Messages in this thread | | | Date | Tue, 16 May 2017 11:30:19 -0400 | From | Steven Rostedt <> | Subject | Re: WARNING at arch/x86/kernel/alternative.c:707 text_poke+0x25d/0x270 |
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On Wed, 17 May 2017 00:15:39 +0900 Masami Hiramatsu <mhiramat@kernel.org> wrote:
> > It appears that the kprobe_optimizer work thread call happened after > > the init pages were freed, causing alternative.c to give the above > > warning because the text that is being unoptimized happens to no longer > > exist. > > Ah, I see. I need to check that case. Actually for the module > init text area, kill_kprobe() correctly kicks kill_optimized_kprobe() > so it should safe. But above case is on the init-text in kernel > itself. I guess module_notifier may not be called for that area...
Hmm, what happens if you add a kprobe to a module, remove it, and then remove the module. If the module is still loaded when it is removed, wouldn't that cause the optimized probe to be delayed? Wouldn't that open a race where the optimizer work queue can be called when no module exists?
-- Steve
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