diff options
Diffstat (limited to 'arch/avr32/lib/strnlen_user.S')
| -rw-r--r-- | arch/avr32/lib/strnlen_user.S | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/avr32/lib/strnlen_user.S b/arch/avr32/lib/strnlen_user.S new file mode 100644 index 00000000000..65ce11afa66 --- /dev/null +++ b/arch/avr32/lib/strnlen_user.S @@ -0,0 +1,67 @@ +/* + * Copy to/from userspace with optional address space checking. + * + * Copyright 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <asm/page.h> +#include <asm/thread_info.h> +#include <asm/processor.h> +#include <asm/asm.h> + + .text + .align 1 + .global strnlen_user + .type strnlen_user, "function" +strnlen_user: + branch_if_kernel r8, __strnlen_user + sub r8, r11, 1 + add r8, r12 + retcs 0 + brmi adjust_length /* do a closer inspection */ + + .global __strnlen_user + .type __strnlen_user, "function" +__strnlen_user: + mov r10, r12 + +10: ld.ub r8, r12++ + cp.w r8, 0 + breq 2f + sub r11, 1 + brne 10b + + sub r12, -1 +2: sub r12, r10 + retal r12 + + + .type adjust_length, "function" +adjust_length: + cp.w r12, 0 /* addr must always be < TASK_SIZE */ + retmi 0 + + pushm lr + lddpc lr, _task_size + sub r11, lr, r12 + mov r9, r11 + rcall __strnlen_user + cp.w r12, r9 + brgt 1f + popm pc +1: popm pc, r12=0 + + .align 2 +_task_size: + .long TASK_SIZE + + .section .fixup, "ax" + .align 1 +19: retal 0 + + .section __ex_table, "a" + .align 2 + .long 10b, 19b |