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From: Ananth N M. <an...@in...> - 2009-06-05 08:36:21
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On Mon, Jun 01, 2009 at 08:37:54PM -0400, Masami Hiramatsu wrote: > Add kprobes-based event tracer on ftrace. > > This tracer is similar to the events tracer which is based on Tracepoint > infrastructure. Instead of Tracepoint, this tracer is based on kprobes(kprobe > and kretprobe). It probes anywhere where kprobes can probe(this means, all > functions body except for __kprobes functions). > > Similar to the events tracer, this tracer doesn't need to be activated via > current_tracer, instead of that, just set probe points via > /sys/kernel/debug/tracing/kprobe_events. And you can set filters on each > probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter. > > This tracer supports following probe arguments for each probe. > > %REG : Fetch register REG > sN : Fetch Nth entry of stack (N >= 0) > @ADDR : Fetch memory at ADDR (ADDR should be in kernel) > @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol) > aN : Fetch function argument. (N >= 0) > rv : Fetch return value. > ra : Fetch return address. > +|-offs(FETCHARG) : fetch memory at FETCHARG +|- offs address. > > See Documentation/trace/kprobes.txt for details. > > Changes from v8: > - Fix wrong argument offsets in format. > - Remove EVENT_TRACING selection in Kconfig. > - Fix debugfs file path. > > Signed-off-by: Masami Hiramatsu <mhi...@re...> > Cc: Christoph Hellwig <hc...@in...> > Cc: Steven Rostedt <ro...@go...> > Cc: Ananth N Mavinakayanahalli <an...@in...> > Cc: Ingo Molnar <mi...@el...> > Cc: Frederic Weisbecker <fwe...@gm...> > Cc: Tom Zanussi <tza...@gm...> The kprobe usage look fine. Tested on x86 and works fine too! Great work, Masami. Acked-by: Ananth N Mavinakayanahalli <an...@in...> |