• Josh Poimboeuf's avatar
    objtool: Support unoptimized frame pointer setup · 607a4029
    Josh Poimboeuf authored
    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: 's avatarArnd Bergmann <arnd@arndb.de>
    Signed-off-by: 's avatarJosh Poimboeuf <jpoimboe@redhat.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Link: http://lkml.kernel.org/r/a468af8b28a69b83fffc6d7668be9b6fcc873699.1506526584.git.jpoimboe@redhat.comSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
    607a4029
decode.c 9.93 KB