From: Masami Hiramatsu <mhiramat@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
stable@vger.kernel.org
Subject: [PATCH 2/3] perf-probe: Check address correctness by map instead of _etext
Date: Thu, 23 Apr 2020 20:01:13 +0900 [thread overview]
Message-ID: <158763967332.30755.4922496724365529088.stgit@devnote2> (raw)
In-Reply-To: <158763965400.30755.14484569071233923742.stgit@devnote2>
Since commit 03db8b583d1c ("perf tools: Fix maps__find_symbol_by_name()")
introduced map address range check in maps__find_symbol_by_name(),
we can not get "_etext" from kernel map because _etext is placed
on the edge of the kernel .text section (= kernel map in perf.)
To fix this issue, this checks the address correctness
by map address range information (map->start and map->end)
instead of using _etext address.
This can cause an error if the target inlined function is
embedded in both __init function and normal function.
For exaample, request_resource() is a normal function but also
embedded in __init reserve_setup(). In this case, the probe point
in reserve_setup() must be skipped. However, without this fix,
it failes to setup all probe points.
================
# ./perf probe -v request_resource
probe-definition(0): request_resource
symbol:request_resource file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/lib/modules/5.5.17-200.fc31.x86_64/vmlinux for symbols
Open Debuginfo file: /usr/lib/debug/lib/modules/5.5.17-200.fc31.x86_64/vmlinux
Try to find probe point from debuginfo.
Matched function: request_resource [15e29ad]
found inline addr: 0xffffffff82fbf892
Probe point found: reserve_setup+204
found inline addr: 0xffffffff810e9790
Probe point found: request_resource+0
Found 2 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Opening /sys/kernel/debug/tracing//README write=0
Writing event: p:probe/request_resource _text+33290386
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
================
With this fix,
================
# ./perf probe request_resource
reserve_setup is out of .text, skip it.
Added new events:
(null):(null) (on request_resource)
probe:request_resource (on request_resource)
You can now use it in all perf tools, such as:
perf record -e probe:request_resource -aR sleep 1
================
Fixes: 03db8b583d1c ("perf tools: Fix maps__find_symbol_by_name()")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
---
tools/perf/util/probe-event.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f75df63309be..a5387e03e365 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -236,21 +236,22 @@ static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
static bool kprobe_blacklist__listed(unsigned long address);
static bool kprobe_warn_out_range(const char *symbol, unsigned long address)
{
- u64 etext_addr = 0;
- int ret;
-
- /* Get the address of _etext for checking non-probable text symbol */
- ret = kernel_get_symbol_address_by_name("_etext", &etext_addr,
- false, false);
+ struct map *map;
+ bool ret = false;
- if (ret == 0 && etext_addr < address)
- pr_warning("%s is out of .text, skip it.\n", symbol);
- else if (kprobe_blacklist__listed(address))
+ map = kernel_get_module_map(NULL);
+ if (map) {
+ ret = address <= map->start || map->end < address;
+ if (ret)
+ pr_warning("%s is out of .text, skip it.\n", symbol);
+ map__put(map);
+ }
+ if (!ret && kprobe_blacklist__listed(address)) {
pr_warning("%s is blacklisted function, skip it.\n", symbol);
- else
- return false;
+ ret = true;
+ }
- return true;
+ return ret;
}
/*
next prev parent reply other threads:[~2020-04-23 11:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 11:00 [PATCH 0/3] perf-probe: Fix __init function and blacklist checking Masami Hiramatsu
2020-04-23 11:01 ` [PATCH 1/3] perf-probe: Fix to check blacklist address correctly Masami Hiramatsu
2020-05-06 16:44 ` Arnaldo Carvalho de Melo
2020-04-23 11:01 ` Masami Hiramatsu [this message]
2020-04-23 14:01 ` [PATCH 2/3] perf-probe: Check address correctness by map instead of _etext Arnaldo Carvalho de Melo
2020-04-23 11:01 ` [PATCH 3/3] perf-probe: Do not show the skipped events Masami Hiramatsu
2020-04-23 14:01 ` Arnaldo Carvalho de Melo
2020-04-23 23:33 ` Masami Hiramatsu
2020-04-24 13:08 ` Arnaldo Carvalho de Melo
2020-05-06 16:48 ` [PATCH 0/3] perf-probe: Fix __init function and blacklist checking Arnaldo Carvalho de Melo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=158763967332.30755.4922496724365529088.stgit@devnote2 \
--to=mhiramat@kernel.org \
--cc=acme@kernel.org \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=namhyung@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).