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Commit 1de3038d authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0a2f7540

tools/perf/Makefile.perf

+9 −0
Original line number Diff line number Diff line
@@ -420,6 +420,13 @@ sndrv_pcm_ioctl_tbl := $(srctree)/tools/perf/trace/beauty/sndrv_pcm_ioctl.sh 
$(sndrv_pcm_ioctl_array): $(sndrv_pcm_hdr_dir)/asound.h $(sndrv_pcm_ioctl_tbl)

	$(Q)$(SHELL) '$(sndrv_pcm_ioctl_tbl)' $(sndrv_pcm_hdr_dir) > $@



kcmp_type_array := $(beauty_outdir)/kcmp_type_array.c

kcmp_hdr_dir := $(srctree)/tools/include/uapi/linux/

kcmp_type_tbl := $(srctree)/tools/perf/trace/beauty/kcmp_type.sh



$(kcmp_type_array): $(kcmp_hdr_dir)/kcmp.h $(kcmp_type_tbl)

	$(Q)$(SHELL) '$(kcmp_type_tbl)' $(kcmp_hdr_dir) > $@



kvm_ioctl_array := $(beauty_ioctl_outdir)/kvm_ioctl_array.c

kvm_hdr_dir := $(srctree)/tools/include/uapi/linux

kvm_ioctl_tbl := $(srctree)/tools/perf/trace/beauty/kvm_ioctl.sh
@@ -553,6 +560,7 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioc 
	$(pkey_alloc_access_rights_array) \

	$(sndrv_pcm_ioctl_array) \

	$(sndrv_ctl_ioctl_array) \

	$(kcmp_type_array) \

	$(kvm_ioctl_array) \

	$(vhost_virtio_ioctl_array) \

	$(madvise_behavior_array) \
@@ -836,6 +844,7 @@ clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clea 
		$(OUTPUT)$(sndrv_ctl_ioctl_array) \

		$(OUTPUT)$(sndrv_pcm_ioctl_array) \

		$(OUTPUT)$(kvm_ioctl_array) \

		$(OUTPUT)$(kcmp_type_array) \

		$(OUTPUT)$(vhost_virtio_ioctl_array) \

		$(OUTPUT)$(perf_ioctl_array) \

		$(OUTPUT)$(prctl_option_array)

tools/perf/builtin-trace.c

+6 −0
Original line number Diff line number Diff line
@@ -633,6 +633,12 @@ static struct syscall_fmt { 
#else

		   [2] = { .scnprintf = SCA_HEX, /* arg */ }, }, },

#endif

	{ .name	    = "kcmp",	    .nr_args = 5,

	  .arg = { [0] = { .name = "pid1",	.scnprintf = SCA_PID, },

		   [1] = { .name = "pid2",	.scnprintf = SCA_PID, },

		   [2] = { .name = "type",	.scnprintf = SCA_KCMP_TYPE, },

		   [3] = { .name = "idx1",	.scnprintf = SCA_KCMP_IDX, },

		   [4] = { .name = "idx2",	.scnprintf = SCA_KCMP_IDX, }, }, },

	{ .name	    = "keyctl",

	  .arg = { [0] = STRARRAY(option, keyctl_options), }, },

	{ .name	    = "kill",

tools/perf/trace/beauty/Build

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ libperf-y += fcntl.o 
ifeq ($(SRCARCH),$(filter $(SRCARCH),x86))

libperf-y += ioctl.o

endif

libperf-y += kcmp.o

libperf-y += pkey_alloc.o

libperf-y += prctl.o

libperf-y += statx.o

tools/perf/trace/beauty/beauty.h

+6 −0
Original line number Diff line number Diff line
@@ -81,6 +81,12 @@ size_t syscall_arg__scnprintf_fcntl_arg(char *bf, size_t size, struct syscall_ar 
size_t syscall_arg__scnprintf_ioctl_cmd(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_IOCTL_CMD syscall_arg__scnprintf_ioctl_cmd



size_t syscall_arg__scnprintf_kcmp_type(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_KCMP_TYPE syscall_arg__scnprintf_kcmp_type



size_t syscall_arg__scnprintf_kcmp_idx(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_KCMP_IDX syscall_arg__scnprintf_kcmp_idx



size_t syscall_arg__scnprintf_pkey_alloc_access_rights(char *bf, size_t size, struct syscall_arg *arg);

#define SCA_PKEY_ALLOC_ACCESS_RIGHTS syscall_arg__scnprintf_pkey_alloc_access_rights

tools/perf/trace/beauty/kcmp.c

0 → 100644
+44 −0
Original line number Diff line number Diff line 
/*

 * trace/beauty/kcmp.c

 *

 *  Copyright (C) 2017, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>

 *

 * Released under the GPL v2. (and only v2, not any later version)

 */



#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);

}



static size_t kcmp__scnprintf_type(int type, char *bf, size_t size)

{

	static DEFINE_STRARRAY(kcmp_types);

	return strarray__scnprintf(&strarray__kcmp_types, bf, size, "%d", type);

}



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 */



	return kcmp__scnprintf_type(type, bf, size);

}