perf symbol: Fail to read phdr workaround
The perf jvmti agent doesn't create program headers, in this case fallback on section headers as happened previously. Committer notes: To test this, from a public post by Ian: 1) download a Java workload dacapo-9.12-MR1-bach.jar from https://sourceforge.net/projects/dacapobench/ 2) build perf such as "make -C tools/perf O=/tmp/perf NO_LIBBFD=1" it should detect Java and create /tmp/perf/libperf-jvmti.so 3) run perf with the jvmti agent: perf record -k 1 java -agentpath:/tmp/perf/libperf-jvmti.so -jar dacapo-9.12-MR1-bach.jar -n 10 fop 4) run perf inject: perf inject -i perf.data -o perf-injected.data -j 5) run perf report perf report -i perf-injected.data | grep org.apache.fop With this patch reverted I see lots of symbols like: 0.00% java jitted-388040-4656.so [.] org.apache.fop.fo.FObj.bind(org.apache.fop.fo.PropertyList) With the patch (2d86612a ("perf symbol: Correct address for bss symbols")) I see lots of: dso__load_sym_internal: failed to find program header for symbol: Lorg/apache/fop/fo/FObj;bind(Lorg/apache/fop/fo/PropertyList;)V st_value: 0x40 Fixes: 2d86612a ("perf symbol: Correct address for bss symbols") Reviewed-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: Leo Yan <leo.yan@linaro.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20220731164923.691193-1-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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