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Adrian Hunter
de19e5c3c5
trigger_on() means that the trigger is available but not ready, however
trigger_on() was making it ready. That can segfault if the signal comes
before trigger_ready(). e.g. (USR2 signal delivery not shown)
$ perf record -e intel_pt//u -S sleep 1
perf: Segmentation fault
Obtained 16 stack frames.
/home/ahunter/bin/perf(sighandler_dump_stack+0x40) [0x4ec550]
/lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
/home/ahunter/bin/perf(perf_evsel__disable+0x26) [0x4b9dd6]
/home/ahunter/bin/perf() [0x43a45b]
/lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
/lib/x86_64-linux-gnu/libc.so.6(__xstat64+0x15) [0x7fa7641d2cc5]
/home/ahunter/bin/perf() [0x4ec6c9]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4eca15]
/home/ahunter/bin/perf(machine__create_kernel_maps+0x257) [0x4f0b77]
/home/ahunter/bin/perf(perf_session__new+0xc0) [0x4f86f0]
/home/ahunter/bin/perf(cmd_record+0x722) [0x43c132]
/home/ahunter/bin/perf() [0x4a11ae]
/home/ahunter/bin/perf(main+0x5d4) [0x427fb4]
Note, for testing purposes, this is hard to hit unless you add some sleep()
in builtin-record.c before record__open().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: stable@vger.kernel.org
Fixes: 3dcc4436fa ("perf tools: Introduce trigger class")
Link: http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.