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So far we've been suppressing common stuff such as "MAP_" in the mmap
flags, showing "SHARED" instead of "MAP_SHARED", allow for those
prefixes (and a few suffixes) to be shown:
# trace -e *map,open*,*seek sleep 1
openat("/etc/ld.so.cache", CLOEXEC) = 3
mmap(0, 109093, READ, PRIVATE, 3, 0) = 0x7ff61c695000
openat("/lib64/libc.so.6", CLOEXEC) = 3
lseek(3, 792, SET) = 792
mmap(0, 8192, READ|WRITE, PRIVATE|ANONYMOUS) = 0x7ff61c693000
lseek(3, 792, SET) = 792
lseek(3, 864, SET) = 864
mmap(0, 1857568, READ, PRIVATE|DENYWRITE, 3, 0) = 0x7ff61c4cd000
mmap(0x7ff61c4ef000, 1363968, EXEC|READ, PRIVATE|FIXED|DENYWRITE, 3, 139264) = 0x7ff61c4ef000
mmap(0x7ff61c63c000, 311296, READ, PRIVATE|FIXED|DENYWRITE, 3, 1503232) = 0x7ff61c63c000
mmap(0x7ff61c689000, 24576, READ|WRITE, PRIVATE|FIXED|DENYWRITE, 3, 1814528) = 0x7ff61c689000
mmap(0x7ff61c68f000, 14368, READ|WRITE, PRIVATE|FIXED|ANONYMOUS) = 0x7ff61c68f000
munmap(0x7ff61c695000, 109093) = 0
openat("/usr/lib/locale/locale-archive", CLOEXEC) = 3
mmap(0, 217749968, READ, PRIVATE, 3, 0) = 0x7ff60f523000
#
# vim ~/.perfconfig
#
# perf config
llvm.dump-obj=true
trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
trace.show_zeros=yes
trace.show_duration=no
trace.no_inherit=yes
trace.show_timestamp=no
trace.show_arg_names=no
trace.args_alignment=0
trace.string_quote="
trace.show_prefix=yes
#
#
# trace -e *map,open*,*seek sleep 1
openat(AT_FDCWD, "/etc/ld.so.cache", O_CLOEXEC) = 3
mmap(0, 109093, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7ebbe59000
openat(AT_FDCWD, "/lib64/libc.so.6", O_CLOEXEC) = 3
lseek(3, 792, SEEK_SET) = 792
mmap(0, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f7ebbe57000
lseek(3, 792, SEEK_SET) = 792
lseek(3, 864, SEEK_SET) = 864
mmap(0, 1857568, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7ebbc91000
mmap(0x7f7ebbcb3000, 1363968, PROT_EXEC|PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 139264) = 0x7f7ebbcb3000
mmap(0x7f7ebbe00000, 311296, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 1503232) = 0x7f7ebbe00000
mmap(0x7f7ebbe4d000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 1814528) = 0x7f7ebbe4d000
mmap(0x7f7ebbe53000, 14368, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS) = 0x7f7ebbe53000
munmap(0x7f7ebbe59000, 109093) = 0
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_CLOEXEC) = 3
mmap(0, 217749968, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7eaece7000
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-mtn1i4rjowjl72trtnbmvjd4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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For some unknown reason there is no entry in tracefs's syscalls for
kcmp, i.e. no tracefs/events/syscalls/sys_{enter,exit}_kcmp, so we need
to provide a data dictionary for the fields.
To beautify the 'type' argument we automatically generate a strarray
from tools/include/uapi/kcmp.h, the idx1 and idx2 args, nowadays used
only if type == KCMP_FILE, are masked for all the other types and a
lookup is made for the thread and fd to show the path, if possible,
getting it from the probe:vfs_getname if in place or from procfs, races
allowing.
A system wide strace like tracing session, with callchains shows just
one user so far in this fedora 25 machine:
# perf trace --max-stack 5 -e kcmp
<SNIP>
1502914.400 ( 0.001 ms): systemd/1 kcmp(pid1: 1 (systemd), pid2: 1 (systemd), type: FILE, idx1: 271<socket:[4723475]>, idx2: 25<socket:[4788686]>) = -1 ENOSYS Function not implemented
syscall (/usr/lib64/libc-2.25.so)
same_fd (/usr/lib/systemd/libsystemd-shared-233.so)
service_add_fd_store (/usr/lib/systemd/systemd)
service_notify_message.lto_priv.127 (/usr/lib/systemd/systemd)
1502914.407 ( 0.001 ms): systemd/1 kcmp(pid1: 1 (systemd), pid2: 1 (systemd), type: FILE, idx1: 270<socket:[4726396]>, idx2: 25<socket:[4788686]>) = -1 ENOSYS Function not implemented
syscall (/usr/lib64/libc-2.25.so)
same_fd (/usr/lib/systemd/libsystemd-shared-233.so)
service_add_fd_store (/usr/lib/systemd/systemd)
service_notify_message.lto_priv.127 (/usr/lib/systemd/systemd)
<SNIP>
The backtraces seem to agree this is really kcmp(), but this system
doesn't have the sys_kcmp(), bummer:
# uname -a
Linux jouet 4.14.0-rc3+ #1 SMP Fri Oct 13 12:21:12 -03 2017 x86_64 x86_64 x86_64 GNU/Linux
# grep kcmp /proc/kallsyms
ffffffffb60b8890 W sys_kcmp
$ grep CONFIG_CHECKPOINT_RESTORE ../build/v4.14.0-rc3+/.config
# CONFIG_CHECKPOINT_RESTORE is not set
$
So systemd uses it, good fedora kernel config has it:
$ grep CONFIG_CHECKPOINT_RESTORE /boot/config-4.13.4-200.fc26.x86_64
CONFIG_CHECKPOINT_RESTORE=y
[acme@jouet linux]$
/me goes to rebuild a kernel...
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-gz5fca968viw8m7hryjqvrln@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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