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    objtool: Add --backtrace support · 7697eee3
    Peter Zijlstra 提交于
    For when you want to know the path that reached your fail state:
    
      $ ./objtool check --no-fp --backtrace arch/x86/lib/usercopy_64.o
      arch/x86/lib/usercopy_64.o: warning: objtool: .altinstr_replacement+0x3: UACCESS disable without MEMOPs: __clear_user()
      arch/x86/lib/usercopy_64.o: warning: objtool:   __clear_user()+0x3a: (alt)
      arch/x86/lib/usercopy_64.o: warning: objtool:   __clear_user()+0x2e: (branch)
      arch/x86/lib/usercopy_64.o: warning: objtool:   __clear_user()+0x18: (branch)
      arch/x86/lib/usercopy_64.o: warning: objtool:   .altinstr_replacement+0xffffffffffffffff: (branch)
      arch/x86/lib/usercopy_64.o: warning: objtool:   __clear_user()+0x5: (alt)
      arch/x86/lib/usercopy_64.o: warning: objtool:   __clear_user()+0x0: <=== (func)
    
      0000000000000000 <__clear_user>:
        0:   e8 00 00 00 00          callq  5 <__clear_user+0x5>
                     1: R_X86_64_PLT32       __fentry__-0x4
        5:   90                      nop
        6:   90                      nop
        7:   90                      nop
        8:   48 89 f0                mov    %rsi,%rax
        b:   48 c1 ee 03             shr    $0x3,%rsi
        f:   83 e0 07                and    $0x7,%eax
       12:   48 89 f1                mov    %rsi,%rcx
       15:   48 85 c9                test   %rcx,%rcx
       18:   74 0f                   je     29 <__clear_user+0x29>
       1a:   48 c7 07 00 00 00 00    movq   $0x0,(%rdi)
       21:   48 83 c7 08             add    $0x8,%rdi
       25:   ff c9                   dec    %ecx
       27:   75 f1                   jne    1a <__clear_user+0x1a>
       29:   48 89 c1                mov    %rax,%rcx
       2c:   85 c9                   test   %ecx,%ecx
       2e:   74 0a                   je     3a <__clear_user+0x3a>
       30:   c6 07 00                movb   $0x0,(%rdi)
       33:   48 ff c7                inc    %rdi
       36:   ff c9                   dec    %ecx
       38:   75 f6                   jne    30 <__clear_user+0x30>
       3a:   90                      nop
       3b:   90                      nop
       3c:   90                      nop
       3d:   48 89 c8                mov    %rcx,%rax
       40:   c3                      retq
    Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
    Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: NIngo Molnar <mingo@kernel.org>
    7697eee3
warn.h 1.9 KB