Re: [PATCH v3] tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast

[Steven Rostedt]

On Mon, 8 Dec 2025 12:46:32 -0800
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> >             bash-1165    [001] DBZ.f   269.955762: sys_rt_sigaction -> 0x0
> >                                ^^^^^
> >                             This is just garbage.  
> 
> Yes, but is is the original garbage, and garbage obtained by acceding
> to your request.  ;-)

Yes, here's what it looks like before patch:

            bash-1168    [001] .....    77.498737: sys_wait4 -> 0xfffffffffffffff6
            bash-1168    [001] .....    77.498740: sys_rt_sigreturn()
            bash-1168    [001] .....    77.498765: sys_rt_sigaction(sig: 2, act: 0x7ffef2f08c50, oact: 0x7ffef2f08cf0, sigsetsize: 8)
            bash-1168    [001] .....    77.498770: sys_rt_sigaction -> 0x0
            bash-1168    [001] .....    77.498794: sys_rt_sigprocmask(how: 0, nset: 0, oset: 0x7ffef2f08c70, sigsetsize: 8)
            bash-1168    [001] .....    77.498795: sys_rt_sigprocmask -> 0x0
            bash-1168    [001] .....    77.499055: sys_write(fd: 1, buf: 0x562f0f3aba90 (1b:5d:38:30:30:33:3b:65:6e:64:3d:36:62:62:34:38:38:39:38:2d:32:33:31:33:2d:34:64:38:30:2d:39:30:62:39
:2d:66:33:63:31:36:36:37:62:63:37:37:34:3b:65:78:69:74:3d:73:75:63:63:65:73:73:1b:5c) ".]8003;end=6bb48898-2313-4d80-90b9-f3c1667bc774;exit=success.\", count: 0x3e)
            bash-1168    [001] .l...    77.499099: sys_write -> 0x3e
            bash-1168    [001] .....    77.499196: sys_rt_sigprocmask(how: 0, nset: 0, oset: 0x7ffef2f080c0, sigsetsize: 8)
            bash-1168    [001] .....    77.499198: sys_rt_sigprocmask -> 0x0

[ that lone "l" (el not one) is LAZY_NEED_RESCHED ]

After adding the patch:

            bash-1212    [005] DBZ.f    72.179808: sys_rt_sigprocmask -> 0x0
            bash-1212    [005] DBZ.f    72.179811: sys_ioctl(fd: 0xff, cmd: 0x5401, arg: 0x7ffcaef0e1b0)
            bash-1212    [005] DBZ.f    72.179815: sys_ioctl -> 0x0
            bash-1212    [005] DBZ.f    72.179818: sys_ioctl(fd: 0xff, cmd: 0x5413, arg: 0x7ffcaef0e1c0)
            bash-1212    [005] DBZ.f    72.179823: sys_ioctl -> 0x0
            bash-1212    [005] DBZ.f    72.179862: sys_rt_sigprocmask(how: 2, nset: 0x7ffcaef0e290, oset: 0, sigsetsize: 8)
            bash-1212    [005] DBZ.f    72.179866: sys_rt_sigprocmask -> 0x0
            bash-1212    [005] DBZ.f    72.179884: sys_wait4(upid: 0xffffffffffffffff, stat_addr: 0x7ffcaef0db50, options: 0xb, ru: 0)
            bash-1212    [005] DBZ.f    72.179891: sys_wait4 -> 0xfffffffffffffff6
            bash-1212    [005] DBZ.f    72.179894: sys_rt_sigreturn()


> 
> Perhaps a little bit more constructively, have your conflicting changes
> hit mainline yet?

All my changes have hit mainline.

I believe I did have a solution for fixing the above issue but I was
planning to implement it after the merge window. I can probably do that
today during the keynotes ;-)

-- Steve