Em Thu, Dec 10, 2015 at 05:54:03PM -0500, William Cohen escreveu: > I have noticed that with the 4.4.0 kernels "perf list" has been > segfaulting on both aarch64 and x86_64. Below is the failure on > fedora rawhide running on x86_64:
Ok, this was fixed, but just on the perf/core branch: "perf list: Add support for PERF_COUNT_SW_BPF_OUT" https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/tools/perf/util/parse-events.c?h=perf/core&id=bae9cc41105b9edd74d68a9636be2ba240e74b9e And then this one on top to avoid such things in the future: "perf list: Robustify event printing routine" https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/tools/perf/util/parse-events.c?h=perf/core&id=e37df6c76cb19971f1228bfaff504d8a3ea6f748 I'll cherry-pick those and push to Ingo. Thanks for the report! - Arnaldo > [wcohen@localhost ~]$ rpm -q perf > perf-4.4.0-0.rc4.git0.1.fc24.x86_64 > [wcohen@localhost ~]$ gdb /bin/perf ./core.2110 > GNU gdb (GDB) Fedora 7.10.50.20151113-33.fc24 > Copyright (C) 2015 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-redhat-linux-gnu". > Type "show configuration" for configuration details. > For bug reporting instructions, please see: > <http://www.gnu.org/software/gdb/bugs/>. > Find the GDB manual and other documentation resources online at: > <http://www.gnu.org/software/gdb/documentation/>. > For help, type "help". > Type "apropos word" to search for commands related to "word"... > Reading symbols from /bin/perf...Reading symbols from > /usr/lib/debug/usr/bin/perf.debug...done. > done. > [New LWP 2110] > [Thread debugging using libthread_db enabled] > Using host libthread_db library "/lib64/libthread_db.so.1". > Core was generated by `perf list'. > Program terminated with signal SIGSEGV, Segmentation fault. > #0 0x000055b1fc97fdce in print_symbol_events (type=<optimized out>, > syms=0x55b1fcd81580 <event_symbols_sw+160>, max=<optimized out>, > name_only=<optimized out>, event_glob=<optimized out>) > at util/parse-events.c:1895 > 1895 if (!name_only && strlen(syms->alias)) > Missing separate debuginfos, use: dnf debuginfo-install > bzip2-libs-1.0.6-19.fc24.x86_64 nss-softokn-freebl-3.21.0-3.fc24.x86_64 > (gdb) where > #0 0x000055b1fc97fdce in print_symbol_events (type=<optimized out>, > syms=0x55b1fcd81580 <event_symbols_sw+160>, max=<optimized out>, > name_only=<optimized out>, event_glob=<optimized out>) > at util/parse-events.c:1895 > #1 print_events (event_glob=event_glob@entry=0x0, name_only=false) > at util/parse-events.c:1943 > #2 0x000055b1fc90a63e in cmd_list (argc=0, argv=0x7ffde1523f80, > prefix=<optimized out>) at builtin-list.c:43 > #3 0x000055b1fc95c413 in run_builtin (p=0x55b1fcd803d8 <commands+120>, > argc=1, argv=0x7ffde1523f80) at perf.c:386 > #4 0x000055b1fc8fe308 in handle_internal_command (argv=0x7ffde1523f80, > argc=1) > at perf.c:447 > #5 run_argv (argv=0x7ffde1523d10, argcp=0x7ffde1523d1c) at perf.c:491 > #6 main (argc=1, argv=0x7ffde1523f80) at perf.c:608 > (gdb) > > > I did a git bisect on the kernel source code to find out when "perf list" > broke and the git bisect pointed to the following commit causing the problem: > > # git bisect good > a43eec304259a6c637f4014a6d4767159b6a3aa3 is the first bad commit > commit a43eec304259a6c637f4014a6d4767159b6a3aa3 > Author: Alexei Starovoitov <a...@plumgrid.com> > Date: Tue Oct 20 20:02:34 2015 -0700 > > bpf: introduce bpf_perf_event_output() helper > > This helper is used to send raw data from eBPF program into > special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event. > User space needs to perf_event_open() it (either for one or all cpus) and > store FD into perf_event_array (similar to bpf_perf_event_read() helper) > before eBPF program can send data into it. > > Today the programs triggered by kprobe collect the data and either store > it into the maps or print it via bpf_trace_printk() where latter is the > debug > facility and not suitable to stream the data. This new helper replaces > such bpf_trace_printk() usage and allows programs to have dedicated > channel into user space for post-processing of the raw data collected. > > Signed-off-by: Alexei Starovoitov <a...@kernel.org> > Signed-off-by: David S. Miller <da...@davemloft.net> > > :040000 040000 322abd03170df11e43da73d3fa4f74f1826788e9 > 14f3ee14b7fb4b6c76daf18e026cf67acd3154fa M include > :040000 040000 f84baec2884fe97ec501ae8d45bbb8a7aad3a578 > ea440aeb13f1dd25aa8f2e1dadfc32dbf4b3d2b3 M kernel > > > -Will > -- > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
