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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/mips/lib/strncpy_user.S
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/lib/strncpy_user.S')
-rw-r--r--arch/mips/lib/strncpy_user.S85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/mips/lib/strncpy_user.S b/arch/mips/lib/strncpy_user.S
new file mode 100644
index 000000000..acdff66bd
--- /dev/null
+++ b/arch/mips/lib/strncpy_user.S
@@ -0,0 +1,85 @@
+/*
+ * 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 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\@
+
+ 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
+ .set __strncpy_from_user_asm, __strncpy_from_kernel_asm
+EXPORT_SYMBOL(__strncpy_from_user_asm)
+#endif
+
+__BUILD_STRNCPY_ASM kernel
+EXPORT_SYMBOL(__strncpy_from_kernel_asm)
+
+#ifdef CONFIG_EVA
+ .set push
+ .set eva
+__BUILD_STRNCPY_ASM user
+ .set pop
+EXPORT_SYMBOL(__strncpy_from_user_asm)
+#endif