• Josh Poimboeuf's avatar
    x86/unwind: Silence entry-related warnings · a8b7a923
    Josh Poimboeuf authored
    A few people have reported unwinder warnings like the following:
    
      WARNING: kernel stack frame pointer at ffffc90000fe7ff0 in rsync:1157 has bad value           (null)
      unwind stack type:0 next_sp:          (null) mask:2 graph_idx:0
      ffffc90000fe7f98: ffffc90000fe7ff0 (0xffffc90000fe7ff0)
      ffffc90000fe7fa0: ffffffffb7000f56 (trace_hardirqs_off_thunk+0x1a/0x1c)
      ffffc90000fe7fa8: 0000000000000246 (0x246)
      ffffc90000fe7fb0: 0000000000000000 ...
      ffffc90000fe7fc0: 00007ffe3af639bc (0x7ffe3af639bc)
      ffffc90000fe7fc8: 0000000000000006 (0x6)
      ffffc90000fe7fd0: 00007f80af433fc5 (0x7f80af433fc5)
      ffffc90000fe7fd8: 00007ffe3af638e0 (0x7ffe3af638e0)
      ffffc90000fe7fe0: 00007ffe3af638e0 (0x7ffe3af638e0)
      ffffc90000fe7fe8: 00007ffe3af63970 (0x7ffe3af63970)
      ffffc90000fe7ff0: 0000000000000000 ...
      ffffc90000fe7ff8: ffffffffb7b74b9a (entry_SYSCALL_64_after_swapgs+0x17/0x4f)
    
    This warning can happen when unwinding a code path where an interrupt
    occurred in x86 entry code before it set up the first stack frame.
    Silently ignore any warnings for this case.
    Reported-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Reported-by: default avatarDave Jones <davej@codemonkey.org.uk>
    Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
    Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brian Gerst <brgerst@gmail.com>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Fixes: c32c47c6 ("x86/unwind: Warn on bad frame pointer")
    Link: http://lkml.kernel.org/r/dbd6838826466a60dc23a52098185bc973ce2f1e.1492020577.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    a8b7a923
unwind.h 1.69 KB