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2013-04-29scripts/decodecode: make faulting insn ptr more robustBorislav Petkov1-1/+7
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 <-- trapping instruction 2b:* 0f 0b ud2 <-- trapping instruction 2d:* 0f 0b ud2 <-- trapping instruction Double tagging example: Code: 34 dd 40 30 ad 81 48 c7 c0 80 f6 00 00 48 8b 3c 30 48 01 c6 b8 ff ff ff ff 48 8d 57 f0 48 39 f7 74 2f 49 8b 4c 24 08 48 8b 47 f0 <48> 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) <-- trapping instruction 2f: 75 0e jne 0x3f 31: eb 2a jmp 0x5d 33: 66 90 xchg %ax,%ax 35: 48 8b 40 f0 mov -0x10(%rax),%rax 39:* 48 39 48 08 cmp %rcx,0x8(%rax) <-- trapping instruction 3d: 74 1e je 0x5d 3f: 48 rex.W Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-16scripts/decodecode: Fixup trapping instruction markerBorislav Petkov1-1/+1
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 <-- trapping instruction:(%rsi),%es:(%rdi Fix this by selecting the remaining fields too. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kbuild@vger.kernel.org Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-04scripts: decodecode: remove bashismsRabin Vincent1-5/+5
Remove bashisms to make scripts/decodecode work with other shells. Signed-off-by: Rabin Vincent <rabin@rab.in> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-02-02scripts: add ARM support to decodecodeRabin Vincent1-13/+35
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 <like so> in x86. - ARM mnemonics may include characters such as [] which need to be escaped before being passed to sed for the "<- trapping instruction" substitution. Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Michal Marek <mmarek@suse.cz>
2008-12-03scripts: improve the decodecode scriptArjan van de Ven1-10/+22
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 <-- trapping instruction 2e: 75 05 jne 0x35 30: 89 53 04 mov %edx,0x4(%ebx) 33: eb 07 jmp 0x3c 35: 89 53 08 mov %edx,0x8(%ebx) this patch updates the kernel copy to also have this functionality. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-05-30Mark 'scripts/decodecode' executableLinus Torvalds1-0/+0
.. because it is. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-28kbuild: minor scripts/decodecode updateRandy Dunlap1-2/+15
Remove the tmp file when exiting. Noticed by Arjan van de Ven. Catch mktemp failure and exit with message. Trap kill or other signals and exit cleanly. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-07-16doc/oops-tracing: add Code: decode infoRandy Dunlap1-0/+51
Add info that the Code: bytes line contains <xy> 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 <randy.dunlap@oracle.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>