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| author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2025-09-18 14:43:36 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-25 12:13:45 +0300 |
| commit | b6f29fa5f60367d91e606db64c12e7086423c2d5 (patch) | |
| tree | 574ddbb7942c0b9eaa4ab5f41756df8e79ed7a99 /tools/objtool/arch | |
| parent | 89d40cc647daf6ed0dcdaae5b2892b10c361579d (diff) | |
| download | linux-b6f29fa5f60367d91e606db64c12e7086423c2d5.tar.xz | |
objtool/LoongArch: Mark special atomic instruction as INSN_BUG type
commit 539d7344d4feaea37e05863e9aa86bd31f28e46f upstream.
When compiling with LLVM and CONFIG_RUST is set, there exists the
following objtool warning:
rust/compiler_builtins.o: warning: objtool: __rust__unordsf2(): unexpected end of section .text.unlikely.
objdump shows that the end of section .text.unlikely is an atomic
instruction:
amswap.w $zero, $ra, $zero
According to the LoongArch Reference Manual, if the amswap.w atomic
memory access instruction has the same register number as rd and rj,
the execution will trigger an Instruction Non-defined Exception, so
mark the above instruction as INSN_BUG type to fix the warning.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/objtool/arch')
| -rw-r--r-- | tools/objtool/arch/loongarch/decode.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c index 0b9195f985a6..5687c4996517 100644 --- a/tools/objtool/arch/loongarch/decode.c +++ b/tools/objtool/arch/loongarch/decode.c @@ -281,6 +281,25 @@ static bool decode_insn_reg2i16_fomat(union loongarch_instruction inst, return true; } +static bool decode_insn_reg3_fomat(union loongarch_instruction inst, + struct instruction *insn) +{ + switch (inst.reg3_format.opcode) { + case amswapw_op: + if (inst.reg3_format.rd == LOONGARCH_GPR_ZERO && + inst.reg3_format.rk == LOONGARCH_GPR_RA && + inst.reg3_format.rj == LOONGARCH_GPR_ZERO) { + /* amswap.w $zero, $ra, $zero */ + insn->type = INSN_BUG; + } + break; + default: + return false; + } + + return true; +} + int arch_decode_instruction(struct objtool_file *file, const struct section *sec, unsigned long offset, unsigned int maxlen, struct instruction *insn) @@ -312,6 +331,8 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec return 0; if (decode_insn_reg2i16_fomat(inst, insn)) return 0; + if (decode_insn_reg3_fomat(inst, insn)) + return 0; if (inst.word == 0) { /* andi $zero, $zero, 0x0 */ |