From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
peterz@infradead.org, hpa@zytor.com, tglx@linutronix.de
Subject: Re: [PATCH 2/2] x86/unwind: Make CONFIG_UNWINDER_ORC=y the default in kconfig for 64-bit
Date: Mon, 19 Mar 2018 21:28:03 -0500 [thread overview]
Message-ID: <20180320022803.i46ixerodrhzzewd@treble> (raw)
In-Reply-To: <20180319232255.GF37438@google.com>
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
/*
next prev parent reply other threads:[~2018-03-20 2:28 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20171013052544.euk7yawni47lhmdq@gmail.com>
2017-10-13 20:02 ` [PATCH 1/2] x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*' Josh Poimboeuf
2017-10-14 10:49 ` [tip:x86/asm] " tip-bot for Josh Poimboeuf
2017-10-13 20:02 ` [PATCH 2/2] x86/unwind: Make CONFIG_UNWINDER_ORC=y the default in kconfig for 64-bit Josh Poimboeuf
2017-10-14 10:50 ` [tip:x86/asm] " tip-bot for Josh Poimboeuf
2017-10-19 16:51 ` [2/2] " Andrei Vagin
2017-10-19 18:16 ` Josh Poimboeuf
2017-10-19 22:35 ` Andrei Vagin
2017-10-20 0:38 ` Andrei Vagin
2017-10-20 1:28 ` Josh Poimboeuf
2017-10-20 6:54 ` Andrei Vagin
2018-03-19 18:57 ` [PATCH 2/2] " Matthias Kaehlcke
2018-03-19 19:29 ` Josh Poimboeuf
2018-03-19 20:31 ` Matthias Kaehlcke
2018-03-19 21:20 ` Josh Poimboeuf
2018-03-19 23:22 ` Matthias Kaehlcke
2018-03-20 2:28 ` Josh Poimboeuf [this message]
2018-03-20 19:39 ` Matthias Kaehlcke
2018-03-21 2:45 ` Josh Poimboeuf
2018-03-21 21:19 ` Matthias Kaehlcke
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