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>
Reuse 'mprotect' beautifiers for 'pkey_mprotect'.
System wide tracing pkey_alloc, pkey_free and pkey_mprotect calls, with
backtraces:
# perf trace -e pkey_alloc,pkey_mprotect,pkey_free --max-stack=5
0.000 ( 0.011 ms): pkey/7818 pkey_alloc(init_val: DISABLE_ACCESS|DISABLE_WRITE) = -1 EINVAL Invalid argument
syscall (/usr/lib64/libc-2.25.so)
pkey_alloc (/home/acme/c/pkey)
0.022 ( 0.003 ms): pkey/7818 pkey_mprotect(start: 0x7f28c3890000, len: 4096, prot: READ|WRITE, pkey: -1) = 0
syscall (/usr/lib64/libc-2.25.so)
pkey_mprotect (/home/acme/c/pkey)
0.030 ( 0.002 ms): pkey/7818 pkey_free(pkey: -1 ) = -1 EINVAL Invalid argument
syscall (/usr/lib64/libc-2.25.so)
pkey_free (/home/acme/c/pkey)
The tools/include/uapi/asm-generic/mman-common.h file is used to find
the access rights defines for the pkey_alloc syscall second argument.
Since we have the detector of changes for the tools/include header files
versus its kernel origin (include/uapi/asm-generic/mman-common.h), we'll
get whatever new flag appears for that argument automatically.
This method should be used in other cases where it is easy to generate
those flags tables because the header has properly namespaced defines
like PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
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-3xq5312qlks7wtfzv2sk3nct@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
By using the _IOC_(DIR,NR,TYPE,SIZE) macros to lookup a 'type' keyed
table that then gets indexed by 'nr', falling back to a notation similar
to the one used by 'strace', only more compact, i.e.:
474.356 ( 0.007 ms): gnome-shell/22401 ioctl(fd: 8</dev/dri/card0>, cmd: (READ|WRITE, 0x64, 0xae, 0x1c), arg: 0x7ffc934f7880) = 0
474.369 ( 0.053 ms): gnome-shell/22401 ioctl(fd: 8</dev/dri/card0>, cmd: (READ|WRITE, 0x64, 0xb0, 0x18), arg: 0x7ffc934f77d0) = 0
505.055 ( 0.014 ms): gnome-shell/22401 ioctl(fd: 8</dev/dri/card0>, cmd: (READ|WRITE, 0x64, 0xaf, 0x4), arg: 0x7ffc934f741c) = 0
This also moves it out of builtin-trace.c and into trace/beauty/ioctl.c
to better compartimentalize all these formatters.
Cc: Adrian Hunter <adrian.hunter@intel.com>
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-s3enursdxsvnhdomh6qlte4g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A series of fcntl cmds ignore the third argument, so mask it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
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-6vtl3zq1tauamrhm8o380ptn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To test it, build samples/statx/test_statx, which I did as:
$ make headers_install
$ cc -I ~/git/linux/usr/include samples/statx/test-statx.c -o /tmp/statx
And then use perf trace on it:
# perf trace -e statx /tmp/statx /etc/passwd
statx(/etc/passwd) = 0
results=7ff
Size: 3496 Blocks: 8 IO Block: 4096 regular file
Device: fd:00 Inode: 280156 Links: 1
Access: (0644/-rw-r--r--) Uid: 0 Gid: 0
Access: 2017-03-29 16:01:01.650073438-0300
Modify: 2017-03-10 16:25:14.156479354-0300
Change: 2017-03-10 16:25:14.171479328-0300
0.000 ( 0.007 ms): statx/30648 statx(dfd: CWD, filename: 0x7ef503f4, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff7ef4eb10) = 0
#
Using the test-stat.c options to change the mask:
# perf trace -e statx /tmp/statx -O /etc/passwd > /dev/null
0.000 ( 0.008 ms): statx/30745 statx(dfd: CWD, filename: 0x3a0753f4, flags: SYMLINK_NOFOLLOW, mask: BTIME, buffer: 0x7ffd3a0735c0) = 0
#
# perf trace -e statx /tmp/statx -A /etc/passwd > /dev/null
0.000 ( 0.010 ms): statx/30757 statx(dfd: CWD, filename: 0xa94e63f4, flags: SYMLINK_NOFOLLOW|NO_AUTOMOUNT, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffea94e49d0) = 0
#
# trace --no-inherit -e statx /tmp/statx -F /etc/passwd > /dev/null
0.000 ( 0.011 ms): statx(dfd: CWD, filename: 0x3b02d3f3, flags: SYMLINK_NOFOLLOW|STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffd3b02c850) = 0
#
# trace --no-inherit -e statx /tmp/statx -F -L /etc/passwd > /dev/null
0.000 ( 0.008 ms): statx(dfd: CWD, filename: 0x15cff3f3, flags: STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff15cfdda0) = 0
#
# trace --no-inherit -e statx /tmp/statx -D -O /etc/passwd > /dev/null
0.000 ( 0.009 ms): statx(dfd: CWD, filename: 0xfa37f3f3, flags: SYMLINK_NOFOLLOW|STATX_DONT_SYNC, mask: BTIME, buffer: 0x7ffffa37da20) = 0
#
Adding a probe to get the filename collected as well:
# perf probe 'vfs_getname=getname_flags:72 pathname=result->name:string'
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=result->name:string)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_getname -aR sleep 1
# trace --no-inherit -e statx /tmp/statx -D -O /etc/passwd > /dev/null
0.169 ( 0.007 ms): statx(dfd: CWD, filename: /etc/passwd, flags: SYMLINK_NOFOLLOW|STATX_DONT_SYNC, mask: BTIME, buffer: 0x7ffda9bf50f0) = 0
#
Same technique could be used to collect and beautify the result put in
the 'buffer' argument.
Finally do a system wide 'perf trace' session looking for any use of statx,
then run the test proggie with various flags:
# trace -e statx
16612.967 ( 0.028 ms): statx/4562 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffef195d660) = 0
33064.447 ( 0.011 ms): statx/4569 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW|STATX_FORCE_SYNC, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7ffc5484c790) = 0
36050.891 ( 0.023 ms): statx/4576 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: BTIME, buffer: 0x7ffeb18b66e0) = 0
38039.889 ( 0.023 ms): statx/4584 statx(dfd: CWD, filename: /tmp/statx, flags: SYMLINK_NOFOLLOW, mask: TYPE|MODE|NLINK|UID|GID|ATIME|MTIME|CTIME|INO|SIZE|BLOCKS|BTIME, buffer: 0x7fff1db0ea90) = 0
^C#
This one also starts moving the beautifiers from files directly included
in builtin-trace.c to separate objects + a beauty.h header with
prototypes, so that we can add test cases in tools/perf/tests/ to fire
syscalls with various arguments and then get them intercepted as
syscalls:sys_enter_foo or raw_syscalls:sys_enter + sys_exit to then
format and check that the formatted output is the one we expect.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.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-xvzw8eynffvez5czyzidhrno@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>