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-rw-r--r--arch/avr32/lib/strnlen_user.S67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/avr32/lib/strnlen_user.S b/arch/avr32/lib/strnlen_user.S
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+/*
+ * 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