| Date | Mon, 25 Nov 2019 12:32:45 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH -v5 00/17] Rewrite x86/ftrace to use text_poke (and more) |
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On Mon, 25 Nov 2019 12:55:34 +0900 Masami Hiramatsu <mhiramat@kernel.org> wrote:
> void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries) > ... > on_each_cpu(do_sync_core, NULL, 1); > /* > * sync_core() implies an smp_mb() and orders this store against > * the writing of the new instruction. > */ > bp_patching.vec = NULL; > bp_patching.nr_entries = 0; > } > ----- > > I think the "on_each_cpu(do_sync_core, NULL, 1);" can sync the pipeline > but doesn't ensure all ongoing int3 handling is done. Thus, we may need a
How does it not ensure all ongoing int3 handling is done? int3 is done with interrupts disabled, and the on_each_cpu() requires all CPUs to have had their interrupts enabled, thus int3 handling should be completed. Perhaps we need another sync core?
on_each_cpu(do_sync_core, NULL, 1); bp_patching.nr_entries = 0; on_each_cpu(do_sync_core, NULL, 1); bp_patching.vec = NULL;
?
-- Steve
> bigger wait in between bp_patching.nr_entries = 0 and bp_patching.vec = NULL;
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