| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Just like strncpy() except that if a fault occurs during copying, |
| 3 | * -EFAULT is returned. |
| 4 | * |
| 5 | * Inputs: |
| 6 | * in0: address of destination buffer |
| 7 | * in1: address of string to be copied |
| 8 | * in2: length of buffer in bytes |
| 9 | * Outputs: |
| 10 | * r8: -EFAULT in case of fault or number of bytes copied if no fault |
| 11 | * |
| 12 | * Copyright (C) 1998-2001 Hewlett-Packard Co |
| 13 | * Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com> |
| 14 | * |
| 15 | * 00/03/06 D. Mosberger Fixed to return proper return value (bug found by |
| 16 | * by Andreas Schwab <schwab@suse.de>). |
| 17 | */ |
| 18 | |
| 19 | #include <asm/asmmacro.h> |
| 20 | |
| 21 | GLOBAL_ENTRY(__strncpy_from_user) |
| 22 | alloc r2=ar.pfs,3,0,0,0 |
| 23 | mov r8=0 |
| 24 | mov r9=in1 |
| 25 | ;; |
| 26 | add r10=in1,in2 |
| 27 | cmp.eq p6,p0=r0,in2 |
| 28 | (p6) br.ret.spnt.many rp |
| 29 | |
| 30 | // XXX braindead copy loop---this needs to be optimized |
| 31 | .Loop1: |
| 32 | EX(.Lexit, ld1 r8=[in1],1) |
| 33 | ;; |
| 34 | EX(.Lexit, st1 [in0]=r8,1) |
| 35 | cmp.ne p6,p7=r8,r0 |
| 36 | ;; |
| 37 | (p6) cmp.ne.unc p8,p0=in1,r10 |
| 38 | (p8) br.cond.dpnt.few .Loop1 |
| 39 | ;; |
| 40 | (p6) mov r8=in2 // buffer filled up---return buffer length |
| 41 | (p7) sub r8=in1,r9,1 // return string length (excluding NUL character) |
| 42 | [.Lexit:] |
| 43 | br.ret.sptk.many rp |
| 44 | END(__strncpy_from_user) |