From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>
A new trace-cmd record option is added: "--mmap". When it is set with
combination of -F or -P options, the memory map of the traced applications
is stored in the trace.dat file. A new API tracecmd_search_task_mmap()
can be used to look up into stored memory maps. The map is retrieved from
/proc/<pid>/maps file.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
[
v4 changes:
- 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:
- 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:
- 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.
]
Documentation/trace-cmd-record.1.txt | 3 +
include/trace-cmd/trace-cmd.h | 9 ++
lib/trace-cmd/trace-input.c | 172 ++++++++++++++++++++++++++-
tracecmd/include/trace-local.h | 10 ++
tracecmd/trace-record.c | 159 +++++++++++++++++++++++++
tracecmd/trace-usage.c | 1 +
6 files changed, 350 insertions(+), 4 deletions(-)
diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index 26a8299..4a59de9 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.
+*--mmap*::
+ Used with either *-F* or *-P*, save the traced process memory map into
+ the trace.dat file.
*-C* 'clock'::
Set the trace clock to "clock".
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 6f62ab9..17edb9d 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_PIDMMAPS,
};
enum {
@@ -97,6 +98,12 @@ struct tracecmd_ftrace {
int long_size;
};
+struct lib_mem_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 +215,8 @@ 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 lib_mem_map *tracecmd_search_task_mmap(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 61566ba..d9abbcf 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_mem_maps *pid_mmaps;
/* file information */
size_t header_files_start;
size_t ftrace_files_start;
@@ -2134,6 +2135,166 @@ void tracecmd_set_ts2secs(struct tracecmd_input *handle,
handle->use_trace_clock = false;
}
+static int trace_pid_mmap_cmp(const void *a, const void *b)
+{
+ struct lib_mem_map *map_a = (struct lib_mem_map *)a;
+ struct lib_mem_map *map_b = (struct lib_mem_map *)b;
+
+ if (map_a->start > map_b->start)
+ return 1;
+ if (map_a->start < map_b->start)
+ return -1;
+ return 0;
+}
+
+static void mmap_free(struct pid_mem_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_MMAP_LINE_MAX (PATH_MAX+34)
+static int trace_pid_mmap_load(struct tracecmd_input *handle, char *buf)
+{
+ struct pid_mem_maps *maps = NULL;
+ char mapname[STR_MMAP_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_MMAP_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 lib_mem_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_MMAP_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_mmap_cmp);
+
+ maps->next = handle->pid_mmaps;
+ handle->pid_mmaps = maps;
+
+ return 0;
+
+out_fail:
+ mmap_free(maps);
+ return ret;
+}
+
+static void trace_pid_mmap_free(struct pid_mem_maps *mmaps)
+{
+ struct pid_mem_maps *del;
+
+ while (mmaps) {
+ del = mmaps;
+ mmaps = mmaps->next;
+ mmap_free(del);
+ }
+}
+
+static int trace_pid_mmap_search(const void *a, const void *b)
+{
+ struct lib_mem_map *key = (struct lib_mem_map *)a;
+ struct lib_mem_map *map = (struct lib_mem_map *)b;
+
+ if (key->start >= map->end)
+ return 1;
+ if (key->start < map->start)
+ return -1;
+ return 0;
+}
+
+/**
+ * tracecmd_search_task_mmap - 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
+ * "--mmap". 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 lib_mem_map is returned, containing the name of
+ * the library at given task @addr and the library start and end addresses.
+ */
+struct lib_mem_map *tracecmd_search_task_mmap(struct tracecmd_input *handle,
+ int pid, unsigned long long addr)
+{
+ struct pid_mem_maps *maps;
+ struct lib_mem_map *lib;
+ struct lib_mem_map key;
+
+ if (!handle || !handle->pid_mmaps)
+ return NULL;
+
+ maps = handle->pid_mmaps;
+ 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_mmap_search);
+
+ return lib;
+}
+
static int handle_options(struct tracecmd_input *handle)
{
unsigned long long offset;
@@ -2221,9 +2382,6 @@ 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;
@@ -2233,6 +2391,10 @@ static int handle_options(struct tracecmd_input *handle)
cpus = *(int *)buf;
handle->cpus = tep_read_number(handle->pevent, &cpus, 4);
break;
+ case TRACECMD_OPTION_PIDMMAPS:
+ if (buf[size] == '\0')
+ trace_pid_mmap_load(handle, buf);
+ break;
default:
warning("unknown option %d", option);
break;
@@ -2842,10 +3004,12 @@ void tracecmd_close(struct tracecmd_input *handle)
free(handle->cpu_data);
free(handle->uname);
close(handle->fd);
-
tracecmd_free_hooks(handle->hooks);
handle->hooks = NULL;
+ trace_pid_mmap_free(handle->pid_mmaps);
+ handle->pid_mmaps = 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..ae1632c 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_mem_maps {
+ struct pid_mem_maps *next;
+ struct lib_mem_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_mem_maps *mem_maps;
+
char *max_graph_depth;
int flags;
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 5dc6f17..48081d4 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -84,6 +84,7 @@ static int max_kb;
static bool use_tcp;
static int do_ptrace;
+static int get_mmap;
static int filter_task;
static int filter_pid = -1;
@@ -1062,6 +1063,120 @@ static char *make_pid_filter(char *curr_filter, const char *field)
return filter;
}
+static int get_pid_mmaps(int pid)
+{
+ struct buffer_instance *instance = &top_instance;
+ struct pid_mem_maps *maps = instance->mem_maps;
+ struct pid_mem_maps *m;
+ unsigned long long begin, end, inode, tmp;
+ struct lib_mem_map *map;
+ char mapname[PATH_MAX+1];
+ char fname[PATH_MAX+1];
+ char buf[PATH_MAX+100];
+ char perm[5];
+ char dev[6];
+ 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->mem_maps;
+ instance->mem_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 %llx %s %lld %s",
+ &begin, &end, perm, &tmp, dev, &inode, mapname);
+ if (res == 7 && 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->mem_maps != maps) {
+ m = instance->mem_maps;
+ while (m) {
+ if (m->next == maps) {
+ m->next = maps->next;
+ break;
+ }
+ m = m->next;
+ }
+ } else
+ instance->mem_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_mmaps(void)
+{
+ struct filter_pids *p;
+
+ for (p = filter_pids; p; p = p->next) {
+ if (p->exclude)
+ continue;
+ get_pid_mmaps(p->pid);
+ }
+}
+
static void update_task_filter(void)
{
struct buffer_instance *instance;
@@ -1070,6 +1185,9 @@ static void update_task_filter(void)
if (no_filter)
return;
+ if (get_mmap && filter_pids)
+ get_filter_pid_mmaps();
+
if (filter_task)
add_filter_pid(pid, 0);
@@ -1264,6 +1382,8 @@ static void ptrace_wait(enum trace_type type, int main_pid)
break;
case PTRACE_EVENT_EXIT:
+ if (get_mmap)
+ get_pid_mmaps(main_pid);
ptrace(PTRACE_GETEVENTMSG, pid, NULL, &cstatus);
ptrace(PTRACE_DETACH, pid, NULL, NULL);
break;
@@ -3094,6 +3214,33 @@ static void append_buffer(struct tracecmd_output *handle,
}
}
+
+static void
+add_pid_mem_maps(struct tracecmd_output *handle, struct buffer_instance *instance)
+{
+ struct pid_mem_maps *maps = instance->mem_maps;
+ struct trace_seq s;
+ int i;
+
+ trace_seq_init(&s);
+ while (maps) {
+ if (!maps->nr_lib_maps)
+ 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);
+ tracecmd_add_option(handle, TRACECMD_OPTION_PIDMMAPS,
+ 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)
{
@@ -3287,6 +3434,10 @@ 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_mem_maps(handle, instance);
+ }
+
tracecmd_append_cpu_data(handle, local_cpu_count, temp_files);
for (i = 0; i < max_cpu_count; i++)
@@ -4397,6 +4548,7 @@ void update_first_instance(struct buffer_instance *instance, int topt)
}
enum {
+ OPT_mmap = 244,
OPT_quiet = 245,
OPT_debug = 246,
OPT_no_filter = 247,
@@ -4627,6 +4779,7 @@ static void parse_record_options(int argc,
{"debug", no_argument, NULL, OPT_debug},
{"quiet", no_argument, NULL, OPT_quiet},
{"help", no_argument, NULL, '?'},
+ {"mmap", no_argument, NULL, OPT_mmap},
{"module", required_argument, NULL, OPT_module},
{NULL, 0, NULL, 0}
};
@@ -4858,6 +5011,9 @@ static void parse_record_options(int argc,
case 'i':
ignore_event_not_found = 1;
break;
+ case OPT_mmap:
+ get_mmap = 1;
+ break;
case OPT_date:
ctx->date = 1;
if (ctx->data_flags & DATA_FL_OFFSET)
@@ -4924,6 +5080,9 @@ static void parse_record_options(int argc,
add_func(&ctx->instance->filter_funcs,
ctx->instance->filter_mod, "*");
+ if (filter_task && get_mmap)
+ do_ptrace = 1;
+
if (do_ptrace && !filter_task && (filter_pid < 0))
die(" -c can only be used with -F (or -P with event-fork support)");
if (ctx->do_child && !filter_task &&! filter_pid)
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 406384c..c658ede 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"
+ " --mmap used with -F or -P, save the traced process memory map into the trace.dat file\n"
},
{
"start",
--
2.21.0
|