9b20065351
After commit 5baecbcd9c9a ("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 5baecbcd9c9a 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 5baecbcd9c9a 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: 5baecbcd9c9a ("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.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.