projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 1da177e4 LT |
2 | /* |
| 3 | * Returns 0 if exception before NUL or reaching the supplied limit (N), | |
| 4 | * a value greater than N if the string is longer than the limit, else | |
| 5 | * strlen. | |
| 6 | * | |
| 7 | * Inputs: | |
| 8 | * in0: address of buffer | |
| 9 | * in1: string length limit N | |
| 10 | * Outputs: | |
| 11 | * r8: 0 in case of fault, strlen(buffer)+1 otherwise | |
| 12 | * | |
| 13 | * Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com> | |
| 14 | */ | |
| 15 | ||
| 16 | #include <asm/asmmacro.h> | |
| e007c533 | 17 | #include <asm/export.h> |
| 1da177e4 LT |
18 | |
| 19 | GLOBAL_ENTRY(__strnlen_user) | |
| 20 | .prologue | |
| 21 | alloc r2=ar.pfs,2,0,0,0 | |
| 22 | .save ar.lc, r16 | |
| 23 | mov r16=ar.lc // preserve ar.lc | |
| 24 | ||
| 25 | .body | |
| 26 | ||
| 27 | add r3=-1,in1 | |
| 28 | ;; | |
| 29 | mov ar.lc=r3 | |
| 30 | mov r9=0 | |
| 31 | ;; | |
| 32 | // XXX braindead strlen loop---this needs to be optimized | |
| 33 | .Loop1: | |
| 34 | EXCLR(.Lexit, ld1 r8=[in0],1) | |
| 35 | add r9=1,r9 | |
| 36 | ;; | |
| 37 | cmp.eq p6,p0=r8,r0 | |
| 38 | (p6) br.cond.dpnt .Lexit | |
| 39 | br.cloop.dptk.few .Loop1 | |
| 40 | ||
| 41 | add r9=1,in1 // NUL not found---return N+1 | |
| 42 | ;; | |
| 43 | .Lexit: | |
| 44 | mov r8=r9 | |
| 45 | mov ar.lc=r16 // restore ar.lc | |
| 46 | br.ret.sptk.many rp | |
| 47 | END(__strnlen_user) | |
| e007c533 | 48 | EXPORT_SYMBOL(__strnlen_user) |