[Crash-utility] Re: [PATCH v2 0/5] gdb multi-stack unwinding support

Hi Alexey, The patchset needs to be rebased after upgrading the gdb into version v16.2. If we put the "multi-stack unwinding" together with gdb upgrading, there will be too much modification for one release. So we decided to defer the "multi-stack unwinding" after gdb upgrading. I think I will rebase and re-post the "multi-stack" patches later. Thanks, Tao Liu On Thu, May 1, 2025 at 9:25 AM Alexey Makhalov <alexey.makhalov(a)broadcom.com&gt; wrote: > > Hello Tao and folks! > > What is the status of this patchset? I expected to see it in 9.0. > > Thanks, > --Alexey > > > On 2/20/25 1:44 PM, Tao Liu wrote: >> This patchset is based on Alexy's work [1], and is the follow-up of the >> previous "gdb stack unwinding support for crash utility" patchset. >> >> Currently gdb target analyzes only one task at a time and it backtraces >> only straight stack until end of the stack. If stacks were concatenated >> during exceptions or interrupts, gdb bt will show only the topmost one. >> >> This patchset will introduce multiple stacks support for gdb stack unwinding, >> which can be observed as a different threads from gdb perspective. A >> short usage is as follows: >> >> 'set <PID>' - to switch to a specific task >> 'gdb info threads' - to see list of in-kernel stacks of this task. >> 'gdb thread <ID>' - to switch to the stack. >> 'gdb bt' - to unwind it. >> >> E.g, with the patchset: >> >> crash> bt >> PID: 17636 TASK: ffff88032e0742c0 CPU: 11 COMMAND: "kworker/11:4" >> #0 [ffff88037fca6b58] machine_kexec at ffffffff8103cef2 >> #1 [ffff88037fca6ba8] crash_kexec at ffffffff810c9aa3 >> #2 [ffff88037fca6c70] panic at ffffffff815f0444 >> ... >> #9 [ffff88037fca6ec8] do_nmi at ffffffff815fd980 >> #10 [ffff88037fca6ef0] end_repeat_nmi at ffffffff815fcec1 >> [exception RIP: memcpy+13] >> RIP: ffffffff812f5b1d RSP: ffff88034f2a9728 RFLAGS: 00010046 >> RAX: ffffc900139fe000 RBX: ffff880374b7a1b0 RCX: 0000000000000030 >> RBP: ffff88034f2a9778 R8: 000000007fffffff R9: 00000000ffffffff >> ... >> ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 >> --- <NMI exception stack> --- >> #11 [ffff88034f2a9728] memcpy at ffffffff812f5b1d >> #12 [ffff88034f2a9728] mga_dirty_update at ffffffffa024ad2b [mgag200] >> #13 [ffff88034f2a9780] mga_imageblit at ffffffffa024ae3f [mgag200] >> #14 [ffff88034f2a97a0] bit_putcs at ffffffff813424ef >> ... >> >> crash> info threads >> Id Target Id Frame >> * 1 17636 kworker/11:4 (stack 0) crash_setup_regs (oldregs=0x0, newregs=0xffff88037fca6bb0) >> 2 17636 kworker/11:4 (stack 1) 0xffffffff812f5b1d in memcpy () >> >> crash> thread 2 >> crash> gdb bt >> #0 0xffffffff812f5b1d in memcpy () at arch/x86/lib/memcpy_64.S:69 >> ... >> >> There are 2 stacks of the current task, and we can list/switch-to/unwind >> each stack. >> >> [1]: https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01204.html >> >> v2 -> v1: 1) Rebase this patchset onto gdb-16.2 [2]. >> 2) Improved the silent_call_bt() to catch the error FATAL. >> >> [2]: https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01354.html >> >> Tao Liu (5): >> Add multi-threads support in crash target >> Call cmd_bt silently after "set pid" >> x86_64: Add gdb multi-stack unwind support >> arm64: Add gdb multi-stack unwind support >> ppc64: Add gdb multi-stack unwind support >> >> arm64.c | 85 +++++++++++++++++++++++++++++++-- >> crash_target.c | 49 +++++++++++++++++-- >> defs.h | 3 +- >> gdb_interface.c | 6 +-- >> kernel.c | 43 +++++++++++++++++ >> ppc64.c | 70 +++++++++++++++++++++++---- >> task.c | 4 +- >> x86_64.c | 123 +++++++++++++++++++++++++++++++++++++++++++++--- >> 8 files changed, 354 insertions(+), 29 deletions(-) >> > -- > Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io > To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io > https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ > Contribution Guidelines: https://github.com/crash-utility/crash/wiki