ca5d0674c3
The powerpc strncmp implementation does not correctly handle a zero
length, despite the claim in 0119536cd3
(Add hand-coded assembly strcmp).
Additionally, all the length arguments are size_t, not int, so use
PPC_LCMPI and eq instead of cmpwi and le throughout.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
208 lines
3.4 KiB
ArmAsm
208 lines
3.4 KiB
ArmAsm
/*
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* String handling functions for PowerPC.
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*
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* Copyright (C) 1996 Paul Mackerras.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <asm/processor.h>
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#include <asm/errno.h>
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#include <asm/ppc_asm.h>
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.section __ex_table,"a"
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PPC_LONG_ALIGN
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.text
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_GLOBAL(strcpy)
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addi r5,r3,-1
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addi r4,r4,-1
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1: lbzu r0,1(r4)
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cmpwi 0,r0,0
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stbu r0,1(r5)
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bne 1b
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blr
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/* This clears out any unused part of the destination buffer,
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just as the libc version does. -- paulus */
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_GLOBAL(strncpy)
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PPC_LCMPI 0,r5,0
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beqlr
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mtctr r5
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addi r6,r3,-1
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addi r4,r4,-1
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1: lbzu r0,1(r4)
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cmpwi 0,r0,0
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stbu r0,1(r6)
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bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
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bnelr /* if we didn't hit a null char, we're done */
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mfctr r5
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PPC_LCMPI 0,r5,0 /* any space left in destination buffer? */
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beqlr /* we know r0 == 0 here */
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2: stbu r0,1(r6) /* clear it out if so */
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bdnz 2b
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blr
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_GLOBAL(strcat)
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addi r5,r3,-1
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addi r4,r4,-1
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1: lbzu r0,1(r5)
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cmpwi 0,r0,0
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bne 1b
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addi r5,r5,-1
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1: lbzu r0,1(r4)
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cmpwi 0,r0,0
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stbu r0,1(r5)
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bne 1b
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blr
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_GLOBAL(strcmp)
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addi r5,r3,-1
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addi r4,r4,-1
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1: lbzu r3,1(r5)
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cmpwi 1,r3,0
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lbzu r0,1(r4)
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subf. r3,r0,r3
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beqlr 1
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beq 1b
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blr
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_GLOBAL(strncmp)
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PPC_LCMPI 0,r5,0
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beq- 2f
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mtctr r5
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addi r5,r3,-1
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addi r4,r4,-1
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1: lbzu r3,1(r5)
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cmpwi 1,r3,0
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lbzu r0,1(r4)
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subf. r3,r0,r3
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beqlr 1
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bdnzt eq,1b
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blr
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2: li r3,0
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blr
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_GLOBAL(strlen)
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addi r4,r3,-1
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1: lbzu r0,1(r4)
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cmpwi 0,r0,0
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bne 1b
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subf r3,r3,r4
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blr
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_GLOBAL(memcmp)
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PPC_LCMPI 0,r5,0
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beq- 2f
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mtctr r5
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addi r6,r3,-1
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addi r4,r4,-1
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1: lbzu r3,1(r6)
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lbzu r0,1(r4)
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subf. r3,r0,r3
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bdnzt 2,1b
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blr
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2: li r3,0
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blr
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_GLOBAL(memchr)
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PPC_LCMPI 0,r5,0
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beq- 2f
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mtctr r5
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addi r3,r3,-1
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1: lbzu r0,1(r3)
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cmpw 0,r0,r4
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bdnzf 2,1b
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beqlr
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2: li r3,0
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blr
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_GLOBAL(__clear_user)
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addi r6,r3,-4
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li r3,0
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li r5,0
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cmplwi 0,r4,4
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blt 7f
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/* clear a single word */
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11: stwu r5,4(r6)
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beqlr
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/* clear word sized chunks */
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andi. r0,r6,3
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add r4,r0,r4
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subf r6,r0,r6
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srwi r0,r4,2
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andi. r4,r4,3
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mtctr r0
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bdz 7f
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1: stwu r5,4(r6)
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bdnz 1b
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/* clear byte sized chunks */
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7: cmpwi 0,r4,0
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beqlr
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mtctr r4
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addi r6,r6,3
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8: stbu r5,1(r6)
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bdnz 8b
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blr
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90: mr r3,r4
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blr
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91: mfctr r3
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slwi r3,r3,2
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add r3,r3,r4
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blr
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92: mfctr r3
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blr
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.section __ex_table,"a"
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PPC_LONG 11b,90b
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PPC_LONG 1b,91b
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PPC_LONG 8b,92b
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.text
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_GLOBAL(__strncpy_from_user)
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addi r6,r3,-1
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addi r4,r4,-1
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cmpwi 0,r5,0
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beq 2f
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mtctr r5
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1: lbzu r0,1(r4)
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cmpwi 0,r0,0
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stbu r0,1(r6)
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bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */
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beq 3f
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2: addi r6,r6,1
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3: subf r3,r3,r6
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blr
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99: li r3,-EFAULT
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blr
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.section __ex_table,"a"
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PPC_LONG 1b,99b
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.text
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/* r3 = str, r4 = len (> 0), r5 = top (highest addr) */
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_GLOBAL(__strnlen_user)
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addi r7,r3,-1
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subf r6,r7,r5 /* top+1 - str */
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cmplw 0,r4,r6
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bge 0f
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mr r6,r4
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0: mtctr r6 /* ctr = min(len, top - str) */
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1: lbzu r0,1(r7) /* get next byte */
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cmpwi 0,r0,0
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bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */
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addi r7,r7,1
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subf r3,r3,r7 /* number of bytes we have looked at */
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beqlr /* return if we found a 0 byte */
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cmpw 0,r3,r4 /* did we look at all len bytes? */
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blt 99f /* if not, must have hit top */
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addi r3,r4,1 /* return len + 1 to indicate no null found */
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blr
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99: li r3,0 /* bad address, return 0 */
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blr
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.section __ex_table,"a"
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PPC_LONG 1b,99b
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