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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2018-02-09 02:09:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-22 17:40:02 +0300 |
| commit | 636aaf1b6d8400caf181f5a064080e5f4f71be53 (patch) | |
| tree | b78f156323fe4d637c7118fe1ff09fee97474d26 /arch/x86/ia32 | |
| parent | b2fceb82f99d6a0f78b617497c8d72fa0cf07a35 (diff) | |
| download | linux-636aaf1b6d8400caf181f5a064080e5f4f71be53.tar.xz | |
objtool: Fix segfault in ignore_unreachable_insn()
commit fe24e27128252c230a34a6c628da2bf1676781ea upstream.
Peter Zijlstra's patch for converting WARN() to use UD2 triggered a
bunch of false "unreachable instruction" warnings, which then triggered
a seg fault in ignore_unreachable_insn().
The seg fault happened when it tried to dereference a NULL 'insn->func'
pointer. Thanks to static_cpu_has(), some functions can jump to a
non-function area in the .altinstr_aux section. That breaks
ignore_unreachable_insn()'s assumption that it's always inside the
original function.
Make sure ignore_unreachable_insn() only follows jumps within the
current function.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kbuild test robot <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/bace77a60d5af9b45eddb8f8fb9c776c8de657ef.1518130694.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/ia32')
0 files changed, 0 insertions, 0 deletions