30 Apr, 2013

1 commit

  • It can accidentally happen that the faulting insn (the exact instruction
    bytes) is repeated a little further on in the trace. This causes that
    same instruction to be tagged twice, see example below.

    What we want to do, however, is to track back from the end of the whole
    disassembly so many lines as the slice which starts with the faulting
    instruction is long. This leads us to the actual faulting instruction
    and *then* we tag it.

    While we're at it, we can drop the sed "g" flag because we address only
    this one line.

    Also, if we point to an instruction which changes decoding depending on
    the slice being objdumped, like a Jcc insn, for example, we do not even
    tag it as a faulting instruction because the instruction decode changes
    in the second slice but we use that second format as a regex on the
    fsrst disassembled buffer and more often than not that instruction
    doesn't match.

    Again, simply tag the line which is deduced from the original "<>"
    marking we've received from the kernel.

    This also solves the pathologic issue of multiple tagging like this:

    29:* 0f 0b ud2 39 48 08 75 0e eb 2a 66 90 48 8b 40 f0 48 39 48 08 74 1e 48
    All code
    ========
    0: 34 dd xor $0xdd,%al
    2: 40 30 ad 81 48 c7 c0 xor %bpl,-0x3f38b77f(%rbp)
    9: 80 f6 00 xor $0x0,%dh
    c: 00 48 8b add %cl,-0x75(%rax)
    f: 3c 30 cmp $0x30,%al
    11: 48 01 c6 add %rax,%rsi
    14: b8 ff ff ff ff mov $0xffffffff,%eax
    19: 48 8d 57 f0 lea -0x10(%rdi),%rdx
    1d: 48 39 f7 cmp %rsi,%rdi
    20: 74 2f je 0x51
    22: 49 8b 4c 24 08 mov 0x8(%r12),%rcx
    27: 48 8b 47 f0 mov -0x10(%rdi),%rax
    2b:* 48 39 48 08 cmp %rcx,0x8(%rax)
    Cc: "H. Peter Anvin"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Borislav Petkov
     

17 Aug, 2012

1 commit

  • When dumping "Code: " sections from an oops, the trapping instruction
    %rip points to can be a string copy

    2b:* f3 a5 rep movsl %ds:(%rsi),%es:(%rdi)

    and the line contain a bunch of ":". Current "cut" selects only the and
    the second field output looks funnily overlaid this:

    2b:* f3 a5 rep movsl %ds
    Cc: Linus Torvalds
    Cc: linux-kbuild@vger.kernel.org
    Signed-off-by: Borislav Petkov
    Signed-off-by: Linus Torvalds

    Borislav Petkov
     

04 Jun, 2010

1 commit


02 Feb, 2010

1 commit

  • This patch adds support for decoding ARM oopses to scripts/decodecode.
    The following things are handled:

    - ARCH and CROSS_COMPILE environment variables are respected.

    - The Code: in x86 oopses is in bytes, while it is in either words (4
    bytes) or halfwords for ARM.

    - Some versions of ARM objdump refuse to disassemble instructions
    generated by literal constants (".word 0x..."). The workaround is to
    strip the object file first.

    - The faulting instruction is marked (liked so) in ARM, but
    in x86.

    - ARM mnemonics may include characters such as [] which need to be
    escaped before being passed to sed for the "
    Signed-off-by: Michal Marek

    Rabin Vincent
     

04 Dec, 2008

1 commit

  • kerneloops.org has been using an improved "decodecode" script,
    specifically it has a special marker that shows which line in the assembly
    the oops happened at, like this:

    20: 83 e0 03 and $0x3,%eax
    23: 09 d8 or %ebx,%eax
    25: 85 db test %ebx,%ebx
    27: 89 02 mov %eax,(%edx)
    29: 74 0f je 0x3a
    2b:* 3b 73 04 cmp 0x4(%ebx),%esi
    Reviewed-by: WANG Cong
    Signed-off-by: Andrew Morton
    Signed-off-by: Sam Ravnborg

    Arjan van de Ven
     

31 May, 2008

1 commit


29 Jan, 2008

1 commit


17 Jul, 2007

1 commit

  • Add info that the Code: bytes line contains or (wxyz) in some
    architecture oops reports and what that means.

    Add a script by Andi Kleen that reads the Code: line from an Oops report
    file and generates assembly code from the hex bytes.

    Signed-off-by: Randy Dunlap
    Cc: Andi Kleen
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Randy Dunlap