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* [PATCH v6 0/3] Add new trace-cmd record options: "--proc-map"
@ 2019-08-28 11:24 Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 1/3] trace-cmd: Extend ptrace logic to work with multiple filtered pids Tzvetomir Stoyanov (VMware)
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2019-08-28 11:24 UTC (permalink / raw)
  To: rostedt; +Cc: linux-trace-devel

New options to trace-cmd record are added:
  - "--proc-map" - Saves traced process(es) address map in trace.dat
    file.
  - "--user" - Executes the traced process as given user.

As "--proc-map" option uses trace-cmd ptrace logic, part of this code is
rewritten. There were some leftovers related to this logic, the code is
upadted.

[
   v6 changes:
        - Added warning message when allocation of pids array fails.
	- Put extra brackets around complex blocks in record_trace(),
          as Steven Rostedt suggested.
   v5 changes:
        - Added new patch: 
            "Extend ptrace logic to work with multiple filtered pids"
          It resolves "filter_pid" leftover in ptrace related logic.
        - "--proc-map" does not depend on option -F, it works with any command,
          specified as trace-cmd argument or option -P.
        - Renamed "mmap" to "proc-map" - the option name and the names of
          the functions, variables and defines related to this feature.
   v4 changes:
        - Added check for strdup() failure.
        - Made input user string argument of change_user() and run_cmd()
         constant.
        - Added description of the new "--mmap" trace-cmd option in the 
          program's help and the man page. (Suggested by Slavomir Kaslev)

      Problems, reported by Yordan Karadzhov:
        - Improved the parsing of /proc/<pid>/maps. Made it not so strict, as it
          failed on some machines due to different size of fields. 
        - Implemented trace_pid_mmap_free() cleanup function to free mmap
          related resources at trace-cmd exit.
        - Fixed potential problem with non-terminated string, returned by
          readlink().
        - Coding style fixes.
   v3 changes:
      - "--user" does not depend on option -F, it works with any command,
        specified as trace-cmd argument.
      - Changed tracecmd_search_task_mmap() API to return not only the library
     name, but also the start and end memory addresses.
      - Renamed *tracee* to *task*
      - Improved resources cleanup, in case of an error.
      - Removed (this) changelog from the commit message.
   v2 changes:
     - Check for errors in change_user(). If an error occurs while
       changing the user, the message is printed and the traced 
       process is not executed.
     - Replaced usage of tracecmd_add_option_v() with tracecmd_add_option() API.
     - Added checks to prevent buffer overflow when sscanf (... "%s", buf) is used.
     - Return error in case memory allocation fails.
     - Return error if option string is not in the expected format.
     - Sort memory maps and use binary search to find matching library in the map.


Tzvetomir Stoyanov (VMware) (3):
  trace-cmd: Extend ptrace logic to work with multiple filtered pids
  trace-cmd: Save the tracee address map into the trace.dat file.
  trace-cmd: Add option to execute traced process as given user

 Documentation/trace-cmd-record.1.txt |   6 +
 include/trace-cmd/trace-cmd.h        |  10 +
 lib/trace-cmd/trace-input.c          | 172 +++++++++++++++-
 tracecmd/include/trace-local.h       |  10 +
 tracecmd/trace-record.c              | 286 +++++++++++++++++++++++++--
 tracecmd/trace-usage.c               |   2 +
 6 files changed, 468 insertions(+), 18 deletions(-)

-- 
2.21.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v6 1/3] trace-cmd: Extend ptrace logic to work with multiple filtered pids
  2019-08-28 11:24 [PATCH v6 0/3] Add new trace-cmd record options: "--proc-map" Tzvetomir Stoyanov (VMware)
@ 2019-08-28 11:24 ` Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 2/3] trace-cmd: Save the tracee address map into the trace.dat file Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 3/3] trace-cmd: Add option to execute traced process as given user Tzvetomir Stoyanov (VMware)
  2 siblings, 0 replies; 4+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2019-08-28 11:24 UTC (permalink / raw)
  To: rostedt; +Cc: linux-trace-devel

In the trace-record.c file there is a global variable named "filter_pid".
It is not set anywhere in the code, but there is a logic which relies on it.
This variable is a leftover from the past implementation of trace-cmd
record "-P" option, when it was designed to filter only a single PID.
Now "-P" option works with a list of PIDs, stored in filter_pids global
list. The code is modified to work with filter_pids instead of filter_pid.
This logic is used only if there is no ftrace "options/event-fork" on the
system and we have ptrace support. There is one significant change in
the trace-cmd record behavior in this specific use case:
  - filtered pids are specified with the "-P" option.
  - there is no ftrace "options/event-fork" on the system.
  - there is ptrace support.
The trace continues until Ctrl^C is hit or all filtered PIDs exit,
whatever comes first.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 tracecmd/trace-record.c | 69 +++++++++++++++++++++++++++++++++--------
 1 file changed, 56 insertions(+), 13 deletions(-)

diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 5dc6f17..917f52a 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -86,7 +86,6 @@ static bool use_tcp;
 static int do_ptrace;
 
 static int filter_task;
-static int filter_pid = -1;
 static bool no_filter = false;
 
 static int local_cpu_count;
@@ -866,6 +865,13 @@ static void add_filter_pid(int pid, int exclude)
 	struct filter_pids *p;
 	char buf[100];
 
+	for (p = filter_pids; p; p = p->next) {
+		if (p->pid == pid) {
+			p->exclude = exclude;
+			return;
+		}
+	}
+
 	p = malloc(sizeof(*p));
 	if (!p)
 		die("Failed to allocate pid filter");
@@ -1223,17 +1229,36 @@ static void enable_ptrace(void)
 	ptrace(PTRACE_TRACEME, 0, NULL, 0);
 }
 
-static void ptrace_wait(enum trace_type type, int main_pid)
+static void ptrace_wait(enum trace_type type)
 {
+	struct filter_pids *fpid;
 	unsigned long send_sig;
 	unsigned long child;
 	siginfo_t sig;
+	int main_pids;
 	int cstatus;
 	int status;
+	int i = 0;
+	int *pids;
 	int event;
 	int pid;
 	int ret;
 
+	pids = calloc(nr_filter_pids, sizeof(int));
+	if (!pids) {
+		warning("Unable to allocate array for %d PIDs", nr_filter_pids);
+		return;
+	}
+
+	for (fpid = filter_pids; fpid; fpid = fpid->next) {
+		if (fpid->exclude)
+			continue;
+		pids[i++] = fpid->pid;
+		if (i >= nr_filter_pids)
+			break;
+	}
+	main_pids = i;
+
 	do {
 		ret = trace_waitpid(type, -1, &status, WSTOPPED | __WALL);
 		if (ret < 0)
@@ -1275,11 +1300,24 @@ static void ptrace_wait(enum trace_type type, int main_pid)
 			       PTRACE_O_TRACEEXIT);
 			ptrace(PTRACE_CONT, pid, NULL, send_sig);
 		}
-	} while (!finished && ret > 0 &&
-		 (!WIFEXITED(status) || pid != main_pid));
+		if (WIFEXITED(status) ||
+		   (WIFSTOPPED(status) && event == PTRACE_EVENT_EXIT)) {
+			for (i = 0; i < nr_filter_pids; i++) {
+				if (pid == pids[i]) {
+					pids[i] = 0;
+					main_pids--;
+					if (!main_pids)
+						finished = 1;
+					break;
+				}
+			}
+		}
+	} while (!finished && ret > 0);
+
+	free(pids);
 }
 #else
-static inline void ptrace_wait(enum trace_type type, int main_pid) { }
+static inline void ptrace_wait(enum trace_type type) { }
 static inline void enable_ptrace(void) { }
 static inline void ptrace_attach(int pid) { }
 
@@ -1289,8 +1327,8 @@ static void trace_or_sleep(enum trace_type type)
 {
 	struct timeval tv = { 1 , 0 };
 
-	if (do_ptrace && filter_pid >= 0)
-		ptrace_wait(type, filter_pid);
+	if (do_ptrace && filter_pids)
+		ptrace_wait(type);
 	else if (type & TRACE_TYPE_STREAM)
 		trace_stream_read(pids, recorder_threads, &tv);
 	else
@@ -1327,7 +1365,7 @@ static void run_cmd(enum trace_type type, int argc, char **argv)
 	}
 	if (do_ptrace) {
 		add_filter_pid(pid, 0);
-		ptrace_wait(type, pid);
+		ptrace_wait(type);
 	} else
 		trace_waitpid(type, pid, &status, 0);
 }
@@ -2318,7 +2356,7 @@ create_event(struct buffer_instance *instance, char *path, struct event_list *ol
 	*event = *old_event;
 	add_event(instance, event);
 
-	if (event->filter || filter_task || filter_pid) {
+	if (event->filter || filter_task || filter_pids) {
 		event->filter_file = strdup(path);
 		if (!event->filter_file)
 			die("malloc filter file");
@@ -4924,9 +4962,9 @@ static void parse_record_options(int argc,
 		add_func(&ctx->instance->filter_funcs,
 			 ctx->instance->filter_mod, "*");
 
-	if (do_ptrace && !filter_task && (filter_pid < 0))
+	if (do_ptrace && !filter_task && !nr_filter_pids)
 		die(" -c can only be used with -F (or -P with event-fork support)");
-	if (ctx->do_child && !filter_task &&! filter_pid)
+	if (ctx->do_child && !filter_task && !nr_filter_pids)
 		die(" -c can only be used with -P or -F");
 
 	if ((argc - optind) >= 2) {
@@ -4997,6 +5035,7 @@ static void record_trace(int argc, char **argv,
 {
 	enum trace_type type = get_trace_cmd_type(ctx->curr_cmd);
 	struct buffer_instance *instance;
+	struct filter_pids *pid;
 
 	/*
 	 * If top_instance doesn't have any plugins or events, then
@@ -5083,8 +5122,12 @@ static void record_trace(int argc, char **argv,
 		update_task_filter();
 		tracecmd_enable_tracing();
 		/* We don't ptrace ourself */
-		if (do_ptrace && filter_pid >= 0)
-			ptrace_attach(filter_pid);
+		if (do_ptrace && filter_pids) {
+			for (pid = filter_pids; pid; pid = pid->next) {
+				if (!pid->exclude)
+					ptrace_attach(pid->pid);
+			}
+		}
 		/* sleep till we are woken with Ctrl^C */
 		printf("Hit Ctrl^C to stop recording\n");
 		while (!finished)
-- 
2.21.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v6 2/3] trace-cmd: Save the tracee address map into the trace.dat file.
  2019-08-28 11:24 [PATCH v6 0/3] Add new trace-cmd record options: "--proc-map" Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 1/3] trace-cmd: Extend ptrace logic to work with multiple filtered pids Tzvetomir Stoyanov (VMware)
@ 2019-08-28 11:24 ` Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 3/3] trace-cmd: Add option to execute traced process as given user Tzvetomir Stoyanov (VMware)
  2 siblings, 0 replies; 4+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2019-08-28 11:24 UTC (permalink / raw)
  To: rostedt; +Cc: linux-trace-devel

A new trace-cmd record option is added: "--proc-map". When it is set
the address map of the traced applications is stored in the trace.dat
file. The traced applications can be specified using the option -P,
or as a given 'command'. A new API tracecmd_search_task_map() can be
used to look up into stored address maps. The map is retrieved from
/proc/<pid>/maps file.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 Documentation/trace-cmd-record.1.txt |   3 +
 include/trace-cmd/trace-cmd.h        |  10 ++
 lib/trace-cmd/trace-input.c          | 172 ++++++++++++++++++++++++++-
 tracecmd/include/trace-local.h       |  10 ++
 tracecmd/trace-record.c              | 172 ++++++++++++++++++++++++++-
 tracecmd/trace-usage.c               |   1 +
 6 files changed, 364 insertions(+), 4 deletions(-)

diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index 26a8299..e697f03 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -288,6 +288,9 @@ OPTIONS
 
     '--module snd -n "*"' is equivalent to '-n :mod:snd'
 
+*--proc-map*::
+     Save the traced process address map into the trace.dat file. The traced
+     processes can be specified using the option *-P*, or as a given 'command'.
 
 *--profile*::
     With the *--profile* option, "trace-cmd" will enable tracing that can
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 6f62ab9..c4a437a 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -82,6 +82,7 @@ enum {
 	TRACECMD_OPTION_OFFSET,
 	TRACECMD_OPTION_CPUCOUNT,
 	TRACECMD_OPTION_VERSION,
+	TRACECMD_OPTION_PROCMAPS,
 };
 
 enum {
@@ -97,6 +98,12 @@ struct tracecmd_ftrace {
 	int long_size;
 };
 
+struct tracecmd_proc_addr_map {
+	unsigned long long	start;
+	unsigned long long	end;
+	char			*lib_name;
+};
+
 typedef void (*tracecmd_show_data_func)(struct tracecmd_input *handle,
 					struct tep_record *record);
 typedef void (*tracecmd_handle_init_func)(struct tracecmd_input *handle,
@@ -208,6 +215,9 @@ unsigned long long tracecmd_page_ts(struct tracecmd_input *handle,
 unsigned int tracecmd_record_ts_delta(struct tracecmd_input *handle,
 				      struct tep_record *record);
 
+struct tracecmd_proc_addr_map *
+tracecmd_search_task_map(struct tracecmd_input *handle,
+			 int pid, unsigned long long addr);
 #ifndef SWIG
 /* hack for function graph work around */
 extern __thread struct tracecmd_input *tracecmd_curr_thread_handle;
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 654101f..a6fa7f5 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -101,6 +101,7 @@ struct tracecmd_input {
 	struct tracecmd_ftrace	finfo;
 
 	struct hook_list	*hooks;
+	struct pid_addr_maps	*pid_maps;
 	/* file information */
 	size_t			header_files_start;
 	size_t			ftrace_files_start;
@@ -2136,6 +2137,167 @@ void tracecmd_set_ts2secs(struct tracecmd_input *handle,
 	handle->use_trace_clock = false;
 }
 
+static int trace_pid_map_cmp(const void *a, const void *b)
+{
+	struct tracecmd_proc_addr_map *m_a = (struct tracecmd_proc_addr_map *)a;
+	struct tracecmd_proc_addr_map *m_b = (struct tracecmd_proc_addr_map *)b;
+
+	if (m_a->start > m_b->start)
+		return 1;
+	if (m_a->start < m_b->start)
+		return -1;
+	return 0;
+}
+
+static void procmap_free(struct pid_addr_maps *maps)
+{
+	int i;
+
+	if (!maps)
+		return;
+	if (maps->lib_maps) {
+		for (i = 0; i < maps->nr_lib_maps; i++)
+			free(maps->lib_maps[i].lib_name);
+		free(maps->lib_maps);
+	}
+	free(maps->proc_name);
+	free(maps);
+}
+
+#define STR_PROCMAP_LINE_MAX	(PATH_MAX+22)
+static int trace_pid_map_load(struct tracecmd_input *handle, char *buf)
+{
+	struct pid_addr_maps *maps = NULL;
+	char mapname[STR_PROCMAP_LINE_MAX];
+	char *line;
+	int res;
+	int ret;
+	int i;
+
+	maps = calloc(1, sizeof(*maps));
+	if (!maps)
+		return -ENOMEM;
+
+	ret  = -EINVAL;
+	line = strchr(buf, '\n');
+	if (!line)
+		goto out_fail;
+
+	*line = '\0';
+	if (strlen(buf) > STR_PROCMAP_LINE_MAX)
+		goto out_fail;
+
+	res = sscanf(buf, "%x %x %s", &maps->pid, &maps->nr_lib_maps, mapname);
+	if (res != 3)
+		goto out_fail;
+
+	ret  = -ENOMEM;
+	maps->proc_name = strdup(mapname);
+	if (!maps->proc_name)
+		goto out_fail;
+
+	maps->lib_maps = calloc(maps->nr_lib_maps, sizeof(struct tracecmd_proc_addr_map));
+	if (!maps->lib_maps)
+		goto out_fail;
+
+	buf = line + 1;
+	line = strchr(buf, '\n');
+	for (i = 0; i < maps->nr_lib_maps; i++) {
+		if (!line)
+			break;
+		*line = '\0';
+		if (strlen(buf) > STR_PROCMAP_LINE_MAX)
+			break;
+		res = sscanf(buf, "%llx %llx %s", &maps->lib_maps[i].start,
+			     &maps->lib_maps[i].end, mapname);
+		if (res != 3)
+			break;
+		maps->lib_maps[i].lib_name = strdup(mapname);
+		if (!maps->lib_maps[i].lib_name)
+			goto out_fail;
+		buf = line + 1;
+		line = strchr(buf, '\n');
+	}
+
+	ret  = -EINVAL;
+	if (i != maps->nr_lib_maps)
+		goto out_fail;
+
+	qsort(maps->lib_maps, maps->nr_lib_maps,
+	      sizeof(*maps->lib_maps), trace_pid_map_cmp);
+
+	maps->next = handle->pid_maps;
+	handle->pid_maps = maps;
+
+	return 0;
+
+out_fail:
+	procmap_free(maps);
+	return ret;
+}
+
+static void trace_pid_map_free(struct pid_addr_maps *maps)
+{
+	struct pid_addr_maps *del;
+
+	while (maps) {
+		del = maps;
+		maps = maps->next;
+		procmap_free(del);
+	}
+}
+
+static int trace_pid_map_search(const void *a, const void *b)
+{
+	struct tracecmd_proc_addr_map *key = (struct tracecmd_proc_addr_map *)a;
+	struct tracecmd_proc_addr_map *map = (struct tracecmd_proc_addr_map *)b;
+
+	if (key->start >= map->end)
+		return 1;
+	if (key->start < map->start)
+		return -1;
+	return 0;
+}
+
+/**
+ * tracecmd_search_task_map - Search task memory address map
+ * @handle: input handle to the trace.dat file
+ * @pid: pid of the task
+ * @addr: address from the task memory space.
+ *
+ * Map of the task memory can be saved in the trace.dat file, using the option
+ * "--proc-map". If there is such information, this API can be used to look up
+ * into this memory map to find what library is loaded at the given @addr.
+ *
+ * A pointer to struct tracecmd_proc_addr_map is returned, containing the name
+ * of the library at given task @addr and the library start and end addresses.
+ */
+struct tracecmd_proc_addr_map *
+tracecmd_search_task_map(struct tracecmd_input *handle,
+			 int pid, unsigned long long addr)
+{
+	struct tracecmd_proc_addr_map *lib;
+	struct tracecmd_proc_addr_map key;
+	struct pid_addr_maps *maps;
+
+	if (!handle || !handle->pid_maps)
+		return NULL;
+
+	maps = handle->pid_maps;
+	while (maps) {
+		if (maps->pid == pid)
+			break;
+		maps = maps->next;
+	}
+	if (!maps || !maps->nr_lib_maps || !maps->lib_maps)
+		return NULL;
+	key.start = addr;
+	lib = bsearch(&key, maps->lib_maps, maps->nr_lib_maps,
+		      sizeof(*maps->lib_maps), trace_pid_map_search);
+
+	return lib;
+}
+
 static int handle_options(struct tracecmd_input *handle)
 {
 	unsigned long long offset;
@@ -2223,9 +2385,6 @@ static int handle_options(struct tracecmd_input *handle)
 		case TRACECMD_OPTION_UNAME:
 			handle->uname = strdup(buf);
 			break;
-		case TRACECMD_OPTION_VERSION:
-			handle->version = strdup(buf);
-			break;
 		case TRACECMD_OPTION_HOOK:
 			hook = tracecmd_create_event_hook(buf);
 			hook->next = handle->hooks;
@@ -2235,6 +2394,10 @@ static int handle_options(struct tracecmd_input *handle)
 			cpus = *(int *)buf;
 			handle->cpus = tep_read_number(handle->pevent, &cpus, 4);
 			break;
+		case TRACECMD_OPTION_PROCMAPS:
+			if (buf[size-1] == '\0')
+				trace_pid_map_load(handle, buf);
+			break;
 		default:
 			warning("unknown option %d", option);
 			break;
@@ -2848,6 +3011,9 @@ void tracecmd_close(struct tracecmd_input *handle)
 	tracecmd_free_hooks(handle->hooks);
 	handle->hooks = NULL;
 
+	trace_pid_map_free(handle->pid_maps);
+	handle->pid_maps = NULL;
+
 	if (handle->flags & TRACECMD_FL_BUFFER_INSTANCE)
 		tracecmd_close(handle->parent);
 	else {
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 1cad3cc..78c52dc 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -157,6 +157,14 @@ struct func_list {
 	const char *mod;
 };
 
+struct pid_addr_maps {
+	struct pid_addr_maps		*next;
+	struct tracecmd_proc_addr_map	*lib_maps;
+	unsigned int			nr_lib_maps;
+	char				*proc_name;
+	int				pid;
+};
+
 struct buffer_instance {
 	struct buffer_instance	*next;
 	const char		*name;
@@ -183,6 +191,8 @@ struct buffer_instance {
 	struct tracecmd_msg_handle *msg_handle;
 	struct tracecmd_output *network_handle;
 
+	struct pid_addr_maps	*pid_maps;
+
 	char			*max_graph_depth;
 
 	int			flags;
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 917f52a..4a20339 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -84,6 +84,8 @@ static int max_kb;
 static bool use_tcp;
 
 static int do_ptrace;
+static int do_children;
+static int get_procmap;
 
 static int filter_task;
 static bool no_filter = false;
@@ -1068,6 +1070,121 @@ static char *make_pid_filter(char *curr_filter, const char *field)
 	return filter;
 }
 
+#define _STRINGIFY(x) #x
+#define STRINGIFY(x) _STRINGIFY(x)
+
+static int get_pid_addr_maps(int pid)
+{
+	struct buffer_instance *instance = &top_instance;
+	struct pid_addr_maps *maps = instance->pid_maps;
+	struct tracecmd_proc_addr_map *map;
+	unsigned long long begin, end;
+	struct pid_addr_maps *m;
+	char mapname[PATH_MAX+1];
+	char fname[PATH_MAX+1];
+	char buf[PATH_MAX+100];
+	FILE *f;
+	int ret;
+	int res;
+	int i;
+
+	sprintf(fname, "/proc/%d/exe", pid);
+	ret = readlink(fname, mapname, PATH_MAX);
+	if (ret >= PATH_MAX || ret < 0)
+		return -ENOENT;
+	mapname[ret] = 0;
+
+	sprintf(fname, "/proc/%d/maps", pid);
+	f = fopen(fname, "r");
+	if (!f)
+		return -ENOENT;
+
+	while (maps) {
+		if (pid == maps->pid)
+			break;
+		maps = maps->next;
+	}
+
+	ret = -ENOMEM;
+	if (!maps) {
+		maps = calloc(1, sizeof(*maps));
+		if (!maps)
+			goto out_fail;
+		maps->pid = pid;
+		maps->next = instance->pid_maps;
+		instance->pid_maps = maps;
+	} else {
+		for (i = 0; i < maps->nr_lib_maps; i++)
+			free(maps->lib_maps[i].lib_name);
+		free(maps->lib_maps);
+		maps->lib_maps = NULL;
+		maps->nr_lib_maps = 0;
+		free(maps->proc_name);
+	}
+
+	maps->proc_name = strdup(mapname);
+	if (!maps->proc_name)
+		goto out;
+
+	while (fgets(buf, sizeof(buf), f)) {
+		mapname[0] = '\0';
+		res = sscanf(buf, "%llx-%llx %*s %*x %*s %*d %"STRINGIFY(PATH_MAX)"s",
+			     &begin, &end, mapname);
+		if (res == 3 && mapname[0] != '\0') {
+			map = realloc(maps->lib_maps,
+				      (maps->nr_lib_maps + 1) * sizeof(*map));
+			if (!map)
+				goto out_fail;
+			map[maps->nr_lib_maps].end = end;
+			map[maps->nr_lib_maps].start = begin;
+			map[maps->nr_lib_maps].lib_name = strdup(mapname);
+			if (!map[maps->nr_lib_maps].lib_name)
+				goto out_fail;
+			maps->lib_maps = map;
+			maps->nr_lib_maps++;
+		}
+	}
+out:
+	fclose(f);
+	return 0;
+
+out_fail:
+	fclose(f);
+	if (maps) {
+		for (i = 0; i < maps->nr_lib_maps; i++)
+			free(maps->lib_maps[i].lib_name);
+		if (instance->pid_maps != maps) {
+			m = instance->pid_maps;
+			while (m) {
+				if (m->next == maps) {
+					m->next = maps->next;
+					break;
+				}
+				m = m->next;
+			}
+		} else
+			instance->pid_maps = maps->next;
+		free(maps->lib_maps);
+		maps->lib_maps = NULL;
+		maps->nr_lib_maps = 0;
+		free(maps->proc_name);
+		maps->proc_name = NULL;
+		free(maps);
+	}
+	return ret;
+}
+
+static void get_filter_pid_maps(void)
+{
+	struct filter_pids *p;
+
+	for (p = filter_pids; p; p = p->next) {
+		if (p->exclude)
+			continue;
+		get_pid_addr_maps(p->pid);
+	}
+}
+
 static void update_task_filter(void)
 {
 	struct buffer_instance *instance;
@@ -1076,6 +1193,9 @@ static void update_task_filter(void)
 	if (no_filter)
 		return;
 
+	if (get_procmap && filter_pids)
+		get_filter_pid_maps();
+
 	if (filter_task)
 		add_filter_pid(pid, 0);
 
@@ -1289,6 +1409,8 @@ static void ptrace_wait(enum trace_type type)
 				break;
 
 			case PTRACE_EVENT_EXIT:
+				if (get_procmap)
+					get_pid_addr_maps(pid);
 				ptrace(PTRACE_GETEVENTMSG, pid, NULL, &cstatus);
 				ptrace(PTRACE_DETACH, pid, NULL, NULL);
 				break;
@@ -1365,6 +1487,7 @@ static void run_cmd(enum trace_type type, int argc, char **argv)
 	}
 	if (do_ptrace) {
 		add_filter_pid(pid, 0);
+		ptrace_attach(pid);
 		ptrace_wait(type);
 	} else
 		trace_waitpid(type, pid, &status, 0);
@@ -3132,6 +3255,36 @@ static void append_buffer(struct tracecmd_output *handle,
 	}
 }
 
+
+static void
+add_pid_maps(struct tracecmd_output *handle, struct buffer_instance *instance)
+{
+	struct pid_addr_maps *maps = instance->pid_maps;
+	struct trace_seq s;
+	int i;
+
+	trace_seq_init(&s);
+	while (maps) {
+		if (!maps->nr_lib_maps) {
+			maps = maps->next;
+			continue;
+		}
+		trace_seq_reset(&s);
+		trace_seq_printf(&s, "%x %x %s\n",
+				 maps->pid, maps->nr_lib_maps, maps->proc_name);
+		for (i = 0; i < maps->nr_lib_maps; i++)
+			trace_seq_printf(&s, "%llx %llx %s\n",
+					maps->lib_maps[i].start,
+					maps->lib_maps[i].end,
+					maps->lib_maps[i].lib_name);
+		trace_seq_terminate(&s);
+		tracecmd_add_option(handle, TRACECMD_OPTION_PROCMAPS,
+				    s.len + 1, s.buffer);
+		maps = maps->next;
+	}
+	trace_seq_destroy(&s);
+}
+
 static void
 add_buffer_stat(struct tracecmd_output *handle, struct buffer_instance *instance)
 {
@@ -3325,6 +3478,10 @@ static void record_data(struct common_record_context *ctx)
 		if (!no_top_instance() && !top_instance.msg_handle)
 			print_stat(&top_instance);
 
+		for_all_instances(instance) {
+			add_pid_maps(handle, instance);
+		}
+
 		tracecmd_append_cpu_data(handle, local_cpu_count, temp_files);
 
 		for (i = 0; i < max_cpu_count; i++)
@@ -4435,6 +4592,7 @@ void update_first_instance(struct buffer_instance *instance, int topt)
 }
 
 enum {
+	OPT_procmap		= 244,
 	OPT_quiet		= 245,
 	OPT_debug		= 246,
 	OPT_no_filter		= 247,
@@ -4665,6 +4823,7 @@ static void parse_record_options(int argc,
 			{"debug", no_argument, NULL, OPT_debug},
 			{"quiet", no_argument, NULL, OPT_quiet},
 			{"help", no_argument, NULL, '?'},
+			{"proc-map", no_argument, NULL, OPT_procmap},
 			{"module", required_argument, NULL, OPT_module},
 			{NULL, 0, NULL, 0}
 		};
@@ -4754,6 +4913,7 @@ static void parse_record_options(int argc,
 				die("-c invalid: ptrace not supported");
 #endif
 				do_ptrace = 1;
+				do_children = 1;
 			} else {
 				save_option("event-fork");
 				ctx->do_child = 1;
@@ -4896,6 +5056,9 @@ static void parse_record_options(int argc,
 		case 'i':
 			ignore_event_not_found = 1;
 			break;
+		case OPT_procmap:
+			get_procmap = 1;
+			break;
 		case OPT_date:
 			ctx->date = 1;
 			if (ctx->data_flags & DATA_FL_OFFSET)
@@ -4962,7 +5125,7 @@ static void parse_record_options(int argc,
 		add_func(&ctx->instance->filter_funcs,
 			 ctx->instance->filter_mod, "*");
 
-	if (do_ptrace && !filter_task && !nr_filter_pids)
+	if (do_children && !filter_task && !nr_filter_pids)
 		die(" -c can only be used with -F (or -P with event-fork support)");
 	if (ctx->do_child && !filter_task && !nr_filter_pids)
 		die(" -c can only be used with -P or -F");
@@ -4976,6 +5139,13 @@ static void parse_record_options(int argc,
 			    "Did you mean 'record'?");
 		ctx->run_command = 1;
 	}
+
+	if (get_procmap) {
+		if (!ctx->run_command && !nr_filter_pids)
+			warning("--proc-map is ignored, no command or filtered PIDs are specified.");
+		else
+			do_ptrace = 1;
+	}
 }
 
 static enum trace_type get_trace_cmd_type(enum trace_cmd cmd)
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 406384c..7a67784 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -57,6 +57,7 @@ static struct usage_help usage_help[] = {
 		"             (use with caution)\n"
 		"          --max-graph-depth limit function_graph depth\n"
 		"          --no-filter include trace-cmd threads in the trace\n"
+		"          --proc-map save the traced processes address map into the trace.dat file\n"
 	},
 	{
 		"start",
-- 
2.21.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH v6 3/3] trace-cmd: Add option to execute traced process as given user
  2019-08-28 11:24 [PATCH v6 0/3] Add new trace-cmd record options: "--proc-map" Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 1/3] trace-cmd: Extend ptrace logic to work with multiple filtered pids Tzvetomir Stoyanov (VMware)
  2019-08-28 11:24 ` [PATCH v6 2/3] trace-cmd: Save the tracee address map into the trace.dat file Tzvetomir Stoyanov (VMware)
@ 2019-08-28 11:24 ` Tzvetomir Stoyanov (VMware)
  2 siblings, 0 replies; 4+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2019-08-28 11:24 UTC (permalink / raw)
  To: rostedt; +Cc: linux-trace-devel

A new trace-cmd record option is added: "--user". When it is set with
combination of option -F, the traced process is executed in the context
of the specified user.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 Documentation/trace-cmd-record.1.txt |  3 ++
 tracecmd/trace-record.c              | 49 ++++++++++++++++++++++++++--
 tracecmd/trace-usage.c               |  1 +
 3 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index e697f03..bb18e88 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -119,6 +119,9 @@ OPTIONS
      Used with either *-F* (or *-P* if kernel supports it) to trace the process'
      children too.
 
+*--user*::
+     Execute the specified *command* as given user.
+
 *-C* 'clock'::
      Set the trace clock to "clock".
 
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 4a20339..9b7357f 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -33,6 +33,8 @@
 #include <errno.h>
 #include <limits.h>
 #include <libgen.h>
+#include <pwd.h>
+#include <grp.h>
 
 #include "version.h"
 #include "trace-local.h"
@@ -208,6 +210,7 @@ struct common_record_context {
 	struct buffer_instance *instance;
 	const char *output;
 	char *date2ts;
+	char *user;
 	int data_flags;
 
 	int record_all;
@@ -1457,7 +1460,34 @@ static void trace_or_sleep(enum trace_type type)
 		sleep(10);
 }
 
-static void run_cmd(enum trace_type type, int argc, char **argv)
+static int change_user(const char *user)
+{
+	struct passwd *pwd;
+
+	if (!user)
+		return 0;
+
+	pwd = getpwnam(user);
+	if (!pwd)
+		return -1;
+	if (initgroups(user, pwd->pw_gid) < 0)
+		return -1;
+	if (setgid(pwd->pw_gid) < 0)
+		return -1;
+	if (setuid(pwd->pw_uid) < 0)
+		return -1;
+
+	if (setenv("HOME", pwd->pw_dir, 1) < 0)
+		return -1;
+	if (setenv("USER", pwd->pw_name, 1) < 0)
+		return -1;
+	if (setenv("LOGNAME", pwd->pw_name, 1) < 0)
+		return -1;
+
+	return 0;
+}
+
+static void run_cmd(enum trace_type type, const char *user, int argc, char **argv)
 {
 	int status;
 	int pid;
@@ -1478,6 +1508,10 @@ static void run_cmd(enum trace_type type, int argc, char **argv)
 			dup2(save_stdout, 1);
 			close(save_stdout);
 		}
+
+		if (change_user(user) < 0)
+			die("Failed to change user to %s", user);
+
 		if (execvp(argv[0], argv)) {
 			fprintf(stderr, "\n********************\n");
 			fprintf(stderr, " Unable to exec %s\n", argv[0]);
@@ -4592,6 +4626,7 @@ void update_first_instance(struct buffer_instance *instance, int topt)
 }
 
 enum {
+	OPT_user		= 243,
 	OPT_procmap		= 244,
 	OPT_quiet		= 245,
 	OPT_debug		= 246,
@@ -4824,6 +4859,7 @@ static void parse_record_options(int argc,
 			{"quiet", no_argument, NULL, OPT_quiet},
 			{"help", no_argument, NULL, '?'},
 			{"proc-map", no_argument, NULL, OPT_procmap},
+			{"user", required_argument, NULL, OPT_user},
 			{"module", required_argument, NULL, OPT_module},
 			{NULL, 0, NULL, 0}
 		};
@@ -5056,6 +5092,11 @@ static void parse_record_options(int argc,
 		case 'i':
 			ignore_event_not_found = 1;
 			break;
+		case OPT_user:
+			ctx->user = strdup(optarg);
+			if (!ctx->user)
+				die("Failed to allocate user name");
+			break;
 		case OPT_procmap:
 			get_procmap = 1;
 			break;
@@ -5139,7 +5180,9 @@ static void parse_record_options(int argc,
 			    "Did you mean 'record'?");
 		ctx->run_command = 1;
 	}
-
+	if (ctx->user && !ctx->run_command)
+		warning("--user %s is ignored, no command is specified",
+			ctx->user);
 	if (get_procmap) {
 		if (!ctx->run_command && !nr_filter_pids)
 			warning("--proc-map is ignored, no command or filtered PIDs are specified.");
@@ -5287,7 +5330,7 @@ static void record_trace(int argc, char **argv,
 	}
 
 	if (ctx->run_command)
-		run_cmd(type, (argc - optind) - 1, &argv[optind + 1]);
+		run_cmd(type, ctx->user, (argc - optind) - 1, &argv[optind + 1]);
 	else {
 		update_task_filter();
 		tracecmd_enable_tracing();
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 7a67784..20cb66f 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -58,6 +58,7 @@ static struct usage_help usage_help[] = {
 		"          --max-graph-depth limit function_graph depth\n"
 		"          --no-filter include trace-cmd threads in the trace\n"
 		"          --proc-map save the traced processes address map into the trace.dat file\n"
+		"          --user execute the specified [command ...] as given user\n"
 	},
 	{
 		"start",
-- 
2.21.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, back to index

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-28 11:24 [PATCH v6 0/3] Add new trace-cmd record options: "--proc-map" Tzvetomir Stoyanov (VMware)
2019-08-28 11:24 ` [PATCH v6 1/3] trace-cmd: Extend ptrace logic to work with multiple filtered pids Tzvetomir Stoyanov (VMware)
2019-08-28 11:24 ` [PATCH v6 2/3] trace-cmd: Save the tracee address map into the trace.dat file Tzvetomir Stoyanov (VMware)
2019-08-28 11:24 ` [PATCH v6 3/3] trace-cmd: Add option to execute traced process as given user Tzvetomir Stoyanov (VMware)

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