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authorHe Kuang <hekuang@huawei.com>2015-06-18 02:49:10 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-06-23 18:21:44 -0300
commit7c31bb8c95ed269062ff7c7cc4a28b84a2b0f3a6 (patch)
tree3fca3f14138d9a2ddcd2920cdc947c241ada4938 /tools
parentfe692ac86adbbbbf9745909aafe0c87fd7fc6368 (diff)
downloadop-kernel-dev-7c31bb8c95ed269062ff7c7cc4a28b84a2b0f3a6.zip
op-kernel-dev-7c31bb8c95ed269062ff7c7cc4a28b84a2b0f3a6.tar.gz
perf probe: Fix failure to probe events on arm
Fix failure to probe events on arm, the problem was introduced by commit 5a51fcd1f30c ("perf probe: Skip kernel symbols which is out of .text"). For some architectures, the '_etext' label is not in the .text section (in the .notes section for arm/arm64). Labels out of the .text section are not loaded as symbols and we get a zero value when looking up its addresses, which causes all events to be wrongly skipped. This patch skips checking the text address range when failing to get the address of '_etext' and thus fixes the problem. The problem can be reproduced on arm as follows: # perf probe --add='generic_perform_write' generic_perform_write+0 is out of .text, skip it. Probe point 'generic_perform_write' not found. Error: Failed to add events. After this patch: # perf probe --add='generic_perform_write' Added new event: probe:generic_perform_write (on generic_perform_write) You can now use it in all perf tools, such as: perf record -e probe:generic_perform_write -aR sleep 1 Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1434595750-129791-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/probe-event.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 076527b..381f23a 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -249,8 +249,12 @@ 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;
+
/* Get the address of _etext for checking non-probable text symbol */
- if (kernel_get_symbol_address_by_name("_etext", false) < address)
+ etext_addr = kernel_get_symbol_address_by_name("_etext", false);
+
+ if (etext_addr != 0 && etext_addr < address)
pr_warning("%s is out of .text, skip it.\n", symbol);
else if (kprobe_blacklist__listed(address))
pr_warning("%s is blacklisted function, skip it.\n", symbol);
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