Messages in this thread | | | From | Song Shuai <> | Date | Tue, 22 Nov 2022 02:37:37 +0000 | Subject | Re: [PATCH] ftrace: avoid replacing the list func with itself |
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Steven Rostedt <rostedt@goodmis.org> 于2022年11月22日周二 02:34写道: > > On Tue, 22 Nov 2022 02:28:25 +0000 > Song Shuai <suagrfillet@gmail.com> wrote: > > > Song Shuai <suagrfillet@gmail.com> 于2022年10月26日周三 13:20写道: > > > > > > The list func (ftrace_ops_list_func) will be patched first > > > before the transition between old and new calls are set, > > > which fixed the race described in this commit `59338f75`. > > > > > > While ftrace_trace_function changes from the list func to a > > > ftrace_ops func, like unregistering the klp_ops to leave the only > > > global_ops in ftrace_ops_list, the ftrace_[regs]_call will be > > > replaced with the list func although it already exists. So there > > > should be a condition to avoid this. > > > > > > This patch backups saved_ftrace_func by saved_ftrace_func_old > > > which will be compared with the list func before trying to patch it. > > > > > Ping... > > Thanks for the ping. I had thought I had replied to this, but I don't > see it in my sent folder. I may have been distracted, and lost the > message. > > I'll take a look at it tomorrow. > > -- Steve No problem, thanks!
-- Song
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