diff options
author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-04-23 14:01:13 +0300 |
---|---|---|
committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-05-28 16:03:24 +0300 |
commit | 2ae5d0d7d8868df7c05c2013c0b9cddd4d40610e (patch) | |
tree | 52bc911d4f53f60619bd074c5c76be9588dbd321 /tools/perf/util/probe-event.c | |
parent | 80526491c2ca6abc028c0f0dbb0707a1f35fb18a (diff) | |
download | linux-2ae5d0d7d8868df7c05c2013c0b9cddd4d40610e.tar.xz |
perf probe: Check address correctness by map instead of _etext
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>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158763967332.30755.4922496724365529088.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/probe-event.c')
-rw-r--r-- | tools/perf/util/probe-event.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 63d936f6e993..a08f373d3305 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; } /* |