From: Peter Zijlstra <peterz@infradead.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Leo Yan <leo.yan@linaro.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V4 03/13] kprobes: Add symbols for kprobe insn pages
Date: Tue, 24 Mar 2020 13:31:08 +0100 [thread overview]
Message-ID: <20200324123108.GO20696@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200304090633.420-4-adrian.hunter@intel.com>
On Wed, Mar 04, 2020 at 11:06:23AM +0200, Adrian Hunter wrote:
> Symbols are needed for tools to describe instruction addresses. Pages
> allocated for kprobe's purposes need symbols to be created for them.
> Add such symbols to be visible via /proc/kallsyms.
>
> Note: kprobe insn pages are not used if ftrace is configured. To see the
> effect of this patch, the kernel must be configured with:
>
> # CONFIG_FUNCTION_TRACER is not set
> CONFIG_KPROBES=y
>
> and for optimised kprobes:
>
> CONFIG_OPTPROBES=y
>
> Example on x86:
>
> # perf probe __schedule
> Added new event:
> probe:__schedule (on __schedule)
> # cat /proc/kallsyms | grep '\[__builtin__kprobes\]'
> ffffffffc00d4000 t kprobe_insn_page [__builtin__kprobes]
> ffffffffc00d6000 t kprobe_optinsn_page [__builtin__kprobes]
>
I'm confused; why are you iterating pages and not slots? A 'page' is not
a symbol, they contain text, sometimes.
If you iterate slots you can even get them a proper name; something
like:
optinsn-sym+xxx [__builtin__kprobes]
insn-sym+xxx [__builtin__kprobes]
next prev parent reply other threads:[~2020-03-24 12:31 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 9:06 [PATCH V4 00/13] perf/x86: Add perf text poke events Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 01/13] perf: Add perf text poke event Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 02/13] perf/x86: Add support for perf text poke event for text_poke_bp_batch() callers Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 03/13] kprobes: Add symbols for kprobe insn pages Adrian Hunter
2020-03-05 5:58 ` Masami Hiramatsu
2020-03-05 6:10 ` Alexei Starovoitov
2020-03-05 9:04 ` Masami Hiramatsu
2020-03-24 12:31 ` Peter Zijlstra [this message]
2020-03-24 12:54 ` Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 04/13] kprobes: Add perf ksymbol events " Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 05/13] perf/x86: Add perf text poke events for kprobes Adrian Hunter
2020-03-24 12:21 ` Peter Zijlstra
2020-03-26 1:58 ` Masami Hiramatsu
2020-03-26 7:42 ` Adrian Hunter
2020-03-27 8:36 ` [PATCH V5 " Adrian Hunter
2020-03-31 23:44 ` Masami Hiramatsu
2020-04-01 10:13 ` Peter Zijlstra
2020-03-04 9:06 ` [PATCH V4 06/13] ftrace: Add symbols for ftrace trampolines Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 07/13] ftrace: Add perf ksymbol events " Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 08/13] ftrace: Add perf text poke " Adrian Hunter
2020-04-01 10:09 ` Peter Zijlstra
2020-04-01 10:42 ` Adrian Hunter
2020-04-01 11:14 ` Peter Zijlstra
2020-03-04 9:06 ` [PATCH V4 09/13] perf kcore_copy: Fix module map when there are no modules loaded Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 10/13] perf evlist: Disable 'immediate' events last Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 11/13] perf tools: Add support for PERF_RECORD_TEXT_POKE Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 12/13] perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL Adrian Hunter
2020-03-04 9:06 ` [PATCH V4 13/13] perf intel-pt: Add support for text poke events Adrian Hunter
2020-03-16 7:07 ` [PATCH V4 00/13] perf/x86: Add perf " Adrian Hunter
2020-03-24 9:29 ` Adrian Hunter
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