* [PATCH v2 0/5] tracefs library
@ 2020-01-06 15:40 Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 1/5] trace-cmd: Introduce libtracefs library Tzvetomir Stoyanov (VMware)
` (4 more replies)
0 siblings, 5 replies; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Add a skeleton for new library: libtracefs, providing APIs
for accessing files from tracefs. The library files are added in
lib/tracefs
include/tracefs
It is built and installed by trace-cmd targets
make libs
make install_libs
[
v2 changes:
- Fix copyright of the newly created files
- Remove tracefs_write_file() API, add it as a local helper function
]
Tzvetomir Stoyanov (VMware) (5):
trace-cmd: Introduce libtracefs library
kernel-shark: Use new tracefs library
trace-cmd: New libtracefs APIs for ftrace instances
trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and
systems
trace-cmd,kernel-shark: New libtracefs APIs for loading ftrace events
Makefile | 27 +-
include/trace-cmd/trace-cmd.h | 21 -
include/tracefs/tracefs.h | 56 +++
kernel-shark/CMakeLists.txt | 3 +-
kernel-shark/build/FindTraceCmd.cmake | 30 ++
kernel-shark/src/CMakeLists.txt | 2 +
kernel-shark/src/KsCaptureDialog.cpp | 4 +-
kernel-shark/src/libkshark.h | 1 +
lib/trace-cmd/trace-input.c | 95 ----
lib/trace-cmd/trace-output.c | 3 +-
lib/trace-cmd/trace-recorder.c | 7 +-
lib/trace-cmd/trace-util.c | 629 ------------------------
lib/tracefs/Makefile | 48 ++
lib/tracefs/include/tracefs-local.h | 13 +
lib/tracefs/tracefs-events.c | 661 ++++++++++++++++++++++++++
lib/tracefs/tracefs-instance.c | 267 +++++++++++
lib/tracefs/tracefs-utils.c | 226 +++++++++
tracecmd/Makefile | 2 +-
tracecmd/include/trace-local.h | 5 +-
tracecmd/trace-check-events.c | 5 +-
tracecmd/trace-list.c | 21 +-
tracecmd/trace-record.c | 373 ++++++---------
tracecmd/trace-show.c | 7 +-
tracecmd/trace-snapshot.c | 9 +-
tracecmd/trace-stack.c | 9 +-
tracecmd/trace-stat.c | 38 +-
26 files changed, 1531 insertions(+), 1031 deletions(-)
create mode 100644 include/tracefs/tracefs.h
create mode 100644 lib/tracefs/Makefile
create mode 100644 lib/tracefs/include/tracefs-local.h
create mode 100644 lib/tracefs/tracefs-events.c
create mode 100644 lib/tracefs/tracefs-instance.c
create mode 100644 lib/tracefs/tracefs-utils.c
--
2.24.1
^ permalink raw reply [flat|nested] 15+ messages in thread
* [PATCH v2 1/5] trace-cmd: Introduce libtracefs library
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
@ 2020-01-06 15:40 ` Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 2/5] kernel-shark: Use new tracefs library Tzvetomir Stoyanov (VMware)
` (3 subsequent siblings)
4 siblings, 0 replies; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Add a skeleton for new library: libtracefs.
It provides APIs for accessing files from tracefs.
- Added new directories
lib/tracefs
include/tracefs
- Integrated the libtracefs build into the trace-cmd compilation
- The library is installed by "make install_libs" in:
libtrasefs.so in $(libdir)/tracefs
trasefs.h in $(includedir)/tracefs
- Added implementation of initial APIs:
char *tracefs_get_tracing_file(const char *name);
void tracefs_put_tracing_file(char *name);
const char *tracefs_get_tracing_dir(void);
char *tracefs_find_tracing_dir(void);
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
Makefile | 27 +++-
include/trace-cmd/trace-cmd.h | 9 --
include/tracefs/tracefs.h | 20 +++
lib/trace-cmd/trace-output.c | 3 +-
lib/trace-cmd/trace-recorder.c | 7 +-
lib/trace-cmd/trace-util.c | 136 ---------------------
lib/tracefs/Makefile | 46 +++++++
lib/tracefs/include/tracefs-local.h | 12 ++
lib/tracefs/tracefs-utils.c | 183 ++++++++++++++++++++++++++++
tracecmd/Makefile | 2 +-
tracecmd/trace-check-events.c | 3 +-
tracecmd/trace-list.c | 19 +--
tracecmd/trace-record.c | 127 +++++++++----------
tracecmd/trace-show.c | 5 +-
tracecmd/trace-snapshot.c | 9 +-
tracecmd/trace-stack.c | 9 +-
tracecmd/trace-stat.c | 17 +--
17 files changed, 390 insertions(+), 244 deletions(-)
create mode 100644 include/tracefs/tracefs.h
create mode 100644 lib/tracefs/Makefile
create mode 100644 lib/tracefs/include/tracefs-local.h
create mode 100644 lib/tracefs/tracefs-utils.c
diff --git a/Makefile b/Makefile
index 48d88e7..aa803ba 100644
--- a/Makefile
+++ b/Makefile
@@ -183,12 +183,19 @@ LIBTRACECMD_DIR = $(obj)/lib/trace-cmd
LIBTRACECMD_STATIC = $(LIBTRACECMD_DIR)/libtracecmd.a
LIBTRACECMD_SHARED = $(LIBTRACECMD_DIR)/libtracecmd.so
-TRACE_LIBS = -L$(LIBTRACECMD_DIR) -ltracecmd -L$(LIBTRACEEVENT_DIR) -ltraceevent
+LIBTRACEFS_DIR = $(obj)/lib/tracefs
+LIBTRACEFS_STATIC = $(LIBTRACEFS_DIR)/libtracefs.a
+LIBTRACEFS_SHARED = $(LIBTRACEFS_DIR)/libtracefs.so
+
+TRACE_LIBS = -L$(LIBTRACECMD_DIR) -ltracecmd \
+ -L$(LIBTRACEEVENT_DIR) -ltraceevent \
+ -L$(LIBTRACEFS_DIR) -ltracefs
export LIBS TRACE_LIBS
export LIBTRACEEVENT_DIR LIBTRACECMD_DIR
export LIBTRACECMD_STATIC LIBTRACECMD_SHARED
export LIBTRACEEVENT_STATIC LIBTRACEEVENT_SHARED
+export LIBTRACEFS_STATIC LIBTRACEFS_SHARED
export Q SILENT VERBOSE EXT
@@ -198,8 +205,10 @@ include scripts/utils.mk
INCLUDES = -I$(src)/include -I$(src)/../../include
INCLUDES += -I$(src)/include/traceevent
INCLUDES += -I$(src)/include/trace-cmd
+INCLUDES += -I$(src)/include/tracefs
INCLUDES += -I$(src)/lib/traceevent/include
INCLUDES += -I$(src)/lib/trace-cmd/include
+INCLUDES += -I$(src)/lib/tracefs/include
INCLUDES += -I$(src)/tracecmd/include
INCLUDES += -I$(obj)/tracecmd/include
@@ -277,7 +286,7 @@ gui: force $(CMD_TARGETS) $(kshark-dir)/build/Makefile
@echo "gui build complete"
@echo " kernelshark located at $(kshark-dir)/bin"
-trace-cmd: force $(LIBTRACEEVENT_STATIC) $(LIBTRACECMD_STATIC)
+trace-cmd: force $(LIBTRACEEVENT_STATIC) $(LIBTRACECMD_STATIC) $(LIBTRACEFS_STATIC)
$(Q)$(MAKE) -C $(src)/tracecmd $(obj)/tracecmd/$@
$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
@@ -292,12 +301,21 @@ $(LIBTRACECMD_STATIC): force
$(LIBTRACECMD_SHARED): force
$(Q)$(MAKE) -C $(src)/lib/trace-cmd $@
+$(LIBTRACEFS_STATIC): force
+ $(Q)$(MAKE) -C $(src)/lib/tracefs $@
+
+$(LIBTRACEFS_SHARED): force
+ $(Q)$(MAKE) -C $(src)/lib/tracefs $@
+
+
libtraceevent.so: $(LIBTRACEEVENT_SHARED)
libtraceevent.a: $(LIBTRACEEVENT_STATIC)
libtracecmd.a: $(LIBTRACECMD_STATIC)
libtracecmd.so: $(LIBTRACECMD_SHARED)
+libtracefs.a: $(LIBTRACEFS_STATIC)
+libtracefs.so: $(LIBTRACEFS_SHARED)
-libs: $(LIBTRACECMD_SHARED) $(LIBTRACEEVENT_SHARED)
+libs: $(LIBTRACECMD_SHARED) $(LIBTRACEEVENT_SHARED) $(LIBTRACEFS_SHARED)
plugins: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir $(obj)/lib/traceevent/plugins/trace_python_dir
$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins
@@ -353,10 +371,12 @@ install_gui: install_cmd gui
install_libs: libs
$(Q)$(call do_install,$(LIBTRACECMD_SHARED),$(libdir_SQ)/trace-cmd)
$(Q)$(call do_install,$(LIBTRACEEVENT_SHARED),$(libdir_SQ)/traceevent)
+ $(Q)$(call do_install,$(LIBTRACEFS_SHARED),$(libdir_SQ)/tracefs)
$(Q)$(call do_install,$(src)/include/traceevent/event-parse.h,$(includedir_SQ)/traceevent)
$(Q)$(call do_install,$(src)/include/traceevent/trace-seq.h,$(includedir_SQ)/traceevent)
$(Q)$(call do_install,$(src)/include/trace-cmd/trace-cmd.h,$(includedir_SQ)/trace-cmd)
$(Q)$(call do_install,$(src)/include/trace-cmd/trace-filter-hash.h,$(includedir_SQ)/trace-cmd)
+ $(Q)$(call do_install,$(src)/include/tracefs/tracefs.h,$(includedir_SQ)/tracefs)
doc:
$(MAKE) -C $(src)/Documentation all
@@ -379,6 +399,7 @@ clean:
$(RM) tags TAGS cscope*
$(MAKE) -C $(src)/lib/traceevent clean
$(MAKE) -C $(src)/lib/trace-cmd clean
+ $(MAKE) -C $(src)/lib/tracefs clean
$(MAKE) -C $(src)/lib/traceevent/plugins clean
$(MAKE) -C $(src)/python clean
$(MAKE) -C $(src)/tracecmd clean
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 13afce7..66736ae 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -64,12 +64,6 @@ static inline int tracecmd_host_bigendian(void)
return *ptr == 0x01020304;
}
-/* tracecmd_get_tracing_dir must *not* be freed */
-const char *tracecmd_get_tracing_dir(void);
-
-/* tracecmd_find_tracing_dir must be freed */
-char *tracecmd_find_tracing_dir(void);
-
/* --- Opening and Reading the trace.dat file --- */
enum {
@@ -208,9 +202,6 @@ tracecmd_get_show_data_func(struct tracecmd_input *handle);
void tracecmd_set_show_data_func(struct tracecmd_input *handle,
tracecmd_show_data_func func);
-char *tracecmd_get_tracing_file(const char *name);
-void tracecmd_put_tracing_file(char *name);
-
int tracecmd_record_at_buffer_start(struct tracecmd_input *handle, struct tep_record *record);
unsigned long long tracecmd_page_ts(struct tracecmd_input *handle,
struct tep_record *record);
diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
new file mode 100644
index 0000000..e844c75
--- /dev/null
+++ b/include/tracefs/tracefs.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/*
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+ *
+ */
+#ifndef _TRACE_FS_H
+#define _TRACE_FS_H
+
+#include "traceevent/event-parse.h"
+
+char *tracefs_get_tracing_file(const char *name);
+void tracefs_put_tracing_file(char *name);
+
+/* tracefs_get_tracing_dir must *not* be freed */
+const char *tracefs_get_tracing_dir(void);
+
+/* tracefs_find_tracing_dir must be freed */
+char *tracefs_find_tracing_dir(void);
+
+#endif /* _TRACE_FS_H */
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index be4d3f5..a3dda27 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -20,6 +20,7 @@
#include <errno.h>
#include <glob.h>
+#include "tracefs.h"
#include "trace-cmd-local.h"
#include "list.h"
#include "trace-msg.h"
@@ -238,7 +239,7 @@ static tsize_t copy_file(struct tracecmd_output *handle,
static const char *find_tracing_dir(struct tracecmd_output *handle)
{
if (!handle->tracing_dir)
- handle->tracing_dir = tracecmd_find_tracing_dir();
+ handle->tracing_dir = tracefs_find_tracing_dir();
return handle->tracing_dir;
}
diff --git a/lib/trace-cmd/trace-recorder.c b/lib/trace-cmd/trace-recorder.c
index 36c9a96..2a6e2b6 100644
--- a/lib/trace-cmd/trace-recorder.c
+++ b/lib/trace-cmd/trace-recorder.c
@@ -12,6 +12,7 @@
#include <unistd.h>
#include <errno.h>
+#include "tracefs.h"
#include "trace-cmd.h"
#include "event-utils.h"
@@ -306,7 +307,7 @@ struct tracecmd_recorder *tracecmd_create_recorder_fd(int fd, int cpu, unsigned
{
const char *tracing;
- tracing = tracecmd_get_tracing_dir();
+ tracing = tracefs_get_tracing_dir();
if (!tracing) {
errno = ENODEV;
return NULL;
@@ -319,7 +320,7 @@ struct tracecmd_recorder *tracecmd_create_recorder(const char *file, int cpu, un
{
const char *tracing;
- tracing = tracecmd_get_tracing_dir();
+ tracing = tracefs_get_tracing_dir();
if (!tracing) {
errno = ENODEV;
return NULL;
@@ -333,7 +334,7 @@ tracecmd_create_recorder_maxkb(const char *file, int cpu, unsigned flags, int ma
{
const char *tracing;
- tracing = tracecmd_get_tracing_dir();
+ tracing = tracefs_get_tracing_dir();
if (!tracing) {
errno = ENODEV;
return NULL;
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index b5bb0d5..1394469 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -23,8 +23,6 @@
#include "event-utils.h"
#define LOCAL_PLUGIN_DIR ".trace-cmd/plugins"
-#define TRACEFS_PATH "/sys/kernel/tracing"
-#define DEBUGFS_PATH "/sys/kernel/debug"
#define PROC_STACK_FILE "/proc/sys/kernel/stack_tracer_enabled"
int tracecmd_disable_sys_plugins;
@@ -33,9 +31,6 @@ static bool debug;
static FILE *logfp;
-#define _STR(x) #x
-#define STR(x) _STR(x)
-
/**
* tracecmd_set_debug - Set debug mode of the tracecmd library
* @set_debug: The new "debug" mode. If true, the tracecmd library is
@@ -147,113 +142,6 @@ void tracecmd_parse_ftrace_printk(struct tep_handle *pevent,
}
}
-static int mount_debugfs(void)
-{
- struct stat st;
- int ret;
-
- /* make sure debugfs exists */
- ret = stat(DEBUGFS_PATH, &st);
- if (ret < 0)
- return -1;
-
- ret = mount("nodev", DEBUGFS_PATH,
- "debugfs", 0, NULL);
-
- return ret;
-}
-
-static int mount_tracefs(void)
-{
- struct stat st;
- int ret;
-
- /* make sure debugfs exists */
- ret = stat(TRACEFS_PATH, &st);
- if (ret < 0)
- return -1;
-
- ret = mount("nodev", TRACEFS_PATH,
- "tracefs", 0, NULL);
-
- return ret;
-}
-
-char *tracecmd_find_tracing_dir(void)
-{
- char *debug_str = NULL;
- char fspath[PATH_MAX+1];
- char *tracing_dir;
- char type[100];
- int use_debug = 0;
- FILE *fp;
-
- if ((fp = fopen("/proc/mounts","r")) == NULL) {
- warning("Can't open /proc/mounts for read");
- return NULL;
- }
-
- while (fscanf(fp, "%*s %"
- STR(PATH_MAX)
- "s %99s %*s %*d %*d\n",
- fspath, type) == 2) {
- if (strcmp(type, "tracefs") == 0)
- break;
- if (!debug_str && strcmp(type, "debugfs") == 0) {
- debug_str = strdup(fspath);
- if (!debug_str) {
- fclose(fp);
- return NULL;
- }
- }
- }
- fclose(fp);
-
- if (strcmp(type, "tracefs") != 0) {
- if (mount_tracefs() < 0) {
- if (debug_str) {
- strncpy(fspath, debug_str, PATH_MAX);
- fspath[PATH_MAX] = 0;
- } else {
- if (mount_debugfs() < 0) {
- warning("debugfs not mounted, please mount");
- free(debug_str);
- return NULL;
- }
- strcpy(fspath, DEBUGFS_PATH);
- }
- use_debug = 1;
- } else
- strcpy(fspath, TRACEFS_PATH);
- }
- free(debug_str);
-
- if (use_debug) {
- int ret;
-
- ret = asprintf(&tracing_dir, "%s/tracing", fspath);
- if (ret < 0)
- return NULL;
- } else {
- tracing_dir = strdup(fspath);
- if (!tracing_dir)
- return NULL;
- }
-
- return tracing_dir;
-}
-
-const char *tracecmd_get_tracing_dir(void)
-{
- static const char *tracing_dir;
-
- if (tracing_dir)
- return tracing_dir;
-
- tracing_dir = tracecmd_find_tracing_dir();
- return tracing_dir;
-}
-
/* FIXME: append_file() is duplicated and could be consolidated */
static char *append_file(const char *dir, const char *name)
{
@@ -863,30 +751,6 @@ void trace_util_free_plugin_files(char **files)
free(files);
}
-char *tracecmd_get_tracing_file(const char *name)
-{
- static const char *tracing;
- char *file;
- int ret;
-
- if (!tracing) {
- tracing = tracecmd_find_tracing_dir();
- if (!tracing)
- return NULL;
- }
-
- ret = asprintf(&file, "%s/%s", tracing, name);
- if (ret < 0)
- return NULL;
-
- return file;
-}
-
-void tracecmd_put_tracing_file(char *name)
-{
- free(name);
-}
-
void __noreturn __vdie(const char *fmt, va_list ap)
{
int ret = errno;
diff --git a/lib/tracefs/Makefile b/lib/tracefs/Makefile
new file mode 100644
index 0000000..86d7845
--- /dev/null
+++ b/lib/tracefs/Makefile
@@ -0,0 +1,46 @@
+
+
+include $(src)/scripts/utils.mk
+
+bdir:=$(obj)/lib/tracefs
+
+DEFAULT_TARGET = $(bdir)/libtracefs.a
+
+OBJS =
+OBJS += tracefs-utils.o
+
+OBJS := $(OBJS:%.o=$(bdir)/%.o)
+DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)
+
+all: $(DEFAULT_TARGET)
+
+$(bdir):
+ @mkdir -p $(bdir)
+
+$(OBJS): | $(bdir)
+$(DEPS): | $(bdir)
+
+$(bdir)/libtracefs.a: $(OBJS)
+ $(Q)$(call do_build_static_lib)
+
+$(bdir)/libtracefs.so: $(OBJS)
+ $(Q)$(call do_compile_shared_library)
+
+$(bdir)/%.o: %.c
+ $(Q)$(call do_fpic_compile)
+
+$(DEPS): $(bdir)/.%.d: %.c
+ $(Q)$(CC) -M $(CPPFLAGS) $(CFLAGS) $< > $@
+
+$(OBJS): $(bdir)/%.o : $(bdir)/.%.d
+
+dep_includes := $(wildcard $(DEPS))
+
+ifneq ($(dep_includes),)
+ include $(dep_includes)
+endif
+
+clean:
+ $(RM) $(bdir)/*.a $(bdir)/*.so $(bdir)/*.o $(bdir)/.*.d
+
+.PHONY: clean
diff --git a/lib/tracefs/include/tracefs-local.h b/lib/tracefs/include/tracefs-local.h
new file mode 100644
index 0000000..231edd1
--- /dev/null
+++ b/lib/tracefs/include/tracefs-local.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/*
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+ *
+ */
+#ifndef _TRACE_FS_LOCAL_H
+#define _TRACE_FS_LOCAL_H
+
+/* Can be overridden */
+void warning(const char *fmt, ...);
+
+#endif /* _TRACE_FS_LOCAL_H */
diff --git a/lib/tracefs/tracefs-utils.c b/lib/tracefs/tracefs-utils.c
new file mode 100644
index 0000000..0ef16fc
--- /dev/null
+++ b/lib/tracefs/tracefs-utils.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * Updates:
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+ *
+ */
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <linux/limits.h>
+
+#include "tracefs.h"
+
+#define TRACEFS_PATH "/sys/kernel/tracing"
+#define DEBUGFS_PATH "/sys/kernel/debug"
+
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+void __attribute__((weak)) warning(const char *fmt, ...)
+{
+}
+
+static int mount_tracefs(void)
+{
+ struct stat st;
+ int ret;
+
+ /* make sure debugfs exists */
+ ret = stat(TRACEFS_PATH, &st);
+ if (ret < 0)
+ return -1;
+
+ ret = mount("nodev", TRACEFS_PATH,
+ "tracefs", 0, NULL);
+
+ return ret;
+}
+
+static int mount_debugfs(void)
+{
+ struct stat st;
+ int ret;
+
+ /* make sure debugfs exists */
+ ret = stat(DEBUGFS_PATH, &st);
+ if (ret < 0)
+ return -1;
+
+ ret = mount("nodev", DEBUGFS_PATH,
+ "debugfs", 0, NULL);
+
+ return ret;
+}
+
+/**
+ * tracefs_find_tracing_dir - Find tracing directory
+ *
+ * Returns string containing the full path to the system's tracing directory.
+ * The string must be freed by free()
+ */
+char *tracefs_find_tracing_dir(void)
+{
+ char *debug_str = NULL;
+ char fspath[PATH_MAX+1];
+ char *tracing_dir;
+ char type[100];
+ int use_debug = 0;
+ FILE *fp;
+
+ fp = fopen("/proc/mounts", "r");
+ if (!fp) {
+ warning("Can't open /proc/mounts for read");
+ return NULL;
+ }
+
+ while (fscanf(fp, "%*s %"
+ STR(PATH_MAX)
+ "s %99s %*s %*d %*d\n",
+ fspath, type) == 2) {
+ if (strcmp(type, "tracefs") == 0)
+ break;
+ if (!debug_str && strcmp(type, "debugfs") == 0) {
+ debug_str = strdup(fspath);
+ if (!debug_str) {
+ fclose(fp);
+ return NULL;
+ }
+ }
+ }
+ fclose(fp);
+
+ if (strcmp(type, "tracefs") != 0) {
+ if (mount_tracefs() < 0) {
+ if (debug_str) {
+ strncpy(fspath, debug_str, PATH_MAX);
+ fspath[PATH_MAX] = 0;
+ } else {
+ if (mount_debugfs() < 0) {
+ warning("debugfs not mounted, please mount");
+ free(debug_str);
+ return NULL;
+ }
+ strcpy(fspath, DEBUGFS_PATH);
+ }
+ use_debug = 1;
+ } else
+ strcpy(fspath, TRACEFS_PATH);
+ }
+ free(debug_str);
+
+ if (use_debug) {
+ int ret;
+
+ ret = asprintf(&tracing_dir, "%s/tracing", fspath);
+ if (ret < 0)
+ return NULL;
+ } else {
+ tracing_dir = strdup(fspath);
+ if (!tracing_dir)
+ return NULL;
+ }
+
+ return tracing_dir;
+}
+
+/**
+ * tracefs_get_tracing_dir - Get tracing directory
+ *
+ * Returns string containing the full path to the system's tracing directory.
+ * Must use tracefs_put_tracing_file() to free the returned string.
+ */
+const char *tracefs_get_tracing_dir(void)
+{
+ static const char *tracing_dir;
+
+ if (tracing_dir)
+ return tracing_dir;
+
+ tracing_dir = tracefs_find_tracing_dir();
+ return tracing_dir;
+}
+
+/**
+ * tracefs_get_tracing_file - Get tracing file
+ * @name: tracing file name
+ *
+ * Returns string containing the full path to a tracing file in
+ * the system's tracing directory.
+ *
+ * Must use tracefs_put_tracing_file() to free the returned string.
+ */
+char *tracefs_get_tracing_file(const char *name)
+{
+ static const char *tracing;
+ char *file;
+ int ret;
+
+ if (!tracing) {
+ tracing = tracefs_find_tracing_dir();
+ if (!tracing)
+ return NULL;
+ }
+
+ ret = asprintf(&file, "%s/%s", tracing, name);
+ if (ret < 0)
+ return NULL;
+
+ return file;
+}
+
+/**
+ * tracefs_put_tracing_file - Free tracing file or directory name
+ *
+ * Frees tracing file or directory, returned by
+ * tracefs_get_tracing_file() or tracefs_get_tracing_dir() APIs
+ */
+void tracefs_put_tracing_file(char *name)
+{
+ free(name);
+}
diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index 29a623b..d00d8e0 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -62,7 +62,7 @@ $(all_objs): | $(bdir)
$(bdir)/trace-cmd: $(ALL_OBJS)
$(Q)$(do_app_build)
-$(bdir)/trace-cmd: $(LIBTRACECMD_STATIC) $(LIBTRACEEVENT_STATIC)
+$(bdir)/trace-cmd: $(LIBTRACECMD_STATIC) $(LIBTRACEEVENT_STATIC) $(LIBTRACEFS_STATIC)
$(bdir)/%.o: %.c
$(Q)$(call do_compile)
diff --git a/tracecmd/trace-check-events.c b/tracecmd/trace-check-events.c
index b09fcd0..a8ee60a 100644
--- a/tracecmd/trace-check-events.c
+++ b/tracecmd/trace-check-events.c
@@ -7,6 +7,7 @@
#include <getopt.h>
#include <errno.h>
+#include "tracefs.h"
#include "trace-local.h"
void trace_check_events(int argc, char **argv)
@@ -28,7 +29,7 @@ void trace_check_events(int argc, char **argv)
break;
}
}
- tracing = tracecmd_get_tracing_dir();
+ tracing = tracefs_get_tracing_dir();
if (!tracing) {
printf("Can not find or mount tracing directory!\n"
diff --git a/tracecmd/trace-list.c b/tracecmd/trace-list.c
index 65099a5..86e3358 100644
--- a/tracecmd/trace-list.c
+++ b/tracecmd/trace-list.c
@@ -6,6 +6,7 @@
#include <stdlib.h>
+#include "tracefs.h"
#include "trace-local.h"
@@ -35,7 +36,7 @@ void show_instance_file(struct buffer_instance *instance, const char *name)
path = get_instance_file(instance, name);
dump_file_content(path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
enum {
@@ -49,9 +50,9 @@ void show_file(const char *name)
{
char *path;
- path = tracecmd_get_tracing_file(name);
+ path = tracefs_get_tracing_file(name);
dump_file_content(path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
typedef int (*process_file_func)(char *buf, int len);
@@ -86,11 +87,11 @@ static void process_file_re(process_file_func func,
free(str);
- path = tracecmd_get_tracing_file(name);
+ path = tracefs_get_tracing_file(name);
fp = fopen(path, "r");
if (!fp)
die("reading %s", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
do {
n = getline(&buf, &l, fp);
@@ -132,12 +133,12 @@ static char *get_event_file(const char *type, char *buf, int len)
if (!event)
die("no event found in %s\n", buf);
- path = tracecmd_get_tracing_file("events");
+ path = tracefs_get_tracing_file("events");
ret = asprintf(&file, "%s/%s/%s/%s", path, system, event, type);
if (ret < 0)
die("Failed to allocate event file %s %s", system, event);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return file;
}
@@ -282,9 +283,9 @@ static void show_buffers(void)
char *path;
int printed = 0;
- path = tracecmd_get_tracing_file("instances");
+ path = tracefs_get_tracing_file("instances");
dir = opendir(path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (!dir)
die("Can not read instance directory");
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 80b2234..5355813 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -39,6 +39,7 @@
#include <linux/vm_sockets.h>
#endif
+#include "tracefs.h"
#include "version.h"
#include "trace-local.h"
#include "trace-msg.h"
@@ -337,21 +338,21 @@ static void test_set_event_pid(void)
if (tested)
return;
- path = tracecmd_get_tracing_file("set_event_pid");
+ path = tracefs_get_tracing_file("set_event_pid");
ret = stat(path, &st);
if (!ret) {
have_set_event_pid = 1;
reset_save_file(path, RESET_DEFAULT_PRIO);
}
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
- path = tracecmd_get_tracing_file("options/event-fork");
+ path = tracefs_get_tracing_file("options/event-fork");
ret = stat(path, &st);
if (!ret) {
have_event_fork = 1;
reset_save_file(path, RESET_DEFAULT_PRIO);
}
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
tested = 1;
}
@@ -442,13 +443,13 @@ static int __add_all_instances(const char *tracing_dir)
*/
void add_all_instances(void)
{
- char *tracing_dir = tracecmd_find_tracing_dir();
+ char *tracing_dir = tracefs_find_tracing_dir();
if (!tracing_dir)
die("malloc");
__add_all_instances(tracing_dir);
- tracecmd_put_tracing_file(tracing_dir);
+ tracefs_put_tracing_file(tracing_dir);
}
/**
@@ -474,7 +475,7 @@ void tracecmd_stat_cpu_instance(struct buffer_instance *instance,
path = get_instance_file(instance, file);
free(file);
fd = open(path, O_RDONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (fd < 0)
return;
@@ -772,9 +773,9 @@ static int set_ftrace(int set, int use_proc)
int ret;
/* First check if the function-trace option exists */
- path = tracecmd_get_tracing_file("options/function-trace");
+ path = tracefs_get_tracing_file("options/function-trace");
ret = set_ftrace_enable(path, set);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
/* Always enable ftrace_enable proc file when set is true */
if (ret < 0 || set || use_proc)
@@ -790,7 +791,7 @@ static int set_ftrace(int set, int use_proc)
*
* Returns the path name of the @file for the given @instance.
*
- * Must use tracecmd_put_tracing_file() to free the returned string.
+ * Must use tracefs_put_tracing_file() to free the returned string.
*/
char *
get_instance_file(struct buffer_instance *instance, const char *file)
@@ -803,10 +804,10 @@ get_instance_file(struct buffer_instance *instance, const char *file)
ret = asprintf(&buf, "instances/%s/%s", instance->name, file);
if (ret < 0)
die("Failed to allocate name for %s/%s", instance->name, file);
- path = tracecmd_get_tracing_file(buf);
+ path = tracefs_get_tracing_file(buf);
free(buf);
} else
- path = tracecmd_get_tracing_file(file);
+ path = tracefs_get_tracing_file(file);
return path;
}
@@ -825,7 +826,7 @@ get_instance_dir(struct buffer_instance *instance)
ret = asprintf(&buf, "instances/%s", instance->name);
if (ret < 0)
die("Failed to allocate for instance %s", instance->name);
- path = tracecmd_get_tracing_file(buf);
+ path = tracefs_get_tracing_file(buf);
free(buf);
return path;
@@ -868,7 +869,7 @@ write_instance_file(struct buffer_instance *instance,
ret = stat(path, &st);
if (ret == 0)
ret = write_file(path, str, type);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return ret;
}
@@ -886,7 +887,7 @@ static void __clear_trace(struct buffer_instance *instance)
fp = fopen(path, "w");
if (!fp)
die("writing to '%s'", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
fwrite("0", 1, 1, fp);
fclose(fp);
}
@@ -905,11 +906,11 @@ static void clear_trace(void)
char *path;
/* reset the trace */
- path = tracecmd_get_tracing_file("trace");
+ path = tracefs_get_tracing_file("trace");
fp = fopen(path, "w");
if (!fp)
die("writing to '%s'", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
fwrite("0", 1, 1, fp);
fclose(fp);
}
@@ -956,7 +957,7 @@ static void update_ftrace_pid(const char *pid, int reset)
if (fd >= 0)
close(fd);
if (path)
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
fd = -1;
path = NULL;
return;
@@ -970,7 +971,7 @@ static void update_ftrace_pid(const char *pid, int reset)
if (fd < 0) {
if (!path)
- path = tracecmd_get_tracing_file("set_ftrace_pid");
+ path = tracefs_get_tracing_file("set_ftrace_pid");
if (!path)
return;
ret = stat(path, &st);
@@ -1601,12 +1602,12 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
* plugin for those if name is "nop".
*/
if (!strncmp(name, "nop", 3)) {
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return;
}
die("writing to '%s'", path);
}
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
fwrite(name, 1, strlen(name), fp);
fclose(fp);
@@ -1619,11 +1620,11 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
path = get_instance_file(instance, "options/func_stack_trace");
fp = fopen(path, "w");
if (!fp) {
- tracecmd_put_tracing_file(path);
- path = tracecmd_get_tracing_file("options/func_stack_trace");
+ tracefs_put_tracing_file(path);
+ path = tracefs_get_tracing_file("options/func_stack_trace");
fp = fopen(path, "w");
if (!fp) {
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return;
}
}
@@ -1632,7 +1633,7 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
* the original content.
*/
add_reset_file(path, "0", RESET_HIGH_PRIO);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
fwrite(&zero, 1, 1, fp);
fclose(fp);
}
@@ -1662,11 +1663,11 @@ static int set_option(const char *option)
FILE *fp;
char *path;
- path = tracecmd_get_tracing_file("trace_options");
+ path = tracefs_get_tracing_file("trace_options");
fp = fopen(path, "w");
if (!fp)
warning("writing to '%s'", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (!fp)
return -1;
@@ -1693,7 +1694,7 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance)
path = get_instance_file(instance, "current_tracer");
ret = stat(path, &st);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (ret < 0)
return;
@@ -1727,7 +1728,7 @@ static void add_reset_options(void)
if (keep)
return;
- path = tracecmd_get_tracing_file("trace_options");
+ path = tracefs_get_tracing_file("trace_options");
content = get_file_content(path);
for (opt = options; opt; opt = opt->next) {
@@ -1790,7 +1791,7 @@ static void add_reset_options(void)
add_reset_file(path, option, RESET_DEFAULT_PRIO);
}
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
free(content);
}
@@ -1819,14 +1820,14 @@ static void set_saved_cmdlines_size(struct common_record_context *ctx)
if (!ctx->saved_cmdlines_size)
return;
- path = tracecmd_get_tracing_file("saved_cmdlines_size");
+ path = tracefs_get_tracing_file("saved_cmdlines_size");
if (!path)
goto err;
reset_save_file(path, RESET_DEFAULT_PRIO);
fd = open(path, O_WRONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (fd < 0)
goto err;
@@ -1852,7 +1853,7 @@ static int trace_check_file_exists(struct buffer_instance *instance, char *file)
path = get_instance_file(instance, file);
ret = stat(path, &st);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return ret < 0 ? 0 : 1;
}
@@ -1884,11 +1885,11 @@ static void old_update_events(const char *name, char update)
name = "*:*";
/* need to use old way */
- path = tracecmd_get_tracing_file("set_event");
+ path = tracefs_get_tracing_file("set_event");
fp = fopen(path, "w");
if (!fp)
die("opening '%s'", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
/* Disable the event with "!" */
if (update == '0')
@@ -1935,12 +1936,12 @@ reset_events_instance(struct buffer_instance *instance)
die("opening to '%s'", path);
ret = write(fd, &c, 1);
close(fd);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
path = get_instance_file(instance, "events/*/filter");
globbuf.gl_offs = 0;
ret = glob(path, 0, NULL, &globbuf);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (ret < 0)
return;
@@ -2182,9 +2183,9 @@ static void check_tracing_enabled(void)
char *path;
if (fd < 0) {
- path = tracecmd_get_tracing_file("tracing_enabled");
+ path = tracefs_get_tracing_file("tracing_enabled");
fd = open(path, O_WRONLY | O_CLOEXEC);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (fd < 0)
return;
@@ -2205,7 +2206,7 @@ static int open_instance_fd(struct buffer_instance *instance,
if (is_top_instance(instance))
die("opening '%s'", path);
}
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return fd;
}
@@ -2526,7 +2527,7 @@ static void set_mask(struct buffer_instance *instance)
close(fd);
out:
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
free(instance->cpumask);
instance->cpumask = NULL;
}
@@ -2583,7 +2584,7 @@ static void set_clock(struct buffer_instance *instance)
add_reset_file(path, str, RESET_DEFAULT_PRIO);
free(content);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
write_instance_file(instance, "trace_clock", instance->clock, "clock");
}
@@ -2598,7 +2599,7 @@ static void set_max_graph_depth(struct buffer_instance *instance, char *max_grap
path = get_instance_file(instance, "max_graph_depth");
reset_save_file(path, RESET_DEFAULT_PRIO);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
ret = write_instance_file(instance, "max_graph_depth", max_graph_depth,
NULL);
if (ret < 0)
@@ -2721,7 +2722,7 @@ static int expand_event_files(struct buffer_instance *instance,
globbuf.gl_offs = 0;
ret = glob(path, 0, NULL, &globbuf);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
free(p);
if (ret < 0)
@@ -3182,7 +3183,7 @@ create_recorder_instance_pipe(struct buffer_instance *instance,
if (instance->name)
path = get_instance_dir(instance);
else
- path = tracecmd_find_tracing_dir();
+ path = tracefs_find_tracing_dir();
if (!path)
die("malloc");
@@ -3193,7 +3194,7 @@ create_recorder_instance_pipe(struct buffer_instance *instance,
recorder = tracecmd_create_buffer_recorder_fd(brass[1], cpu, flags, path);
if (instance->name)
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return recorder;
}
@@ -3234,7 +3235,7 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
record = tracecmd_create_buffer_recorder_maxkb(file, cpu, recorder_flags,
path, max_kb);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return record;
}
@@ -3287,9 +3288,9 @@ static int create_recorder(struct buffer_instance *instance, int cpu,
if (instance->name && !is_agent(instance))
path = get_instance_dir(instance);
else
- path = tracecmd_find_tracing_dir();
+ path = tracefs_find_tracing_dir();
recorder = tracecmd_create_buffer_recorder_fd(fd, cpu, flags, path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
} else {
file = get_temp_file(instance, cpu);
recorder = create_recorder_instance(instance, file, cpu, brass);
@@ -4124,7 +4125,7 @@ static int write_func_file(struct buffer_instance *instance,
close(fd);
ret = 0;
free:
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return ret;
failed:
die("Failed to write %s to %s.\n"
@@ -4142,7 +4143,7 @@ static int functions_filtered(struct buffer_instance *instance)
path = get_instance_file(instance, "set_ftrace_filter");
fd = open(path, O_RDONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (fd < 0) {
if (is_top_instance(instance))
warning("Can not set set_ftrace_filter");
@@ -4265,7 +4266,7 @@ static unsigned long long find_time_stamp(struct tep_handle *pevent)
int fd;
int r;
- path = tracecmd_get_tracing_file("per_cpu");
+ path = tracefs_get_tracing_file("per_cpu");
if (!path)
return 0;
@@ -4304,7 +4305,7 @@ static unsigned long long find_time_stamp(struct tep_handle *pevent)
closedir(dir);
out:
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return ts;
}
@@ -4319,7 +4320,7 @@ static char *read_instance_file(struct buffer_instance *instance, char *file, in
path = get_instance_file(instance, file);
fd = open(path, O_RDONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (fd < 0) {
warning("%s not found, --date ignored", file);
return NULL;
@@ -4400,9 +4401,9 @@ static char *get_date_to_ts(void)
goto out_pevent;
}
- path = tracecmd_get_tracing_file("trace_marker");
+ path = tracefs_get_tracing_file("trace_marker");
tfd = open(path, O_WRONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
if (tfd < 0) {
warning("Can not open 'trace_marker', --date ignored");
goto out_pevent;
@@ -4491,7 +4492,7 @@ static void set_buffer_size_instance(struct buffer_instance *instance)
warning("Can't write to %s", path);
close(fd);
out:
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
void set_buffer_size(void)
@@ -4560,7 +4561,7 @@ static void clear_instance_triggers(struct buffer_instance *instance)
trace_event_iter_free(iter);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void
@@ -4621,7 +4622,7 @@ static void clear_instance_filters(struct buffer_instance *instance)
trace_event_iter_free(iter);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void clear_filters(void)
@@ -4687,7 +4688,7 @@ static void clear_func_filters(void)
for (i = 0; files[i]; i++) {
path = get_instance_file(instance, files[i]);
clear_func_filter(path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
}
}
@@ -4712,7 +4713,7 @@ static void make_instances(void)
} else
/* Don't delete instances that already exist */
instance->flags |= BUFFER_FL_KEEP;
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
}
@@ -4734,7 +4735,7 @@ void tracecmd_remove_instances(void)
ret = rmdir(path);
if (ret < 0)
die("rmdir %s", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
}
@@ -5043,7 +5044,7 @@ static int test_stacktrace_trigger(struct buffer_instance *instance)
ret = 1;
close(fd);
out:
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return ret;
}
diff --git a/tracecmd/trace-show.c b/tracecmd/trace-show.c
index 96bfe77..391d329 100644
--- a/tracecmd/trace-show.c
+++ b/tracecmd/trace-show.c
@@ -7,6 +7,7 @@
#include <getopt.h>
#include <errno.h>
+#include "tracefs.h"
#include "trace-local.h"
enum {
@@ -157,9 +158,9 @@ void trace_show(int argc, char **argv)
if (show_name) {
char *name;
- name = tracecmd_get_tracing_file(file);
+ name = tracefs_get_tracing_file(file);
printf("%s\n", name);
- tracecmd_put_tracing_file(name);
+ tracefs_put_tracing_file(name);
}
show_file(file);
if (buffer)
diff --git a/tracecmd/trace-snapshot.c b/tracecmd/trace-snapshot.c
index a9a512a..34630b4 100644
--- a/tracecmd/trace-snapshot.c
+++ b/tracecmd/trace-snapshot.c
@@ -12,6 +12,7 @@
#include <fcntl.h>
#include <unistd.h>
+#include "tracefs.h"
#include "trace-local.h"
static void write_file(const char *name, char *val)
@@ -20,7 +21,7 @@ static void write_file(const char *name, char *val)
int fd;
ssize_t n;
- path = tracecmd_get_tracing_file(name);
+ path = tracefs_get_tracing_file(name);
fd = open(path, O_WRONLY);
if (fd < 0)
die("writing %s", path);
@@ -29,7 +30,7 @@ static void write_file(const char *name, char *val)
if (n < 0)
die("failed to write to %s\n", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
close(fd);
}
@@ -91,11 +92,11 @@ void trace_snapshot (int argc, char **argv)
file = cpu_path;
}
- name = tracecmd_get_tracing_file(file);
+ name = tracefs_get_tracing_file(file);
ret = stat(name, &st);
if (ret < 0)
die("Snapshot feature is not supported by this kernel");
- tracecmd_put_tracing_file(name);
+ tracefs_put_tracing_file(name);
if (!reset_snap && !take_snap && !free_snap) {
show_file(file);
diff --git a/tracecmd/trace-stack.c b/tracecmd/trace-stack.c
index bb002c0..5e88b36 100644
--- a/tracecmd/trace-stack.c
+++ b/tracecmd/trace-stack.c
@@ -15,6 +15,7 @@
#include <unistd.h>
#include <errno.h>
+#include "tracefs.h"
#include "trace-local.h"
#define PROC_FILE "/proc/sys/kernel/stack_tracer_enabled"
@@ -86,7 +87,7 @@ static void reset_trace(void)
int fd;
int n;
- path = tracecmd_get_tracing_file("stack_max_size");
+ path = tracefs_get_tracing_file("stack_max_size");
fd = open(path, O_WRONLY);
if (fd < 0)
die("writing %s", path);
@@ -95,7 +96,7 @@ static void reset_trace(void)
n = write(fd, buf, 1);
if (n < 0)
die("writing into %s", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
close(fd);
}
@@ -116,11 +117,11 @@ static void read_trace(void)
else
printf("(stack tracer not running)\n");
- path = tracecmd_get_tracing_file("stack_trace");
+ path = tracefs_get_tracing_file("stack_trace");
fp = fopen(path, "r");
if (!fp)
die("reading to '%s'", path);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
while ((r = getline(&buf, &n, fp)) >= 0) {
/*
diff --git a/tracecmd/trace-stat.c b/tracecmd/trace-stat.c
index 538f4ad..7a1d9bb 100644
--- a/tracecmd/trace-stat.c
+++ b/tracecmd/trace-stat.c
@@ -13,6 +13,7 @@
#include <fcntl.h>
#include <ctype.h>
+#include "tracefs.h"
#include "trace-local.h"
#ifndef BUFSIZ
@@ -32,7 +33,7 @@ static int get_instance_file_fd(struct buffer_instance *instance,
path = get_instance_file(instance, file);
fd = open(path, O_RDONLY);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return fd;
}
@@ -383,7 +384,7 @@ static void report_events(struct buffer_instance *instance)
if (!processed && !processed_part)
printf(" (none enabled)\n");
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void
@@ -456,7 +457,7 @@ static void report_event_filters(struct buffer_instance *instance)
trace_event_iter_free(iter);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void
@@ -529,7 +530,7 @@ static void report_event_triggers(struct buffer_instance *instance)
trace_event_iter_free(iter);
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
enum func_states {
@@ -604,7 +605,7 @@ static void report_graph_funcs(struct buffer_instance *instance)
list_functions(path, "Function Graph Filter");
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
path = get_instance_file(instance, "set_graph_notrace");
if (!path)
@@ -612,7 +613,7 @@ static void report_graph_funcs(struct buffer_instance *instance)
list_functions(path, "Function Graph No Trace");
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void report_ftrace_filters(struct buffer_instance *instance)
@@ -625,7 +626,7 @@ static void report_ftrace_filters(struct buffer_instance *instance)
list_functions(path, "Function Filter");
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
path = get_instance_file(instance, "set_ftrace_notrace");
if (!path)
@@ -633,7 +634,7 @@ static void report_ftrace_filters(struct buffer_instance *instance)
list_functions(path, "Function No Trace");
- tracecmd_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
}
static void report_buffers(struct buffer_instance *instance)
--
2.24.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v2 2/5] kernel-shark: Use new tracefs library
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 1/5] trace-cmd: Introduce libtracefs library Tzvetomir Stoyanov (VMware)
@ 2020-01-06 15:40 ` Tzvetomir Stoyanov (VMware)
2020-01-08 19:05 ` Steven Rostedt
2020-01-08 20:09 ` Steven Rostedt
2020-01-06 15:40 ` [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances Tzvetomir Stoyanov (VMware)
` (2 subsequent siblings)
4 siblings, 2 replies; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Link libtracefs to kernel-shark and use its API:
tracefs_get_tracing_dir()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
kernel-shark/CMakeLists.txt | 3 ++-
kernel-shark/build/FindTraceCmd.cmake | 30 +++++++++++++++++++++++++++
kernel-shark/src/CMakeLists.txt | 2 ++
kernel-shark/src/KsCaptureDialog.cpp | 4 ++--
kernel-shark/src/libkshark.h | 1 +
5 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/kernel-shark/CMakeLists.txt b/kernel-shark/CMakeLists.txt
index 20478b9..8786b83 100644
--- a/kernel-shark/CMakeLists.txt
+++ b/kernel-shark/CMakeLists.txt
@@ -76,7 +76,8 @@ endif (CMAKE_BUILD_TYPE MATCHES Package)
include_directories(${KS_DIR}/src/
${KS_DIR}/build/src/
${JSONC_INCLUDE_DIR}
- ${TRACECMD_INCLUDE_DIR})
+ ${TRACECMD_INCLUDE_DIR}
+ ${TRACEFS_INCLUDE_DIR})
message("")
message(STATUS "C flags : " ${CMAKE_C_FLAGS})
diff --git a/kernel-shark/build/FindTraceCmd.cmake b/kernel-shark/build/FindTraceCmd.cmake
index d3e145c..f27fafe 100644
--- a/kernel-shark/build/FindTraceCmd.cmake
+++ b/kernel-shark/build/FindTraceCmd.cmake
@@ -6,6 +6,8 @@
# TRACEEVENT_FOUND, If false, do not try to use traceevent.
#
# TRACECMD_INCLUDE_DIR, where to find trace-cmd header.
+# TRACEFS_INCLUDE_DIR, where to find tracefs header.
+# TRACEFS_LIBRARY, the tracefs library.
# TRACECMD_LIBRARY, the trace-cmd library.
# TRACECMD_FOUND, If false, do not try to use trace-cmd.
@@ -31,12 +33,21 @@ find_path(TRACECMD_INCLUDE_DIR NAMES trace-cmd/trace-cmd.h
PATHS $ENV{TRACE_CMD}/include/
${CMAKE_SOURCE_DIR}/../include/
NO_DEFAULT_PATH)
+find_path(TRACEFS_INCLUDE_DIR NAMES tracefs/tracefs.h
+ PATHS $ENV{TRACE_CMD}/include/
+ ${CMAKE_SOURCE_DIR}/../include/
+ NO_DEFAULT_PATH)
find_library(TRACECMD_LIBRARY NAMES trace-cmd/libtracecmd.a
PATHS $ENV{TRACE_CMD}/lib/
${CMAKE_SOURCE_DIR}/../lib/
NO_DEFAULT_PATH)
+find_library(TRACEFS_LIBRARY NAMES trace-cmd/libtracefs.a
+ PATHS $ENV{TRACE_CMD}/lib/
+ ${CMAKE_SOURCE_DIR}/../lib/
+ NO_DEFAULT_PATH)
+
find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.a
PATHS $ENV{TRACE_CMD}/lib/
${CMAKE_SOURCE_DIR}/../lib/
@@ -46,7 +57,9 @@ find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.a
# search was successful "find_path" will do nothing this time.
find_program(TRACECMD_EXECUTABLE NAMES trace-cmd)
find_path(TRACECMD_INCLUDE_DIR NAMES trace-cmd/trace-cmd.h)
+find_path(TRACEFS_INCLUDE_DIR NAMES tracefs/tracefs.h)
find_library(TRACECMD_LIBRARY NAMES trace-cmd/libtracecmd.so)
+find_library(TRACEFS_LIBRARY NAMES tracefs/libtracefs.so)
find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.so)
IF (TRACECMD_INCLUDE_DIR AND TRACECMD_LIBRARY)
@@ -65,6 +78,23 @@ ELSE (TRACECMD_FOUND)
ENDIF (TRACECMD_FOUND)
+IF (TRACEFS_INCLUDE_DIR AND TRACEFS_LIBRARY)
+
+ SET(TRACEFS_FOUND TRUE)
+
+ENDIF (TRACEFS_INCLUDE_DIR AND TRACEFS_LIBRARY)
+
+IF (TRACEFS_FOUND)
+
+ MESSAGE(STATUS "Found tracefs: ${TRACEFS_LIBRARY}")
+
+ELSE (TRACEFS_FOUND)
+
+ MESSAGE(FATAL_ERROR "\nCould not find tracefs!\n")
+
+ENDIF (TRACEFS_FOUND)
+
+
IF (TRACEEVENT_LIBRARY)
SET(TRACEEVENT_FOUND TRUE)
diff --git a/kernel-shark/src/CMakeLists.txt b/kernel-shark/src/CMakeLists.txt
index e20a030..33b5db8 100644
--- a/kernel-shark/src/CMakeLists.txt
+++ b/kernel-shark/src/CMakeLists.txt
@@ -9,6 +9,7 @@ add_library(kshark SHARED libkshark.c
target_link_libraries(kshark ${TRACEEVENT_LIBRARY}
${TRACECMD_LIBRARY}
+ ${TRACEFS_LIBRARY}
${JSONC_LIBRARY}
${CMAKE_DL_LIBS})
@@ -69,6 +70,7 @@ if (Qt5Widgets_FOUND AND Qt5Network_FOUND)
Qt5::Network
${TRACEEVENT_LIBRARY}
${TRACECMD_LIBRARY}
+ ${TRACEFS_LIBRARY}
${CMAKE_DL_LIBS})
set_target_properties(kshark-gui PROPERTIES SUFFIX ".so.${KS_VERSION_STRING}")
diff --git a/kernel-shark/src/KsCaptureDialog.cpp b/kernel-shark/src/KsCaptureDialog.cpp
index ad05917..548b6fb 100644
--- a/kernel-shark/src/KsCaptureDialog.cpp
+++ b/kernel-shark/src/KsCaptureDialog.cpp
@@ -26,7 +26,7 @@ extern "C" {
static inline tep_handle *local_events()
{
- return tracecmd_local_events(tracecmd_get_tracing_dir());
+ return tracecmd_local_events(tracefs_get_tracing_dir());
}
/**
@@ -204,7 +204,7 @@ QStringList KsCaptureControl::_getPlugins()
QStringList pluginList;
char **all_plugins;
- all_plugins = tracecmd_local_plugins(tracecmd_get_tracing_dir());
+ all_plugins = tracecmd_local_plugins(tracefs_get_tracing_dir());
if (!all_plugins)
return pluginList;
diff --git a/kernel-shark/src/libkshark.h b/kernel-shark/src/libkshark.h
index 3407db1..b05aa90 100644
--- a/kernel-shark/src/libkshark.h
+++ b/kernel-shark/src/libkshark.h
@@ -28,6 +28,7 @@ extern "C" {
#include "trace-cmd/trace-cmd.h"
#include "trace-cmd/trace-filter-hash.h"
#include "traceevent/event-parse.h"
+#include "tracefs/tracefs.h"
// KernelShark
#include "libkshark-plugin.h"
--
2.24.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 1/5] trace-cmd: Introduce libtracefs library Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 2/5] kernel-shark: Use new tracefs library Tzvetomir Stoyanov (VMware)
@ 2020-01-06 15:40 ` Tzvetomir Stoyanov (VMware)
2020-01-08 19:37 ` Steven Rostedt
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 5/5] trace-cmd,kernel-shark: New libtracefs APIs for loading ftrace events Tzvetomir Stoyanov (VMware)
4 siblings, 1 reply; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
The functionality related to ftrace instances is moved from
trace-cmd application to libtracefs. The following new
library APIs are introduced:
struct tracefs_instance;
struct tracefs_instance *tracefs_alloc_instance(const char *name);
int tracefs_free_instance(struct tracefs_instance *instance);
int tracefs_make_instance(struct tracefs_instance *instance);
int tracefs_remove_instance(struct tracefs_instance *instance);
char *tracefs_get_instance_name(struct tracefs_instance *instance);
char *tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
char *tracefs_get_instance_dir(struct tracefs_instance *instance);
int tracefs_write_instance_file(struct tracefs_instance *instance,
const char *file, const char *str, const char *type);
char *tracefs_read_instance_file(struct tracefs_instance *instance, char *file, int *psize);
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
include/tracefs/tracefs.h | 17 ++
lib/tracefs/Makefile | 1 +
lib/tracefs/include/tracefs-local.h | 1 +
lib/tracefs/tracefs-instance.c | 267 ++++++++++++++++++++++++++++
lib/tracefs/tracefs-utils.c | 43 +++++
tracecmd/include/trace-local.h | 5 +-
tracecmd/trace-list.c | 2 +-
tracecmd/trace-record.c | 264 +++++++++------------------
tracecmd/trace-show.c | 2 +
tracecmd/trace-stat.c | 21 ++-
10 files changed, 431 insertions(+), 192 deletions(-)
create mode 100644 lib/tracefs/tracefs-instance.c
diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
index e844c75..6b27ff7 100644
--- a/include/tracefs/tracefs.h
+++ b/include/tracefs/tracefs.h
@@ -17,4 +17,21 @@ const char *tracefs_get_tracing_dir(void);
/* tracefs_find_tracing_dir must be freed */
char *tracefs_find_tracing_dir(void);
+/* ftarce instances */
+struct tracefs_instance;
+
+struct tracefs_instance *tracefs_alloc_instance(const char *name);
+int tracefs_free_instance(struct tracefs_instance *instance);
+int tracefs_make_instance(struct tracefs_instance *instance);
+int tracefs_remove_instance(struct tracefs_instance *instance);
+char *tracefs_get_instance_name(struct tracefs_instance *instance);
+char *
+tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
+char *tracefs_get_instance_dir(struct tracefs_instance *instance);
+int tracefs_write_instance_file(struct tracefs_instance *instance,
+ const char *file, const char *str,
+ const char *type);
+char *tracefs_read_instance_file(struct tracefs_instance *instance,
+ char *file, int *psize);
+
#endif /* _TRACE_FS_H */
diff --git a/lib/tracefs/Makefile b/lib/tracefs/Makefile
index 86d7845..4030272 100644
--- a/lib/tracefs/Makefile
+++ b/lib/tracefs/Makefile
@@ -8,6 +8,7 @@ DEFAULT_TARGET = $(bdir)/libtracefs.a
OBJS =
OBJS += tracefs-utils.o
+OBJS += tracefs-instance.o
OBJS := $(OBJS:%.o=$(bdir)/%.o)
DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)
diff --git a/lib/tracefs/include/tracefs-local.h b/lib/tracefs/include/tracefs-local.h
index 231edd1..fe327a0 100644
--- a/lib/tracefs/include/tracefs-local.h
+++ b/lib/tracefs/include/tracefs-local.h
@@ -8,5 +8,6 @@
/* Can be overridden */
void warning(const char *fmt, ...);
+int str_read_file(const char *file, char **buffer);
#endif /* _TRACE_FS_LOCAL_H */
diff --git a/lib/tracefs/tracefs-instance.c b/lib/tracefs/tracefs-instance.c
new file mode 100644
index 0000000..14e8eed
--- /dev/null
+++ b/lib/tracefs/tracefs-instance.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * Updates:
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "tracefs.h"
+#include "tracefs-local.h"
+
+struct tracefs_instance {
+ char *name;
+};
+
+/**
+ * tracefs_alloc_instance - allocate a new ftrace instance
+ * @name: The name of the instance (instance will point to this)
+ *
+ * Returns a newly allocated instance, or NULL in case of an error.
+ */
+struct tracefs_instance *tracefs_alloc_instance(const char *name)
+{
+ struct tracefs_instance *instance;
+
+ instance = calloc(1, sizeof(*instance));
+ if (!instance)
+ return NULL;
+ if (name)
+ instance->name = strdup(name);
+
+ return instance;
+}
+
+/**
+ * tracefs_free_instance - Free an instance, previously allocated by
+ tracefs_alloc_instance()
+ * @instance: Pointer to the instance to be freed
+ *
+ * Returns -1 in case of an error, or 0 otherwise.
+ */
+int tracefs_free_instance(struct tracefs_instance *instance)
+{
+ if (!instance)
+ return -1;
+
+ free(instance->name);
+ free(instance);
+ return 0;
+}
+
+/**
+ * tracefs_make_instance - Create a new ftrace instance
+ * @instance: Pointer to the instance to be created
+ *
+ * Returns 1 if the instance already exist, 0 if the instance
+ * is created successful or -1 in case of an error
+ */
+int tracefs_make_instance(struct tracefs_instance *instance)
+{
+ struct stat st;
+ char *path;
+ int ret;
+
+ path = tracefs_get_instance_dir(instance);
+ ret = stat(path, &st);
+ if (ret < 0) {
+ ret = mkdir(path, 0777);
+ if (ret < 0)
+ return ret;
+
+ } else
+ ret = 1;
+ tracefs_put_tracing_file(path);
+ return ret;
+}
+
+/**
+ * tracefs_remove_instance - Remove a ftrace instance
+ * @instance: Pointer to the instance to be removed
+ *
+ * Returns -1 in case of an error, or 0 otherwise.
+ */
+int tracefs_remove_instance(struct tracefs_instance *instance)
+{
+ char *path;
+ int ret;
+
+ if (!instance || !instance->name) {
+ warning("Cannot remove top instance");
+ return -1;
+ }
+
+ path = tracefs_get_instance_dir(instance);
+ ret = rmdir(path);
+ tracefs_put_tracing_file(path);
+
+ return ret;
+}
+
+/**
+ * tracefs_get_instance_file - return the path to an instance file.
+ * @instance: ftrace instance, can be NULL for the top instance
+ * @file: name of file to return
+ *
+ * Returns the path of the @file for the given @instance, or NULL in
+ * case of an error.
+ *
+ * Must use tracefs_put_tracing_file() to free the returned string.
+ */
+char *
+tracefs_get_instance_file(struct tracefs_instance *instance, const char *file)
+{
+ char *path;
+ char *buf;
+ int ret;
+
+ if (instance && instance->name) {
+ ret = asprintf(&buf, "instances/%s/%s", instance->name, file);
+ if (ret < 0) {
+ warning("Failed to allocate name for %s/%s",
+ instance->name, file);
+ return NULL;
+ }
+ path = tracefs_get_tracing_file(buf);
+ free(buf);
+ } else
+ path = tracefs_get_tracing_file(file);
+
+ return path;
+}
+
+/**
+ * tracefs_get_instance_dir - return the path to the instance directory.
+ * @instance: ftrace instance, can be NULL for the top instance
+ *
+ * Returns the full path to the instance directory
+ *
+ * Must use tracefs_put_tracing_file() to free the returned string.
+ */
+char *tracefs_get_instance_dir(struct tracefs_instance *instance)
+{
+ char *buf;
+ char *path;
+ int ret;
+
+ if (instance && instance->name) {
+ ret = asprintf(&buf, "instances/%s", instance->name);
+ if (ret < 0) {
+ warning("Failed to allocate path for instance %s",
+ instance->name);
+ return NULL;
+ }
+ path = tracefs_get_tracing_file(buf);
+ free(buf);
+ } else
+ path = tracefs_find_tracing_dir();
+
+ return path;
+}
+
+/**
+ * tracefs_get_instance_name - return the name of an instance
+ * @instance: ftrace instance
+ *
+ * Returns the name of the given @instance.
+ * The returned string must *not* be freed.
+ */
+char *tracefs_get_instance_name(struct tracefs_instance *instance)
+{
+ if (instance)
+ return instance->name;
+ return NULL;
+}
+
+static int write_file(const char *file, const char *str, const char *type)
+{
+ char buf[BUFSIZ];
+ int ret;
+ int fd;
+
+ fd = open(file, O_WRONLY | O_TRUNC);
+ if (fd < 0) {
+ warning("Failed to open '%s'", file);
+ return -1;
+ }
+ ret = write(fd, str, strlen(str));
+ close(fd);
+ if (ret < 0 && type) {
+ /* write failed */
+ fd = open(file, O_RDONLY);
+ if (fd < 0) {
+ warning("Failed to write in '%s'", file);
+ return -1;
+ }
+
+ while ((ret = read(fd, buf, BUFSIZ)) > 0)
+ fprintf(stderr, "%.*s", ret, buf);
+ warning("Failed %s of %s\n", type, file);
+ close(fd);
+ }
+ return ret;
+}
+
+
+/**
+ * tracefs_write_instance_file - Write in trace file of specific instance.
+ * @instance: ftrace instance, can be NULL for the top instance
+ * @file: name of the file
+ * @str: nul terminated string, that will be written in the file.
+ * @type: nul terminated string, describing the current write operation.
+ * Used for logging purposes.
+ *
+ * Returns the number of written bytes, or -1 in case of an error
+ */
+int tracefs_write_instance_file(struct tracefs_instance *instance,
+ const char *file, const char *str,
+ const char *type)
+{
+ struct stat st;
+ char *path;
+ int ret;
+
+ path = tracefs_get_instance_file(instance, file);
+ ret = stat(path, &st);
+ if (ret == 0)
+ ret = write_file(path, str, type);
+ tracefs_put_tracing_file(path);
+
+ return ret;
+}
+
+/**
+ * tracefs_read_instance_file - Read from a trace file of specific instance.
+ * @instance: ftrace instance, can be NULL for the top instance
+ * @file: name of the file
+ * @psize: returns the number of bytes read
+ *
+ * Returns a pointer to a nul terminated string, read from the file, or NULL in
+ * case of an error.
+ * The return string must be freed by free()
+ */
+char *tracefs_read_instance_file(struct tracefs_instance *instance,
+ char *file, int *psize)
+{
+ char *buf = NULL;
+ int size = 0;
+ char *path;
+
+ path = tracefs_get_instance_file(instance, file);
+
+ size = str_read_file(path, &buf);
+
+ tracefs_put_tracing_file(path);
+ if (buf && psize)
+ *psize = size;
+
+ return buf;
+}
diff --git a/lib/tracefs/tracefs-utils.c b/lib/tracefs/tracefs-utils.c
index 0ef16fc..bdab130 100644
--- a/lib/tracefs/tracefs-utils.c
+++ b/lib/tracefs/tracefs-utils.c
@@ -10,6 +10,9 @@
#include <sys/mount.h>
#include <sys/stat.h>
#include <linux/limits.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
#include "tracefs.h"
@@ -181,3 +184,43 @@ void tracefs_put_tracing_file(char *name)
{
free(name);
}
+
+int str_read_file(const char *file, char **buffer)
+{
+ char stbuf[BUFSIZ];
+ char *buf = NULL;
+ int size = 0;
+ char *nbuf;
+ int fd;
+ int r;
+
+ fd = open(file, O_RDONLY);
+ if (fd < 0) {
+ warning("File %s not found", file);
+ return -1;
+ }
+
+ do {
+ r = read(fd, stbuf, BUFSIZ);
+ if (r <= 0)
+ continue;
+ nbuf = realloc(buf, size+r+1);
+ if (!nbuf) {
+ warning("Failed to allocate file buffer");
+ size = -1;
+ break;
+ }
+ buf = nbuf;
+ memcpy(buf+size, stbuf, r);
+ size += r;
+ } while (r);
+
+ close(fd);
+ if (size > 0) {
+ buf[size] = '\0';
+ *buffer = buf;
+ } else
+ free(buf);
+
+ return size;
+}
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index fedc0b7..c7310e5 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -181,7 +181,7 @@ struct pid_addr_maps {
struct buffer_instance {
struct buffer_instance *next;
- const char *name;
+ struct tracefs_instance *tracefs;
char *cpumask;
struct event_list *events;
struct event_list **event_next;
@@ -225,6 +225,8 @@ struct buffer_instance {
bool use_fifos;
};
+void init_top_instance(void);
+
extern struct buffer_instance top_instance;
extern struct buffer_instance *buffer_instances;
extern struct buffer_instance *first_instance;
@@ -238,7 +240,6 @@ extern struct buffer_instance *first_instance;
struct buffer_instance *create_instance(const char *name);
void add_instance(struct buffer_instance *instance, int cpu_count);
-char *get_instance_file(struct buffer_instance *instance, const char *file);
void update_first_instance(struct buffer_instance *instance, int topt);
void show_instance_file(struct buffer_instance *instance, const char *name);
diff --git a/tracecmd/trace-list.c b/tracecmd/trace-list.c
index 86e3358..d5c0707 100644
--- a/tracecmd/trace-list.c
+++ b/tracecmd/trace-list.c
@@ -34,7 +34,7 @@ void show_instance_file(struct buffer_instance *instance, const char *name)
{
char *path;
- path = get_instance_file(instance, name);
+ path = tracefs_get_instance_file(instance->tracefs, name);
dump_file_content(path);
tracefs_put_tracing_file(path);
}
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 5355813..62f67d5 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -174,7 +174,7 @@ static struct reset_file *reset_files;
/* Triggers need to be cleared in a special way */
static struct reset_file *reset_triggers;
-struct buffer_instance top_instance = { .flags = BUFFER_FL_KEEP };
+struct buffer_instance top_instance;
struct buffer_instance *buffer_instances;
struct buffer_instance *first_instance;
@@ -372,7 +372,11 @@ struct buffer_instance *create_instance(const char *name)
if (!instance)
return NULL;
memset(instance, 0, sizeof(*instance));
- instance->name = name;
+ instance->tracefs = tracefs_alloc_instance(name);
+ if (!instance->tracefs) {
+ free(instance);
+ return NULL;
+ }
return instance;
}
@@ -472,7 +476,7 @@ void tracecmd_stat_cpu_instance(struct buffer_instance *instance,
return;
snprintf(file, 40, "per_cpu/cpu%d/stats", cpu);
- path = get_instance_file(instance, file);
+ path = tracefs_get_instance_file(instance->tracefs, file);
free(file);
fd = open(path, O_RDONLY);
tracefs_put_tracing_file(path);
@@ -511,10 +515,11 @@ static void reset_event_list(struct buffer_instance *instance)
static char *get_temp_file(struct buffer_instance *instance, int cpu)
{
- const char *name = instance->name;
+ const char *name;
char *file = NULL;
int size;
+ name = tracefs_get_instance_name(instance->tracefs);
if (name) {
size = snprintf(file, 0, "%s.%s.cpu%d", output_file, name, cpu);
file = malloc(size + 1);
@@ -558,9 +563,10 @@ static void put_temp_file(char *file)
static void delete_temp_file(struct buffer_instance *instance, int cpu)
{
- const char *name = instance->name;
+ const char *name;
char file[PATH_MAX];
+ name = tracefs_get_instance_name(instance->tracefs);
if (name)
snprintf(file, PATH_MAX, "%s.%s.cpu%d", output_file, name, cpu);
else
@@ -784,54 +790,6 @@ static int set_ftrace(int set, int use_proc)
return 0;
}
-/**
- * get_instance_file - return the path to a instance file.
- * @instance: buffer instance for the file
- * @file: name of file to return
- *
- * Returns the path name of the @file for the given @instance.
- *
- * Must use tracefs_put_tracing_file() to free the returned string.
- */
-char *
-get_instance_file(struct buffer_instance *instance, const char *file)
-{
- char *buf;
- char *path;
- int ret;
-
- if (instance->name) {
- ret = asprintf(&buf, "instances/%s/%s", instance->name, file);
- if (ret < 0)
- die("Failed to allocate name for %s/%s", instance->name, file);
- path = tracefs_get_tracing_file(buf);
- free(buf);
- } else
- path = tracefs_get_tracing_file(file);
-
- return path;
-}
-
-static char *
-get_instance_dir(struct buffer_instance *instance)
-{
- char *buf;
- char *path;
- int ret;
-
- /* only works for instances */
- if (!instance->name)
- return NULL;
-
- ret = asprintf(&buf, "instances/%s", instance->name);
- if (ret < 0)
- die("Failed to allocate for instance %s", instance->name);
- path = tracefs_get_tracing_file(buf);
- free(buf);
-
- return path;
-}
-
static int write_file(const char *file, const char *str, const char *type)
{
char buf[BUFSIZ];
@@ -857,23 +815,6 @@ static int write_file(const char *file, const char *str, const char *type)
return ret;
}
-static int
-write_instance_file(struct buffer_instance *instance,
- const char *file, const char *str, const char *type)
-{
- struct stat st;
- char *path;
- int ret;
-
- path = get_instance_file(instance, file);
- ret = stat(path, &st);
- if (ret == 0)
- ret = write_file(path, str, type);
- tracefs_put_tracing_file(path);
-
- return ret;
-}
-
static void __clear_trace(struct buffer_instance *instance)
{
FILE *fp;
@@ -883,7 +824,7 @@ static void __clear_trace(struct buffer_instance *instance)
return;
/* reset the trace */
- path = get_instance_file(instance, "trace");
+ path = tracefs_get_instance_file(instance->tracefs, "trace");
fp = fopen(path, "w");
if (!fp)
die("writing to '%s'", path);
@@ -917,8 +858,8 @@ static void clear_trace(void)
static void reset_max_latency(struct buffer_instance *instance)
{
- write_instance_file(instance,
- "tracing_max_latency", "0", "max_latency");
+ tracefs_write_instance_file(instance->tracefs,
+ "tracing_max_latency", "0", "max_latency");
}
static void add_filter_pid(int pid, int exclude)
@@ -1364,7 +1305,8 @@ static void add_event_pid(const char *buf)
struct buffer_instance *instance;
for_all_instances(instance)
- write_instance_file(instance, "set_event_pid", buf, "event_pid");
+ tracefs_write_instance_file(instance->tracefs,
+ "set_event_pid", buf, "event_pid");
}
static void add_new_filter_pid(int pid)
@@ -1593,7 +1535,7 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
if (is_guest(instance))
return;
- path = get_instance_file(instance, "current_tracer");
+ path = tracefs_get_instance_file(instance->tracefs, "current_tracer");
fp = fopen(path, "w");
if (!fp) {
/*
@@ -1617,7 +1559,7 @@ set_plugin_instance(struct buffer_instance *instance, const char *name)
/* Make sure func_stack_trace option is disabled */
/* First try instance file, then top level */
- path = get_instance_file(instance, "options/func_stack_trace");
+ path = tracefs_get_instance_file(instance->tracefs, "options/func_stack_trace");
fp = fopen(path, "w");
if (!fp) {
tracefs_put_tracing_file(path);
@@ -1678,8 +1620,6 @@ static int set_option(const char *option)
return 0;
}
-static char *read_instance_file(struct buffer_instance *instance, char *file, int *psize);
-
static void disable_func_stack_trace_instance(struct buffer_instance *instance)
{
struct stat st;
@@ -1692,13 +1632,14 @@ static void disable_func_stack_trace_instance(struct buffer_instance *instance)
if (is_guest(instance))
return;
- path = get_instance_file(instance, "current_tracer");
+ path = tracefs_get_instance_file(instance->tracefs, "current_tracer");
ret = stat(path, &st);
tracefs_put_tracing_file(path);
if (ret < 0)
return;
- content = read_instance_file(instance, "current_tracer", &size);
+ content = tracefs_read_instance_file(instance->tracefs,
+ "current_tracer", &size);
cond = strstrip(content);
if (memcmp(cond, "function", size - (cond - content)) !=0)
goto out;
@@ -1851,7 +1792,7 @@ static int trace_check_file_exists(struct buffer_instance *instance, char *file)
char *path;
int ret;
- path = get_instance_file(instance, file);
+ path = tracefs_get_instance_file(instance->tracefs, file);
ret = stat(path, &st);
tracefs_put_tracing_file(path);
@@ -1930,7 +1871,7 @@ reset_events_instance(struct buffer_instance *instance)
}
c = '0';
- path = get_instance_file(instance, "events/enable");
+ path = tracefs_get_instance_file(instance->tracefs, "events/enable");
fd = open(path, O_WRONLY);
if (fd < 0)
die("opening to '%s'", path);
@@ -1938,7 +1879,7 @@ reset_events_instance(struct buffer_instance *instance)
close(fd);
tracefs_put_tracing_file(path);
- path = get_instance_file(instance, "events/*/filter");
+ path = tracefs_get_instance_file(instance->tracefs, "events/*/filter");
globbuf.gl_offs = 0;
ret = glob(path, 0, NULL, &globbuf);
tracefs_put_tracing_file(path);
@@ -2199,7 +2140,7 @@ static int open_instance_fd(struct buffer_instance *instance,
int fd;
char *path;
- path = get_instance_file(instance, file);
+ path = tracefs_get_instance_file(instance->tracefs, file);
fd = open(path, flags);
if (fd < 0) {
/* instances may not be created yet */
@@ -2508,7 +2449,7 @@ static void set_mask(struct buffer_instance *instance)
if (!instance->cpumask)
return;
- path = get_instance_file(instance, "tracing_cpumask");
+ path = tracefs_get_instance_file(instance->tracefs, "tracing_cpumask");
if (!path)
die("could not allocate path");
reset_save_file(path, RESET_DEFAULT_PRIO);
@@ -2569,7 +2510,8 @@ static void set_clock(struct buffer_instance *instance)
return;
/* The current clock is in brackets, reset it when we are done */
- content = read_instance_file(instance, "trace_clock", NULL);
+ content = tracefs_read_instance_file(instance->tracefs,
+ "trace_clock", NULL);
/* check if first clock is set */
if (*content == '[')
@@ -2580,13 +2522,14 @@ static void set_clock(struct buffer_instance *instance)
die("Can not find clock in trace_clock");
str = strtok(NULL, "]");
}
- path = get_instance_file(instance, "trace_clock");
+ path = tracefs_get_instance_file(instance->tracefs, "trace_clock");
add_reset_file(path, str, RESET_DEFAULT_PRIO);
free(content);
tracefs_put_tracing_file(path);
- write_instance_file(instance, "trace_clock", instance->clock, "clock");
+ tracefs_write_instance_file(instance->tracefs,
+ "trace_clock", instance->clock, "clock");
}
static void set_max_graph_depth(struct buffer_instance *instance, char *max_graph_depth)
@@ -2597,11 +2540,11 @@ static void set_max_graph_depth(struct buffer_instance *instance, char *max_grap
if (is_guest(instance))
return;
- path = get_instance_file(instance, "max_graph_depth");
+ path = tracefs_get_instance_file(instance->tracefs, "max_graph_depth");
reset_save_file(path, RESET_DEFAULT_PRIO);
tracefs_put_tracing_file(path);
- ret = write_instance_file(instance, "max_graph_depth", max_graph_depth,
- NULL);
+ ret = tracefs_write_instance_file(instance->tracefs, "max_graph_depth",
+ max_graph_depth, NULL);
if (ret < 0)
die("could not write to max_graph_depth");
}
@@ -2718,7 +2661,7 @@ static int expand_event_files(struct buffer_instance *instance,
if (ret < 0)
die("Failed to allocate event filter path for %s", file);
- path = get_instance_file(instance, p);
+ path = tracefs_get_instance_file(instance->tracefs, p);
globbuf.gl_offs = 0;
ret = glob(path, 0, NULL, &globbuf);
@@ -3180,10 +3123,7 @@ create_recorder_instance_pipe(struct buffer_instance *instance,
unsigned flags = recorder_flags | TRACECMD_RECORD_BLOCK;
char *path;
- if (instance->name)
- path = get_instance_dir(instance);
- else
- path = tracefs_find_tracing_dir();
+ path = tracefs_get_instance_dir(instance->tracefs);
if (!path)
die("malloc");
@@ -3193,8 +3133,7 @@ create_recorder_instance_pipe(struct buffer_instance *instance,
recorder = tracecmd_create_buffer_recorder_fd(brass[1], cpu, flags, path);
- if (instance->name)
- tracefs_put_tracing_file(path);
+ tracefs_put_tracing_file(path);
return recorder;
}
@@ -3228,10 +3167,10 @@ create_recorder_instance(struct buffer_instance *instance, const char *file, int
if (brass)
return create_recorder_instance_pipe(instance, cpu, brass);
- if (!instance->name)
+ if (!tracefs_get_instance_name(instance->tracefs))
return tracecmd_create_recorder_maxkb(file, cpu, recorder_flags, max_kb);
- path = get_instance_dir(instance);
+ path = tracefs_get_instance_dir(instance->tracefs);
record = tracecmd_create_buffer_recorder_maxkb(file, cpu, recorder_flags,
path, max_kb);
@@ -3285,8 +3224,8 @@ static int create_recorder(struct buffer_instance *instance, int cpu,
}
if (fd < 0)
die("Failed connecting to client");
- if (instance->name && !is_agent(instance))
- path = get_instance_dir(instance);
+ if (tracefs_get_instance_name(instance->tracefs) && !is_agent(instance))
+ path = tracefs_get_instance_dir(instance->tracefs);
else
path = tracefs_find_tracing_dir();
recorder = tracecmd_create_buffer_recorder_fd(fd, cpu, flags, path);
@@ -3597,9 +3536,11 @@ static void connect_to_agent(struct buffer_instance *instance)
unsigned int *ports;
int i, *fds = NULL;
bool use_fifos = false;
+ char *name;
+ name = tracefs_get_instance_name(instance->tracefs);
if (!no_fifos) {
- nr_fifos = open_guest_fifos(instance->name, &fds);
+ nr_fifos = open_guest_fifos(name, &fds);
use_fifos = nr_fifos > 0;
}
@@ -3626,7 +3567,7 @@ static void connect_to_agent(struct buffer_instance *instance)
if (nr_cpus != nr_fifos) {
warning("number of FIFOs (%d) for guest %s differs "
"from number of virtual CPUs (%d)",
- nr_fifos, instance->name, nr_cpus);
+ nr_fifos, name, nr_cpus);
nr_cpus = nr_cpus < nr_fifos ? nr_cpus : nr_fifos;
}
free(ports);
@@ -3652,7 +3593,8 @@ static void setup_guest(struct buffer_instance *instance)
int fd;
/* Create a place to store the guest meta data */
- file = get_guest_file(output_file, instance->name);
+ file = get_guest_file(output_file,
+ tracefs_get_instance_name(instance->tracefs));
if (!file)
die("Failed to allocate memory");
@@ -3828,7 +3770,8 @@ add_buffer_stat(struct tracecmd_output *handle, struct buffer_instance *instance
int i;
trace_seq_init(&s);
- trace_seq_printf(&s, "\nBuffer: %s\n\n", instance->name);
+ trace_seq_printf(&s, "\nBuffer: %s\n\n",
+ tracefs_get_instance_name(instance->tracefs));
tracecmd_add_option(handle, TRACECMD_OPTION_CPUSTAT,
s.len+1, s.buffer);
trace_seq_destroy(&s);
@@ -3894,7 +3837,8 @@ static void print_stat(struct buffer_instance *instance)
return;
if (!is_top_instance(instance))
- printf("\nBuffer: %s\n\n", instance->name);
+ printf("\nBuffer: %s\n\n",
+ tracefs_get_instance_name(instance->tracefs));
for (cpu = 0; cpu < instance->cpu_count; cpu++)
trace_seq_do_printf(&instance->s_print[cpu]);
@@ -3934,7 +3878,8 @@ static void write_guest_file(struct buffer_instance *instance)
char **temp_files;
int i, fd;
- file = get_guest_file(output_file, instance->name);
+ file = get_guest_file(output_file,
+ tracefs_get_instance_name(instance->tracefs));
if (!file)
die("Failed to allocate memory");
@@ -4050,7 +3995,7 @@ static void record_data(struct common_record_context *ctx)
continue;
buffer_options[i++] = tracecmd_add_buffer_option(handle,
- instance->name,
+ tracefs_get_instance_name(instance->tracefs),
cpus);
add_buffer_stat(handle, instance);
}
@@ -4097,7 +4042,7 @@ static int write_func_file(struct buffer_instance *instance,
if (!*list)
return 0;
- path = get_instance_file(instance, file);
+ path = tracefs_get_instance_file(instance->tracefs, file);
fd = open(path, O_WRONLY | O_TRUNC);
if (fd < 0)
@@ -4141,7 +4086,7 @@ static int functions_filtered(struct buffer_instance *instance)
char *path;
int fd;
- path = get_instance_file(instance, "set_ftrace_filter");
+ path = tracefs_get_instance_file(instance->tracefs, "set_ftrace_filter");
fd = open(path, O_RDONLY);
tracefs_put_tracing_file(path);
if (fd < 0) {
@@ -4149,7 +4094,7 @@ static int functions_filtered(struct buffer_instance *instance)
warning("Can not set set_ftrace_filter");
else
warning("Can not set set_ftrace_filter for %s",
- instance->name);
+ tracefs_get_instance_name(instance->tracefs));
return 0;
}
@@ -4309,45 +4254,9 @@ static unsigned long long find_time_stamp(struct tep_handle *pevent)
return ts;
}
-static char *read_instance_file(struct buffer_instance *instance, char *file, int *psize)
-{
- char buffer[BUFSIZ];
- char *path;
- char *buf;
- int size = 0;
- int fd;
- int r;
-
- path = get_instance_file(instance, file);
- fd = open(path, O_RDONLY);
- tracefs_put_tracing_file(path);
- if (fd < 0) {
- warning("%s not found, --date ignored", file);
- return NULL;
- }
- do {
- r = read(fd, buffer, BUFSIZ);
- if (r <= 0)
- continue;
- if (size)
- buf = realloc(buf, size+r+1);
- else
- buf = malloc(r+1);
- if (!buf)
- die("Failed to allocate instance file buffer");
- memcpy(buf+size, buffer, r);
- size += r;
- } while (r);
-
- buf[size] = '\0';
- if (psize)
- *psize = size;
- return buf;
-}
-
static char *read_file(char *file, int *psize)
{
- return read_instance_file(&top_instance, file, psize);
+ return tracefs_read_instance_file(top_instance.tracefs, file, psize);
}
/*
@@ -4480,7 +4389,7 @@ static void set_buffer_size_instance(struct buffer_instance *instance)
snprintf(buf, BUFSIZ, "%d", buffer_size);
- path = get_instance_file(instance, "buffer_size_kb");
+ path = tracefs_get_instance_file(instance->tracefs, "buffer_size_kb");
fd = open(path, O_WRONLY);
if (fd < 0) {
warning("can't open %s", path);
@@ -4541,7 +4450,7 @@ static void clear_instance_triggers(struct buffer_instance *instance)
enum event_iter_type type;
enum event_process processed = PROCESSED_NONE;
- path = get_instance_file(instance, "events");
+ path = tracefs_get_instance_file(instance->tracefs, "events");
if (!path)
die("malloc");
@@ -4602,7 +4511,7 @@ static void clear_instance_filters(struct buffer_instance *instance)
enum event_iter_type type;
enum event_process processed = PROCESSED_NONE;
- path = get_instance_file(instance, "events");
+ path = tracefs_get_instance_file(instance->tracefs, "events");
if (!path)
die("malloc");
@@ -4638,7 +4547,8 @@ static void reset_clock(void)
struct buffer_instance *instance;
for_all_instances(instance)
- write_instance_file(instance, "trace_clock", "local", "clock");
+ tracefs_write_instance_file(instance->tracefs,
+ "trace_clock", "local", "clock");
}
static void reset_cpu_mask(void)
@@ -4657,7 +4567,8 @@ static void reset_cpu_mask(void)
strcat(buf, ",ffffffff");
for_all_instances(instance)
- write_instance_file(instance, "tracing_cpumask", buf, "cpumask");
+ tracefs_write_instance_file(instance->tracefs,
+ "tracing_cpumask", buf, "cpumask");
}
static void reset_event_pid(void)
@@ -4686,7 +4597,7 @@ static void clear_func_filters(void)
for_all_instances(instance) {
for (i = 0; files[i]; i++) {
- path = get_instance_file(instance, files[i]);
+ path = tracefs_get_instance_file(instance->tracefs, files[i]);
clear_func_filter(path);
tracefs_put_tracing_file(path);
}
@@ -4696,32 +4607,20 @@ static void clear_func_filters(void)
static void make_instances(void)
{
struct buffer_instance *instance;
- struct stat st;
- char *path;
- int ret;
for_each_instance(instance) {
if (is_guest(instance))
continue;
-
- path = get_instance_dir(instance);
- ret = stat(path, &st);
- if (ret < 0) {
- ret = mkdir(path, 0777);
- if (ret < 0)
- die("mkdir %s", path);
- } else
+ if (tracefs_make_instance(instance->tracefs) > 0) {
/* Don't delete instances that already exist */
instance->flags |= BUFFER_FL_KEEP;
- tracefs_put_tracing_file(path);
+ }
}
}
void tracecmd_remove_instances(void)
{
struct buffer_instance *instance;
- char *path;
- int ret;
for_each_instance(instance) {
/* Only delete what we created */
@@ -4731,11 +4630,7 @@ void tracecmd_remove_instances(void)
close(instance->tracing_on_fd);
instance->tracing_on_fd = 0;
}
- path = get_instance_dir(instance);
- ret = rmdir(path);
- if (ret < 0)
- die("rmdir %s", path);
- tracefs_put_tracing_file(path);
+ tracefs_remove_instance(instance->tracefs);
}
}
@@ -5029,7 +4924,8 @@ static int test_stacktrace_trigger(struct buffer_instance *instance)
int ret = 0;
int fd;
- path = get_instance_file(instance, "events/sched/sched_switch/trigger");
+ path = tracefs_get_instance_file(instance->tracefs,
+ "events/sched/sched_switch/trigger");
clear_trigger(path);
@@ -5211,6 +5107,15 @@ void update_first_instance(struct buffer_instance *instance, int topt)
first_instance = buffer_instances;
}
+void init_top_instance(void)
+{
+ if (!top_instance.tracefs)
+ top_instance.tracefs = tracefs_alloc_instance(NULL);
+ top_instance.cpu_count = count_cpus();
+ top_instance.flags = BUFFER_FL_KEEP;
+ init_instance(&top_instance);
+}
+
enum {
OPT_user = 243,
OPT_procmap = 244,
@@ -5235,7 +5140,7 @@ void trace_stop(int argc, char **argv)
int topt = 0;
struct buffer_instance *instance = &top_instance;
- init_instance(instance);
+ init_top_instance();
for (;;) {
int c;
@@ -5276,7 +5181,7 @@ void trace_restart(int argc, char **argv)
int topt = 0;
struct buffer_instance *instance = &top_instance;
- init_instance(instance);
+ init_top_instance();
for (;;) {
int c;
@@ -5318,7 +5223,7 @@ void trace_reset(int argc, char **argv)
int topt = 0;
struct buffer_instance *instance = &top_instance;
- init_instance(instance);
+ init_top_instance();
/* if last arg is -a, then -b and -d apply to all instances */
int last_specified_all = 0;
@@ -5403,9 +5308,8 @@ static void init_common_record_context(struct common_record_context *ctx,
memset(ctx, 0, sizeof(*ctx));
ctx->instance = &top_instance;
ctx->curr_cmd = curr_cmd;
- init_instance(ctx->instance);
local_cpu_count = count_cpus();
- ctx->instance->cpu_count = local_cpu_count;
+ init_top_instance();
}
#define IS_EXTRACT(ctx) ((ctx)->curr_cmd == CMD_extract)
diff --git a/tracecmd/trace-show.c b/tracecmd/trace-show.c
index 391d329..a6f2102 100644
--- a/tracecmd/trace-show.c
+++ b/tracecmd/trace-show.c
@@ -52,6 +52,8 @@ void trace_show(int argc, char **argv)
{NULL, 0, NULL, 0}
};
+ init_top_instance();
+
while ((c = getopt_long(argc-1, argv+1, "B:c:fsp",
long_options, &option_index)) >= 0) {
switch (c) {
diff --git a/tracecmd/trace-stat.c b/tracecmd/trace-stat.c
index 7a1d9bb..948118c 100644
--- a/tracecmd/trace-stat.c
+++ b/tracecmd/trace-stat.c
@@ -31,7 +31,7 @@ static int get_instance_file_fd(struct buffer_instance *instance,
char *path;
int fd;
- path = get_instance_file(instance, file);
+ path = tracefs_get_instance_file(instance->tracefs, file);
fd = open(path, O_RDONLY);
tracefs_put_tracing_file(path);
@@ -348,7 +348,7 @@ static void report_events(struct buffer_instance *instance)
free(str);
- path = get_instance_file(instance, "events");
+ path = tracefs_get_instance_file(instance->tracefs, "events");
if (!path)
die("malloc");
@@ -437,7 +437,7 @@ static void report_event_filters(struct buffer_instance *instance)
enum event_iter_type type;
enum event_process processed = PROCESSED_NONE;
- path = get_instance_file(instance, "events");
+ path = tracefs_get_instance_file(instance->tracefs, "events");
if (!path)
die("malloc");
@@ -510,7 +510,7 @@ static void report_event_triggers(struct buffer_instance *instance)
enum event_iter_type type;
enum event_process processed = PROCESSED_NONE;
- path = get_instance_file(instance, "events");
+ path = tracefs_get_instance_file(instance->tracefs, "events");
if (!path)
die("malloc");
@@ -599,7 +599,7 @@ static void report_graph_funcs(struct buffer_instance *instance)
{
char *path;
- path = get_instance_file(instance, "set_graph_function");
+ path = tracefs_get_instance_file(instance->tracefs, "set_graph_function");
if (!path)
die("malloc");
@@ -607,7 +607,7 @@ static void report_graph_funcs(struct buffer_instance *instance)
tracefs_put_tracing_file(path);
- path = get_instance_file(instance, "set_graph_notrace");
+ path = tracefs_get_instance_file(instance->tracefs, "set_graph_notrace");
if (!path)
die("malloc");
@@ -620,7 +620,7 @@ static void report_ftrace_filters(struct buffer_instance *instance)
{
char *path;
- path = get_instance_file(instance, "set_ftrace_filter");
+ path = tracefs_get_instance_file(instance->tracefs, "set_ftrace_filter");
if (!path)
die("malloc");
@@ -628,7 +628,7 @@ static void report_ftrace_filters(struct buffer_instance *instance)
tracefs_put_tracing_file(path);
- path = get_instance_file(instance, "set_ftrace_notrace");
+ path = tracefs_get_instance_file(instance->tracefs, "set_ftrace_notrace");
if (!path)
die("malloc");
@@ -858,7 +858,8 @@ static void stat_instance(struct buffer_instance *instance)
if (instance != &top_instance) {
if (instance != first_instance)
printf("---------------\n");
- printf("Instance: %s\n", instance->name);
+ printf("Instance: %s\n",
+ tracefs_get_instance_name(instance->tracefs));
}
report_plugin(instance);
@@ -883,6 +884,8 @@ void trace_stat (int argc, char **argv)
int status;
int c;
+ init_top_instance();
+
for (;;) {
c = getopt(argc-1, argv+1, "tB:");
if (c == -1)
--
2.24.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
` (2 preceding siblings ...)
2020-01-06 15:40 ` [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances Tzvetomir Stoyanov (VMware)
@ 2020-01-06 15:40 ` Tzvetomir Stoyanov (VMware)
2020-01-08 20:22 ` Steven Rostedt
` (2 more replies)
2020-01-06 15:40 ` [PATCH v2 5/5] trace-cmd,kernel-shark: New libtracefs APIs for loading ftrace events Tzvetomir Stoyanov (VMware)
4 siblings, 3 replies; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
The functionality related to ftrace events and systems
is moved from trace-cmd application and libtracecmd to libtracefs.
The following libtracecmd APIs are removed:
tracecmd_read_page_record();
tracecmd_event_systems();
tracecmd_system_events();
tracecmd_local_plugins();
tracecmd_add_list();
tracecmd_free_list();
The following new library APIs are introduced:
tracefs_read_page_record();
tracefs_event_systems();
tracefs_system_events();
tracefs_local_plugins();
tracefs_iterate_raw_events();
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
include/trace-cmd/trace-cmd.h | 8 -
include/tracefs/tracefs.h | 15 +
kernel-shark/src/KsCaptureDialog.cpp | 2 +-
lib/trace-cmd/trace-input.c | 95 ------
lib/trace-cmd/trace-util.c | 265 ---------------
lib/tracefs/Makefile | 1 +
lib/tracefs/tracefs-events.c | 476 +++++++++++++++++++++++++++
tracecmd/trace-record.c | 2 +-
8 files changed, 494 insertions(+), 370 deletions(-)
create mode 100644 lib/tracefs/tracefs-events.c
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 66736ae..30bb144 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -24,15 +24,10 @@ void tracecmd_parse_ftrace_printk(struct tep_handle *pevent, char *file, unsigne
extern int tracecmd_disable_sys_plugins;
extern int tracecmd_disable_plugins;
-char **tracecmd_event_systems(const char *tracing_dir);
-char **tracecmd_system_events(const char *tracing_dir, const char *system);
struct tep_handle *tracecmd_local_events(const char *tracing_dir);
int tracecmd_fill_local_events(const char *tracing_dir,
struct tep_handle *pevent, int *parsing_failures);
-char **tracecmd_local_plugins(const char *tracing_dir);
-char **tracecmd_add_list(char **list, const char *name, int len);
-void tracecmd_free_list(char **list);
int *tracecmd_add_id(int *list, int id, int len);
enum {
@@ -143,9 +138,6 @@ void tracecmd_print_stats(struct tracecmd_input *handle);
void tracecmd_print_uname(struct tracecmd_input *handle);
void tracecmd_print_version(struct tracecmd_input *handle);
-struct tep_record *
-tracecmd_read_page_record(struct tep_handle *pevent, void *page, int size,
- struct tep_record *last_record);
struct tep_record *
tracecmd_peek_data(struct tracecmd_input *handle, int cpu);
diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
index 6b27ff7..c66250c 100644
--- a/include/tracefs/tracefs.h
+++ b/include/tracefs/tracefs.h
@@ -34,4 +34,19 @@ int tracefs_write_instance_file(struct tracefs_instance *instance,
char *tracefs_read_instance_file(struct tracefs_instance *instance,
char *file, int *psize);
+/* events */
+struct tep_record *
+tracefs_read_page_record(struct tep_handle *tep, void *page, int size,
+ struct tep_record *last_record);
+char **tracefs_event_systems(const char *tracing_dir);
+char **tracefs_system_events(const char *tracing_dir, const char *system);
+int tracefs_iterate_raw_events(struct tep_handle *tep,
+ struct tracefs_instance *instance,
+ int (*callback)(struct tep_event *,
+ struct tep_record *,
+ int, void *),
+ void *callback_context);
+
+char **tracefs_local_plugins(const char *tracing_dir);
+
#endif /* _TRACE_FS_H */
diff --git a/kernel-shark/src/KsCaptureDialog.cpp b/kernel-shark/src/KsCaptureDialog.cpp
index 548b6fb..49c8755 100644
--- a/kernel-shark/src/KsCaptureDialog.cpp
+++ b/kernel-shark/src/KsCaptureDialog.cpp
@@ -204,7 +204,7 @@ QStringList KsCaptureControl::_getPlugins()
QStringList pluginList;
char **all_plugins;
- all_plugins = tracecmd_local_plugins(tracefs_get_tracing_dir());
+ all_plugins = tracefs_local_plugins(tracefs_get_tracing_dir());
if (!all_plugins)
return pluginList;
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 3b187e3..67c7236 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -1663,101 +1663,6 @@ tracecmd_translate_data(struct tracecmd_input *handle,
return record;
}
-/**
- * tracecmd_read_page_record - read a record off of a page
- * @pevent: pevent used to parse the page
- * @page: the page to read
- * @size: the size of the page
- * @last_record: last record read from this page.
- *
- * If a ring buffer page is available, and the need to parse it
- * without having a handle, then this function can be used.
- *
- * The @pevent needs to be initialized to have the page header information
- * already available.
- *
- * The @last_record is used to know where to read the next record from.
- * If @last_record is NULL, the first record on the page will be read.
- *
- * Returns:
- * A newly allocated record that must be freed with free_record() if
- * a record is found. Otherwise NULL is returned if the record is bad
- * or no more records exist.
- */
-struct tep_record *
-tracecmd_read_page_record(struct tep_handle *pevent, void *page, int size,
- struct tep_record *last_record)
-{
- unsigned long long ts;
- struct kbuffer *kbuf;
- struct tep_record *record = NULL;
- enum kbuffer_long_size long_size;
- enum kbuffer_endian endian;
- void *ptr;
-
- if (tep_is_file_bigendian(pevent))
- endian = KBUFFER_ENDIAN_BIG;
- else
- endian = KBUFFER_ENDIAN_LITTLE;
-
- if (tep_get_header_page_size(pevent) == 8)
- long_size = KBUFFER_LSIZE_8;
- else
- long_size = KBUFFER_LSIZE_4;
-
- kbuf = kbuffer_alloc(long_size, endian);
- if (!kbuf)
- return NULL;
-
- kbuffer_load_subbuffer(kbuf, page);
- if (kbuffer_subbuffer_size(kbuf) > size) {
- warning("tracecmd_read_page_record: page_size > size");
- goto out_free;
- }
-
- if (last_record) {
- if (last_record->data < page || last_record->data >= (page + size)) {
- warning("tracecmd_read_page_record: bad last record (size=%u)",
- last_record->size);
- goto out_free;
- }
-
- ptr = kbuffer_read_event(kbuf, &ts);
- while (ptr < last_record->data) {
- ptr = kbuffer_next_event(kbuf, NULL);
- if (!ptr)
- break;
- if (ptr == last_record->data)
- break;
- }
- if (ptr != last_record->data) {
- warning("tracecmd_read_page_record: could not find last_record");
- goto out_free;
- }
- ptr = kbuffer_next_event(kbuf, &ts);
- } else
- ptr = kbuffer_read_event(kbuf, &ts);
-
- if (!ptr)
- goto out_free;
-
- record = malloc(sizeof(*record));
- if (!record)
- return NULL;
- memset(record, 0, sizeof(*record));
-
- record->ts = ts;
- record->size = kbuffer_event_size(kbuf);
- record->record_size = kbuffer_curr_size(kbuf);
- record->cpu = 0;
- record->data = ptr;
- record->ref_count = 1;
-
- out_free:
- kbuffer_free(kbuf);
- return record;
-}
-
/**
* tracecmd_peek_data - return the record at the current location.
* @handle: input handle for the trace.dat file
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index 1394469..1554e88 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -153,56 +153,6 @@ static char *append_file(const char *dir, const char *name)
return ret < 0 ? NULL : file;
}
-/**
- * tracecmd_add_list - add an new string to a string list.
- * @list: list to add the string to (may be NULL)
- * @name: the string to add
- * @len: current length of list of strings.
- *
- * The typical usage is:
- *
- * systems = tracecmd_add_list(systems, name, len++);
- *
- * Returns the new allocated list with an allocated name added.
- * The list will end with NULL.
- */
-char **tracecmd_add_list(char **list, const char *name, int len)
-{
- if (!list)
- list = malloc(sizeof(*list) * 2);
- else
- list = realloc(list, sizeof(*list) * (len + 2));
- if (!list)
- return NULL;
-
- list[len] = strdup(name);
- if (!list[len])
- return NULL;
-
- list[len + 1] = NULL;
-
- return list;
-}
-
-/**
- * tracecmd_free_list - free a list created with tracecmd_add_list.
- * @list: The list to free.
- *
- * Frees the list as well as the names within the list.
- */
-void tracecmd_free_list(char **list)
-{
- int i;
-
- if (!list)
- return;
-
- for (i = 0; list[i]; i++)
- free(list[i]);
-
- free(list);
-}
-
/**
* tracecmd_add_id - add an int to the event id list
* @list: list to add the id to
@@ -233,160 +183,6 @@ int *tracecmd_add_id(int *list, int id, int len)
return list;
}
-/**
- * tracecmd_event_systems - return list of systems for tracing
- * @tracing_dir: directory holding the "events" directory
- *
- * Returns an allocated list of system names. Both the names and
- * the list must be freed with free().
- * The list returned ends with a "NULL" pointer.
- */
-char **tracecmd_event_systems(const char *tracing_dir)
-{
- struct dirent *dent;
- char **systems = NULL;
- char *events_dir;
- struct stat st;
- DIR *dir;
- int len = 0;
- int ret;
-
- if (!tracing_dir)
- return NULL;
-
- events_dir = append_file(tracing_dir, "events");
- if (!events_dir)
- return NULL;
-
- /*
- * Search all the directories in the events directory,
- * and collect the ones that have the "enable" file.
- */
- ret = stat(events_dir, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode))
- goto out_free;
-
- dir = opendir(events_dir);
- if (!dir)
- goto out_free;
-
- while ((dent = readdir(dir))) {
- const char *name = dent->d_name;
- char *enable;
- char *sys;
-
- if (strcmp(name, ".") == 0 ||
- strcmp(name, "..") == 0)
- continue;
-
- sys = append_file(events_dir, name);
- ret = stat(sys, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode)) {
- free(sys);
- continue;
- }
-
- enable = append_file(sys, "enable");
-
- ret = stat(enable, &st);
- if (ret >= 0)
- systems = tracecmd_add_list(systems, name, len++);
-
- free(enable);
- free(sys);
- }
-
- closedir(dir);
-
- out_free:
- free(events_dir);
- return systems;
-}
-
-/**
- * tracecmd_system_events - return list of events for system
- * @tracing_dir: directory holding the "events" directory
- * @system: the system to return the events for
- *
- * Returns an allocated list of event names. Both the names and
- * the list must be freed with free().
- * The list returned ends with a "NULL" pointer.
- */
-char **tracecmd_system_events(const char *tracing_dir, const char *system)
-{
- struct dirent *dent;
- char **events = NULL;
- char *events_dir;
- char *system_dir;
- struct stat st;
- DIR *dir;
- int len = 0;
- int ret;
-
- if (!tracing_dir || !system)
- return NULL;
-
- events_dir = append_file(tracing_dir, "events");
- if (!events_dir)
- return NULL;
-
- /*
- * Search all the directories in the systems directory,
- * and collect the ones that have the "enable" file.
- */
- ret = stat(events_dir, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode))
- goto out_free;
-
- system_dir = append_file(events_dir, system);
- if (!system_dir)
- goto out_free;
-
- ret = stat(system_dir, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode))
- goto out_free_sys;
-
- dir = opendir(system_dir);
- if (!dir)
- goto out_free_sys;
-
- while ((dent = readdir(dir))) {
- const char *name = dent->d_name;
- char *enable;
- char *event;
-
- if (strcmp(name, ".") == 0 ||
- strcmp(name, "..") == 0)
- continue;
-
- event = append_file(system_dir, name);
- ret = stat(event, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode)) {
- free(event);
- continue;
- }
-
- enable = append_file(event, "enable");
-
- ret = stat(enable, &st);
- if (ret >= 0)
- events = tracecmd_add_list(events, name, len++);
-
- free(enable);
- free(event);
- }
-
- closedir(dir);
-
- out_free_sys:
- free(system_dir);
-
- out_free:
- free(events_dir);
-
- return events;
-}
-
static int read_file(const char *file, char **buffer)
{
char *buf;
@@ -604,67 +400,6 @@ int tracecmd_fill_local_events(const char *tracing_dir,
return ret;
}
-/**
- * tracecmd_local_plugins - returns an array of available tracer plugins
- * @tracing_dir: The directory that contains the tracing directory
- *
- * Returns an allocate list of plugins. The array ends with NULL.
- * Both the plugin names and array must be freed with free().
- */
-char **tracecmd_local_plugins(const char *tracing_dir)
-{
- char *available_tracers;
- struct stat st;
- char **plugins = NULL;
- char *buf;
- char *str, *saveptr;
- char *plugin;
- int slen;
- int len;
- int ret;
-
- if (!tracing_dir)
- return NULL;
-
- available_tracers = append_file(tracing_dir, "available_tracers");
- if (!available_tracers)
- return NULL;
-
- ret = stat(available_tracers, &st);
- if (ret < 0)
- goto out_free;
-
- len = read_file(available_tracers, &buf);
- if (len < 0)
- goto out_free;
-
- len = 0;
- for (str = buf; ; str = NULL) {
- plugin = strtok_r(str, " ", &saveptr);
- if (!plugin)
- break;
- if (!(slen = strlen(plugin)))
- continue;
-
- /* chop off any newlines */
- if (plugin[slen - 1] == '\n')
- plugin[slen - 1] = '\0';
-
- /* Skip the non tracers */
- if (strcmp(plugin, "nop") == 0 ||
- strcmp(plugin, "none") == 0)
- continue;
-
- plugins = tracecmd_add_list(plugins, plugin, len++);
- }
- free(buf);
-
- out_free:
- free(available_tracers);
-
- return plugins;
-}
-
struct add_plugin_data {
int ret;
int index;
diff --git a/lib/tracefs/Makefile b/lib/tracefs/Makefile
index 4030272..5763e06 100644
--- a/lib/tracefs/Makefile
+++ b/lib/tracefs/Makefile
@@ -9,6 +9,7 @@ DEFAULT_TARGET = $(bdir)/libtracefs.a
OBJS =
OBJS += tracefs-utils.o
OBJS += tracefs-instance.o
+OBJS += tracefs-events.o
OBJS := $(OBJS:%.o=$(bdir)/%.o)
DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)
diff --git a/lib/tracefs/tracefs-events.c b/lib/tracefs/tracefs-events.c
new file mode 100644
index 0000000..5d40f06
--- /dev/null
+++ b/lib/tracefs/tracefs-events.c
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * Updates:
+ * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
+ *
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "kbuffer.h"
+#include "tracefs.h"
+#include "tracefs-local.h"
+
+/**
+ * tracefs_read_page_record - read a record off of a page
+ * @tep: tep used to parse the page
+ * @page: the page to read
+ * @size: the size of the page
+ * @last_record: last record read from this page
+ *
+ * If a ring buffer page is available, and the need to parse it
+ * without having a handle, then this function can be used
+ *
+ * The @tep needs to be initialized to have the page header information
+ * already available.
+ *
+ * The @last_record is used to know where to read the next record from
+ * If @last_record is NULL, the first record on the page will be read
+ *
+ * Returns:
+ * A newly allocated record that must be freed with free_record() if
+ * a record is found. Otherwise NULL is returned if the record is bad
+ * or no more records exist
+ */
+struct tep_record *
+tracefs_read_page_record(struct tep_handle *tep, void *page, int size,
+ struct tep_record *last_record)
+{
+ unsigned long long ts;
+ struct kbuffer *kbuf;
+ struct tep_record *record = NULL;
+ enum kbuffer_long_size long_size;
+ enum kbuffer_endian endian;
+ void *ptr;
+
+ if (tep_is_file_bigendian(tep))
+ endian = KBUFFER_ENDIAN_BIG;
+ else
+ endian = KBUFFER_ENDIAN_LITTLE;
+
+ if (tep_get_header_page_size(tep) == 8)
+ long_size = KBUFFER_LSIZE_8;
+ else
+ long_size = KBUFFER_LSIZE_4;
+
+ kbuf = kbuffer_alloc(long_size, endian);
+ if (!kbuf)
+ return NULL;
+
+ kbuffer_load_subbuffer(kbuf, page);
+ if (kbuffer_subbuffer_size(kbuf) > size) {
+ warning("%s: page_size > size", __func__);
+ goto out_free;
+ }
+
+ if (last_record) {
+ if (last_record->data < page || last_record->data >= (page + size)) {
+ warning("%s: bad last record (size=%u)",
+ __func__, last_record->size);
+ goto out_free;
+ }
+
+ ptr = kbuffer_read_event(kbuf, &ts);
+ while (ptr < last_record->data) {
+ ptr = kbuffer_next_event(kbuf, NULL);
+ if (!ptr)
+ break;
+ if (ptr == last_record->data)
+ break;
+ }
+ if (ptr != last_record->data) {
+ warning("$s: could not find last_record", __func__);
+ goto out_free;
+ }
+ ptr = kbuffer_next_event(kbuf, &ts);
+ } else
+ ptr = kbuffer_read_event(kbuf, &ts);
+
+ if (!ptr)
+ goto out_free;
+
+ record = malloc(sizeof(*record));
+ if (!record)
+ return NULL;
+ memset(record, 0, sizeof(*record));
+
+ record->ts = ts;
+ record->size = kbuffer_event_size(kbuf);
+ record->record_size = kbuffer_curr_size(kbuf);
+ record->cpu = 0;
+ record->data = ptr;
+ record->ref_count = 1;
+
+ out_free:
+ kbuffer_free(kbuf);
+ return record;
+}
+
+static void free_record(struct tep_record *record)
+{
+ if (!record)
+ return;
+
+ if (record->ref_count > 0)
+ record->ref_count--;
+ if (record->ref_count)
+ return;
+
+ free(record);
+}
+
+static int
+get_events_in_page(struct tep_handle *tep, void *page,
+ int size, int cpu,
+ int (*callback)(struct tep_event *,
+ struct tep_record *,
+ int, void *),
+ void *callback_context)
+{
+ struct tep_record *last_record = NULL;
+ struct tep_event *event = NULL;
+ struct tep_record *record;
+ int id, cnt = 0;
+
+ if (size <= 0)
+ return 0;
+
+ while (true) {
+ event = NULL;
+ record = tracefs_read_page_record(tep, page, size, last_record);
+ if (!record)
+ break;
+ free_record(last_record);
+ id = tep_data_type(tep, record);
+ event = tep_find_event(tep, id);
+ if (event && callback) {
+ if (callback(event, record, cpu, callback_context))
+ break;
+ }
+ last_record = record;
+ }
+ free_record(last_record);
+
+ return cnt;
+}
+
+/*
+ * tracefs_iterate_raw_events - Iterate through events in trace_pipe_raw
+ * per CPU trace files
+ * @tep: a handle to the trace event parser context
+ * @instance: ftrace instance, can be NULL for the top instance
+ * @callback: A user function, called for each record from the file
+ * @callback_context: A custom context, passed to the user callback function
+ *
+ * If the @callback returns non-zero, the iteration stops - in that case all
+ * records from the current page will be lost from future reads
+ *
+ * Returns -1 in case of an error, or 0 otherwise
+ */
+int tracefs_iterate_raw_events(struct tep_handle *tep,
+ struct tracefs_instance *instance,
+ int (*callback)(struct tep_event *,
+ struct tep_record *,
+ int, void *),
+ void *callback_context)
+{
+ unsigned int p_size;
+ struct dirent *dent;
+ char file[PATH_MAX];
+ void *page = NULL;
+ struct stat st;
+ char *path;
+ DIR *dir;
+ int ret;
+ int cpu;
+ int fd;
+ int r;
+
+ p_size = getpagesize();
+ path = tracefs_get_instance_file(instance, "per_cpu");
+ if (!path)
+ return -1;
+ dir = opendir(path);
+ if (!dir) {
+ ret = -1;
+ goto error;
+ }
+ page = malloc(p_size);
+ if (!page) {
+ ret = -1;
+ goto error;
+ }
+ while ((dent = readdir(dir))) {
+ const char *name = dent->d_name;
+
+ if (strlen(name) < 4 || strncmp(name, "cpu", 3) != 0)
+ continue;
+ cpu = atoi(name + 3);
+ sprintf(file, "%s/%s", path, name);
+ ret = stat(file, &st);
+ if (ret < 0 || !S_ISDIR(st.st_mode))
+ continue;
+
+ sprintf(file, "%s/%s/trace_pipe_raw", path, name);
+ fd = open(file, O_RDONLY | O_NONBLOCK);
+ if (fd < 0)
+ continue;
+ do {
+ r = read(fd, page, p_size);
+ if (r > 0)
+ get_events_in_page(tep, page, r, cpu,
+ callback, callback_context);
+ } while (r > 0);
+ close(fd);
+ }
+ ret = 0;
+
+error:
+ if (dir)
+ closedir(dir);
+ free(page);
+ tracefs_put_tracing_file(path);
+ return ret;
+}
+
+static char **add_list_string(char **list, const char *name, int len)
+{
+ if (!list)
+ list = malloc(sizeof(*list) * 2);
+ else
+ list = realloc(list, sizeof(*list) * (len + 2));
+ if (!list)
+ return NULL;
+
+ list[len] = strdup(name);
+ if (!list[len])
+ return NULL;
+
+ list[len + 1] = NULL;
+
+ return list;
+}
+
+static char *append_file(const char *dir, const char *name)
+{
+ char *file;
+ int ret;
+
+ ret = asprintf(&file, "%s/%s", dir, name);
+
+ return ret < 0 ? NULL : file;
+}
+
+/**
+ * tracefs_event_systems - return list of systems for tracing
+ * @tracing_dir: directory holding the "events" directory
+ * if NULL, top tracing directory is used
+ *
+ * Returns an allocated list of system names. Both the names and
+ * the list must be freed with free()
+ * The list returned ends with a "NULL" pointer
+ */
+char **tracefs_event_systems(const char *tracing_dir)
+{
+ struct dirent *dent;
+ char **systems = NULL;
+ char *events_dir;
+ struct stat st;
+ DIR *dir;
+ int len = 0;
+ int ret;
+
+ if (!tracing_dir)
+ tracing_dir = tracefs_get_tracing_dir();
+
+ if (!tracing_dir)
+ return NULL;
+
+ events_dir = append_file(tracing_dir, "events");
+ if (!events_dir)
+ return NULL;
+
+ /*
+ * Search all the directories in the events directory,
+ * and collect the ones that have the "enable" file.
+ */
+ ret = stat(events_dir, &st);
+ if (ret < 0 || !S_ISDIR(st.st_mode))
+ goto out_free;
+
+ dir = opendir(events_dir);
+ if (!dir)
+ goto out_free;
+
+ while ((dent = readdir(dir))) {
+ const char *name = dent->d_name;
+ char *enable;
+ char *sys;
+
+ if (strcmp(name, ".") == 0 ||
+ strcmp(name, "..") == 0)
+ continue;
+
+ sys = append_file(events_dir, name);
+ ret = stat(sys, &st);
+ if (ret < 0 || !S_ISDIR(st.st_mode)) {
+ free(sys);
+ continue;
+ }
+
+ enable = append_file(sys, "enable");
+
+ ret = stat(enable, &st);
+ if (ret >= 0)
+ systems = add_list_string(systems, name, len++);
+
+ free(enable);
+ free(sys);
+ }
+
+ closedir(dir);
+
+ out_free:
+ free(events_dir);
+ return systems;
+}
+
+/**
+ * tracefs_system_events - return list of events for system
+ * @tracing_dir: directory holding the "events" directory
+ * @system: the system to return the events for
+ *
+ * Returns an allocated list of event names. Both the names and
+ * the list must be freed with free()
+ * The list returned ends with a "NULL" pointer
+ */
+char **tracefs_system_events(const char *tracing_dir, const char *system)
+{
+ struct dirent *dent;
+ char **events = NULL;
+ char *system_dir = NULL;
+ struct stat st;
+ DIR *dir;
+ int len = 0;
+ int ret;
+
+ if (!tracing_dir)
+ tracing_dir = tracefs_get_tracing_dir();
+
+ if (!tracing_dir || !system)
+ return NULL;
+
+ asprintf(&system_dir, "%s/events/%s", tracing_dir, system);
+ if (!system_dir)
+ return NULL;
+
+ ret = stat(system_dir, &st);
+ if (ret < 0 || !S_ISDIR(st.st_mode))
+ goto out_free;
+
+ dir = opendir(system_dir);
+ if (!dir)
+ goto out_free;
+
+ while ((dent = readdir(dir))) {
+ const char *name = dent->d_name;
+ char *enable;
+ char *event;
+
+ if (strcmp(name, ".") == 0 ||
+ strcmp(name, "..") == 0)
+ continue;
+
+ event = append_file(system_dir, name);
+ ret = stat(event, &st);
+ if (ret < 0 || !S_ISDIR(st.st_mode)) {
+ free(event);
+ continue;
+ }
+
+ enable = append_file(event, "enable");
+
+ ret = stat(enable, &st);
+ if (ret >= 0)
+ events = add_list_string(events, name, len++);
+
+ free(enable);
+ free(event);
+ }
+
+ closedir(dir);
+
+ out_free:
+ free(system_dir);
+
+ return events;
+}
+
+/**
+ * tracefs_local_plugins - returns an array of available tracer plugins
+ * @tracing_dir: The directory that contains the tracing directory
+ *
+ * Returns an allocate list of plugins. The array ends with NULL
+ * Both the plugin names and array must be freed with free()
+ */
+char **tracefs_local_plugins(const char *tracing_dir)
+{
+ char *available_tracers;
+ struct stat st;
+ char **plugins = NULL;
+ char *buf;
+ char *str, *saveptr;
+ char *plugin;
+ int slen;
+ int len;
+ int ret;
+
+ if (!tracing_dir)
+ return NULL;
+
+ available_tracers = append_file(tracing_dir, "available_tracers");
+ if (!available_tracers)
+ return NULL;
+
+ ret = stat(available_tracers, &st);
+ if (ret < 0)
+ goto out_free;
+
+ len = str_read_file(available_tracers, &buf);
+ if (len < 0)
+ goto out_free;
+
+ len = 0;
+ for (str = buf; ; str = NULL) {
+ plugin = strtok_r(str, " ", &saveptr);
+ if (!plugin)
+ break;
+ slen = strlen(plugin);
+ if (!slen)
+ continue;
+
+ /* chop off any newlines */
+ if (plugin[slen - 1] == '\n')
+ plugin[slen - 1] = '\0';
+
+ /* Skip the non tracers */
+ if (strcmp(plugin, "nop") == 0 ||
+ strcmp(plugin, "none") == 0)
+ continue;
+
+ plugins = add_list_string(plugins, plugin, len++);
+ }
+ free(buf);
+
+ out_free:
+ free(available_tracers);
+
+ return plugins;
+}
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 62f67d5..1d91e87 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -4178,7 +4178,7 @@ find_ts_in_page(struct tep_handle *pevent, void *page, int size)
return 0;
while (!ts) {
- record = tracecmd_read_page_record(pevent, page, size,
+ record = tracefs_read_page_record(pevent, page, size,
last_record);
if (!record)
break;
--
2.24.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v2 5/5] trace-cmd,kernel-shark: New libtracefs APIs for loading ftrace events
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
` (3 preceding siblings ...)
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
@ 2020-01-06 15:40 ` Tzvetomir Stoyanov (VMware)
4 siblings, 0 replies; 15+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-01-06 15:40 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
The functionality related to loading local ftrace events
to a pet handler is moved from libtracecmd to libtracefs.
The following libtracecmd APIs are removed:
tracecmd_local_events();
tracecmd_fill_local_events();
The following new library APIs are introduced:
tracefs_local_events();
tracefs_fill_local_events();
The APIs are reimplemented to reuse functionality from
tracefs_event_systems() and
tracefs_system_events()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
include/trace-cmd/trace-cmd.h | 4 -
include/tracefs/tracefs.h | 4 +
kernel-shark/src/KsCaptureDialog.cpp | 2 +-
lib/trace-cmd/trace-util.c | 228 ---------------------------
lib/tracefs/tracefs-events.c | 185 ++++++++++++++++++++++
tracecmd/trace-check-events.c | 2 +-
6 files changed, 191 insertions(+), 234 deletions(-)
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 30bb144..da5bd2d 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -24,10 +24,6 @@ void tracecmd_parse_ftrace_printk(struct tep_handle *pevent, char *file, unsigne
extern int tracecmd_disable_sys_plugins;
extern int tracecmd_disable_plugins;
-struct tep_handle *tracecmd_local_events(const char *tracing_dir);
-int tracecmd_fill_local_events(const char *tracing_dir,
- struct tep_handle *pevent, int *parsing_failures);
-
int *tracecmd_add_id(int *list, int id, int len);
enum {
diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
index c66250c..998671b 100644
--- a/include/tracefs/tracefs.h
+++ b/include/tracefs/tracefs.h
@@ -49,4 +49,8 @@ int tracefs_iterate_raw_events(struct tep_handle *tep,
char **tracefs_local_plugins(const char *tracing_dir);
+struct tep_handle *tracefs_local_events(const char *tracing_dir);
+int tracefs_fill_local_events(const char *tracing_dir,
+ struct tep_handle *tep, int *parsing_failures);
+
#endif /* _TRACE_FS_H */
diff --git a/kernel-shark/src/KsCaptureDialog.cpp b/kernel-shark/src/KsCaptureDialog.cpp
index 49c8755..409eb0e 100644
--- a/kernel-shark/src/KsCaptureDialog.cpp
+++ b/kernel-shark/src/KsCaptureDialog.cpp
@@ -26,7 +26,7 @@ extern "C" {
static inline tep_handle *local_events()
{
- return tracecmd_local_events(tracefs_get_tracing_dir());
+ return tracefs_local_events(tracefs_get_tracing_dir());
}
/**
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index 1554e88..795e83d 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -142,17 +142,6 @@ void tracecmd_parse_ftrace_printk(struct tep_handle *pevent,
}
}
-/* FIXME: append_file() is duplicated and could be consolidated */
-static char *append_file(const char *dir, const char *name)
-{
- char *file;
- int ret;
-
- ret = asprintf(&file, "%s/%s", dir, name);
-
- return ret < 0 ? NULL : file;
-}
-
/**
* tracecmd_add_id - add an int to the event id list
* @list: list to add the id to
@@ -183,223 +172,6 @@ int *tracecmd_add_id(int *list, int id, int len)
return list;
}
-static int read_file(const char *file, char **buffer)
-{
- char *buf;
- int len = 0;
- int fd;
- int r;
-
- fd = open(file, O_RDONLY);
- if (fd < 0)
- return -1;
-
- buf = malloc(BUFSIZ + 1);
- if (!buf) {
- len = -1;
- goto out;
- }
-
- while ((r = read(fd, buf + len, BUFSIZ)) > 0) {
- len += r;
- buf = realloc(buf, len + BUFSIZ + 1);
- if (!buf) {
- len = -1;
- goto out;
- }
- }
-
- *buffer = buf;
- buf[len] = 0;
- out:
- close(fd);
-
- return len;
-}
-
-static int load_events(struct tep_handle *pevent, const char *system,
- const char *sys_dir)
-{
- struct dirent *dent;
- struct stat st;
- DIR *dir;
- int len = 0;
- int ret = 0, failure = 0;
-
- ret = stat(sys_dir, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode))
- return EINVAL;
-
- dir = opendir(sys_dir);
- if (!dir)
- return errno;
-
- while ((dent = readdir(dir))) {
- const char *name = dent->d_name;
- char *event;
- char *format;
- char *buf;
-
- if (strcmp(name, ".") == 0 ||
- strcmp(name, "..") == 0)
- continue;
-
- event = append_file(sys_dir, name);
- ret = stat(event, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode))
- goto free_event;
-
- format = append_file(event, "format");
- ret = stat(format, &st);
- if (ret < 0)
- goto free_format;
-
- len = read_file(format, &buf);
- if (len < 0)
- goto free_format;
-
- ret = tep_parse_event(pevent, buf, len, system);
- free(buf);
- free_format:
- free(format);
- free_event:
- free(event);
- if (ret)
- failure = ret;
- }
-
- closedir(dir);
- return failure;
-}
-
-static int read_header(struct tep_handle *pevent, const char *events_dir)
-{
- struct stat st;
- char *header;
- char *buf;
- int len;
- int ret = -1;
-
- header = append_file(events_dir, "header_page");
-
- ret = stat(header, &st);
- if (ret < 0)
- goto out;
-
- len = read_file(header, &buf);
- if (len < 0)
- goto out;
-
- tep_parse_header_page(pevent, buf, len, sizeof(long));
-
- free(buf);
-
- ret = 0;
- out:
- free(header);
- return ret;
-}
-
-/**
- * tracecmd_local_events - create a pevent from the events on system
- * @tracing_dir: The directory that contains the events.
- *
- * Returns a pevent structure that contains the pevents local to
- * the system.
- */
-struct tep_handle *tracecmd_local_events(const char *tracing_dir)
-{
- struct tep_handle *pevent = NULL;
-
- pevent = tep_alloc();
- if (!pevent)
- return NULL;
-
- if (tracecmd_fill_local_events(tracing_dir, pevent, NULL)) {
- tep_free(pevent);
- pevent = NULL;
- }
-
- return pevent;
-}
-
-/**
- * tracecmd_fill_local_events - Fill a pevent with the events on system
- * @tracing_dir: The directory that contains the events.
- * @pevent: Allocated pevent which will be filled
- * @parsing_failures: return number of failures while parsing the event files
- *
- * Returns whether the operation succeeded
- */
-int tracecmd_fill_local_events(const char *tracing_dir,
- struct tep_handle *pevent, int *parsing_failures)
-{
- struct dirent *dent;
- char *events_dir;
- struct stat st;
- DIR *dir;
- int ret;
-
- if (!tracing_dir)
- return -1;
- if (parsing_failures)
- *parsing_failures = 0;
-
- events_dir = append_file(tracing_dir, "events");
- if (!events_dir)
- return -1;
-
- ret = stat(events_dir, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode)) {
- ret = -1;
- goto out_free;
- }
-
- dir = opendir(events_dir);
- if (!dir) {
- ret = -1;
- goto out_free;
- }
-
- ret = read_header(pevent, events_dir);
- if (ret < 0) {
- ret = -1;
- goto out_free;
- }
-
- while ((dent = readdir(dir))) {
- const char *name = dent->d_name;
- char *sys;
-
- if (strcmp(name, ".") == 0 ||
- strcmp(name, "..") == 0)
- continue;
-
- sys = append_file(events_dir, name);
- ret = stat(sys, &st);
- if (ret < 0 || !S_ISDIR(st.st_mode)) {
- free(sys);
- continue;
- }
-
- ret = load_events(pevent, name, sys);
-
- free(sys);
-
- if (ret && parsing_failures)
- (*parsing_failures)++;
- }
-
- closedir(dir);
- /* always succeed because parsing failures are not critical */
- ret = 0;
-
- out_free:
- free(events_dir);
-
- return ret;
-}
-
struct add_plugin_data {
int ret;
int index;
diff --git a/lib/tracefs/tracefs-events.c b/lib/tracefs/tracefs-events.c
index 5d40f06..805db86 100644
--- a/lib/tracefs/tracefs-events.c
+++ b/lib/tracefs/tracefs-events.c
@@ -474,3 +474,188 @@ char **tracefs_local_plugins(const char *tracing_dir)
return plugins;
}
+
+static int load_events(struct tep_handle *tep,
+ const char *tracing_dir, const char *system)
+{
+ int ret = 0, failure = 0;
+ char **events = NULL;
+ struct stat st;
+ int len = 0;
+ int i;
+
+ events = tracefs_system_events(tracing_dir, system);
+ if (!events)
+ return -ENOENT;
+
+ for (i = 0; events[i]; i++) {
+ char *format;
+ char *buf;
+
+ ret = asprintf(&format, "%s/events/%s/%s/format",
+ tracing_dir, system, events[i]);
+ if (ret < 0) {
+ failure = -ENOMEM;
+ break;
+ }
+
+ ret = stat(format, &st);
+ if (ret < 0)
+ goto next_event;
+
+ len = str_read_file(format, &buf);
+ if (len < 0)
+ goto next_event;
+
+ ret = tep_parse_event(tep, buf, len, system);
+ free(buf);
+next_event:
+ free(format);
+ if (ret)
+ failure = ret;
+ }
+
+ if (events) {
+ for (i = 0; events[i]; i++)
+ free(events[i]);
+ free(events);
+ }
+ return failure;
+}
+
+static int read_header(struct tep_handle *tep, const char *tracing_dir)
+{
+ struct stat st;
+ char *header;
+ char *buf;
+ int len;
+ int ret = -1;
+
+ header = append_file(tracing_dir, "events/header_page");
+
+ ret = stat(header, &st);
+ if (ret < 0)
+ goto out;
+
+ len = str_read_file(header, &buf);
+ if (len < 0)
+ goto out;
+
+ tep_parse_header_page(tep, buf, len, sizeof(long));
+
+ free(buf);
+
+ ret = 0;
+ out:
+ free(header);
+ return ret;
+}
+
+static bool contains(const char *name, const char * const *names)
+{
+ if (!names)
+ return false;
+ for (; *names; names++)
+ if (strcmp(name, *names) == 0)
+ return true;
+ return false;
+}
+
+static int tracecmd_fill_local_events_system(const char *tracing_dir,
+ struct tep_handle *tep,
+ const char * const *sys_names,
+ int *parsing_failures)
+{
+ char **systems = NULL;
+ int ret;
+ int i;
+
+ if (!tracing_dir)
+ tracing_dir = tracefs_get_tracing_dir();
+ if (!tracing_dir)
+ return -1;
+
+ systems = tracefs_event_systems(tracing_dir);
+ if (!systems)
+ return -1;
+
+ ret = read_header(tep, tracing_dir);
+ if (ret < 0) {
+ ret = -1;
+ goto out;
+ }
+
+ if (parsing_failures)
+ *parsing_failures = 0;
+
+ for (i = 0; systems[i]; i++) {
+ if (sys_names && !contains(systems[i], sys_names))
+ continue;
+ ret = load_events(tep, tracing_dir, systems[i]);
+ if (ret && parsing_failures)
+ (*parsing_failures)++;
+ }
+ /* always succeed because parsing failures are not critical */
+ ret = 0;
+out:
+ if (systems) {
+ for (i = 0; systems[i]; i++)
+ free(systems[i]);
+ free(systems);
+ }
+ return ret;
+}
+
+/**
+ * tracecmd_local_events_system - create a tep from the events of the specified subsystem.
+ *
+ * @tracing_dir: The directory that contains the events.
+ * @sys_name: Array of system names, to load the events from.
+ * The last element from the array must be NULL
+ *
+ * Returns a tep structure that contains the tep local to
+ * the system.
+ */
+struct tep_handle *tracecmd_local_events_system(const char *tracing_dir,
+ const char * const *sys_names)
+{
+ struct tep_handle *tep = NULL;
+
+ tep = tep_alloc();
+ if (!tep)
+ return NULL;
+
+ if (tracecmd_fill_local_events_system(tracing_dir, tep, sys_names, NULL)) {
+ tep_free(tep);
+ tep = NULL;
+ }
+
+ return tep;
+}
+
+/**
+ * tracefs_local_events - create a tep from the events on system
+ * @tracing_dir: The directory that contains the events.
+ *
+ * Returns a tep structure that contains the teps local to
+ * the system.
+ */
+struct tep_handle *tracefs_local_events(const char *tracing_dir)
+{
+ return tracecmd_local_events_system(tracing_dir, NULL);
+}
+
+/**
+ * tracefs_fill_local_events - Fill a tep with the events on system
+ * @tracing_dir: The directory that contains the events.
+ * @tep: Allocated tep handler which will be filled
+ * @parsing_failures: return number of failures while parsing the event files
+ *
+ * Returns whether the operation succeeded
+ */
+int tracefs_fill_local_events(const char *tracing_dir,
+ struct tep_handle *tep, int *parsing_failures)
+{
+ return tracecmd_fill_local_events_system(tracing_dir, tep,
+ NULL, parsing_failures);
+}
diff --git a/tracecmd/trace-check-events.c b/tracecmd/trace-check-events.c
index a8ee60a..d37af67 100644
--- a/tracecmd/trace-check-events.c
+++ b/tracecmd/trace-check-events.c
@@ -50,7 +50,7 @@ void trace_check_events(int argc, char **argv)
tep_set_flag(pevent, TEP_DISABLE_SYS_PLUGINS);
list = tep_load_plugins(pevent);
- ret = tracecmd_fill_local_events(tracing, pevent, &parsing_failures);
+ ret = tracefs_fill_local_events(tracing, pevent, &parsing_failures);
if (ret || parsing_failures)
ret = EINVAL;
tep_unload_plugins(list, pevent);
--
2.24.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/5] kernel-shark: Use new tracefs library
2020-01-06 15:40 ` [PATCH v2 2/5] kernel-shark: Use new tracefs library Tzvetomir Stoyanov (VMware)
@ 2020-01-08 19:05 ` Steven Rostedt
2020-01-08 20:09 ` Steven Rostedt
1 sibling, 0 replies; 15+ messages in thread
From: Steven Rostedt @ 2020-01-08 19:05 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:55 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> Link libtracefs to kernel-shark and use its API:
> tracefs_get_tracing_dir()
>
This needs to be merged into the first patch, because the first patch
breaks the build, with breaks bisectability, which is a no-no.
-- Steve
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
> kernel-shark/CMakeLists.txt | 3 ++-
> kernel-shark/build/FindTraceCmd.cmake | 30 +++++++++++++++++++++++++++
> kernel-shark/src/CMakeLists.txt | 2 ++
> kernel-shark/src/KsCaptureDialog.cpp | 4 ++--
> kernel-shark/src/libkshark.h | 1 +
> 5 files changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/kernel-shark/CMakeLists.txt b/kernel-shark/CMakeLists.txt
> index 20478b9..8786b83 100644
> --- a/kernel-shark/CMakeLists.txt
> +++ b/kernel-shark/CMakeLists.txt
> @@ -76,7 +76,8 @@ endif (CMAKE_BUILD_TYPE MATCHES Package)
> include_directories(${KS_DIR}/src/
> ${KS_DIR}/build/src/
> ${JSONC_INCLUDE_DIR}
> - ${TRACECMD_INCLUDE_DIR})
> + ${TRACECMD_INCLUDE_DIR}
> + ${TRACEFS_INCLUDE_DIR})
>
> message("")
> message(STATUS "C flags : " ${CMAKE_C_FLAGS})
> diff --git a/kernel-shark/build/FindTraceCmd.cmake b/kernel-shark/build/FindTraceCmd.cmake
> index d3e145c..f27fafe 100644
> --- a/kernel-shark/build/FindTraceCmd.cmake
> +++ b/kernel-shark/build/FindTraceCmd.cmake
> @@ -6,6 +6,8 @@
> # TRACEEVENT_FOUND, If false, do not try to use traceevent.
> #
> # TRACECMD_INCLUDE_DIR, where to find trace-cmd header.
> +# TRACEFS_INCLUDE_DIR, where to find tracefs header.
> +# TRACEFS_LIBRARY, the tracefs library.
> # TRACECMD_LIBRARY, the trace-cmd library.
> # TRACECMD_FOUND, If false, do not try to use trace-cmd.
>
> @@ -31,12 +33,21 @@ find_path(TRACECMD_INCLUDE_DIR NAMES trace-cmd/trace-cmd.h
> PATHS $ENV{TRACE_CMD}/include/
> ${CMAKE_SOURCE_DIR}/../include/
> NO_DEFAULT_PATH)
> +find_path(TRACEFS_INCLUDE_DIR NAMES tracefs/tracefs.h
> + PATHS $ENV{TRACE_CMD}/include/
> + ${CMAKE_SOURCE_DIR}/../include/
> + NO_DEFAULT_PATH)
>
> find_library(TRACECMD_LIBRARY NAMES trace-cmd/libtracecmd.a
> PATHS $ENV{TRACE_CMD}/lib/
> ${CMAKE_SOURCE_DIR}/../lib/
> NO_DEFAULT_PATH)
>
> +find_library(TRACEFS_LIBRARY NAMES trace-cmd/libtracefs.a
> + PATHS $ENV{TRACE_CMD}/lib/
> + ${CMAKE_SOURCE_DIR}/../lib/
> + NO_DEFAULT_PATH)
> +
> find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.a
> PATHS $ENV{TRACE_CMD}/lib/
> ${CMAKE_SOURCE_DIR}/../lib/
> @@ -46,7 +57,9 @@ find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.a
> # search was successful "find_path" will do nothing this time.
> find_program(TRACECMD_EXECUTABLE NAMES trace-cmd)
> find_path(TRACECMD_INCLUDE_DIR NAMES trace-cmd/trace-cmd.h)
> +find_path(TRACEFS_INCLUDE_DIR NAMES tracefs/tracefs.h)
> find_library(TRACECMD_LIBRARY NAMES trace-cmd/libtracecmd.so)
> +find_library(TRACEFS_LIBRARY NAMES tracefs/libtracefs.so)
> find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.so)
>
> IF (TRACECMD_INCLUDE_DIR AND TRACECMD_LIBRARY)
> @@ -65,6 +78,23 @@ ELSE (TRACECMD_FOUND)
>
> ENDIF (TRACECMD_FOUND)
>
> +IF (TRACEFS_INCLUDE_DIR AND TRACEFS_LIBRARY)
> +
> + SET(TRACEFS_FOUND TRUE)
> +
> +ENDIF (TRACEFS_INCLUDE_DIR AND TRACEFS_LIBRARY)
> +
> +IF (TRACEFS_FOUND)
> +
> + MESSAGE(STATUS "Found tracefs: ${TRACEFS_LIBRARY}")
> +
> +ELSE (TRACEFS_FOUND)
> +
> + MESSAGE(FATAL_ERROR "\nCould not find tracefs!\n")
> +
> +ENDIF (TRACEFS_FOUND)
> +
> +
> IF (TRACEEVENT_LIBRARY)
>
> SET(TRACEEVENT_FOUND TRUE)
> diff --git a/kernel-shark/src/CMakeLists.txt b/kernel-shark/src/CMakeLists.txt
> index e20a030..33b5db8 100644
> --- a/kernel-shark/src/CMakeLists.txt
> +++ b/kernel-shark/src/CMakeLists.txt
> @@ -9,6 +9,7 @@ add_library(kshark SHARED libkshark.c
>
> target_link_libraries(kshark ${TRACEEVENT_LIBRARY}
> ${TRACECMD_LIBRARY}
> + ${TRACEFS_LIBRARY}
> ${JSONC_LIBRARY}
> ${CMAKE_DL_LIBS})
>
> @@ -69,6 +70,7 @@ if (Qt5Widgets_FOUND AND Qt5Network_FOUND)
> Qt5::Network
> ${TRACEEVENT_LIBRARY}
> ${TRACECMD_LIBRARY}
> + ${TRACEFS_LIBRARY}
> ${CMAKE_DL_LIBS})
>
> set_target_properties(kshark-gui PROPERTIES SUFFIX ".so.${KS_VERSION_STRING}")
> diff --git a/kernel-shark/src/KsCaptureDialog.cpp b/kernel-shark/src/KsCaptureDialog.cpp
> index ad05917..548b6fb 100644
> --- a/kernel-shark/src/KsCaptureDialog.cpp
> +++ b/kernel-shark/src/KsCaptureDialog.cpp
> @@ -26,7 +26,7 @@ extern "C" {
>
> static inline tep_handle *local_events()
> {
> - return tracecmd_local_events(tracecmd_get_tracing_dir());
> + return tracecmd_local_events(tracefs_get_tracing_dir());
> }
>
> /**
> @@ -204,7 +204,7 @@ QStringList KsCaptureControl::_getPlugins()
> QStringList pluginList;
> char **all_plugins;
>
> - all_plugins = tracecmd_local_plugins(tracecmd_get_tracing_dir());
> + all_plugins = tracecmd_local_plugins(tracefs_get_tracing_dir());
>
> if (!all_plugins)
> return pluginList;
> diff --git a/kernel-shark/src/libkshark.h b/kernel-shark/src/libkshark.h
> index 3407db1..b05aa90 100644
> --- a/kernel-shark/src/libkshark.h
> +++ b/kernel-shark/src/libkshark.h
> @@ -28,6 +28,7 @@ extern "C" {
> #include "trace-cmd/trace-cmd.h"
> #include "trace-cmd/trace-filter-hash.h"
> #include "traceevent/event-parse.h"
> +#include "tracefs/tracefs.h"
>
> // KernelShark
> #include "libkshark-plugin.h"
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances
2020-01-06 15:40 ` [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances Tzvetomir Stoyanov (VMware)
@ 2020-01-08 19:37 ` Steven Rostedt
2020-01-09 13:29 ` Tzvetomir Stoyanov
0 siblings, 1 reply; 15+ messages in thread
From: Steven Rostedt @ 2020-01-08 19:37 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:56 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> The functionality related to ftrace instances is moved from
> trace-cmd application to libtracefs. The following new
> library APIs are introduced:
> struct tracefs_instance;
> struct tracefs_instance *tracefs_alloc_instance(const char *name);
> int tracefs_free_instance(struct tracefs_instance *instance);
> int tracefs_make_instance(struct tracefs_instance *instance);
> int tracefs_remove_instance(struct tracefs_instance *instance);
I'm thinking that "make" should be "create" and "remove" should be
"destroy". The "make" and "remove" does match "mkdir" and "rmdir" but
that's just the behind-the-scenes of what the OS does. But from an
application point of view, "create" and "destroy" seem more
appropriate.
What do you think?
> char *tracefs_get_instance_name(struct tracefs_instance *instance);
> char *tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
> char *tracefs_get_instance_dir(struct tracefs_instance *instance);
> int tracefs_write_instance_file(struct tracefs_instance *instance,
> const char *file, const char *str, const char *type);
> char *tracefs_read_instance_file(struct tracefs_instance *instance, char *file, int *psize);
Also, another naming convention used commonly, is when you have a set
of functions working on the same thing, is to use the name of what it
is working on first. That is, instead of the above, we should have:
tracefs_instance_alloc()
tracefs_instance_free()
tracefs_instance_create() (instead of "make")
tracefs_instance_destroy() (instead of "remove")
tracefs_instance_get_name()
tracefs_instance_get_file()
tracefs_instance_file_read()
tracefs_instance_file_write()
That way it is easier to find these functions with just searching for
"tracefs_instance"
The "get_*" is ok to keep, but as I showed above, I think "_file_read"
and "_file_write" is a better name.
[ more below ]
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
> include/tracefs/tracefs.h | 17 ++
> lib/tracefs/Makefile | 1 +
> lib/tracefs/include/tracefs-local.h | 1 +
> lib/tracefs/tracefs-instance.c | 267 ++++++++++++++++++++++++++++
> lib/tracefs/tracefs-utils.c | 43 +++++
> tracecmd/include/trace-local.h | 5 +-
> tracecmd/trace-list.c | 2 +-
> tracecmd/trace-record.c | 264 +++++++++------------------
> tracecmd/trace-show.c | 2 +
> tracecmd/trace-stat.c | 21 ++-
> 10 files changed, 431 insertions(+), 192 deletions(-)
> create mode 100644 lib/tracefs/tracefs-instance.c
>
> diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
> index e844c75..6b27ff7 100644
> --- a/include/tracefs/tracefs.h
> +++ b/include/tracefs/tracefs.h
> @@ -17,4 +17,21 @@ const char *tracefs_get_tracing_dir(void);
> /* tracefs_find_tracing_dir must be freed */
> char *tracefs_find_tracing_dir(void);
>
> +/* ftarce instances */
> +struct tracefs_instance;
> +
> +struct tracefs_instance *tracefs_alloc_instance(const char *name);
> +int tracefs_free_instance(struct tracefs_instance *instance);
> +int tracefs_make_instance(struct tracefs_instance *instance);
> +int tracefs_remove_instance(struct tracefs_instance *instance);
> +char *tracefs_get_instance_name(struct tracefs_instance *instance);
> +char *
> +tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
> +char *tracefs_get_instance_dir(struct tracefs_instance *instance);
> +int tracefs_write_instance_file(struct tracefs_instance *instance,
> + const char *file, const char *str,
> + const char *type);
> +char *tracefs_read_instance_file(struct tracefs_instance *instance,
> + char *file, int *psize);
> +
> #endif /* _TRACE_FS_H */
> diff --git a/lib/tracefs/Makefile b/lib/tracefs/Makefile
> index 86d7845..4030272 100644
> --- a/lib/tracefs/Makefile
> +++ b/lib/tracefs/Makefile
> @@ -8,6 +8,7 @@ DEFAULT_TARGET = $(bdir)/libtracefs.a
>
> OBJS =
> OBJS += tracefs-utils.o
> +OBJS += tracefs-instance.o
>
> OBJS := $(OBJS:%.o=$(bdir)/%.o)
> DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)
> diff --git a/lib/tracefs/include/tracefs-local.h b/lib/tracefs/include/tracefs-local.h
> index 231edd1..fe327a0 100644
> --- a/lib/tracefs/include/tracefs-local.h
> +++ b/lib/tracefs/include/tracefs-local.h
> @@ -8,5 +8,6 @@
>
> /* Can be overridden */
> void warning(const char *fmt, ...);
> +int str_read_file(const char *file, char **buffer);
>
> #endif /* _TRACE_FS_LOCAL_H */
> diff --git a/lib/tracefs/tracefs-instance.c b/lib/tracefs/tracefs-instance.c
> new file mode 100644
> index 0000000..14e8eed
> --- /dev/null
> +++ b/lib/tracefs/tracefs-instance.c
> @@ -0,0 +1,267 @@
> +// SPDX-License-Identifier: LGPL-2.1
> +/*
> + * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
> + *
> + * Updates:
> + * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
> + *
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +
> +#include "tracefs.h"
> +#include "tracefs-local.h"
> +
> +struct tracefs_instance {
> + char *name;
> +};
> +
> +/**
> + * tracefs_alloc_instance - allocate a new ftrace instance
> + * @name: The name of the instance (instance will point to this)
> + *
> + * Returns a newly allocated instance, or NULL in case of an error.
> + */
> +struct tracefs_instance *tracefs_alloc_instance(const char *name)
> +{
> + struct tracefs_instance *instance;
> +
> + instance = calloc(1, sizeof(*instance));
> + if (!instance)
> + return NULL;
> + if (name)
> + instance->name = strdup(name);
We can remove make this a little simpler (and with the name check):
instance = calloc(1, sizeof(*instance));
if (instance && name) {
instance->name = strdup(name);
if (!instance->name) {
free(instance);
instance = NULL;
}
}
return instance;
> +
> + return instance;
> +}
> +
> +/**
> + * tracefs_free_instance - Free an instance, previously allocated by
> + tracefs_alloc_instance()
> + * @instance: Pointer to the instance to be freed
> + *
> + * Returns -1 in case of an error, or 0 otherwise.
I don't think the free should return a value. Make it void.
> + */
> +int tracefs_free_instance(struct tracefs_instance *instance)
> +{
> + if (!instance)
> + return -1;
> +
> + free(instance->name);
> + free(instance);
> + return 0;
> +}
> +
> +/**
> + * tracefs_make_instance - Create a new ftrace instance
> + * @instance: Pointer to the instance to be created
> + *
> + * Returns 1 if the instance already exist, 0 if the instance
> + * is created successful or -1 in case of an error
> + */
> +int tracefs_make_instance(struct tracefs_instance *instance)
> +{
> + struct stat st;
> + char *path;
> + int ret;
> +
> + path = tracefs_get_instance_dir(instance);
> + ret = stat(path, &st);
> + if (ret < 0) {
> + ret = mkdir(path, 0777);
> + if (ret < 0)
> + return ret;
Remove the check of ret here, as the return skips the freeing of path.
Should be just:
if (ret < 0)
ret = mkdir(path, 0777);
else
ret = 1;
> +
> + } else
> + ret = 1;
> + tracefs_put_tracing_file(path);
> + return ret;
> +}
> +
> +/**
> + * tracefs_remove_instance - Remove a ftrace instance
> + * @instance: Pointer to the instance to be removed
> + *
> + * Returns -1 in case of an error, or 0 otherwise.
> + */
> +int tracefs_remove_instance(struct tracefs_instance *instance)
> +{
> + char *path;
> + int ret;
> +
> + if (!instance || !instance->name) {
> + warning("Cannot remove top instance");
> + return -1;
> + }
> +
> + path = tracefs_get_instance_dir(instance);
path could be NULL here due to failed allocation. Need to check that
and return an error.
> + ret = rmdir(path);
> + tracefs_put_tracing_file(path);
> +
> + return ret;
> +}
> +
> +/**
> + * tracefs_get_instance_file - return the path to an instance file.
> + * @instance: ftrace instance, can be NULL for the top instance
> + * @file: name of file to return
> + *
> + * Returns the path of the @file for the given @instance, or NULL in
> + * case of an error.
> + *
> + * Must use tracefs_put_tracing_file() to free the returned string.
> + */
> +char *
> +tracefs_get_instance_file(struct tracefs_instance *instance, const char *file)
> +{
> + char *path;
> + char *buf;
> + int ret;
> +
> + if (instance && instance->name) {
> + ret = asprintf(&buf, "instances/%s/%s", instance->name, file);
> + if (ret < 0) {
> + warning("Failed to allocate name for %s/%s",
> + instance->name, file);
For this being in a library, we should probably remove warnings.
> + return NULL;
> + }
> + path = tracefs_get_tracing_file(buf);
> + free(buf);
> + } else
> + path = tracefs_get_tracing_file(file);
> +
> + return path;
> +}
> +
> +/**
> + * tracefs_get_instance_dir - return the path to the instance directory.
> + * @instance: ftrace instance, can be NULL for the top instance
> + *
> + * Returns the full path to the instance directory
> + *
> + * Must use tracefs_put_tracing_file() to free the returned string.
> + */
> +char *tracefs_get_instance_dir(struct tracefs_instance *instance)
> +{
> + char *buf;
> + char *path;
> + int ret;
> +
> + if (instance && instance->name) {
> + ret = asprintf(&buf, "instances/%s", instance->name);
> + if (ret < 0) {
> + warning("Failed to allocate path for instance %s",
> + instance->name);
> + return NULL;
> + }
> + path = tracefs_get_tracing_file(buf);
> + free(buf);
> + } else
> + path = tracefs_find_tracing_dir();
> +
> + return path;
> +}
> +
> +/**
> + * tracefs_get_instance_name - return the name of an instance
> + * @instance: ftrace instance
> + *
> + * Returns the name of the given @instance.
> + * The returned string must *not* be freed.
> + */
> +char *tracefs_get_instance_name(struct tracefs_instance *instance)
> +{
> + if (instance)
> + return instance->name;
> + return NULL;
> +}
> +
> +static int write_file(const char *file, const char *str, const char *type)
> +{
> + char buf[BUFSIZ];
> + int ret;
> + int fd;
> +
> + fd = open(file, O_WRONLY | O_TRUNC);
> + if (fd < 0) {
> + warning("Failed to open '%s'", file);
> + return -1;
> + }
> + ret = write(fd, str, strlen(str));
> + close(fd);
> + if (ret < 0 && type) {
> + /* write failed */
> + fd = open(file, O_RDONLY);
> + if (fd < 0) {
> + warning("Failed to write in '%s'", file);
> + return -1;
> + }
> +
> + while ((ret = read(fd, buf, BUFSIZ)) > 0)
> + fprintf(stderr, "%.*s", ret, buf);
> + warning("Failed %s of %s\n", type, file);
The library function should not bother reading the file on error. This
is only applicable for some (one or two) files in the instance
directory. Thus remove this code.
> + close(fd);
> + }
> + return ret;
> +}
> +
> +
> +/**
> + * tracefs_write_instance_file - Write in trace file of specific instance.
> + * @instance: ftrace instance, can be NULL for the top instance
> + * @file: name of the file
> + * @str: nul terminated string, that will be written in the file.
> + * @type: nul terminated string, describing the current write operation.
> + * Used for logging purposes.
> + *
> + * Returns the number of written bytes, or -1 in case of an error
> + */
> +int tracefs_write_instance_file(struct tracefs_instance *instance,
> + const char *file, const char *str,
> + const char *type)
Let's get rid of the "type", it's confusing for a library function. If
the output should be read, that should be for a different operation.
> +{
> + struct stat st;
> + char *path;
> + int ret;
> +
> + path = tracefs_get_instance_file(instance, file);
Need to check for path == NULL.
> + ret = stat(path, &st);
> + if (ret == 0)
> + ret = write_file(path, str, type);
> + tracefs_put_tracing_file(path);
> +
> + return ret;
> +}
> +
> +/**
> + * tracefs_read_instance_file - Read from a trace file of specific instance.
> + * @instance: ftrace instance, can be NULL for the top instance
> + * @file: name of the file
> + * @psize: returns the number of bytes read
> + *
> + * Returns a pointer to a nul terminated string, read from the file, or NULL in
> + * case of an error.
> + * The return string must be freed by free()
> + */
> +char *tracefs_read_instance_file(struct tracefs_instance *instance,
> + char *file, int *psize)
> +{
> + char *buf = NULL;
> + int size = 0;
> + char *path;
> +
> + path = tracefs_get_instance_file(instance, file);
Need to check for path == NULL.
> +
> + size = str_read_file(path, &buf);
> +
> + tracefs_put_tracing_file(path);
> + if (buf && psize)
> + *psize = size;
> +
> + return buf;
> +}
> diff --git a/lib/tracefs/tracefs-utils.c b/lib/tracefs/tracefs-utils.c
> index 0ef16fc..bdab130 100644
> --- a/lib/tracefs/tracefs-utils.c
> +++ b/lib/tracefs/tracefs-utils.c
> @@ -10,6 +10,9 @@
> #include <sys/mount.h>
> #include <sys/stat.h>
> #include <linux/limits.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <unistd.h>
>
> #include "tracefs.h"
>
> @@ -181,3 +184,43 @@ void tracefs_put_tracing_file(char *name)
> {
> free(name);
> }
> +
> +int str_read_file(const char *file, char **buffer)
> +{
> + char stbuf[BUFSIZ];
> + char *buf = NULL;
> + int size = 0;
> + char *nbuf;
> + int fd;
> + int r;
> +
> + fd = open(file, O_RDONLY);
> + if (fd < 0) {
> + warning("File %s not found", file);
> + return -1;
> + }
> +
> + do {
> + r = read(fd, stbuf, BUFSIZ);
> + if (r <= 0)
> + continue;
> + nbuf = realloc(buf, size+r+1);
> + if (!nbuf) {
> + warning("Failed to allocate file buffer");
Again, we should remove warnings from the library function. But this
can be done later. I just wanted to document that we need to do that.
> + size = -1;
> + break;
> + }
> + buf = nbuf;
> + memcpy(buf+size, stbuf, r);
> + size += r;
> + } while (r);
Hmm, this probably should be:
} while (r > 0);
(I know this was broken before this patch)
> +
> + close(fd);
> + if (size > 0) {
Hmm, if r is less than zero here, we have a bug. Perhaps this needs to
be:
if (r == 0 && size > 0) {
> + buf[size] = '\0';
> + *buffer = buf;
> + } else
> + free(buf);
> +
> + return size;
> +}
-- Steve
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 2/5] kernel-shark: Use new tracefs library
2020-01-06 15:40 ` [PATCH v2 2/5] kernel-shark: Use new tracefs library Tzvetomir Stoyanov (VMware)
2020-01-08 19:05 ` Steven Rostedt
@ 2020-01-08 20:09 ` Steven Rostedt
1 sibling, 0 replies; 15+ messages in thread
From: Steven Rostedt @ 2020-01-08 20:09 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:55 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> diff --git a/kernel-shark/build/FindTraceCmd.cmake b/kernel-shark/build/FindTraceCmd.cmake
> index d3e145c..f27fafe 100644
> --- a/kernel-shark/build/FindTraceCmd.cmake
> +++ b/kernel-shark/build/FindTraceCmd.cmake
> @@ -6,6 +6,8 @@
> # TRACEEVENT_FOUND, If false, do not try to use traceevent.
> #
> # TRACECMD_INCLUDE_DIR, where to find trace-cmd header.
> +# TRACEFS_INCLUDE_DIR, where to find tracefs header.
> +# TRACEFS_LIBRARY, the tracefs library.
> # TRACECMD_LIBRARY, the trace-cmd library.
> # TRACECMD_FOUND, If false, do not try to use trace-cmd.
>
> @@ -31,12 +33,21 @@ find_path(TRACECMD_INCLUDE_DIR NAMES trace-cmd/trace-cmd.h
> PATHS $ENV{TRACE_CMD}/include/
> ${CMAKE_SOURCE_DIR}/../include/
> NO_DEFAULT_PATH)
> +find_path(TRACEFS_INCLUDE_DIR NAMES tracefs/tracefs.h
> + PATHS $ENV{TRACE_CMD}/include/
> + ${CMAKE_SOURCE_DIR}/../include/
> + NO_DEFAULT_PATH)
>
> find_library(TRACECMD_LIBRARY NAMES trace-cmd/libtracecmd.a
> PATHS $ENV{TRACE_CMD}/lib/
> ${CMAKE_SOURCE_DIR}/../lib/
> NO_DEFAULT_PATH)
>
> +find_library(TRACEFS_LIBRARY NAMES trace-cmd/libtracefs.a
I believe the above should be "tracefs/libtracefs.a" (I had to change
this to get it to compile).
-- Steve
> + PATHS $ENV{TRACE_CMD}/lib/
> + ${CMAKE_SOURCE_DIR}/../lib/
> + NO_DEFAULT_PATH)
> +
> find_library(TRACEEVENT_LIBRARY NAMES traceevent/libtraceevent.a
> PATHS $ENV{TRACE_CMD}/lib/
> ${CMAKE_SOURCE_DIR}/../lib/
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
@ 2020-01-08 20:22 ` Steven Rostedt
2020-01-09 13:37 ` Tzvetomir Stoyanov
2020-01-08 21:09 ` Steven Rostedt
2020-01-09 2:32 ` Steven Rostedt
2 siblings, 1 reply; 15+ messages in thread
From: Steven Rostedt @ 2020-01-08 20:22 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:57 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> The functionality related to ftrace events and systems
> is moved from trace-cmd application and libtracecmd to libtracefs.
>
> The following libtracecmd APIs are removed:
> tracecmd_read_page_record();
> tracecmd_event_systems();
> tracecmd_system_events();
> tracecmd_local_plugins();
> tracecmd_add_list();
> tracecmd_free_list();
>
> The following new library APIs are introduced:
> tracefs_read_page_record();
> tracefs_event_systems();
> tracefs_system_events();
> tracefs_local_plugins();
Hmm, we need to discuss plugins a bit more. I'm not sure they are
needed for either libtracecmd nor libtracefs. We have plugins for
libtraceevent which is just a better way to present the event, but I'm
imagining that plugins are going to be more specific to trace-cmd
directly. Maybe they can be packaged with libtracecmd, but I'm not
seeing a need for libtracefs.
What do you have in mind?
-- Steve
> tracefs_iterate_raw_events();
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
>
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
2020-01-08 20:22 ` Steven Rostedt
@ 2020-01-08 21:09 ` Steven Rostedt
2020-01-09 14:14 ` Tzvetomir Stoyanov
2020-01-09 2:32 ` Steven Rostedt
2 siblings, 1 reply; 15+ messages in thread
From: Steven Rostedt @ 2020-01-08 21:09 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:57 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> --- /dev/null
> +++ b/lib/tracefs/tracefs-events.c
> @@ -0,0 +1,476 @@
> +// SPDX-License-Identifier: LGPL-2.1
> +/*
> + * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
> + *
> + * Updates:
> + * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
> + *
> + */
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <dirent.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +
> +#include "kbuffer.h"
> +#include "tracefs.h"
> +#include "tracefs-local.h"
> +
> +/**
> + * tracefs_read_page_record - read a record off of a page
> + * @tep: tep used to parse the page
> + * @page: the page to read
> + * @size: the size of the page
> + * @last_record: last record read from this page
> + *
> + * If a ring buffer page is available, and the need to parse it
> + * without having a handle, then this function can be used
Not having a handle to what? Ah, I wrote this back in 2011. And that
"handle" meant a tracecmd_input_handle. Hmm, I think we need a
tracefs_handle of some sort for this, because it will slow down
tracefs_iterate_raw_events() very much so).
> + *
> + * The @tep needs to be initialized to have the page header information
> + * already available.
> + *
> + * The @last_record is used to know where to read the next record from
> + * If @last_record is NULL, the first record on the page will be read
> + *
> + * Returns:
> + * A newly allocated record that must be freed with free_record() if
Hmm, free_record() needs a prefix ("tracefs_") ?
> + * a record is found. Otherwise NULL is returned if the record is bad
> + * or no more records exist
> + */
> +struct tep_record *
> +tracefs_read_page_record(struct tep_handle *tep, void *page, int size,
> + struct tep_record *last_record)
> +{
> + unsigned long long ts;
> + struct kbuffer *kbuf;
> + struct tep_record *record = NULL;
> + enum kbuffer_long_size long_size;
> + enum kbuffer_endian endian;
> + void *ptr;
> +
> + if (tep_is_file_bigendian(tep))
> + endian = KBUFFER_ENDIAN_BIG;
> + else
> + endian = KBUFFER_ENDIAN_LITTLE;
> +
> + if (tep_get_header_page_size(tep) == 8)
> + long_size = KBUFFER_LSIZE_8;
> + else
> + long_size = KBUFFER_LSIZE_4;
> +
> + kbuf = kbuffer_alloc(long_size, endian);
> + if (!kbuf)
> + return NULL;
> +
> + kbuffer_load_subbuffer(kbuf, page);
> + if (kbuffer_subbuffer_size(kbuf) > size) {
> + warning("%s: page_size > size", __func__);
> + goto out_free;
> + }
> +
> + if (last_record) {
> + if (last_record->data < page || last_record->data >= (page + size)) {
> + warning("%s: bad last record (size=%u)",
> + __func__, last_record->size);
> + goto out_free;
> + }
> +
> + ptr = kbuffer_read_event(kbuf, &ts);
> + while (ptr < last_record->data) {
Here we are doing a linear search of last_record.
I could probably add a quicker solution to this by finding the next
record by passing in last_record->data and last_record->ts to a kbuffer
function, at the bottom.
> + ptr = kbuffer_next_event(kbuf, NULL);
> + if (!ptr)
> + break;
> + if (ptr == last_record->data)
> + break;
> + }
> + if (ptr != last_record->data) {
> + warning("$s: could not find last_record", __func__);
> + goto out_free;
> + }
> + ptr = kbuffer_next_event(kbuf, &ts);
> + } else
> + ptr = kbuffer_read_event(kbuf, &ts);
> +
> + if (!ptr)
> + goto out_free;
> +
> + record = malloc(sizeof(*record));
> + if (!record)
> + return NULL;
> + memset(record, 0, sizeof(*record));
> +
> + record->ts = ts;
> + record->size = kbuffer_event_size(kbuf);
> + record->record_size = kbuffer_curr_size(kbuf);
> + record->cpu = 0;
> + record->data = ptr;
> + record->ref_count = 1;
> +
> + out_free:
> + kbuffer_free(kbuf);
> + return record;
> +}
> +
> +static void free_record(struct tep_record *record)
> +{
> + if (!record)
> + return;
> +
> + if (record->ref_count > 0)
> + record->ref_count--;
> + if (record->ref_count)
> + return;
> +
> + free(record);
> +}
> +
> +static int
> +get_events_in_page(struct tep_handle *tep, void *page,
> + int size, int cpu,
> + int (*callback)(struct tep_event *,
> + struct tep_record *,
> + int, void *),
> + void *callback_context)
> +{
> + struct tep_record *last_record = NULL;
> + struct tep_event *event = NULL;
> + struct tep_record *record;
> + int id, cnt = 0;
> +
> + if (size <= 0)
> + return 0;
> +
> + while (true) {
> + event = NULL;
> + record = tracefs_read_page_record(tep, page, size, last_record);
This is very slow because the above function does a linear search to
find the next record each time! It would be much better to keep a kbuf
reference and use that.
> + if (!record)
> + break;
> + free_record(last_record);
> + id = tep_data_type(tep, record);
> + event = tep_find_event(tep, id);
> + if (event && callback) {
> + if (callback(event, record, cpu, callback_context))
> + break;
> + }
> + last_record = record;
> + }
> + free_record(last_record);
> +
> + return cnt;
> +}
> +
Here's a patch (untested ;-) that should help speed up the reading by
using the last record from before. This may even be able to help speed
up other parts of the code.
-- Steve
diff --git a/lib/traceevent/kbuffer-parse.c b/lib/traceevent/kbuffer-parse.c
index b18dedc4..ecbb64e9 100644
--- a/lib/traceevent/kbuffer-parse.c
+++ b/lib/traceevent/kbuffer-parse.c
@@ -649,6 +649,40 @@ void *kbuffer_read_at_offset(struct kbuffer *kbuf, int offset,
return data;
}
+/**
+ * kbuffer_set_position - set kbuf to index to a current offset and timestamp
+ * @kbuf: The kbuffer to read from
+ * @offset: The offset to set the current postion to
+ * @ts: The timestamp to set the kbuffer to.
+ *
+ * This routine is used to set the current position saved in @kbuf.
+ * This can be used in conjunction with using kbuffer_curr_offset() to
+ * get the offset of an event retrieved from the @kbuf subbuffer, and
+ * also using the time stamp that was retrived from that same event.
+ * This will set the position of @kbuf back to the state it was when
+ * it returned that event.
+ *
+ * Returns zero on success, -1 otherwise.
+ */
+int kbuffer_set_position(struct kbuffer *kbuf, int offset,
+ unsigned long long *ts)
+{
+ int ret;
+
+ offset -= kbuf->start;
+
+ if (offset < 0 || offset >= kbuf->size || !ts)
+ return -1; /* Bad offset */
+
+ kbuf->next = offset;
+ ret = next_event(kbuf);
+ if (ret < 0)
+ return -1;
+
+ kbuf->timestamp = *ts;
+ return 0;
+}
+
/**
* kbuffer_subbuffer_size - the size of the loaded subbuffer
* @kbuf: The kbuffer to read from
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
2020-01-08 20:22 ` Steven Rostedt
2020-01-08 21:09 ` Steven Rostedt
@ 2020-01-09 2:32 ` Steven Rostedt
2 siblings, 0 replies; 15+ messages in thread
From: Steven Rostedt @ 2020-01-09 2:32 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Mon, 6 Jan 2020 17:40:57 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> +static char **add_list_string(char **list, const char *name, int len)
> +{
> + if (!list)
> + list = malloc(sizeof(*list) * 2);
> + else
> + list = realloc(list, sizeof(*list) * (len + 2));
I know this was copied from my old code, but this is to document that
we need to add another patch (separate patch, to keep this patch as
more of a move), but the above really should just be:
list = realloc(list, sizeof(*list) * (len + 2));
as realloc is malloc when the first parameter is NULL.
> + if (!list)
> + return NULL;
> +
> + list[len] = strdup(name);
> + if (!list[len])
> + return NULL;
> +
> + list[len + 1] = NULL;
> +
> + return list;
> +}
> +
> +static char *append_file(const char *dir, const char *name)
> +{
> + char *file;
> + int ret;
> +
> + ret = asprintf(&file, "%s/%s", dir, name);
> +
> + return ret < 0 ? NULL : file;
> +}
> +
> +/**
> + * tracefs_event_systems - return list of systems for tracing
> + * @tracing_dir: directory holding the "events" directory
> + * if NULL, top tracing directory is used
> + *
> + * Returns an allocated list of system names. Both the names and
> + * the list must be freed with free()
> + * The list returned ends with a "NULL" pointer
We really should have a helper function to free this list. Perhaps we
should call it: tracefs_list_free()?
> + */
> +char **tracefs_event_systems(const char *tracing_dir)
> +{
> + struct dirent *dent;
> + char **systems = NULL;
> + char *events_dir;
> + struct stat st;
> + DIR *dir;
> + int len = 0;
> + int ret;
> +
> + if (!tracing_dir)
> + tracing_dir = tracefs_get_tracing_dir();
> +
> + if (!tracing_dir)
> + return NULL;
> +
> + events_dir = append_file(tracing_dir, "events");
> + if (!events_dir)
> + return NULL;
> +
> + /*
> + * Search all the directories in the events directory,
> + * and collect the ones that have the "enable" file.
> + */
> + ret = stat(events_dir, &st);
> + if (ret < 0 || !S_ISDIR(st.st_mode))
> + goto out_free;
> +
> + dir = opendir(events_dir);
> + if (!dir)
> + goto out_free;
> +
> + while ((dent = readdir(dir))) {
> + const char *name = dent->d_name;
> + char *enable;
> + char *sys;
> +
> + if (strcmp(name, ".") == 0 ||
> + strcmp(name, "..") == 0)
> + continue;
> +
> + sys = append_file(events_dir, name);
> + ret = stat(sys, &st);
> + if (ret < 0 || !S_ISDIR(st.st_mode)) {
> + free(sys);
> + continue;
> + }
> +
> + enable = append_file(sys, "enable");
> +
> + ret = stat(enable, &st);
> + if (ret >= 0)
> + systems = add_list_string(systems, name, len++);
> +
> + free(enable);
> + free(sys);
> + }
> +
> + closedir(dir);
> +
> + out_free:
> + free(events_dir);
> + return systems;
> +}
> +
> +/**
> + * tracefs_system_events - return list of events for system
> + * @tracing_dir: directory holding the "events" directory
> + * @system: the system to return the events for
> + *
> + * Returns an allocated list of event names. Both the names and
> + * the list must be freed with free()
> + * The list returned ends with a "NULL" pointer
And have this free with tracefs_list_free() too.
> + */
> +char **tracefs_system_events(const char *tracing_dir, const char *system)
> +{
> + struct dirent *dent;
> + char **events = NULL;
> + char *system_dir = NULL;
> + struct stat st;
> + DIR *dir;
> + int len = 0;
> + int ret;
> +
> + if (!tracing_dir)
> + tracing_dir = tracefs_get_tracing_dir();
> +
> + if (!tracing_dir || !system)
> + return NULL;
> +
> + asprintf(&system_dir, "%s/events/%s", tracing_dir, system);
> + if (!system_dir)
> + return NULL;
> +
> + ret = stat(system_dir, &st);
> + if (ret < 0 || !S_ISDIR(st.st_mode))
> + goto out_free;
> +
> + dir = opendir(system_dir);
> + if (!dir)
> + goto out_free;
> +
> + while ((dent = readdir(dir))) {
> + const char *name = dent->d_name;
> + char *enable;
> + char *event;
> +
> + if (strcmp(name, ".") == 0 ||
> + strcmp(name, "..") == 0)
> + continue;
> +
> + event = append_file(system_dir, name);
> + ret = stat(event, &st);
> + if (ret < 0 || !S_ISDIR(st.st_mode)) {
> + free(event);
> + continue;
> + }
> +
> + enable = append_file(event, "enable");
> +
> + ret = stat(enable, &st);
> + if (ret >= 0)
> + events = add_list_string(events, name, len++);
> +
> + free(enable);
> + free(event);
> + }
> +
> + closedir(dir);
> +
> + out_free:
> + free(system_dir);
> +
> + return events;
> +}
> +
> +/**
> + * tracefs_local_plugins - returns an array of available tracer plugins
Let's not call this "local_plugins" as the name is a misnomer (what
they were called back in 2010, but are no longer called that). Let's
change this to their real name:
tracefs_tracers()
-- Steve
> + * @tracing_dir: The directory that contains the tracing directory
> + *
> + * Returns an allocate list of plugins. The array ends with NULL
> + * Both the plugin names and array must be freed with free()
> + */
> +char **tracefs_local_plugins(const char *tracing_dir)
> +{
> + char *available_tracers;
> + struct stat st;
> + char **plugins = NULL;
> + char *buf;
> + char *str, *saveptr;
> + char *plugin;
> + int slen;
> + int len;
> + int ret;
> +
> + if (!tracing_dir)
> + return NULL;
> +
> + available_tracers = append_file(tracing_dir, "available_tracers");
> + if (!available_tracers)
> + return NULL;
> +
> + ret = stat(available_tracers, &st);
> + if (ret < 0)
> + goto out_free;
> +
> + len = str_read_file(available_tracers, &buf);
> + if (len < 0)
> + goto out_free;
> +
> + len = 0;
> + for (str = buf; ; str = NULL) {
> + plugin = strtok_r(str, " ", &saveptr);
> + if (!plugin)
> + break;
> + slen = strlen(plugin);
> + if (!slen)
> + continue;
> +
> + /* chop off any newlines */
> + if (plugin[slen - 1] == '\n')
> + plugin[slen - 1] = '\0';
> +
> + /* Skip the non tracers */
> + if (strcmp(plugin, "nop") == 0 ||
> + strcmp(plugin, "none") == 0)
> + continue;
> +
> + plugins = add_list_string(plugins, plugin, len++);
> + }
> + free(buf);
> +
> + out_free:
> + free(available_tracers);
> +
> + return plugins;
> +}
> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 62f67d5..1d91e87 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -4178,7 +4178,7 @@ find_ts_in_page(struct tep_handle *pevent, void *page, int size)
> return 0;
>
> while (!ts) {
> - record = tracecmd_read_page_record(pevent, page, size,
> + record = tracefs_read_page_record(pevent, page, size,
> last_record);
> if (!record)
> break;
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances
2020-01-08 19:37 ` Steven Rostedt
@ 2020-01-09 13:29 ` Tzvetomir Stoyanov
0 siblings, 0 replies; 15+ messages in thread
From: Tzvetomir Stoyanov @ 2020-01-09 13:29 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-trace-devel
On Wed, Jan 8, 2020 at 9:37 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Mon, 6 Jan 2020 17:40:56 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
> > The functionality related to ftrace instances is moved from
> > trace-cmd application to libtracefs. The following new
> > library APIs are introduced:
> > struct tracefs_instance;
> > struct tracefs_instance *tracefs_alloc_instance(const char *name);
> > int tracefs_free_instance(struct tracefs_instance *instance);
> > int tracefs_make_instance(struct tracefs_instance *instance);
> > int tracefs_remove_instance(struct tracefs_instance *instance);
>
> I'm thinking that "make" should be "create" and "remove" should be
> "destroy". The "make" and "remove" does match "mkdir" and "rmdir" but
> that's just the behind-the-scenes of what the OS does. But from an
> application point of view, "create" and "destroy" seem more
> appropriate.
>
> What do you think?
>
>
> > char *tracefs_get_instance_name(struct tracefs_instance *instance);
> > char *tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
> > char *tracefs_get_instance_dir(struct tracefs_instance *instance);
> > int tracefs_write_instance_file(struct tracefs_instance *instance,
> > const char *file, const char *str, const char *type);
> > char *tracefs_read_instance_file(struct tracefs_instance *instance, char *file, int *psize);
>
> Also, another naming convention used commonly, is when you have a set
> of functions working on the same thing, is to use the name of what it
> is working on first. That is, instead of the above, we should have:
>
> tracefs_instance_alloc()
> tracefs_instance_free()
> tracefs_instance_create() (instead of "make")
> tracefs_instance_destroy() (instead of "remove")
> tracefs_instance_get_name()
> tracefs_instance_get_file()
> tracefs_instance_file_read()
> tracefs_instance_file_write()
>
> That way it is easier to find these functions with just searching for
> "tracefs_instance"
>
> The "get_*" is ok to keep, but as I showed above, I think "_file_read"
> and "_file_write" is a better name.
>
> [ more below ]
>
> >
> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> > ---
> > include/tracefs/tracefs.h | 17 ++
> > lib/tracefs/Makefile | 1 +
> > lib/tracefs/include/tracefs-local.h | 1 +
> > lib/tracefs/tracefs-instance.c | 267 ++++++++++++++++++++++++++++
> > lib/tracefs/tracefs-utils.c | 43 +++++
> > tracecmd/include/trace-local.h | 5 +-
> > tracecmd/trace-list.c | 2 +-
> > tracecmd/trace-record.c | 264 +++++++++------------------
> > tracecmd/trace-show.c | 2 +
> > tracecmd/trace-stat.c | 21 ++-
> > 10 files changed, 431 insertions(+), 192 deletions(-)
> > create mode 100644 lib/tracefs/tracefs-instance.c
> >
> > diff --git a/include/tracefs/tracefs.h b/include/tracefs/tracefs.h
> > index e844c75..6b27ff7 100644
> > --- a/include/tracefs/tracefs.h
> > +++ b/include/tracefs/tracefs.h
> > @@ -17,4 +17,21 @@ const char *tracefs_get_tracing_dir(void);
> > /* tracefs_find_tracing_dir must be freed */
> > char *tracefs_find_tracing_dir(void);
> >
> > +/* ftarce instances */
> > +struct tracefs_instance;
> > +
> > +struct tracefs_instance *tracefs_alloc_instance(const char *name);
> > +int tracefs_free_instance(struct tracefs_instance *instance);
> > +int tracefs_make_instance(struct tracefs_instance *instance);
> > +int tracefs_remove_instance(struct tracefs_instance *instance);
> > +char *tracefs_get_instance_name(struct tracefs_instance *instance);
> > +char *
> > +tracefs_get_instance_file(struct tracefs_instance *instance, const char *file);
> > +char *tracefs_get_instance_dir(struct tracefs_instance *instance);
> > +int tracefs_write_instance_file(struct tracefs_instance *instance,
> > + const char *file, const char *str,
> > + const char *type);
> > +char *tracefs_read_instance_file(struct tracefs_instance *instance,
> > + char *file, int *psize);
> > +
> > #endif /* _TRACE_FS_H */
> > diff --git a/lib/tracefs/Makefile b/lib/tracefs/Makefile
> > index 86d7845..4030272 100644
> > --- a/lib/tracefs/Makefile
> > +++ b/lib/tracefs/Makefile
> > @@ -8,6 +8,7 @@ DEFAULT_TARGET = $(bdir)/libtracefs.a
> >
> > OBJS =
> > OBJS += tracefs-utils.o
> > +OBJS += tracefs-instance.o
> >
> > OBJS := $(OBJS:%.o=$(bdir)/%.o)
> > DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)
> > diff --git a/lib/tracefs/include/tracefs-local.h b/lib/tracefs/include/tracefs-local.h
> > index 231edd1..fe327a0 100644
> > --- a/lib/tracefs/include/tracefs-local.h
> > +++ b/lib/tracefs/include/tracefs-local.h
> > @@ -8,5 +8,6 @@
> >
> > /* Can be overridden */
> > void warning(const char *fmt, ...);
> > +int str_read_file(const char *file, char **buffer);
> >
> > #endif /* _TRACE_FS_LOCAL_H */
> > diff --git a/lib/tracefs/tracefs-instance.c b/lib/tracefs/tracefs-instance.c
> > new file mode 100644
> > index 0000000..14e8eed
> > --- /dev/null
> > +++ b/lib/tracefs/tracefs-instance.c
> > @@ -0,0 +1,267 @@
> > +// SPDX-License-Identifier: LGPL-2.1
> > +/*
> > + * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
> > + *
> > + * Updates:
> > + * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
> > + *
> > + */
> > +
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <unistd.h>
> > +#include <errno.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> > +
> > +#include "tracefs.h"
> > +#include "tracefs-local.h"
> > +
> > +struct tracefs_instance {
> > + char *name;
> > +};
> > +
> > +/**
> > + * tracefs_alloc_instance - allocate a new ftrace instance
> > + * @name: The name of the instance (instance will point to this)
> > + *
> > + * Returns a newly allocated instance, or NULL in case of an error.
> > + */
> > +struct tracefs_instance *tracefs_alloc_instance(const char *name)
> > +{
> > + struct tracefs_instance *instance;
> > +
> > + instance = calloc(1, sizeof(*instance));
> > + if (!instance)
> > + return NULL;
> > + if (name)
> > + instance->name = strdup(name);
>
> We can remove make this a little simpler (and with the name check):
>
> instance = calloc(1, sizeof(*instance));
> if (instance && name) {
> instance->name = strdup(name);
> if (!instance->name) {
> free(instance);
> instance = NULL;
> }
> }
>
> return instance;
>
> > +
> > + return instance;
> > +}
> > +
> > +/**
> > + * tracefs_free_instance - Free an instance, previously allocated by
> > + tracefs_alloc_instance()
> > + * @instance: Pointer to the instance to be freed
> > + *
> > + * Returns -1 in case of an error, or 0 otherwise.
>
> I don't think the free should return a value. Make it void.
>
> > + */
> > +int tracefs_free_instance(struct tracefs_instance *instance)
> > +{
> > + if (!instance)
> > + return -1;
> > +
> > + free(instance->name);
> > + free(instance);
> > + return 0;
> > +}
> > +
> > +/**
> > + * tracefs_make_instance - Create a new ftrace instance
> > + * @instance: Pointer to the instance to be created
> > + *
> > + * Returns 1 if the instance already exist, 0 if the instance
> > + * is created successful or -1 in case of an error
> > + */
> > +int tracefs_make_instance(struct tracefs_instance *instance)
> > +{
> > + struct stat st;
> > + char *path;
> > + int ret;
> > +
> > + path = tracefs_get_instance_dir(instance);
> > + ret = stat(path, &st);
> > + if (ret < 0) {
> > + ret = mkdir(path, 0777);
> > + if (ret < 0)
> > + return ret;
>
> Remove the check of ret here, as the return skips the freeing of path.
>
> Should be just:
>
> if (ret < 0)
> ret = mkdir(path, 0777);
> else
> ret = 1;
>
> > +
> > + } else
> > + ret = 1;
> > + tracefs_put_tracing_file(path);
> > + return ret;
> > +}
> > +
> > +/**
> > + * tracefs_remove_instance - Remove a ftrace instance
> > + * @instance: Pointer to the instance to be removed
> > + *
> > + * Returns -1 in case of an error, or 0 otherwise.
> > + */
> > +int tracefs_remove_instance(struct tracefs_instance *instance)
> > +{
> > + char *path;
> > + int ret;
> > +
> > + if (!instance || !instance->name) {
> > + warning("Cannot remove top instance");
> > + return -1;
> > + }
> > +
> > + path = tracefs_get_instance_dir(instance);
>
> path could be NULL here due to failed allocation. Need to check that
> and return an error.
>
> > + ret = rmdir(path);
> > + tracefs_put_tracing_file(path);
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * tracefs_get_instance_file - return the path to an instance file.
> > + * @instance: ftrace instance, can be NULL for the top instance
> > + * @file: name of file to return
> > + *
> > + * Returns the path of the @file for the given @instance, or NULL in
> > + * case of an error.
> > + *
> > + * Must use tracefs_put_tracing_file() to free the returned string.
> > + */
> > +char *
> > +tracefs_get_instance_file(struct tracefs_instance *instance, const char *file)
> > +{
> > + char *path;
> > + char *buf;
> > + int ret;
> > +
> > + if (instance && instance->name) {
> > + ret = asprintf(&buf, "instances/%s/%s", instance->name, file);
> > + if (ret < 0) {
> > + warning("Failed to allocate name for %s/%s",
> > + instance->name, file);
>
> For this being in a library, we should probably remove warnings.
>
> > + return NULL;
> > + }
> > + path = tracefs_get_tracing_file(buf);
> > + free(buf);
> > + } else
> > + path = tracefs_get_tracing_file(file);
> > +
> > + return path;
> > +}
> > +
> > +/**
> > + * tracefs_get_instance_dir - return the path to the instance directory.
> > + * @instance: ftrace instance, can be NULL for the top instance
> > + *
> > + * Returns the full path to the instance directory
> > + *
> > + * Must use tracefs_put_tracing_file() to free the returned string.
> > + */
> > +char *tracefs_get_instance_dir(struct tracefs_instance *instance)
> > +{
> > + char *buf;
> > + char *path;
> > + int ret;
> > +
> > + if (instance && instance->name) {
> > + ret = asprintf(&buf, "instances/%s", instance->name);
> > + if (ret < 0) {
> > + warning("Failed to allocate path for instance %s",
> > + instance->name);
> > + return NULL;
> > + }
> > + path = tracefs_get_tracing_file(buf);
> > + free(buf);
> > + } else
> > + path = tracefs_find_tracing_dir();
> > +
> > + return path;
> > +}
> > +
> > +/**
> > + * tracefs_get_instance_name - return the name of an instance
> > + * @instance: ftrace instance
> > + *
> > + * Returns the name of the given @instance.
> > + * The returned string must *not* be freed.
> > + */
> > +char *tracefs_get_instance_name(struct tracefs_instance *instance)
> > +{
> > + if (instance)
> > + return instance->name;
> > + return NULL;
> > +}
> > +
> > +static int write_file(const char *file, const char *str, const char *type)
> > +{
> > + char buf[BUFSIZ];
> > + int ret;
> > + int fd;
> > +
> > + fd = open(file, O_WRONLY | O_TRUNC);
> > + if (fd < 0) {
> > + warning("Failed to open '%s'", file);
> > + return -1;
> > + }
> > + ret = write(fd, str, strlen(str));
> > + close(fd);
> > + if (ret < 0 && type) {
> > + /* write failed */
> > + fd = open(file, O_RDONLY);
> > + if (fd < 0) {
> > + warning("Failed to write in '%s'", file);
> > + return -1;
> > + }
> > +
> > + while ((ret = read(fd, buf, BUFSIZ)) > 0)
> > + fprintf(stderr, "%.*s", ret, buf);
> > + warning("Failed %s of %s\n", type, file);
>
> The library function should not bother reading the file on error. This
> is only applicable for some (one or two) files in the instance
> directory. Thus remove this code.
>
> > + close(fd);
> > + }
> > + return ret;
> > +}
> > +
> > +
> > +/**
> > + * tracefs_write_instance_file - Write in trace file of specific instance.
> > + * @instance: ftrace instance, can be NULL for the top instance
> > + * @file: name of the file
> > + * @str: nul terminated string, that will be written in the file.
> > + * @type: nul terminated string, describing the current write operation.
> > + * Used for logging purposes.
> > + *
> > + * Returns the number of written bytes, or -1 in case of an error
> > + */
> > +int tracefs_write_instance_file(struct tracefs_instance *instance,
> > + const char *file, const char *str,
> > + const char *type)
>
> Let's get rid of the "type", it's confusing for a library function. If
> the output should be read, that should be for a different operation.
>
>
> > +{
> > + struct stat st;
> > + char *path;
> > + int ret;
> > +
> > + path = tracefs_get_instance_file(instance, file);
>
> Need to check for path == NULL.
>
> > + ret = stat(path, &st);
> > + if (ret == 0)
> > + ret = write_file(path, str, type);
> > + tracefs_put_tracing_file(path);
> > +
> > + return ret;
> > +}
> > +
> > +/**
> > + * tracefs_read_instance_file - Read from a trace file of specific instance.
> > + * @instance: ftrace instance, can be NULL for the top instance
> > + * @file: name of the file
> > + * @psize: returns the number of bytes read
> > + *
> > + * Returns a pointer to a nul terminated string, read from the file, or NULL in
> > + * case of an error.
> > + * The return string must be freed by free()
> > + */
> > +char *tracefs_read_instance_file(struct tracefs_instance *instance,
> > + char *file, int *psize)
> > +{
> > + char *buf = NULL;
> > + int size = 0;
> > + char *path;
> > +
> > + path = tracefs_get_instance_file(instance, file);
>
> Need to check for path == NULL.
>
> > +
> > + size = str_read_file(path, &buf);
> > +
> > + tracefs_put_tracing_file(path);
> > + if (buf && psize)
> > + *psize = size;
> > +
> > + return buf;
> > +}
> > diff --git a/lib/tracefs/tracefs-utils.c b/lib/tracefs/tracefs-utils.c
> > index 0ef16fc..bdab130 100644
> > --- a/lib/tracefs/tracefs-utils.c
> > +++ b/lib/tracefs/tracefs-utils.c
> > @@ -10,6 +10,9 @@
> > #include <sys/mount.h>
> > #include <sys/stat.h>
> > #include <linux/limits.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> > +#include <unistd.h>
> >
> > #include "tracefs.h"
> >
> > @@ -181,3 +184,43 @@ void tracefs_put_tracing_file(char *name)
> > {
> > free(name);
> > }
> > +
> > +int str_read_file(const char *file, char **buffer)
> > +{
> > + char stbuf[BUFSIZ];
> > + char *buf = NULL;
> > + int size = 0;
> > + char *nbuf;
> > + int fd;
> > + int r;
> > +
> > + fd = open(file, O_RDONLY);
> > + if (fd < 0) {
> > + warning("File %s not found", file);
> > + return -1;
> > + }
> > +
> > + do {
> > + r = read(fd, stbuf, BUFSIZ);
> > + if (r <= 0)
> > + continue;
> > + nbuf = realloc(buf, size+r+1);
> > + if (!nbuf) {
> > + warning("Failed to allocate file buffer");
>
> Again, we should remove warnings from the library function. But this
> can be done later. I just wanted to document that we need to do that.
>
> > + size = -1;
> > + break;
> > + }
> > + buf = nbuf;
> > + memcpy(buf+size, stbuf, r);
> > + size += r;
> > + } while (r);
>
> Hmm, this probably should be:
>
> } while (r > 0);
>
> (I know this was broken before this patch)
>
> > +
> > + close(fd);
> > + if (size > 0) {
>
> Hmm, if r is less than zero here, we have a bug. Perhaps this needs to
> be:
>
> if (r == 0 && size > 0) {
>
> > + buf[size] = '\0';
> > + *buffer = buf;
> > + } else
> > + free(buf);
> > +
> > + return size;
> > +}
>
>
Thanks Steve! It makes sense, will include these changes in the next version.
> -- Steve
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-08 20:22 ` Steven Rostedt
@ 2020-01-09 13:37 ` Tzvetomir Stoyanov
0 siblings, 0 replies; 15+ messages in thread
From: Tzvetomir Stoyanov @ 2020-01-09 13:37 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-trace-devel
On Wed, Jan 8, 2020 at 10:22 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Mon, 6 Jan 2020 17:40:57 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
> > The functionality related to ftrace events and systems
> > is moved from trace-cmd application and libtracecmd to libtracefs.
> >
> > The following libtracecmd APIs are removed:
> > tracecmd_read_page_record();
> > tracecmd_event_systems();
> > tracecmd_system_events();
> > tracecmd_local_plugins();
> > tracecmd_add_list();
> > tracecmd_free_list();
> >
> > The following new library APIs are introduced:
> > tracefs_read_page_record();
> > tracefs_event_systems();
> > tracefs_system_events();
> > tracefs_local_plugins();
>
> Hmm, we need to discuss plugins a bit more. I'm not sure they are
> needed for either libtracecmd nor libtracefs. We have plugins for
> libtraceevent which is just a better way to present the event, but I'm
> imagining that plugins are going to be more specific to trace-cmd
> directly. Maybe they can be packaged with libtracecmd, but I'm not
> seeing a need for libtracefs.
>
> What do you have in mind?
>
May be the API name is confusing, it is not about the library plugins.
It returns the list of
plugins from "available_tracers" file. We can rename the API to
tracefs_local_tracers() ?
Tracers are referred as "plugins" in ftrace docs, that's why the API
is named this way.
> -- Steve
>
>
> > tracefs_iterate_raw_events();
> >
> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> > ---
> >
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems
2020-01-08 21:09 ` Steven Rostedt
@ 2020-01-09 14:14 ` Tzvetomir Stoyanov
0 siblings, 0 replies; 15+ messages in thread
From: Tzvetomir Stoyanov @ 2020-01-09 14:14 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-trace-devel
On Wed, Jan 8, 2020 at 11:09 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Mon, 6 Jan 2020 17:40:57 +0200
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
>
> > --- /dev/null
> > +++ b/lib/tracefs/tracefs-events.c
> > @@ -0,0 +1,476 @@
> > +// SPDX-License-Identifier: LGPL-2.1
> > +/*
> > + * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
> > + *
> > + * Updates:
> > + * Copyright (C) 2019, VMware, Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
> > + *
> > + */
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <dirent.h>
> > +#include <unistd.h>
> > +#include <errno.h>
> > +#include <sys/stat.h>
> > +#include <fcntl.h>
> > +
> > +#include "kbuffer.h"
> > +#include "tracefs.h"
> > +#include "tracefs-local.h"
> > +
> > +/**
> > + * tracefs_read_page_record - read a record off of a page
> > + * @tep: tep used to parse the page
> > + * @page: the page to read
> > + * @size: the size of the page
> > + * @last_record: last record read from this page
> > + *
> > + * If a ring buffer page is available, and the need to parse it
> > + * without having a handle, then this function can be used
>
> Not having a handle to what? Ah, I wrote this back in 2011. And that
> "handle" meant a tracecmd_input_handle. Hmm, I think we need a
> tracefs_handle of some sort for this, because it will slow down
> tracefs_iterate_raw_events() very much so).
>
I'm not sure how tracefs_handle could speed up the events iteration,
but I can think about it in a context of a different patch. The
current patch set
is just a skeleton of the new library, most of the code is moved from
the application
or libtracecmd with almost no modifications.
>
> > + *
> > + * The @tep needs to be initialized to have the page header information
> > + * already available.
> > + *
> > + * The @last_record is used to know where to read the next record from
> > + * If @last_record is NULL, the first record on the page will be read
> > + *
> > + * Returns:
> > + * A newly allocated record that must be freed with free_record() if
>
> Hmm, free_record() needs a prefix ("tracefs_") ?
Actually free_record() is not exported as libtracefs API, which is
confusing. There is
free_record() libtracecmd API, which is used in the trace-cmd context. May be it
is better to have tracefs_free_record() , or to use the one from libtracecmd ?
>
> > + * a record is found. Otherwise NULL is returned if the record is bad
> > + * or no more records exist
> > + */
> > +struct tep_record *
> > +tracefs_read_page_record(struct tep_handle *tep, void *page, int size,
> > + struct tep_record *last_record)
> > +{
> > + unsigned long long ts;
> > + struct kbuffer *kbuf;
> > + struct tep_record *record = NULL;
> > + enum kbuffer_long_size long_size;
> > + enum kbuffer_endian endian;
> > + void *ptr;
> > +
> > + if (tep_is_file_bigendian(tep))
> > + endian = KBUFFER_ENDIAN_BIG;
> > + else
> > + endian = KBUFFER_ENDIAN_LITTLE;
> > +
> > + if (tep_get_header_page_size(tep) == 8)
> > + long_size = KBUFFER_LSIZE_8;
> > + else
> > + long_size = KBUFFER_LSIZE_4;
> > +
> > + kbuf = kbuffer_alloc(long_size, endian);
> > + if (!kbuf)
> > + return NULL;
> > +
> > + kbuffer_load_subbuffer(kbuf, page);
> > + if (kbuffer_subbuffer_size(kbuf) > size) {
> > + warning("%s: page_size > size", __func__);
> > + goto out_free;
> > + }
> > +
> > + if (last_record) {
> > + if (last_record->data < page || last_record->data >= (page + size)) {
> > + warning("%s: bad last record (size=%u)",
> > + __func__, last_record->size);
> > + goto out_free;
> > + }
> > +
> > + ptr = kbuffer_read_event(kbuf, &ts);
> > + while (ptr < last_record->data) {
>
> Here we are doing a linear search of last_record.
>
> I could probably add a quicker solution to this by finding the next
> record by passing in last_record->data and last_record->ts to a kbuffer
> function, at the bottom.
>
>
> > + ptr = kbuffer_next_event(kbuf, NULL);
> > + if (!ptr)
> > + break;
> > + if (ptr == last_record->data)
> > + break;
> > + }
> > + if (ptr != last_record->data) {
> > + warning("$s: could not find last_record", __func__);
> > + goto out_free;
> > + }
> > + ptr = kbuffer_next_event(kbuf, &ts);
> > + } else
> > + ptr = kbuffer_read_event(kbuf, &ts);
> > +
> > + if (!ptr)
> > + goto out_free;
> > +
> > + record = malloc(sizeof(*record));
> > + if (!record)
> > + return NULL;
> > + memset(record, 0, sizeof(*record));
> > +
> > + record->ts = ts;
> > + record->size = kbuffer_event_size(kbuf);
> > + record->record_size = kbuffer_curr_size(kbuf);
> > + record->cpu = 0;
> > + record->data = ptr;
> > + record->ref_count = 1;
> > +
> > + out_free:
> > + kbuffer_free(kbuf);
> > + return record;
> > +}
> > +
> > +static void free_record(struct tep_record *record)
> > +{
> > + if (!record)
> > + return;
> > +
> > + if (record->ref_count > 0)
> > + record->ref_count--;
> > + if (record->ref_count)
> > + return;
> > +
> > + free(record);
> > +}
> > +
> > +static int
> > +get_events_in_page(struct tep_handle *tep, void *page,
> > + int size, int cpu,
> > + int (*callback)(struct tep_event *,
> > + struct tep_record *,
> > + int, void *),
> > + void *callback_context)
> > +{
> > + struct tep_record *last_record = NULL;
> > + struct tep_event *event = NULL;
> > + struct tep_record *record;
> > + int id, cnt = 0;
> > +
> > + if (size <= 0)
> > + return 0;
> > +
> > + while (true) {
> > + event = NULL;
> > + record = tracefs_read_page_record(tep, page, size, last_record);
>
> This is very slow because the above function does a linear search to
> find the next record each time! It would be much better to keep a kbuf
> reference and use that.
>
>
> > + if (!record)
> > + break;
> > + free_record(last_record);
> > + id = tep_data_type(tep, record);
> > + event = tep_find_event(tep, id);
> > + if (event && callback) {
> > + if (callback(event, record, cpu, callback_context))
> > + break;
> > + }
> > + last_record = record;
> > + }
> > + free_record(last_record);
> > +
> > + return cnt;
> > +}
> > +
>
> Here's a patch (untested ;-) that should help speed up the reading by
> using the last record from before. This may even be able to help speed
> up other parts of the code.
>
> -- Steve
>
> diff --git a/lib/traceevent/kbuffer-parse.c b/lib/traceevent/kbuffer-parse.c
> index b18dedc4..ecbb64e9 100644
> --- a/lib/traceevent/kbuffer-parse.c
> +++ b/lib/traceevent/kbuffer-parse.c
> @@ -649,6 +649,40 @@ void *kbuffer_read_at_offset(struct kbuffer *kbuf, int offset,
> return data;
> }
>
> +/**
> + * kbuffer_set_position - set kbuf to index to a current offset and timestamp
> + * @kbuf: The kbuffer to read from
> + * @offset: The offset to set the current postion to
> + * @ts: The timestamp to set the kbuffer to.
> + *
> + * This routine is used to set the current position saved in @kbuf.
> + * This can be used in conjunction with using kbuffer_curr_offset() to
> + * get the offset of an event retrieved from the @kbuf subbuffer, and
> + * also using the time stamp that was retrived from that same event.
> + * This will set the position of @kbuf back to the state it was when
> + * it returned that event.
> + *
> + * Returns zero on success, -1 otherwise.
> + */
> +int kbuffer_set_position(struct kbuffer *kbuf, int offset,
> + unsigned long long *ts)
> +{
> + int ret;
> +
> + offset -= kbuf->start;
> +
> + if (offset < 0 || offset >= kbuf->size || !ts)
> + return -1; /* Bad offset */
> +
> + kbuf->next = offset;
> + ret = next_event(kbuf);
> + if (ret < 0)
> + return -1;
> +
> + kbuf->timestamp = *ts;
> + return 0;
> +}
> +
> /**
> * kbuffer_subbuffer_size - the size of the loaded subbuffer
> * @kbuf: The kbuffer to read from
Thanks Steven! I'll test it and add it in the next version of the patch set.
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2020-01-09 14:14 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-06 15:40 [PATCH v2 0/5] tracefs library Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 1/5] trace-cmd: Introduce libtracefs library Tzvetomir Stoyanov (VMware)
2020-01-06 15:40 ` [PATCH v2 2/5] kernel-shark: Use new tracefs library Tzvetomir Stoyanov (VMware)
2020-01-08 19:05 ` Steven Rostedt
2020-01-08 20:09 ` Steven Rostedt
2020-01-06 15:40 ` [PATCH v2 3/5] trace-cmd: New libtracefs APIs for ftrace instances Tzvetomir Stoyanov (VMware)
2020-01-08 19:37 ` Steven Rostedt
2020-01-09 13:29 ` Tzvetomir Stoyanov
2020-01-06 15:40 ` [PATCH v2 4/5] trace-cmd,kernel-shark: New libtracefs APIs for ftrace events and systems Tzvetomir Stoyanov (VMware)
2020-01-08 20:22 ` Steven Rostedt
2020-01-09 13:37 ` Tzvetomir Stoyanov
2020-01-08 21:09 ` Steven Rostedt
2020-01-09 14:14 ` Tzvetomir Stoyanov
2020-01-09 2:32 ` Steven Rostedt
2020-01-06 15:40 ` [PATCH v2 5/5] trace-cmd,kernel-shark: New libtracefs APIs for loading ftrace events Tzvetomir Stoyanov (VMware)
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