Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 21 Sep 2017 15:27:37 +0200 | Subject | Re: gcc-8 objtool warnings |
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On Tue, Sep 19, 2017 at 11:39 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote: > On Tue, Sep 19, 2017 at 10:43:31PM +0200, Arnd Bergmann wrote:
> ----- > From: Josh Poimboeuf <jpoimboe@redhat.com> > Subject: [PATCH] objtool: Support unoptimized frame pointer setup > > Arnd Bergmann reported a bunch of warnings like: > > crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without frame pointer save/setup > crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without frame pointer save/setup > crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call without frame pointer save/setup > crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call without frame pointer save/setup > crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19: call without frame pointer save/setup > > and > > arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch register > arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call without frame pointer save/setup > > With certain rare configurations, GCC sometimes sets up the frame > pointer with: > > lea (%rsp),%rbp > > instead of: > > mov %rsp,%rbp > > The instructions are equivalent, so treat the former like the latter. > > Reported-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Confirmed, this fixes many configurations that had warnings before, currently testing with gcc-6.3.
Arnd
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