Re: [PATCH 39/79] libperf: Add perf_evlist__add function

From: Jiri Olsa
Date: Mon Jul 22 2019 - 18:22:18 EST


On Mon, Jul 22, 2019 at 04:09:35PM -0300, Arnaldo Carvalho de Melo wrote:

SNIP

>
> Right after applying this patch my alias for building perf crashes:
>
> I.e. I have:
>
> alias m='perf stat -e cycles:u,instructions:u make -k O=/tmp/build/perf -C tools/perf install-bin'
>
> And I'm applyin your series patch by patch, it stopped working when I
> tried to build the next patch in this series, as the previous one caused
> the segfault below, investigating...
>
> (gdb) run stat sleep 1
> Starting program: /root/bin/perf stat sleep 1
> Missing separate debuginfos, use: dnf debuginfo-install glibc-2.29-15.fc30.x86_64
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib64/libthread_db.so.1".
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x00000000004f6b55 in __perf_evlist__propagate_maps (evlist=0xbb34c0, evsel=0x0) at util/evlist.c:161
> 161 if (!evsel->own_cpus || evlist->has_user_cpus) {
> Missing separate debuginfos, use: dnf debuginfo-install bzip2-libs-1.0.6-29.fc30.x86_64 elfutils-libelf-0.176-3.fc30.x86_64 elfutils-libs-0.176-3.fc30.x86_64 glib2-2.60.4-1.fc30.x86_64 libbabeltrace-1.5.6-2.fc30.x86_64 libgcc-9.1.1-1.fc30.x86_64 libunwind-1.3.1-2.fc30.x86_64 libuuid-2.33.2-1.fc30.x86_64 libxcrypt-4.4.6-2.fc30.x86_64 libzstd-1.4.0-1.fc30.x86_64 numactl-libs-2.0.12-2.fc30.x86_64 pcre-8.43-2.fc30.x86_64 perl-libs-5.28.2-436.fc30.x86_64 popt-1.16-17.fc30.x86_64 python2-libs-2.7.16-2.fc30.x86_64 slang-2.3.2-5.fc30.x86_64 xz-libs-5.2.4-5.fc30.x86_64 zlib-1.2.11-15.fc30.x86_64
> (gdb) p evsel
> $1 = (struct evsel *) 0x0
> (gdb) p evlist
> $2 = (struct evlist *) 0xbb34c0
> (gdb) bt
> #0 0x00000000004f6b55 in __perf_evlist__propagate_maps (evlist=0xbb34c0, evsel=0x0) at util/evlist.c:161
> #1 0x00000000004f6c7a in perf_evlist__propagate_maps (evlist=0xbb34c0) at util/evlist.c:178
> #2 0x00000000004f955e in perf_evlist__set_maps (evlist=0xbb34c0, cpus=0x0, threads=0x0) at util/evlist.c:1128
> #3 0x00000000004f66f8 in evlist__init (evlist=0xbb34c0, cpus=0x0, threads=0x0) at util/evlist.c:52
> #4 0x00000000004f6790 in evlist__new () at util/evlist.c:64
> #5 0x0000000000456071 in cmd_stat (argc=3, argv=0x7fffffffd670) at builtin-stat.c:1705
> #6 0x00000000004dd0fa in run_builtin (p=0xa21e00 <commands+288>, argc=3, argv=0x7fffffffd670) at perf.c:304
> #7 0x00000000004dd367 in handle_internal_command (argc=3, argv=0x7fffffffd670) at perf.c:356
> #8 0x00000000004dd4ae in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:400
> #9 0x00000000004dd81a in main (argc=3, argv=0x7fffffffd670) at perf.c:522
> (gdb)

hum, with the previous fix of yours applied I dont see this crash

jirka