Messages in this thread |  | | Date | Wed, 3 Oct 2018 17:57:25 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: Symbols not found for some files |
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Em Wed, Oct 03, 2018 at 10:42:39PM +0200, Paul Menzel escreveu: > Dear Linux folks, > > > For profiling the boot on my Debian Sid/unstable system (32-bit user space), > the following service unit is used.
You forgot to mention what is the version of the perf tool in that system, so that I could check if this got fixed somehow after that version.
Can you please provide it?
Thanks,
- Arnaldo
> ``` > $ systemctl cat perf > # /etc/systemd/system/perf.service > > [Unit] > Description=Perf 10 s > DefaultDependencies=no > > [Service] > ExecStart=/usr/local/bin/perf record -F 999 -g -a -o /dev/shm/perf.data > sleep 10 > > [Install] > WantedBy=sysinit.target > ``` > > Running `perf.data` through `perf script`, the messages below are shown. > > ``` > [vdso] with build id 69dd0f0c522f0d3e2a87722d70245ab9725c8b42 not found, > continuing without symbols > /lib/systemd/libsystemd-shared-239.so with build id > 196c7922a15fa971d68775522dd16e82da46ebb3 not found, continuing without > symbols > /lib/systemd/systemd-journald with build id > 9e31591e8c9bb88de06e96a251f34d8a7e201f6c not found, continuing without > symbols > /lib/systemd/systemd with build id 1b92f342a959b6ff370b82092bfadaf1d470a7b9 > not found, continuing without symbols > /lib/systemd/systemd-networkd with build id > 9fa8f6abc1f2e5c1018d0a33be058c22e25efaff not found, continuing without > symbols > /lib/systemd/systemd-logind with build id > 63d664b5f8f8e85274aff6730ec9e924d74c8fed not found, continuing without > symbols > ``` > > But, the debug symbol packages are installed (`systemd-dbgsym`), and GDB > loads the debug symbols just fine. > > ``` > $ gdb --quiet /lib/systemd/libsystemd-shared-239.so > Reading symbols from /lib/systemd/libsystemd-shared-239.so...Reading symbols > from /usr/lib/debug/.build-id/19/6c7922a15fa971d68775522dd16e82da46ebb3.debug...done. > done. > (gdb) > ``` > > Tracing `perf`, it also seems to find them, but does not use them. > > ``` > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f", > 0xbfbd54ac) = -1 ENOENT (No such file or directory) > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f/elf", > 0xbfbd75bc) = -1 ENOENT (No such file or directory) > stat64("03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", 0xbfbd1bfc) = -1 > ENOENT (No such file or directory) > stat64("/lib/i386-linux-gnu/03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", > 0xbfbd1bfc) = -1 ENOENT (No such file or directory) > stat64("/lib/i386-linux-gnu/.debug/03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", > 0xbfbd1bfc) = -1 ENOENT (No such file or directory) > stat64("/usr/lib/debug/lib/i386-linux-gnu/03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", > 0xbfbd1bfc) = -1 ENOENT (No such file or directory) > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f", > 0xbfbd1b5c) = -1 ENOENT (No such file or directory) > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f/elf", > 0xbfbd3c6c) = -1 ENOENT (No such file or directory) > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f", > 0xbfbd1b5c) = -1 ENOENT (No such file or directory) > stat64("/home/kodi/.debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f/debug", > 0xbfbd3c6c) = -1 ENOENT (No such file or directory) > stat64("/usr/lib/debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", > {st_mode=S_IFREG|0644, st_size=4524336, ...}) = 0 > openat(AT_FDCWD, > "/usr/lib/debug/.build-id/a2/03af6935d5ab00f79fe12b4098d27d3f70c19f.debug", > O_RDONLY|O_LARGEFILE) = 91 > ``` > > Looking into `perf` with GDB, the code in `util/symbol.c` below is not > setting `runtime_ss`, because `symsrc__possibly_runtime(ss)` returns false. > Then the for loop is not quit, and continues. > > ``` > if (!syms_ss && symsrc__has_symtab(ss)) { > syms_ss = ss; > next_slot = true; > if (!dso->symsrc_filename) > dso->symsrc_filename = strdup(name); > } > > if (!runtime_ss && symsrc__possibly_runtime(ss)) { > runtime_ss = ss; > next_slot = true; > } > > if (next_slot) { > ss_pos++; > > if (syms_ss && runtime_ss) > break; > } else { > symsrc__destroy(ss); > } > > ``` > > Do you have an idea, why the files from the systemd Debian package cause > problems for `perf` but not GDB? The Debian maintainers mentioned, that LTO > is enabled for the Debian package. > > Please tell me, if you need other information to look into the problem. > > > Kind regards, > > Paul
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