When running the instruction decoder selftest with LLVM=1 and
CONFIG_PVH=y, there is a series of warnings:
arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
arch/x86/tools/insn_decoder_test: warning: ffffffff81000050 ea <unknown>
arch/x86/tools/insn_decoder_test: warning: objdump says 1 bytes, but insn_get_length() says 7
arch/x86/tools/insn_decoder_test: warning: Decoded and checked 7214721 instructions with 1 failures
GNU objdump outputs "(bad)" instead of "<unknown>", which is already
handled in the bad_expr regex, so there is no warning.
$ objdump -d arch/x86/platform/pvh/head.o | grep -E '50:\s+ea'
50: ea (bad)
$ llvm-objdump -d arch/x86/platform/pvh/head.o | grep -E '50:\s+ea'
50: ea <unknown>
Add "<unknown>" to the bad_expr regex to clear up the warning, allowing
the instruction decoder selftest to fully pass with llvm-objdump.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231205-objdump_reformat-awk-handle-llvm-objdump-bad_expr-v1-1-b4a74f39396f@kernel.org
If there is "wait" mnemonic in the line being parsed, it is incorrectly
handled by the script, and an extra line of "fwait" in
objdump_reformat's output is inserted. As insn_decoder_test relies upon
the formatted output, the test fails.
This is reproducible when disassembling with llvm-objdump:
Pre-processed lines:
ffffffff81033e72: 9b wait
ffffffff81033e73: 48 c7 c7 89 50 42 82 movq
After objdump_reformat.awk:
ffffffff81033e72: 9b fwait
ffffffff81033e72: wait
ffffffff81033e73: 48 c7 c7 89 50 42 82 movq
The regex match now accepts spaces or tabs, along with the "fwait"
instruction.
Signed-off-by: Samuel Zeter <samuelzeter@gmail.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20231129-objdump-reformat-llvm-v3-1-0d855e79314d@kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1364
