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riscv: provide memmove implementation

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The memmove used by the kernel feature like KASAN.

Signed-off-by: Nick Hu <nickhu@andestech.com>
Signed-off-by: Nick Hu <nick650823@gmail.com>
Signed-off-by: Nylon Chen <nylon7@andestech.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Nylon Chen 2020-11-30 17:13:19 +08:00 committed by Palmer Dabbelt
parent b5b11a8ac4
commit 04091d6c05
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
4 changed files with 71 additions and 4 deletions
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8
arch/riscv/include/asm/string.h
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@ -12,16 +12,16 @@
#define __HAVE_ARCH_MEMSET
extern asmlinkage void *memset(void *, int, size_t);
extern asmlinkage void *__memset(void *, int, size_t);
#define __HAVE_ARCH_MEMCPY
extern asmlinkage void *memcpy(void *, const void *, size_t);
extern asmlinkage void *__memcpy(void *, const void *, size_t);
#define __HAVE_ARCH_MEMMOVE
extern asmlinkage void *memmove(void *, const void *, size_t);
extern asmlinkage void *__memmove(void *, const void *, size_t);
/* For those files which don't want to check by kasan. */
#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
#define memcpy(dst, src, len) __memcpy(dst, src, len)
#define memset(s, c, n) __memset(s, c, n)
#define memmove(dst, src, len) __memmove(dst, src, len)
#endif
#endif /* _ASM_RISCV_STRING_H */

2
arch/riscv/kernel/riscv_ksyms.c
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@ -11,5 +11,7 @@
*/
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memmove);
EXPORT_SYMBOL(__memset);
EXPORT_SYMBOL(__memcpy);
EXPORT_SYMBOL(__memmove);

1
arch/riscv/lib/Makefile
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@ -2,5 +2,6 @@
lib-y += delay.o
lib-y += memcpy.o
lib-y += memset.o
lib-y += memmove.o
lib-$(CONFIG_MMU) += uaccess.o
lib-$(CONFIG_64BIT) += tishift.o

64
arch/riscv/lib/memmove.S Normal file
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@ -0,0 +1,64 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>
#include <asm/asm.h>
ENTRY(__memmove)
WEAK(memmove)
move t0, a0
move t1, a1
beq a0, a1, exit_memcpy
beqz a2, exit_memcpy
srli t2, a2, 0x2
slt t3, a0, a1
beqz t3, do_reverse
andi a2, a2, 0x3
li t4, 1
beqz t2, byte_copy
word_copy:
lw t3, 0(a1)
addi t2, t2, -1
addi a1, a1, 4
sw t3, 0(a0)
addi a0, a0, 4
bnez t2, word_copy
beqz a2, exit_memcpy
j byte_copy
do_reverse:
add a0, a0, a2
add a1, a1, a2
andi a2, a2, 0x3
li t4, -1
beqz t2, reverse_byte_copy
reverse_word_copy:
addi a1, a1, -4
addi t2, t2, -1
lw t3, 0(a1)
addi a0, a0, -4
sw t3, 0(a0)
bnez t2, reverse_word_copy
beqz a2, exit_memcpy
reverse_byte_copy:
addi a0, a0, -1
addi a1, a1, -1
byte_copy:
lb t3, 0(a1)
addi a2, a2, -1
sb t3, 0(a0)
add a1, a1, t4
add a0, a0, t4
bnez a2, byte_copy
exit_memcpy:
move a0, t0
move a1, t1
ret
END(__memmove)