On Intel test case trace+probe_libc_inet_pton.sh succeeds and the
output is:
[root@f27 perf]# ./perf trace --no-syscalls
-e probe_libc:inet_pton/max-stack=3/ ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.037 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.037/0.037/0.037/0.000 ms
0.000 probe_libc:inet_pton:(7fa40ac618a0))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
getaddrinfo (/usr/lib64/libc-2.26.so)
main (/usr/bin/ping)
The kernel stack unwinder is used, it is specified implicitly
as call-graph=fp (frame pointer).
On s390x only dwarf is available for stack unwinding. It is also
done in user space. This requires different parameter setup
and result checking for s390x and Intel.
This patch adds separate perf trace setup and result checking
for Intel and s390x. On s390x specify this command line to
get a call-graph and handle the different call graph result
checking:
[root@s35lp76 perf]# ./perf trace --no-syscalls
-e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.041 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.041/0.041/0.041/0.000 ms
0.000 probe_libc:inet_pton:(3ffb9942060))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
gaih_inet (inlined)
__GI_getaddrinfo (inlined)
main (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
_start (/usr/bin/ping)
[root@s35lp76 perf]#
Before:
[root@s8360047 perf]# ./perf test -vv 58
58: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 26349
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.079 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.079/0.079/0.079/0.000 ms
0.000 probe_libc:inet_pton:(3ff925c2060))
test child finished with -1
---- end ----
probe libc's inet_pton & backtrace it with ping: FAILED!
[root@s8360047 perf]#
After:
[root@s35lp76 perf]# ./perf test -vv 57
57: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 38708
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.038 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.038/0.038/0.038/0.000 ms
0.000 probe_libc:inet_pton:(3ff87342060))
__GI___inet_pton (/usr/lib64/libc-2.26.so)
gaih_inet (inlined)
__GI_getaddrinfo (inlined)
main (/usr/bin/ping)
__libc_start_main (/usr/lib64/libc-2.26.so)
_start (/usr/bin/ping)
test child finished with 0
---- end ----
probe libc's inet_pton & backtrace it with ping: Ok
[root@s35lp76 perf]#
On Intel the test case runs unchanged and succeeds.
Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180117083831.101001-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'perf test' case "probe libc's inet_pton & backtrace it with ping"
fails on s390x. The reason is the 'realpath /lib64/ld*.so.* | uniq' line
which returns 2 libraries:
root@s35lp76 shell]# realpath /lib64/ld*.so.* | uniq
/usr/lib64/ld-2.26.so
/usr/lib64/ld_pre_smc.so.1.0.1
[root@s35lp76 shell]
This output makes the "perf probe" command lines invalid.
Use ldd tool to find out the libraries required by "bash" and check if
symbol "inet_pton" is part of the "libc" library. Some distros do not
have a /lib64 directory.
I have also added a check for the existence of an IPv6 network interface
before it is being used.
Committer changes:
We can't really use ldd for libc, as in some systems, such as x86_64, it
has hardlinks and then ldd sees one and the kernel the other, so grep
for libc in /proc/self/maps to get the one we'll receive from
PERF_RECORD_MMAP.
Thomas checked this change and acked it.
Signed-off-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Suggested-by: Hendrik Brückner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brückner <brueckner@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20171114133409.GN8836@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In debian/ubuntu, libc.so is located at a different place,
/lib/x86_64-linux-gnu/libc-2.23.so, so it outputs like this when testing:
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.040 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.040/0.040/0.040/0.000 ms
0.000 probe_libc:inet_pton:(7f0e2db741c0))
__GI___inet_pton (/lib/x86_64-linux-gnu/libc-2.23.so)
getaddrinfo (/lib/x86_64-linux-gnu/libc-2.23.so)
[0xffffa9d40f34ff4d] (/bin/ping)
Fix up the libc path to make sure this test works in more OSes.
Committer testing:
When this test fails one can use 'perf test -v', i.e. in verbose mode, where
it'll show the expected backtrace, so, after applying this test:
On Fedora 26:
# perf test -v ping
62: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 23322
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.058 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.058/0.058/0.058/0.000 ms
0.000 probe_libc:inet_pton:(7fe344310d80))
__GI___inet_pton (/usr/lib64/libc-2.25.so)
getaddrinfo (/usr/lib64/libc-2.25.so)
_init (/usr/bin/ping)
test child finished with 0
---- end ----
probe libc's inet_pton & backtrace it with ping: Ok
#
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Li Zhijian <lizhijian@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philip Li <philip.li@intel.com>
Link: http://lkml.kernel.org/r/1508315649-18836-1-git-send-email-lizhijian@cn.fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a library function that checks if 'perf probe' is built into the
tool being tested, skipping tests that need it.
Testing it on a system after removing the library needed to build
'probe' as a perf subcommand:
# perf test ping vfs_getname
59: Use vfs_getname probe to get syscall args filenames : Skip
60: probe libc's inet_pton & backtrace it with ping : Skip
61: Check open filename arg using perf trace + vfs_getname: Skip
62: Add vfs_getname probe to get syscall args filenames : Skip
# perf probe
perf: 'probe' is not a perf-command. See 'perf --help'.
#
Now reinstalling elfutils-libelf-devel on this Fedora 26 system to
rebuild perf and then retest this:
# perf test ping vfs_getname
60: Use vfs_getname probe to get syscall args filenames : Ok
61: probe libc's inet_pton & backtrace it with ping : Ok
62: Check open filename arg using perf trace + vfs_getname: Ok
63: Add vfs_getname probe to get syscall args filenames : Ok
#
Reported-by: Kim Phillips <kim.phillips@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ctdck2gzsskqhjzu3ebb62zm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Installs a probe on libc's inet_pton function, that will use uprobes,
then use 'perf trace' on a ping to localhost asking for just one packet
with the a backtrace 3 levels deep, check that it is what we expect.
This needs no debuginfo package, all is done using the libc ELF symtab
and the CFI info in the binaries.
Testing it:
# perf test ping
61: probe libc's inet_pton & backtrace it with ping : Ok
In verbose mode:
# perf test -v ping
61: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 1007
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.058 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.058/0.058/0.058/0.000 ms
0.000 probe_libc:inet_pton:(7f75fce12a20))
__GI___inet_pton (/usr/lib64/libc-2.24.so)
getaddrinfo (/usr/lib64/libc-2.24.so)
_init (/usr/bin/ping)
test child finished with 0
---- end ----
probe libc's inet_pton & backtrace it with ping: Ok
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-idrntt4nbg15aafu8hjmv7sk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
