From mboxrd@z Thu Jan 1 00:00:00 1970 From: john.garry@huawei.com (John Garry) Date: Tue, 2 Oct 2018 11:20:46 +0100 Subject: perf segmentation fault from NULL dereference In-Reply-To: <20180927030035.GF28040@tassilo.jf.intel.com> References: <712b7c31-f681-7737-71e7-c028b8d2bba5@huawei.com> <20180927030035.GF28040@tassilo.jf.intel.com> Message-ID: <334a114a-bb59-9582-a913-efbb01bd68c5@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 27/09/2018 04:00, Andi Kleen wrote: >> Please me let me know if a valid issue so we can get a fix in. > > If it crashes it must be a valid issue of course. > > But I'm not sure about your bisect. Hard to see how my patch > could cause this. Sometimes bisects go wrong. > You verified by just reverting the patch? It no longer reverts cleanly. And the previous patch - 4ca69ca9db3a - did not have this crash: root at localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (6 samples) ] root at localhost:~# > > First thing I would also try is to run with valgrind or ASan and see if it > reports anything. Here's the valgrind output: root at localhost:~#valgrind --leak-check=yes ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1 ==16025== Memcheck, a memory error detector ==16025== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==16025== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info ==16025== Command: ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1 ==16025== --16025-- WARNING: unhandled arm64-linux syscall: 168 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error 38 (Function not implemented) --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. perf_event_open(..., 0) failed unexpectedly with error 38 (Function not implemented) --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. --16025-- WARNING: unhandled arm64-linux syscall: 241 --16025-- You may be able to write your own handler. --16025-- Read the file README_MISSING_SYSCALL_OR_IOCTL. --16025-- Nevertheless we consider this a bug. Please report --16025-- it at http://valgrind.org/support/bug_reports.html. Error: The sys_perf_event_open() syscall returned with 38 (Function not implemented) for event (armv8_pmuv3_0/br_mis_pred/). /bin/dmesg | grep -i perf may provide additional information. ==16059== ==16059== Process terminating with default action of signal 15 (SIGTERM) ==16059== at 0x486F974: __read_nocancel (syscall-template.S:84) ==16059== by 0x48D02F: read (unistd.h:44) ==16059== by 0x48D02F: perf_evlist__prepare_workload (evlist.c:1471) ==16059== by 0x41AB0F: __cmd_record (builtin-record.c:898) ==16059== by 0x41AB0F: cmd_record (builtin-record.c:1873) ==16059== by 0x476C7F: run_builtin (perf.c:302) ==16059== by 0x476F37: handle_internal_command (perf.c:354) ==16059== by 0x407093: run_argv (perf.c:398) ==16059== by 0x407093: main (perf.c:520) ==16059== ==16059== HEAP SUMMARY: ==16059== in use at exit: 56,239 bytes in 226 blocks ==16059== total heap usage: 1,164 allocs, 938 frees, 2,238,979 bytes allocated ==16059== ==16059== 12 bytes in 1 blocks are definitely lost in loss record 1 of 6 ==16059== at 0x4844B88: malloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16059== ==16059== 344 bytes in 5 blocks are possibly lost in loss record 3 of 6 ==16059== at 0x4846CFC: calloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16059== ==16059== 5,736 bytes in 125 blocks are possibly lost in loss record 4 of 6 ==16059== at 0x4844B88: malloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16059== ==16059== LEAK SUMMARY: ==16059== definitely lost: 12 bytes in 1 blocks ==16059== indirectly lost: 0 bytes in 0 blocks ==16059== possibly lost: 6,080 bytes in 130 blocks ==16059== still reachable: 50,147 bytes in 95 blocks ==16059== suppressed: 0 bytes in 0 blocks ==16059== Reachable blocks (those to which a pointer was found) are not shown. ==16059== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==16059== ==16059== For counts of detected and suppressed errors, rerun with: -v ==16059== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0) ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== Warning: invalid file descriptor -1 in syscall close() ==16025== ==16025== HEAP SUMMARY: ==16025== in use at exit: 26,640 bytes in 209 blocks ==16025== total heap usage: 1,202 allocs, 993 frees, 2,455,112 bytes allocated ==16025== ==16025== 328 bytes in 7 blocks are definitely lost in loss record 2 of 6 ==16025== at 0x4844B88: malloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16025== ==16025== 344 bytes in 5 blocks are possibly lost in loss record 3 of 6 ==16025== at 0x4846CFC: calloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16025== ==16025== 6,000 bytes in 126 blocks are possibly lost in loss record 5 of 6 ==16025== at 0x4844B88: malloc (in /usr/lib/valgrind/vgpreload_memcheck-arm64-linux.so) ==16025== ==16025== LEAK SUMMARY: ==16025== definitely lost: 328 bytes in 7 blocks ==16025== indirectly lost: 0 bytes in 0 blocks ==16025== possibly lost: 6,344 bytes in 131 blocks ==16025== still reachable: 19,968 bytes in 71 blocks ==16025== suppressed: 0 bytes in 0 blocks ==16025== Reachable blocks (those to which a pointer was found) are not shown. ==16025== To see them, rerun with: --leak-check=full --show-leak-kinds=all ==16025== ==16025== For counts of detected and suppressed errors, rerun with: -v ==16025== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0) root at localhost:~# (pretty much the same as previous patch) Cheers, John > > -Andi > > . >