Messages in this thread | | | Date | Tue, 03 Mar 2015 13:11:17 +0900 | From | Masami Hiramatsu <> | Subject | Re: Re: [PATCH perf/core 2/4] perf-probe: Fix to handle aliased symbols in glibc |
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(2015/03/03 12:05), Arnaldo Carvalho de Melo wrote: > Em Mon, Mar 02, 2015 at 11:45:12PM -0300, Arnaldo Carvalho de Melo escreveu: >> Em Tue, Mar 03, 2015 at 11:39:02AM +0900, Masami Hiramatsu escreveu: >>> (2015/03/03 0:46), Arnaldo Carvalho de Melo wrote: >>>> Em Mon, Mar 02, 2015 at 09:49:53PM +0900, Masami Hiramatsu escreveu: >>>>> With this patch; >>>>> ----- >>>>> # ./perf probe -x /usr/lib64/libc-2.17.so -V malloc >>>>> Available variables at malloc >>>>> @<__libc_malloc+0> >>>>> size_t bytes >>>>> # ./perf probe -x /usr/lib64/libc-2.17.so -a "malloc bytes" >>>>> Added new event: >>>>> probe_libc:malloc (on malloc in /usr/lib64/libc-2.17.so with bytes) >>>>> >>>>> You can now use it in all perf tools, such as: >>>>> >>>>> perf record -e probe_libc:malloc -aR sleep 1 >>>> >>>>> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> >>>> >>>> Humm, not working for me, after the patch: >>>> >>>> [root@ssdandy ~]# perf probe -x /usr/lib64/libc-2.17.so -V malloc >>>> Available variables at malloc >>>> @<__malloc_check_init+96> >>>> (No matched variables) >>> >> >> Will try after a 'make build-test' finishes for the current batch >
Thank you for checking this,
> [root@ssdandy ~]# perf probe -vvv -x /usr/lib64/libc-2.17.so -V malloc > probe-definition(0): malloc > symbol:malloc file:(null) line:0 offset:0 return:0 lazy:(null) > 0 arguments > Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.17.so.debug > Searching variables at malloc > Symbol malloc address found : 800c0 > Get 2611 lines from this CU
Hmm, something wrong at here.
> Probe point found: __malloc_check_init+96
This seems that the debuginfo is a bit odd. Could you also run eu-addr2line for 0x800c0 and 0x800b0?
I'm using CentOS7 with a bit newer glibc rpms.
# rpm -q glibc glibc-debuginfo glibc-2.17-55.el7_0.5.x86_64 glibc-debuginfo-2.17-55.el7_0.5.x86_64
And I got following results.
[mhiramat@localhost perf]$ eu-addr2line -fi -e /usr/lib64/libc-2.17.so 0x800c0 __libc_malloc /usr/src/debug/glibc-2.17-c758a686/malloc/malloc.c:2855 [mhiramat@localhost perf]$ eu-addr2line -fi -e /usr/lib64/libc-2.17.so 0x800b0 __malloc_check_init /usr/src/debug/glibc-2.17-c758a686/malloc/hooks.c:75
So, 0x800b0 correctly points __malloc_check_init+96 but its address is not 0x800c0.
Thank you,
> Available variables at malloc > @<__malloc_check_init+96> > (No matched variables) > [root@ssdandy ~]# > > If I add one more 'v' I get the symtabs as read by symbol-elf.c and this is > what is there for the malloc routines:
Yeah, it seems symbol maps works fine. Debuginfo analysis failed.
> > [root@ssdandy ~]# grep malloc /tmp/4 > probe-definition(0): malloc > symbol:malloc file:(null) line:0 offset:0 return:0 lazy:(null) > Searching variables at malloc > symbol__new: ptmalloc_lock_all 0x7b060-0x7b173 > symbol__new: malloc_atfork 0x801c0-0x802dd > symbol__new: ptmalloc_unlock_all2 0x7b180-0x7b21e > symbol__new: ptmalloc_unlock_all 0x7ba90-0x7bb3e > symbol__new: malloc_printerr 0x7bb40-0x7bc28 > symbol__new: malloc_consolidate 0x7c3d0-0x7c9be > symbol__new: _int_malloc 0x7dee0-0x7f32b > symbol__new: malloc_check 0x7f330-0x7f44a > symbol__new: ptmalloc_init.part.8 0x80fe0-0x813d7 > symbol__new: ptmalloc_init 0x813e0-0x813f5 > symbol__new: malloc_hook_ini 0x81400-0x8143c > symbol__new: mallochook 0x82fc0-0x831af > symbol__new: tr_mallochook 0x83fc0-0x8407d > symbol__new: __malloc_set_state 0x814f0-0x819f6 > symbol__new: __malloc_usable_size 0x80d30-0x80e0e > symbol__new: __malloc_trim 0x81d50-0x81fac > symbol__new: __GI___libc_malloc 0x800c0-0x801b5 > symbol__new: __malloc_get_state 0x802e0-0x804db > symbol__new: __malloc_stats 0x820c0-0x822aa > symbol__new: __malloc_check_init 0x80050-0x800bb > symbol__new: __malloc 0x800c0-0x801b5 > symbol__new: malloc_set_state 0x814f0-0x819f6 > symbol__new: malloc 0x800c0-0x801b5 > symbol__new: malloc_info 0x82320-0x8240f > symbol__new: malloc_trim 0x81d50-0x81fac > symbol__new: malloc_usable_size 0x80d30-0x80e0e > symbol__new: malloc_get_state 0x802e0-0x804db > symbol__new: __libc_malloc 0x800c0-0x801b5 > symbol__new: malloc_stats 0x820c0-0x822aa > symbol__new: malloc@plt 0x1f300-0x1f310 > Symbol malloc address found : 800c0 > Probe point found: __malloc_check_init+96 > [root@ssdandy ~]# > >>>> [root@ssdandy ~]# >>>> >>>> And then the one asking for 'bytes' to be collectd fails. >>>> >>>> After processing the other patches I'll try to debug this... >>>> >>>> [root@ssdandy ~]# cat /etc/redhat-release >>>> Red Hat Enterprise Linux Server release 7.0 (Maipo) >>>> [root@ssdandy ~]# rpm -q glibc glibc-debuginfo >>>> glibc-2.17-55.el7_0.3.x86_64 >>>> glibc-debuginfo-2.17-55.el7_0.1.x86_64 >>> ^^^ why is this different from the glibc version?? >>> >>>> [root@ssdandy ~]# >>>> [acme@ssdandy linux]$ readelf -Ws /usr/lib64/libc-2.17.so| grep malloc >>> [...] >>>> 4849: 0000000000080050 107 FUNC LOCAL DEFAULT 12 __malloc_check_init >>> >>> __malloc_check_init+96(0x60) becomes 0x80050 + 0x60 = 0x800b0 >>> >>>> 5351: 00000000000800c0 245 FUNC LOCAL DEFAULT 12 __malloc >>>> 1170: 00000000000800c0 245 FUNC GLOBAL DEFAULT 12 malloc@@GLIBC_2.2.5 >>> >>> that is not 0x800c0, so something goes wrong when translating the address >>> to probe point. Could you check the patch 1/4 was applied? >>> Actually there is a bug in the routine which gets the probe point from >>> address. 1/4 fixes it. >> >> This one? >> >> commit 0104fe69e0287cf3635657b4c6b26a18e0091697 >> Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> >> Date: Mon Mar 2 21:49:46 2015 +0900 >> >> perf probe: Remove bias offset to find probe point by address >> >> Remove bias offset to find probe point by address. >> >> ---------------- >> >> Yes, it is applied. >> >> - Arnaldo > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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