/* * String handling functions for PowerPC. * * Copyright (C) 1996 Paul Mackerras. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <asm/processor.h> #include <asm/errno.h> #include <asm/ppc_asm.h> .section __ex_table,"a" #ifdef CONFIG_PPC64 .align 3 #define EXTBL .llong #else .align 2 #define EXTBL .long #endif .text _GLOBAL(strcpy) addi r5,r3,-1 addi r4,r4,-1 1: lbzu r0,1(r4) cmpwi 0,r0,0 stbu r0,1(r5) bne 1b blr /* This clears out any unused part of the destination buffer, just as the libc version does. -- paulus */ _GLOBAL(strncpy) cmpwi 0,r5,0 beqlr mtctr r5 addi r6,r3,-1 addi r4,r4,-1 1: lbzu r0,1(r4) cmpwi 0,r0,0 stbu r0,1(r6) bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ bnelr /* if we didn't hit a null char, we're done */ mfctr r5 cmpwi 0,r5,0 /* any space left in destination buffer? */ beqlr /* we know r0 == 0 here */ 2: stbu r0,1(r6) /* clear it out if so */ bdnz 2b blr _GLOBAL(strcat) addi r5,r3,-1 addi r4,r4,-1 1: lbzu r0,1(r5) cmpwi 0,r0,0 bne 1b addi r5,r5,-1 1: lbzu r0,1(r4) cmpwi 0,r0,0 stbu r0,1(r5) bne 1b blr _GLOBAL(strcmp) addi r5,r3,-1 addi r4,r4,-1 1: lbzu r3,1(r5) cmpwi 1,r3,0 lbzu r0,1(r4) subf. r3,r0,r3 beqlr 1 beq 1b blr _GLOBAL(strlen) addi r4,r3,-1 1: lbzu r0,1(r4) cmpwi 0,r0,0 bne 1b subf r3,r3,r4 blr _GLOBAL(memcmp) cmpwi 0,r5,0 ble- 2f mtctr r5 addi r6,r3,-1 addi r4,r4,-1 1: lbzu r3,1(r6) lbzu r0,1(r4) subf. r3,r0,r3 bdnzt 2,1b blr 2: li r3,0 blr _GLOBAL(memchr) cmpwi 0,r5,0 ble- 2f mtctr r5 addi r3,r3,-1 1: lbzu r0,1(r3) cmpw 0,r0,r4 bdnzf 2,1b beqlr 2: li r3,0 blr _GLOBAL(__clear_user) addi r6,r3,-4 li r3,0 li r5,0 cmplwi 0,r4,4 blt 7f /* clear a single word */ 11: stwu r5,4(r6) beqlr /* clear word sized chunks */ andi. r0,r6,3 add r4,r0,r4 subf r6,r0,r6 srwi r0,r4,2 andi. r4,r4,3 mtctr r0 bdz 7f 1: stwu r5,4(r6) bdnz 1b /* clear byte sized chunks */ 7: cmpwi 0,r4,0 beqlr mtctr r4 addi r6,r6,3 8: stbu r5,1(r6) bdnz 8b blr 90: mr r3,r4 blr 91: mfctr r3 slwi r3,r3,2 add r3,r3,r4 blr 92: mfctr r3 blr .section __ex_table,"a" EXTBL 11b,90b EXTBL 1b,91b EXTBL 8b,92b .text _GLOBAL(__strncpy_from_user) addi r6,r3,-1 addi r4,r4,-1 cmpwi 0,r5,0 beq 2f mtctr r5 1: lbzu r0,1(r4) cmpwi 0,r0,0 stbu r0,1(r6) bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ beq 3f 2: addi r6,r6,1 3: subf r3,r3,r6 blr 99: li r3,-EFAULT blr .section __ex_table,"a" EXTBL 1b,99b .text /* r3 = str, r4 = len (> 0), r5 = top (highest addr) */ _GLOBAL(__strnlen_user) addi r7,r3,-1 subf r6,r7,r5 /* top+1 - str */ cmplw 0,r4,r6 bge 0f mr r6,r4 0: mtctr r6 /* ctr = min(len, top - str) */ 1: lbzu r0,1(r7) /* get next byte */ cmpwi 0,r0,0 bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */ addi r7,r7,1 subf r3,r3,r7 /* number of bytes we have looked at */ beqlr /* return if we found a 0 byte */ cmpw 0,r3,r4 /* did we look at all len bytes? */ blt 99f /* if not, must have hit top */ addi r3,r4,1 /* return len + 1 to indicate no null found */ blr 99: li r3,0 /* bad address, return 0 */ blr .section __ex_table,"a" EXTBL 1b,99b