Initial implementaton of trace-cmd support for ftrace uprobes.
Two new trace-cmd record / set argumemnts are introduced:
--uprobe file:function
--uprobe-ret file:function
The ftrace (return) probe is set on given function from the file.
Wildcards are supported in the function name:
--uprobe file:*
will set uprobes on all functions from the given file.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
tracecmd/Makefile | 1 +
tracecmd/include/trace-local.h | 18 +++
tracecmd/trace-record.c | 86 ++++++++++++-
tracecmd/trace-uprobes.c | 221 +++++++++++++++++++++++++++++++++
tracecmd/trace-usage.c | 4 +
5 files changed, 329 insertions(+), 1 deletion(-)
create mode 100644 tracecmd/trace-uprobes.c
diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index f9435558..37a5c42b 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -32,6 +32,7 @@ TRACE_CMD_OBJS += trace-list.o
TRACE_CMD_OBJS += trace-usage.o
TRACE_CMD_OBJS += trace-dump.o
TRACE_CMD_OBJS += trace-obj-debug.o
+TRACE_CMD_OBJS += trace-uprobes.o
ifeq ($(VSOCK_DEFINED), 1)
TRACE_CMD_OBJS += trace-tsync.o
endif
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 16adaac5..64626395 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -189,6 +189,21 @@ struct filter_pids {
int exclude;
};
+struct tracecmd_uprobe {
+ struct tracecmd_uprobe *next;
+
+ char *file;
+ int pcount;
+ struct trace_debug_object *debug;
+ char **events;
+ int ecount;
+ int esize;
+};
+int tracecmd_uprobe_new(struct tracecmd_uprobe **list, char *file, char *func);
+int tracecmd_uprobe_remove(struct tracecmd_uprobe *probes);
+void tracecmd_uprobe_free(struct tracecmd_uprobe *probes);
+int tracecmd_uprobe_create(struct tracecmd_uprobe *probes, bool uret);
+
struct buffer_instance {
struct buffer_instance *next;
struct tracefs_instance *tracefs;
@@ -208,6 +223,9 @@ struct buffer_instance {
struct func_list *filter_funcs;
struct func_list *notrace_funcs;
+ struct tracecmd_uprobe *uprobes;
+ struct tracecmd_uprobe *uretprobes;
+
struct opt_list *options;
struct filter_pids *filter_pids;
struct filter_pids *process_pids;
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index a48475b3..0fbc25e0 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -5023,7 +5023,8 @@ static void check_function_plugin(void)
static int __check_doing_something(struct buffer_instance *instance)
{
return is_guest(instance) || (instance->flags & BUFFER_FL_PROFILE) ||
- instance->plugin || instance->events || instance->get_procmap;
+ instance->plugin || instance->events || instance->get_procmap ||
+ instance->uprobes || instance->uretprobes;
}
static void check_doing_something(void)
@@ -5438,6 +5439,8 @@ void init_top_instance(void)
}
enum {
+ OPT_retuprobe = 239,
+ OPT_uprobe = 240,
OPT_fork = 241,
OPT_tsyncinterval = 242,
OPT_user = 243,
@@ -5627,6 +5630,25 @@ void trace_reset(int argc, char **argv)
exit(0);
}
+static int
+uprobe_param(struct buffer_instance *instance, char *param, bool pret)
+{
+ char *str, *file, *func;
+
+ if (!param)
+ return -1;
+
+ file = strtok_r(param, ":", &str);
+ func = strtok_r(NULL, ":", &str);
+
+ if (!file || !func)
+ return -1;
+ if (pret)
+ return tracecmd_uprobe_new(&instance->uretprobes, file, func);
+ else
+ return tracecmd_uprobe_new(&instance->uprobes, file, func);
+}
+
static void init_common_record_context(struct common_record_context *ctx,
enum trace_cmd curr_cmd)
{
@@ -5781,6 +5803,8 @@ static void parse_record_options(int argc,
{"module", required_argument, NULL, OPT_module},
{"tsync-interval", required_argument, NULL, OPT_tsyncinterval},
{"fork", no_argument, NULL, OPT_fork},
+ {"uprobe", required_argument, NULL, OPT_uprobe},
+ {"uprobe-ret", required_argument, NULL, OPT_retuprobe},
{NULL, 0, NULL, 0}
};
@@ -6180,6 +6204,14 @@ static void parse_record_options(int argc,
die("--fork option used for 'start' command only");
fork_process = true;
break;
+ case OPT_uprobe:
+ check_instance_die(ctx->instance, "--uprobe");
+ uprobe_param(ctx->instance, optarg, false);
+ break;
+ case OPT_retuprobe:
+ check_instance_die(ctx->instance, "--uprobe-ret");
+ uprobe_param(ctx->instance, optarg, true);
+ break;
case OPT_quiet:
case 'q':
quiet = true;
@@ -6291,6 +6323,17 @@ static void finalize_record_trace(struct common_record_context *ctx)
set_plugin("nop");
+ for_all_instances(instance) {
+ if (instance->uprobes) {
+ tracecmd_uprobe_remove(instance->uprobes);
+ tracecmd_uprobe_free(instance->uprobes);
+ }
+ if (instance->uretprobes) {
+ tracecmd_uprobe_remove(instance->uretprobes);
+ tracecmd_uprobe_free(instance->uretprobes);
+ }
+ }
+
tracecmd_remove_instances();
/* If tracing_on was enabled before we started, set it on now */
@@ -6322,6 +6365,37 @@ static bool has_local_instances(void)
return false;
}
+static int uprobes_set(struct buffer_instance *instance, bool ret_probe)
+{
+ struct tracecmd_uprobe *list;
+ struct event_list *event;
+ int i, ret;
+
+ if (ret_probe)
+ list = instance->uretprobes;
+ else
+ list = instance->uprobes;
+
+ ret = tracecmd_uprobe_create(list, ret_probe);
+ if (ret < 0)
+ return ret;
+ for (i = 0; i < list->ecount; i++) {
+ event = calloc(1, sizeof(*event));
+ if (!event)
+ break;
+
+ event->event = strdup(list->events[i]);
+ add_event(instance, event);
+
+ if (!recording_all_events())
+ list_event(event->event);
+ }
+
+ if (i < list->ecount)
+ return -1;
+ return 0;
+}
+
/*
* This function contains common code for the following commands:
* record, start, stream, profile.
@@ -6365,6 +6439,16 @@ static void record_trace(int argc, char **argv,
/* Some instances may not be created yet */
if (instance->tracing_on_init_val < 0)
instance->tracing_on_init_val = 1;
+ if (instance->uprobes) {
+ ctx->events = 1;
+ if (uprobes_set(instance, false) < 0)
+ die("Failed to set uprobes");
+ }
+ if (instance->uretprobes) {
+ ctx->events = 1;
+ if (uprobes_set(instance, true) < 0)
+ die("Failed to set return uprobes");
+ }
}
if (ctx->events)
diff --git a/tracecmd/trace-uprobes.c b/tracecmd/trace-uprobes.c
new file mode 100644
index 00000000..87f8c148
--- /dev/null
+++ b/tracecmd/trace-uprobes.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, VMware, Tzvetomir Stoyanov <tz.stoyanov@xxxxxxxxx>
+ *
+ */
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <linux/limits.h>
+#include <ctype.h>
+
+#include "tracefs.h"
+#include "trace-local.h"
+#include "trace-cmd.h"
+
+#define UPROBE_FILE "uprobe_events"
+
+static char *uprobe_event_name(char *file, char *func, bool pret)
+{
+ char *event = NULL;
+ char *fname;
+ int i;
+
+ fname = strrchr(file, '/');
+ if (fname)
+ fname++;
+ if (!fname || *fname == '\0')
+ fname = file;
+
+ asprintf(&event, "%c_%.*s_%.10s", pret ? 'r':'p', 10, fname, func);
+ if (event) {
+ for (i = 0; event[i]; i++) {
+ if (!isalpha(event[i]))
+ event[i] = '_';
+ }
+ }
+ return event;
+}
+
+/**
+ * tracecmd_uprobe_new - Add new uprobe in the uprobe list
+ * @list - list with uprobes, the new one will be added in this list
+ * @file - executable file that will be traced
+ * @func - function from @file
+ * @pret - indicate if this is return probe (true for return uprobe)
+ *
+ * Returns 0 on success or -1 on failure
+ */
+int tracecmd_uprobe_new(struct tracecmd_uprobe **list, char *file, char *func)
+{
+ struct tracecmd_uprobe *probe = *list;
+ bool new_file = false;
+
+ while (probe) {
+ if (!strcmp(probe->file, file))
+ break;
+ probe = probe->next;
+ }
+
+ if (!probe) {
+ probe = calloc(1, sizeof(*probe));
+ if (!probe)
+ return -1;
+
+ probe->file = strdup(file);
+ probe->next = *list;
+ probe->debug = trace_debug_obj_create_file(file);
+ if (!probe->debug)
+ goto error;
+ new_file = true;
+ }
+
+ if (trace_debug_add_resolve_symbol(probe->debug, 0, func) < 0)
+ goto error;
+ probe->pcount++;
+ if (new_file)
+ *list = probe;
+
+ return 0;
+
+error:
+ if (new_file) {
+ if (probe && probe->debug)
+ trace_debug_obj_destroy(probe->debug);
+ free(probe);
+ }
+
+ return -1;
+}
+
+/**
+ * tracecmd_uprobe_free - Free uprobe list
+ * @list - list with uprobes, that wil be freed
+ *
+ */
+void tracecmd_uprobe_free(struct tracecmd_uprobe *probes)
+{
+ struct tracecmd_uprobe *del;
+
+ while (probes) {
+ del = probes;
+ probes = probes->next;
+ trace_debug_obj_destroy(del->debug);
+ free(del->events);
+ free(del->file);
+ free(del);
+ }
+}
+
+struct uprobe_walk {
+ struct tracecmd_uprobe *probe;
+ bool uret;
+ int fd;
+};
+
+static int uprobe_write(struct tracecmd_debug_symbols *symbol, void *data)
+{
+ struct uprobe_walk *context = (struct uprobe_walk *)data;
+ char **events;
+ char probe_str[BUFSIZ];
+
+ if (!symbol->foffset || !symbol->name)
+ return 0;
+
+ if (context->probe->ecount == context->probe->esize) {
+ events = realloc(context->probe->events,
+ (context->probe->esize + 1) * sizeof(char *));
+ if (events) {
+ context->probe->esize++;
+ context->probe->events = events;
+ }
+ }
+ if (!context->probe->events)
+ return -1;
+
+ context->probe->events[context->probe->ecount] = uprobe_event_name(symbol->fname, symbol->name, context->uret);
+ if (!context->probe->events[context->probe->ecount])
+ return -1;
+ snprintf(probe_str, BUFSIZ,
+ "%c:%s %s:0x%llx", context->uret?'r':'p',
+ context->probe->events[context->probe->ecount],
+ symbol->fname, symbol->foffset);
+ write(context->fd, probe_str, strlen(probe_str));
+ context->probe->ecount++;
+
+ return 0;
+}
+
+/**
+ * tracecmd_uprobe_create - Create uprobes in ftrace
+ * @list - list with uprobes, that will be created
+ *
+ * Returns 0 on success or -1 on failure
+ */
+int tracecmd_uprobe_create(struct tracecmd_uprobe *probes, bool uret)
+{
+ char *ufile = tracefs_instance_get_file(NULL, UPROBE_FILE);
+ struct tracecmd_uprobe *probe = probes;
+ struct uprobe_walk context;
+
+ if (!ufile)
+ return -1;
+ context.uret = uret;
+ context.fd = open(ufile, O_WRONLY | O_APPEND);
+ tracefs_put_tracing_file(ufile);
+
+ while (probe) {
+ context.probe = probe;
+ if (trace_debug_resolve_symbols(probe->debug) == 0) {
+ if (!probe->events) {
+ probe->esize = probe->pcount;
+ probe->events = calloc(probe->esize, sizeof(char *));
+ }
+ trace_debug_walk_resolved_symbols(probe->debug,
+ uprobe_write,
+ (void *)&context);
+ }
+ probe = probe->next;
+ }
+ close(context.fd);
+
+ return 0;
+}
+
+/**
+ * tracecmd_uprobe_remove - Remove uprobes from ftrace
+ * @list - list with uprobes, that will be removed
+ *
+ * Returns 0 on success or -1 on failure
+ */
+int tracecmd_uprobe_remove(struct tracecmd_uprobe *probes)
+{
+ char *ufile = tracefs_instance_get_file(NULL, UPROBE_FILE);
+ struct tracecmd_uprobe *probe = probes;
+ char probe_str[BUFSIZ];
+ int fd;
+ int i;
+
+ if (!ufile)
+ return -1;
+ fd = open(ufile, O_WRONLY | O_APPEND);
+ tracefs_put_tracing_file(ufile);
+ if (fd < 0)
+ return -1;
+
+ while (probe) {
+ if (probe->events) {
+ for (i = 0; i < probe->ecount; i++) {
+ snprintf(probe_str, BUFSIZ,
+ "-:%s", probe->events[i]);
+ write(fd, probe_str, strlen(probe_str));
+ }
+ }
+
+ probe = probe->next;
+ }
+
+ close(fd);
+ return 0;
+}
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 3f0b2d07..59708070 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -65,6 +65,8 @@ static struct usage_help usage_help[] = {
" If a negative number is specified, timestamps synchronization is disabled"
" If 0 is specified, no loop is performed - timestamps offset is calculated only twice,"
" at the beginnig and at the end of the trace\n"
+ " --uprobe set the specified [file:function] as uprobe\n"
+ " --uprobe-ret set the specified [file:function] as return uprobe\n"
},
{
"set",
@@ -101,6 +103,8 @@ static struct usage_help usage_help[] = {
" --cmdlines-size change kernel saved_cmdlines_size\n"
" --user execute the specified [command ...] as given user\n"
" --fork return immediately if a command is specified\n"
+ " --uprobe set the specified [file:function] as uprobe\n"
+ " --uprobe-ret set the specified [file:function] as return uprobe\n"
},
{
"start",
--
2.26.2
|