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-rw-r--r--arch/mips/lib/strncpy_user.S65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/mips/lib/strncpy_user.S b/arch/mips/lib/strncpy_user.S
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+++ b/arch/mips/lib/strncpy_user.S
@@ -0,0 +1,65 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1996, 1999 by Ralf Baechle
+ * Copyright (C) 2011 MIPS Technologies, Inc.
+ */
+#include <linux/errno.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+#define EX(insn,reg,addr,handler) \
+9: insn reg, addr; \
+ .section __ex_table,"a"; \
+ PTR_WD 9b, handler; \
+ .previous
+
+/*
+ * Returns: -EFAULT if exception before terminator, N if the entire
+ * buffer filled, else strlen.
+ */
+
+/*
+ * Ugly special case have to check: we might get passed a user space
+ * pointer which wraps into the kernel space. We don't deal with that. If
+ * it happens at most some bytes of the exceptions handlers will be copied.
+ */
+
+LEAF(__strncpy_from_user_asm)
+ move t0, zero
+ move v1, a1
+#ifdef CONFIG_EVA
+ .set push
+ .set eva
+1: EX(lbue, v0, (v1), .Lfault)
+ .set pop
+#else
+1: EX(lbu, v0, (v1), .Lfault)
+#endif
+ PTR_ADDIU v1, 1
+ R10KCBARRIER(0(ra))
+ sb v0, (a0)
+ beqz v0, 2f
+ PTR_ADDIU t0, 1
+ PTR_ADDIU a0, 1
+ bne t0, a2, 1b
+2: PTR_ADDU v0, a1, t0
+ xor v0, a1
+ bltz v0, .Lfault
+ move v0, t0
+ jr ra # return n
+ END(__strncpy_from_user_asm)
+
+.Lfault:
+ li v0, -EFAULT
+ jr ra
+
+ .section __ex_table,"a"
+ PTR_WD 1b, .Lfault
+ .previous
+
+ EXPORT_SYMBOL(__strncpy_from_user_asm)