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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/lib/strnlen_user.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/mips/lib/strnlen_user.S')
-rw-r--r--arch/mips/lib/strnlen_user.S45
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/mips/lib/strnlen_user.S b/arch/mips/lib/strnlen_user.S
new file mode 100644
index 00000000000..6e7a8eed4de
--- /dev/null
+++ b/arch/mips/lib/strnlen_user.S
@@ -0,0 +1,45 @@
+/*
+ * 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, 1998, 1999, 2004 by Ralf Baechle
+ * Copyright (c) 1999 Silicon Graphics, Inc.
+ */
+#include <asm/asm.h>
+#include <asm/offset.h>
+#include <asm/regdef.h>
+
+#define EX(insn,reg,addr,handler) \
+9: insn reg, addr; \
+ .section __ex_table,"a"; \
+ PTR 9b, handler; \
+ .previous
+
+/*
+ * Return the size of a string including the ending NUL character upto a
+ * maximum of a1 or 0 in case of error.
+ *
+ * Note: for performance reasons we deliberately accept that a user may
+ * make strlen_user and strnlen_user access the first few KSEG0
+ * bytes. There's nothing secret there. On 64-bit accessing beyond
+ * the maximum is a tad hairier ...
+ */
+LEAF(__strnlen_user_asm)
+ LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
+ and v0, a0
+ bnez v0, fault
+
+FEXPORT(__strnlen_user_nocheck_asm)
+ move v0, a0
+ PTR_ADDU a1, a0 # stop pointer
+1: beq v0, a1, 1f # limit reached?
+ EX(lb, t0, (v0), fault)
+ PTR_ADDU v0, 1
+ bnez t0, 1b
+1: PTR_SUBU v0, a0
+ jr ra
+ END(__strnlen_user_asm)
+
+fault: move v0, zero
+ jr ra