linux/tools/perf/trace/beauty/kcmp.c

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// SPDX-License-Identifier: LGPL-2.1
perf trace beauty kcmp: Beautify arguments 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>
2017-10-31 22:32:23 +08:00
/*
* trace/beauty/kcmp.c
*
* Copyright (C) 2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include "trace/beauty/beauty.h"
#include <linux/kernel.h>
#include <sys/types.h>
#include <machine.h>
#include <uapi/linux/kcmp.h>
#include "trace/beauty/generated/kcmp_type_array.c"
size_t syscall_arg__scnprintf_kcmp_idx(char *bf, size_t size, struct syscall_arg *arg)
{
unsigned long fd = arg->val;
int type = syscall_arg__val(arg, 2);
pid_t pid;
if (type != KCMP_FILE)
return syscall_arg__scnprintf_long(bf, size, arg);
pid = syscall_arg__val(arg, arg->idx == 3 ? 0 : 1); /* idx1 -> pid1, idx2 -> pid2 */
return pid__scnprintf_fd(arg->trace, pid, fd, bf, size);
}
perf trace: Allow asking for not suppressing common string prefixes 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>
2018-12-15 04:06:47 +08:00
static size_t kcmp__scnprintf_type(int type, char *bf, size_t size, bool show_prefix)
perf trace beauty kcmp: Beautify arguments 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>
2017-10-31 22:32:23 +08:00
{
static DEFINE_STRARRAY(kcmp_types, "KCMP_");
perf trace: Allow asking for not suppressing common string prefixes 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>
2018-12-15 04:06:47 +08:00
return strarray__scnprintf(&strarray__kcmp_types, bf, size, "%d", show_prefix, type);
perf trace beauty kcmp: Beautify arguments 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>
2017-10-31 22:32:23 +08:00
}
size_t syscall_arg__scnprintf_kcmp_type(char *bf, size_t size, struct syscall_arg *arg)
{
unsigned long type = arg->val;
if (type != KCMP_FILE)
arg->mask |= (1 << 3) | (1 << 4); /* Ignore idx1 and idx2 */
perf trace: Allow asking for not suppressing common string prefixes 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>
2018-12-15 04:06:47 +08:00
return kcmp__scnprintf_type(type, bf, size, arg->show_string_prefix);
perf trace beauty kcmp: Beautify arguments 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>
2017-10-31 22:32:23 +08:00
}