Re: perf buildild-list -H dumps core

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Mon, Oct 16, 2017 at 08:52:27AM +0200, Thomas-Mich Richter wrote:
> On 10/13/2017 04:48 PM, Arnaldo Carvalho de Melo wrote:
> 
> Here is the load of perf using gdb:
> 
>  
> 
> [root@s35lp76 core-dump-buildid]# gdb ~/linux/tools/perf/perf
> GNU gdb (GDB) Fedora 7.12.1-48.fc25
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> Reading symbols from /root/linux/tools/perf/perf...done.
> 
> 
> 
> This is the command:
> (gdb) r buildid-list -H 
> Starting program: /root/linux/tools/perf/perf buildid-list -H
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib64/libthread_db.so.1".
> Detaching after fork from child process 249033.
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000000000000000 in ?? ()
> Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x
> (gdb) where
> #0  0x0000000000000000 in ?? ()
> #1  0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18, 
>     evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888, 
>     tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287
> #2  0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>, 
>     sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340
> #3  perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470, 
>     file_offset=file_offset@entry=1136) at util/session.c:1522
> #4  0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>, 
>     data_offset=<optimized out>, session=0x0) at util/session.c:1899
> #5  perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953
> #6  0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>)
>     at builtin-buildid-list.c:83
> #7  cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115
> #8  0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0)
>     at perf.c:296
> #9  0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348
> #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392
> #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536
> (gdb) 

Looks like due to a NULL namespace event handler.  Does patch below
fix it?

Thanks,
Namhyung


diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index ceac0848469d..b3fd62f7e4c9 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -374,6 +374,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
                tool->mmap2 = process_event_stub;
        if (tool->comm == NULL)
                tool->comm = process_event_stub;
+       if (tool->namespaces == NULL)
+               tool->namespaces = process_event_stub;
        if (tool->fork == NULL)
                tool->fork = process_event_stub;
        if (tool->exit == NULL)