linux/scripts/decodecode, branch master

scripts/decodecode: return 0 on success

2026-03-28T04:19:48Z

The decodecode script always returns an exit code of 1, regardless of whether the operation was successful or not. This is because the "cleanup" function, which is registered to run on any script exit via "trap cleanup EXIT", contains an unconditional "exit 1". Remove the "exit 1" from the "cleanup" function so that it only performs the necessary file cleanup without forcing a non-zero exit status. Do that to ensure successful script executions now exit with code 0. Exits due to errors are all handled by the "die()" function and will still correctly exit with code 1. Link: https://lkml.kernel.org/r/20260318150545.2809311-1-derkling@google.com Signed-off-by: Patrick Bellasi Acked-by: Randy Dunlap Signed-off-by: Andrew Morton

scripts/decodecode: add support for LoongArch

2023-12-29T20:22:25Z

An example how to invoke decodecode for loongarch64: $ echo 'Code: 380839f6 380831f9 28412bae <24000ca6> 004081ad 0014cb50 004083e8 02bff34c 58008e91' | \ ARCH=loongarch CROSS_COMPILE=loongarch64-linux-gnu- \ ./scripts/decodecode Code: 380839f6 380831f9 28412bae <24000ca6> 004081ad 0014cb50 004083e8 02bff34c 58008e91 All code ======== 0: 380839f6 ldx.w $fp, $t3, $t2 4: 380831f9 ldx.w $s2, $t3, $t0 8: 28412bae ld.h $t2, $s6, 74(0x4a) c:* 24000ca6 ldptr.w $a2, $a1, 12(0xc) <-- trapping instruction 10: 004081ad slli.w $t1, $t1, 0x0 14: 0014cb50 and $t4, $s3, $t6 18: 004083e8 slli.w $a4, $s8, 0x0 1c: 02bff34c addi.w $t0, $s3, -4(0xffc) 20: 58008e91 beq $t8, $t5, 140(0x8c) # 0xac Code starting with the faulting instruction =========================================== 0: 24000ca6 ldptr.w $a2, $a1, 12(0xc) 4: 004081ad slli.w $t1, $t1, 0x0 8: 0014cb50 and $t4, $s3, $t6 c: 004083e8 slli.w $a4, $s8, 0x0 10: 02bff34c addi.w $t0, $s3, -4(0xffc) 14: 58008e91 beq $t8, $t5, 140(0x8c) # 0xa0 Link: https://lkml.kernel.org/r/MW4PR84MB3145B99B9677BB7887BB26CD8192A@MW4PR84MB3145.NAMPRD84.PROD.OUTLOOK.COM Signed-off-by: Youling Tang Acked-by: Huacai Chen Signed-off-by: Andrew Morton

scripts/decodecode: Add support for RISC-V

2023-02-22T00:53:54Z

RISC-V has some GNU disassembly quirks, e.g. it requires '-D' to properly disassemble .2byte directives similar to Arm [1]. Further, GNU objdump groups RISC-V instruction by 2 or 4 byte chunks, instead doing byte-for-byte. Add the required switches, and translate from short/word to bytes when ARCH is "riscv". An example how to invoke decodecode for RISC-V: $ echo 'Code: bf45 f793 1007 f7d9 50ef 37af d541 b7d9 7097 00c8 (80e7) 6140' | AFLAGS="-march=rv64imac_zicbom_zihintpause" \ ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- ./scripts/decodecode Code: bf45 f793 1007 f7d9 50ef 37af d541 b7d9 7097 00c8 (80e7) 6140 All code ======== 0: bf45 c.j 0xffffffffffffffb0 2: 1007f793 andi a5,a5,256 6: f7d9 c.bnez a5,0xffffffffffffff94 8: 37af50ef jal ra,0xf5382 c: d541 c.beqz a0,0xffffffffffffff94 e: b7d9 c.j 0xffffffffffffffd4 10: 00c87097 auipc ra,0xc87 14:* 614080e7 jalr ra,1556(ra) # 0xc87624 <-- trapping instruction Code starting with the faulting instruction =========================================== 0: 614080e7 jalr ra,1556(ra) [1] https://sourceware.org/bugzilla/show_bug.cgi?id=10263 Signed-off-by: Björn Töpel Tested-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230119074738.708301-3-bjorn@kernel.org Signed-off-by: Palmer Dabbelt

scripts/decodecode: improve faulting line determination

2022-09-12T04:55:05Z

There are cases where the IP pointer in a Code: line in an oops doesn't point at the beginning of an instruction: Code: 0f bd c2 e9 a0 cd b5 e4 48 0f bd c2 e9 97 cd b5 e4 0f 1f 80 00 00 00 00 \ e9 8b cd b5 e4 0f 1f 00 66 0f a3 d0 e9 7f cd b5 e4 0f 1f <80> 00 00 00 \ 00 0f a3 d0 e9 70 cd b5 e4 48 0f a3 d0 e9 67 cd b5 e9 7f cd b5 e4 jmp 0xffffffffe4b5cda8 0f 1f 80 00 00 00 00 nopl 0x0(%rax) ^^ and the current way of determining the faulting instruction line doesn't work because disassembled instructions are counted from the IP byte to the end and when that thing points in the middle, the trailing bytes can be interpreted as different insns: Code starting with the faulting instruction =========================================== 0: 80 00 00 addb $0x0,(%rax) 3: 00 00 add %al,(%rax) whereas, this is part of 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 5: 0f a3 d0 bt %edx,%eax ... leading to: 1d: 0f 1f 00 nopl (%rax) 20: 66 0f a3 d0 bt %dx,%ax 24:* e9 7f cd b5 e4 jmp 0xffffffffe4b5cda8 <-- trapping instruction 29: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 30: 0f a3 d0 bt %edx,%eax which is the wrong faulting instruction. Change the way the faulting line number is determined by matching the opcode bytes from the beginning, leading to correct output: 1d: 0f 1f 00 nopl (%rax) 20: 66 0f a3 d0 bt %dx,%ax 24: e9 7f cd b5 e4 jmp 0xffffffffe4b5cda8 29:* 0f 1f 80 00 00 00 00 nopl 0x0(%rax) <-- trapping instruction 30: 0f a3 d0 bt %edx,%eax While at it, make decodecode use bash as the interpreter - that thing should be present on everything by now. It simplifies the code a lot too. Link: https://lkml.kernel.org/r/20220808085928.29840-1-bp@alien8.de Signed-off-by: Borislav Petkov Cc: Marc Zyngier Cc: Will Deacon Signed-off-by: Andrew Morton

scripts/decodecode: fix faulting instruction no print when opps.file is DOS format

2021-11-06T20:30:32Z

If opps.file is in DOS format, faulting instruction cannot be printed: / # ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- / # ./scripts/decodecode < oops.file [ 0.734345] Code: d0002881 912f9c21 94067e68 d2800001 (b900003f) aarch64-linux-gnu-strip: '/tmp/tmp.5Y9eybnnSi.o': No such file aarch64-linux-gnu-objdump: '/tmp/tmp.5Y9eybnnSi.o': No such file All code ======== 0: d0002881 adrp x1, 0x512000 4: 912f9c21 add x1, x1, #0xbe7 8: 94067e68 bl 0x19f9a8 c: d2800001 mov x1, #0x0 // #0 10: b900003f str wzr, [x1] Code starting with the faulting instruction =========================================== Background: The compilation environment is Ubuntu, and the test environment is Windows. Most logs are generated in the Windows environment. In this way, CR (carriage return) will inevitably appear, which will affect the use of decodecode in the Ubuntu environment. The repaired effect is as follows: / # ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- / # ./scripts/decodecode < oops.file [ 0.734345] Code: d0002881 912f9c21 94067e68 d2800001 (b900003f) All code ======== 0: d0002881 adrp x1, 0x512000 4: 912f9c21 add x1, x1, #0xbe7 8: 94067e68 bl 0x19f9a8 c: d2800001 mov x1, #0x0 // #0 10:* b900003f str wzr, [x1] <-- trapping instruction Code starting with the faulting instruction =========================================== 0: b900003f str wzr, [x1] Link: https://lkml.kernel.org/r/20211008064712.926-1-weidonghui@allwinnertech.com Signed-off-by: weidonghui Acked-by: Borislav Petkov Cc: Marc Zyngier Cc: Will Deacon Cc: Rabin Vincent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scripts/decodecode: add the capability to supply the program counter

2020-10-14T01:38:26Z

So that comparing with objdump output from vmlinux can ease pinpointing where the trapping instruction actually is. An example is better than a thousand words: $ PC=0xffffffff8329a927 ./scripts/decodecode < ~/tmp/syz/gfs2.splat [ 477.379104][T23917] Code: 48 83 ec 28 48 89 3c 24 48 89 54 24 08 e8 c1 b4 4a fe 48 8d bb 00 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 97 05 00 00 48 8b 9b 00 01 00 00 48 85 db 0f 84 All code ======== ffffffff8329a8fd: 48 83 ec 28 sub $0x28,%rsp ffffffff8329a901: 48 89 3c 24 mov %rdi,(%rsp) ffffffff8329a905: 48 89 54 24 08 mov %rdx,0x8(%rsp) ffffffff8329a90a: e8 c1 b4 4a fe callq 0xffffffff81745dd0 ffffffff8329a90f: 48 8d bb 00 01 00 00 lea 0x100(%rbx),%rdi ffffffff8329a916: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax ffffffff8329a91d: fc ff df ffffffff8329a920: 48 89 fa mov %rdi,%rdx ffffffff8329a923: 48 c1 ea 03 shr $0x3,%rdx ffffffff8329a927:* 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction ffffffff8329a92b: 0f 85 97 05 00 00 jne 0xffffffff8329aec8 ffffffff8329a931: 48 8b 9b 00 01 00 00 mov 0x100(%rbx),%rbx ffffffff8329a938: 48 85 db test %rbx,%rbx ffffffff8329a93b: 0f .byte 0xf ffffffff8329a93c: 84 .byte 0x84 Signed-off-by: Borislav Petkov Signed-off-by: Andrew Morton Cc: Marc Zyngier Cc: Will Deacon Cc: Rabin Vincent Link: https://lkml.kernel.org/r/20200930111416.GF6810@zn.tnic Link: https://lkml.kernel.org/r/20200929113238.GC21110@zn.tnic Signed-off-by: Linus Torvalds

scripts/decodecode: fix trapping instruction formatting

2020-05-08T02:27:20Z

If the trapping instruction contains a ':', for a memory access through segment registers for example, the sed substitution will insert the '*' marker in the middle of the instruction instead of the line address: 2b: 65 48 0f c7 0f cmpxchg16b %gs:*(%rdi) <-- trapping instruction I started to think I had forgotten some quirk of the assembly syntax before noticing that it was actually coming from the script. Fix it to add the address marker at the right place for these instructions: 28: 49 8b 06 mov (%r14),%rax 2b:* 65 48 0f c7 0f cmpxchg16b %gs:(%rdi) <-- trapping instruction 30: 0f 94 c0 sete %al Fixes: 18ff44b189e2 ("scripts/decodecode: make faulting insn ptr more robust") Signed-off-by: Ivan Delalande Signed-off-by: Andrew Morton Reviewed-by: Borislav Petkov Link: http://lkml.kernel.org/r/20200419223653.GA31248@visor Signed-off-by: Linus Torvalds

scripts/decodecode: set ARCH when running natively on arm/arm64

2018-12-28T20:11:44Z

When running decodecode natively on arm64, ARCH is likely not to be set, and we end-up with .4byte instead of .inst when generating the disassembly. Similar effects would occur if running natively on a 32bit ARM platform, although that's even less popular. A simple workaround is to populate ARCH when it is not set and that we're running on an arm/arm64 system. Link: http://lkml.kernel.org/r/20181210174659.31054-2-marc.zyngier@arm.com Signed-off-by: Marc Zyngier Acked-by: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scripts/decodecode: make it take multiline Code line

2018-02-01T01:18:34Z

In case of running scripts/decodecode without any parameters in order to give a copy'n'pasted Code line from, for example, email it would parse only first line of it, while in emails it's split to few. ie, when you have a file out of oops the Code line looks like Code: hh hh ... ... hh\n When copy'n'paste from, for example, email where sender or some middle MTA split it, the line looks like: Code: hh hh ... hh\n hh ... ... hh\n hh hh ... hh\n The Code line followed by another oops line usually contains characters out of hex digit + space + < + > set. So add logic to join this split back if and only if the following lines have hex digits, or spaces, or '<', or '>' characters. It will be quite unlikely to have a broken input in well formed Oops or dmesg, thus a simple regex is being used. Link: http://lkml.kernel.org/r/20171212100323.33201-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Will Deacon Cc: Dave Martin Cc: Philippe Ombredanne Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scripts/decodecode: fix decoding for AArch64 (arm64) instructions

2018-01-19T18:09:41Z

There are a couple of problems with the decodecode script and arm64: 1. AArch64 objdump refuses to disassemble .4byte directives as instructions, insisting that they are data values and displaying them as: a94153f3 .word 0xa94153f3 <-- trapping instruction This is resolved by using the .inst directive instead. 2. Disassembly of branch instructions attempts to provide the target as an offset from a symbol, e.g.: 0: 34000082 cbz w2, 10 <.text+0x10> however this falls foul of the grep -v, which matches lines containing ".text" and ends up removing all branch instructions from the dump. This patch resolves both issues by using the .inst directive for 4-byte quantities on arm64 and stripping the resulting binaries (as is done on arm already) to remove the mapping symbols. Link: http://lkml.kernel.org/r/1506596147-23630-1-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon Reviewed-by: Dave Martin Cc: Michal Marek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds