| Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copy to/from userspace with optional address space checking. |
| 3 | * |
| 4 | * Copyright 2004-2006 Atmel Corporation |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | #include <asm/page.h> |
| 11 | #include <asm/thread_info.h> |
| 12 | #include <asm/processor.h> |
| 13 | #include <asm/asm.h> |
| 14 | |
| 15 | .text |
| 16 | .align 1 |
| 17 | .global strnlen_user |
| 18 | .type strnlen_user, "function" |
| 19 | strnlen_user: |
| 20 | branch_if_kernel r8, __strnlen_user |
| 21 | sub r8, r11, 1 |
| 22 | add r8, r12 |
| 23 | retcs 0 |
| 24 | brmi adjust_length /* do a closer inspection */ |
| 25 | |
| 26 | .global __strnlen_user |
| 27 | .type __strnlen_user, "function" |
| 28 | __strnlen_user: |
| 29 | mov r10, r12 |
| 30 | |
| 31 | 10: ld.ub r8, r12++ |
| 32 | cp.w r8, 0 |
| 33 | breq 2f |
| 34 | sub r11, 1 |
| 35 | brne 10b |
| 36 | |
| 37 | sub r12, -1 |
| 38 | 2: sub r12, r10 |
| 39 | retal r12 |
| 40 | |
| 41 | |
| 42 | .type adjust_length, "function" |
| 43 | adjust_length: |
| 44 | cp.w r12, 0 /* addr must always be < TASK_SIZE */ |
| 45 | retmi 0 |
| 46 | |
| 47 | pushm lr |
| 48 | lddpc lr, _task_size |
| 49 | sub r11, lr, r12 |
| 50 | mov r9, r11 |
| 51 | rcall __strnlen_user |
| 52 | cp.w r12, r9 |
| 53 | brgt 1f |
| 54 | popm pc |
| 55 | 1: popm pc, r12=0 |
| 56 | |
| 57 | .align 2 |
| 58 | _task_size: |
| 59 | .long TASK_SIZE |
| 60 | |
| 61 | .section .fixup, "ax" |
| 62 | .align 1 |
| 63 | 19: retal 0 |
| 64 | |
| 65 | .section __ex_table, "a" |
| 66 | .align 2 |
| 67 | .long 10b, 19b |