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| author | Peter Zijlstra <peterz@infradead.org> | 2021-06-10 09:04:29 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-06-11 08:53:06 +0200 |
| commit | 2d49b721dc18c113d5221f4cf5a6104eb66cb7f2 (patch) | |
| tree | ab75c8cfd9dafa5f54af3988bcb7c595380e307c | |
| parent | 584fd3b31889852d0d6f3dd1e3d8e9619b660d2c (diff) | |
| download | linux-2d49b721dc18c113d5221f4cf5a6104eb66cb7f2.tar.gz | |
objtool: Only rewrite unconditional retpoline thunk calls
It turns out that the compilers generate conditional branches to the
retpoline thunks like:
5d5: 0f 85 00 00 00 00 jne 5db <cpuidle_reflect+0x22>
5d7: R_X86_64_PLT32 __x86_indirect_thunk_r11-0x4
while the rewrite can only handle JMP/CALL to the thunks. The result
is the alternative wrecking the code. Make sure to skip writing the
alternatives for conditional branches.
Fixes: 9bc0bb50727c ("objtool/x86: Rewrite retpoline thunk calls")
Reported-by: Lukasz Majczak <lma@semihalf.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
| -rw-r--r-- | tools/objtool/arch/x86/decode.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 24295d39713b2..523aa4157f801 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -747,6 +747,10 @@ int arch_rewrite_retpolines(struct objtool_file *file) list_for_each_entry(insn, &file->retpoline_call_list, call_node) { + if (insn->type != INSN_JUMP_DYNAMIC && + insn->type != INSN_CALL_DYNAMIC) + continue; + if (!strcmp(insn->sec->name, ".text.__x86.indirect_thunk")) continue; |