x86/tools: objdump_reformat.awk: Skip bad instructions from llvm-objdump

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

x86/tools: objdump_reformat.awk: Allow for spaces

GNU objdump and LLVM objdump have differing output formats.
Specifically, GNU objump will format its output as: address:<tab>hex,
whereas LLVM objdump displays its output as address:<space>hex.

objdump_reformat.awk incorrectly handles this discrepancy due to
the unexpected space and as a result insn_decoder_test fails, as
its input is garbled.

The instruction line being tokenized now handles a space and colon,
or tab delimiter.

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-v3-2-0d855e79314d@kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1364

x86/tools: objdump_reformat.awk: Ensure regex matches fwait

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

x86/tools: Rename distill.awk to objdump_reformat.awk

Rename distill.awk to objdump_reformat.awk because it more
clearly expresses its purpose of re-formatting the output
of objdump so that insn_decoder_test can read it.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/151153625409.22827.10470603625519700259.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>