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fcf77d0162
Some assembler symbols are not kprobe safe, such as handle_syscall (used as syscall exception handler), *memset*/*memcpy*/*memmove* (may cause recursive exceptions), they can not be instrumented, just blacklist them for kprobing. Here is a related problem and discussion: Link: https://lore.kernel.org/lkml/20230114143859.7ccc45c1c5d9ce302113ab0a@kernel.org/ Tested-by: Jeff Xie <xiehuan09@gmail.com> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
99 lines
1.6 KiB
ArmAsm
99 lines
1.6 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#include <asm/alternative-asm.h>
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#include <asm/asm.h>
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#include <asm/asmmacro.h>
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#include <asm/cpu.h>
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#include <asm/export.h>
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#include <asm/regdef.h>
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SYM_FUNC_START(memcpy)
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/*
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* Some CPUs support hardware unaligned access
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*/
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ALTERNATIVE "b __memcpy_generic", \
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"b __memcpy_fast", CPU_FEATURE_UAL
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SYM_FUNC_END(memcpy)
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_ASM_NOKPROBE(memcpy)
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EXPORT_SYMBOL(memcpy)
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/*
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* void *__memcpy_generic(void *dst, const void *src, size_t n)
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*
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* a0: dst
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* a1: src
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* a2: n
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*/
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SYM_FUNC_START(__memcpy_generic)
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move a3, a0
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beqz a2, 2f
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1: ld.b t0, a1, 0
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st.b t0, a0, 0
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addi.d a0, a0, 1
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addi.d a1, a1, 1
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addi.d a2, a2, -1
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bgt a2, zero, 1b
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2: move a0, a3
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jr ra
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SYM_FUNC_END(__memcpy_generic)
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_ASM_NOKPROBE(__memcpy_generic)
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/*
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* void *__memcpy_fast(void *dst, const void *src, size_t n)
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*
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* a0: dst
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* a1: src
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* a2: n
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*/
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SYM_FUNC_START(__memcpy_fast)
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move a3, a0
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beqz a2, 3f
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ori a4, zero, 64
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blt a2, a4, 2f
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/* copy 64 bytes at a time */
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1: ld.d t0, a1, 0
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ld.d t1, a1, 8
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ld.d t2, a1, 16
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ld.d t3, a1, 24
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ld.d t4, a1, 32
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ld.d t5, a1, 40
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ld.d t6, a1, 48
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ld.d t7, a1, 56
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st.d t0, a0, 0
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st.d t1, a0, 8
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st.d t2, a0, 16
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st.d t3, a0, 24
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st.d t4, a0, 32
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st.d t5, a0, 40
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st.d t6, a0, 48
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st.d t7, a0, 56
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addi.d a0, a0, 64
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addi.d a1, a1, 64
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addi.d a2, a2, -64
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bge a2, a4, 1b
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beqz a2, 3f
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/* copy the remaining bytes */
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2: ld.b t0, a1, 0
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st.b t0, a0, 0
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addi.d a0, a0, 1
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addi.d a1, a1, 1
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addi.d a2, a2, -1
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bgt a2, zero, 2b
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/* return */
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3: move a0, a3
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jr ra
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SYM_FUNC_END(__memcpy_fast)
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_ASM_NOKPROBE(__memcpy_fast)
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