diff options
Diffstat (limited to 'sysdeps/x86_64/strcpy_chk.S')
| -rw-r--r-- | sysdeps/x86_64/strcpy_chk.S | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/sysdeps/x86_64/strcpy_chk.S b/sysdeps/x86_64/strcpy_chk.S deleted file mode 100644 index 24e51c66f1..0000000000 --- a/sysdeps/x86_64/strcpy_chk.S +++ /dev/null @@ -1,208 +0,0 @@ -/* strcpy/stpcpy checking implementation for x86-64. - Copyright (C) 2002-2015 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Andreas Jaeger <aj@suse.de>, 2002. - Adopted into checking version by Jakub Jelinek <jakub@redhat.com>. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> -#include "asm-syntax.h" - -#ifndef USE_AS_STPCPY_CHK -# define STRCPY_CHK __strcpy_chk -#endif - - .text -ENTRY (STRCPY_CHK) - movq %rsi, %rcx /* Source register. */ - andl $7, %ecx /* mask alignment bits */ -#ifndef USE_AS_STPCPY_CHK - movq %rdi, %r10 /* Duplicate destination pointer. */ -#endif - jz 5f /* aligned => start loop */ - - cmpq $8, %rdx /* Check if only few bytes left in - destination. */ - jb 50f - - subq $8, %rcx /* We need to align to 8 bytes. */ - addq %rcx, %rdx /* Subtract count of stored bytes - in the cycle below from destlen. */ - - /* Search the first bytes directly. */ -0: - movb (%rsi), %al /* Fetch a byte */ - testb %al, %al /* Is it NUL? */ - movb %al, (%rdi) /* Store it */ - jz 4f /* If it was NUL, done! */ - incq %rsi - incq %rdi - incl %ecx - jnz 0b - -5: - movq $0xfefefefefefefeff,%r8 - cmpq $32, %rdx /* Are there enough bytes in destination - for the next unrolled round? */ - jb 60f /* If not, avoid the unrolled loop. */ - - /* Now the sources is aligned. Unfortunatly we cannot force - to have both source and destination aligned, so ignore the - alignment of the destination. */ - .p2align 4 -1: - /* 1st unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 3f /* found NUL => return pointer */ - - movq %rax, (%rdi) /* Write value to destination. */ - addq $8, %rdi /* Adjust pointer. */ - - /* 2nd unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 3f /* found NUL => return pointer */ - - movq %rax, (%rdi) /* Write value to destination. */ - addq $8, %rdi /* Adjust pointer. */ - - /* 3rd unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 3f /* found NUL => return pointer */ - - movq %rax, (%rdi) /* Write value to destination. */ - addq $8, %rdi /* Adjust pointer. */ - - /* 4th unroll. */ - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 3f /* found NUL => return pointer */ - - subq $32, %rdx /* Adjust destlen. */ - movq %rax, (%rdi) /* Write value to destination. */ - addq $8, %rdi /* Adjust pointer. */ - cmpq $32, %rdx /* Are there enough bytes in destination - for the next unrolled round? */ - jae 1b /* Next iteration. */ - -60: - cmpq $8, %rdx /* Are there enough bytes in destination - for the next unrolled round? */ - jb 50f /* Now, copy and check byte by byte. */ - - movq (%rsi), %rax /* Read double word (8 bytes). */ - addq $8, %rsi /* Adjust pointer for next word. */ - movq %rax, %r9 /* Save a copy for NUL finding. */ - addq %r8, %r9 /* add the magic value to the word. We get - carry bits reported for each byte which - is *not* 0 */ - jnc 3f /* highest byte is NUL => return pointer */ - xorq %rax, %r9 /* (word+magic)^word */ - orq %r8, %r9 /* set all non-carry bits */ - incq %r9 /* add 1: if one carry bit was *not* set - the addition will not result in 0. */ - - jnz 3f /* found NUL => return pointer */ - - subq $8, %rdx /* Adjust destlen. */ - movq %rax, (%rdi) /* Write value to destination. */ - addq $8, %rdi /* Adjust pointer. */ - jmp 60b /* Next iteration. */ - - /* Do the last few bytes. %rax contains the value to write. - The loop is unrolled twice. */ - .p2align 4 -3: - /* Note that stpcpy needs to return with the value of the NUL - byte. */ - movb %al, (%rdi) /* 1st byte. */ - testb %al, %al /* Is it NUL. */ - jz 4f /* yes, finish. */ - incq %rdi /* Increment destination. */ - movb %ah, (%rdi) /* 2nd byte. */ - testb %ah, %ah /* Is it NUL?. */ - jz 4f /* yes, finish. */ - incq %rdi /* Increment destination. */ - shrq $16, %rax /* Shift... */ - jmp 3b /* and look at next two bytes in %rax. */ - -51: - /* Search the bytes directly, checking for overflows. */ - incq %rsi - incq %rdi - decq %rdx - jz HIDDEN_JUMPTARGET (__chk_fail) -52: - movb (%rsi), %al /* Fetch a byte */ - testb %al, %al /* Is it NUL? */ - movb %al, (%rdi) /* Store it */ - jnz 51b /* If it was NUL, done! */ -4: -#ifdef USE_AS_STPCPY_CHK - movq %rdi, %rax /* Destination is return value. */ -#else - movq %r10, %rax /* Source is return value. */ -#endif - retq - -50: - testq %rdx, %rdx - jnz 52b - jmp HIDDEN_JUMPTARGET (__chk_fail) - -END (STRCPY_CHK) |