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Andi Kleen
5d1dc10ba3
[ Upstream commit 96167167b6 ]
'perf script' crashes currently when printing mixed trace points and
other events because the trace format does not handle events without
trace meta data. Add a simple check to avoid that.
% cat > test.c
main()
{
printf("Hello world\n");
}
^D
% gcc -g -o test test.c
% sudo perf probe -x test 'test.c:3'
% perf record -e '{cpu/cpu-cycles,period=10000/,probe_test:main}:S' ./test
% perf script
<segfault>
Committer testing:
Before:
# perf probe -x /lib64/libc-2.28.so malloc
Added new event:
probe_libc:malloc (on malloc in /usr/lib64/libc-2.28.so)
You can now use it in all perf tools, such as:
perf record -e probe_libc:malloc -aR sleep 1
# perf probe -l
probe_libc:malloc (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.28.so)
# perf record -e '{cpu/cpu-cycles,period=10000/,probe_libc:*}:S' sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.023 MB perf.data (40 samples) ]
# perf script
Segmentation fault (core dumped)
^C
#
After:
# perf script | head -6
sleep 2888 94796.944981: 16198 cpu/cpu-cycles,period=10000/: ffffffff925dc04f get_random_u32+0x1f (/lib/modules/5.0.0-rc2+/build/vmlinux)
sleep 2888 [-01] 94796.944981: probe_libc:malloc:
sleep 2888 94796.944983: 4713 cpu/cpu-cycles,period=10000/: ffffffff922763af change_protection+0xcf (/lib/modules/5.0.0-rc2+/build/vmlinux)
sleep 2888 [-01] 94796.944983: probe_libc:malloc:
sleep 2888 94796.944986: 9934 cpu/cpu-cycles,period=10000/: ffffffff922777e0 move_page_tables+0x0 (/lib/modules/5.0.0-rc2+/build/vmlinux)
sleep 2888 [-01] 94796.944986: probe_libc:malloc:
#
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190117194834.21940-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
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.