .Lloop_8
.Lhandle_7:
andl $7,%edx
jz .Lende
.p2align 4
.Lloop_1:
decl %edx
movb %al,(%rdi)
leaq 1(%rdi),%rdi
jnz .Lloop_1
.Lende:
movq %r10,%rax
ret
CFI_RESTORE_STATE
.Lbad_alignment:
cmpq $7,%rdx
jbe .Lhandle_7
movq %rax,(%rdi) /* unaligned store */
movq $8,%r8
subq %r9,%r8
addq %r8,%rdi
subq %r8,%rdx
jmp .Lafter_bad_alignment
.Lfinal:
CFI_ENDPROC
ENDPROC(memset)
ENDPROC(__memset)
/* Some CPUs support enhanced REP MOVSB/STOSB feature.
* It is recommended to use this when possible.
*
* If enhanced REP MOVSB/STOSB feature is not available, use fast string
* instructions.
*
* Otherwise, use original memset function.
*
* In .altinstructions section, ERMS feature is placed after REG_GOOD
* feature to implement the right patch order.
*/
.section .altinstructions,"a"
altinstruction_entry __memset,.Lmemset_c,X86_FEATURE_REP_GOOD,\
.Lfinal-__memset,.Lmemset_e-.Lmemset_c
altinstruction_entry __memset,.Lmemset_c_e,X86_FEATURE_ERMS, \
.Lfinal-__memset,.Lmemset_e_e-.Lmemset_c_e
.previous