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.makha...@broadcom.com> 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(-)
> >
> --
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