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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-07-17 20:36:57 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-18 21:01:10 +0200 |
| commit | b68b9907069a8d3a65bc16a35360bf8f8603c8fa (patch) | |
| tree | ca8c51c1d05a67376139dd523809d6d84d8ccf57 /arch | |
| parent | 9fe7b7642fe2c5158904d06fe31b740ca0695a01 (diff) | |
| download | linux-b68b9907069a8d3a65bc16a35360bf8f8603c8fa.tar.bz2 | |
objtool: Support conditional retpolines
A Clang-built kernel is showing the following warning:
arch/x86/kernel/platform-quirks.o: warning: objtool: x86_early_init_platform_quirks()+0x84: unreachable instruction
That corresponds to this code:
7e: 0f 85 00 00 00 00 jne 84 <x86_early_init_platform_quirks+0x84>
80: R_X86_64_PC32 __x86_indirect_thunk_r11-0x4
84: c3 retq
This is a conditional retpoline sibling call, which is now possible
thanks to retpolines. Objtool hasn't seen that before. It's
incorrectly interpreting the conditional jump as an unconditional
dynamic jump.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/30d4c758b267ef487fb97e6ecb2f148ad007b554.1563413318.git.jpoimboe@redhat.com
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions