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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/mips/lib/strncpy_user.S
Initial import
Diffstat (limited to 'arch/mips/lib/strncpy_user.S')
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diff --git a/arch/mips/lib/strncpy_user.S b/arch/mips/lib/strncpy_user.S
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+/*
+ * 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/regdef.h>
+
+#define EX(insn,reg,addr,handler) \
+9: insn reg, addr; \
+ .section __ex_table,"a"; \
+ PTR 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.
+ */
+
+ .macro __BUILD_STRNCPY_ASM func
+LEAF(__strncpy_from_\func\()_asm)
+ LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
+ and v0, a1
+ bnez v0, .Lfault\@
+
+FEXPORT(__strncpy_from_\func\()_nocheck_asm)
+ move t0, zero
+ move v1, a1
+.ifeqs "\func","kernel"
+1: EX(lbu, v0, (v1), .Lfault\@)
+.else
+1: EX(lbue, 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_\func\()_asm)
+
+.Lfault\@:
+ li v0, -EFAULT
+ jr ra
+
+ .section __ex_table,"a"
+ PTR 1b, .Lfault\@
+ .previous
+
+ .endm
+
+#ifndef CONFIG_EVA
+ /* Set aliases */
+ .global __strncpy_from_user_asm
+ .global __strncpy_from_user_nocheck_asm
+ .set __strncpy_from_user_asm, __strncpy_from_kernel_asm
+ .set __strncpy_from_user_nocheck_asm, __strncpy_from_kernel_nocheck_asm
+#endif
+
+__BUILD_STRNCPY_ASM kernel
+
+#ifdef CONFIG_EVA
+ .set push
+ .set eva
+__BUILD_STRNCPY_ASM user
+ .set pop
+#endif