Messages in this thread Patch in this message | | | Date | Mon, 19 Mar 2018 21:28:03 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 2/2] x86/unwind: Make CONFIG_UNWINDER_ORC=y the default in kconfig for 64-bit |
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On Mon, Mar 19, 2018 at 04:22:55PM -0700, Matthias Kaehlcke wrote: > > Here's a (surprisingly easy) fix for this particular issue, though I'd > > be shocked if there weren't a bunch more issues lurking elsewhere. Let > > me know how it goes. > > Thanks for having a look, this fixes the vast majority of warnings in > a defconfig build!
Wow. Consider me shocked :-)
> The remaining warnings are: > > arch/x86/mm/pti.o: warning: objtool: pti_init() falls through to next > function pti_user_pagetable_walk_pmd() > s/debugfs/file.o: warning: objtool: full_proxy_llseek() falls through to next function full_proxy_read() > fs/debugfs/file.o: warning: objtool: full_proxy_read() falls through to next function full_proxy_write() > fs/debugfs/file.o: warning: objtool: full_proxy_write() falls through to next function full_proxy_poll() > fs/debugfs/file.o: warning: objtool: full_proxy_poll() falls through to next function full_proxy_unlocked_ioctl() > fs/debugfs/file.o: warning: objtool: full_proxy_unlocked_ioctl() falls through to next function fops_u8_open()
These all seem to be related to some weirdness with the UD2 instruction, not necessarily an objtool issue per se.
Any chance this fixes some of the warnings? If not, I can try to build with clang and look a little deeper.
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index ab4711c63601..315a8757b565 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -124,7 +124,12 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, # define ASM_UNREACHABLE #endif #ifndef unreachable -# define unreachable() do { annotate_reachable(); do { } while (1); } while (0) +#define unreachable() \ + do { \ + annotate_unreachable(); \ + barrier_before_unreachable(); \ + __builtin_unreachable(); \ + } while (0) #endif /*
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