perf symbols: Take into account symfs setting when reading file build ID
After commit 5baecbcd ("perf symbols: we can now read separate debug-info files based on a build ID") and when --symfs option is used perf failed to pick up symbols for file with the same name between host and sysroot specified by --symfs option. One can see message like this: bin/bash with build id 26f0062cb6950d4d1ab0fd9c43eae8b10ca42062 not found, continuing without symbols It happens because code added by 5baecbcd opens files directly by dso->long_name without symbol_conf.symfs consideration, which as result picks one from the host. It reads its build ID and later even code finds another proper file in directory pointed by --symfs perf ignores it because build id mismatches. Fix is to use __symbol__join_symfs to adjust file name according to --symfs setting. If no --symfs passed the operation would noop and picks the same host file as before. Also note in latter tree after 5baecbcd commit additional check for '!dso->has_build_id' was added, so to observe error condition 'perf record' should run with --no-buildid, so perf.data itself would not have build id for target binary in buildid perf section and 'perf report' will pass '!dso->has_build_id' condition. Or target binary should not have build id, but the same binary on host has build id, again '!dso->has_build_id' will pass in this case and incorrect build id could be read if --symfs is used. Signed-off-by: Victor Kamensky <kamensky@cisco.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Chris Phlipot <cphlipot0@gmail.com> Cc: Dima Kogan <dima@secretsauce.net> Cc: He Kuang <hekuang@huawei.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: xe-linux-external@cisco.com Fixes: 5baecbcd ("perf symbols: we can now read separate debug-info files based on a build ID") Link: http://lkml.kernel.org/r/1486424908-17094-1-git-send-email-kamensky@cisco.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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