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authorJosh Poimboeuf <[email protected]>2018-03-22 13:00:37 -0500
committerIngo Molnar <[email protected]>2018-03-27 08:21:29 +0200
commit3c1f05835cbf9fdfe60b81c718d82ceb94b6c55e (patch)
treeb554c520676ffc32a1c8c2dc3e77f200b6a27816 /lib/usercopy.c
parentd8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9 (diff)
objtool: Add Clang support
Since the ORC unwinder was made the default on x86_64, Clang-built defconfig kernels have triggered some new objtool warnings: drivers/gpu/drm/i915/i915_gpu_error.o: warning: objtool: i915_error_printf()+0x6c: return with modified stack frame drivers/gpu/drm/i915/intel_display.o: warning: objtool: pipe_config_err()+0xa6: return with modified stack frame The problem is that objtool has never seen clang-built binaries before. Shockingly enough, objtool is apparently able to follow the code flow mostly fine, except for one instruction sequence. Instead of a LEAVE instruction, clang restores RSP and RBP the long way: 67c: 48 89 ec mov %rbp,%rsp 67f: 5d pop %rbp Teach objtool about this new code sequence. Reported-and-test-by: Matthias Kaehlcke <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Matthias Kaehlcke <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/fce88ce81c356eedcae7f00ed349cfaddb3363cc.1521741586.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'lib/usercopy.c')
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