On 19.06.19 г. 11:39 ч., tz.stoyanov@xxxxxxxxx wrote:
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>
---
[
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.
]
include/trace-cmd/trace-cmd.h | 9 ++
lib/trace-cmd/trace-input.c | 149 ++++++++++++++++++++++++++++++-
tracecmd/include/trace-local.h | 10 +++
tracecmd/trace-record.c | 158 +++++++++++++++++++++++++++++++++
4 files changed, 323 insertions(+), 3 deletions(-)
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,
};
...
+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;
+
+ 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 %4s %llx %5s %lld %s",
We tried testing the patch and we found that the memory map file is not properly parsed. The problem seems to get solved if we replace the line above with
res = sscanf(buf, "%llx-%llx %4s %llx %s %lld %s", Thanks! Yordan
+ &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 +1184,9 @@ 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 +1381,8 @@ 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 +3213,33 @@ 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 +3433,10 @@ 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 +4547,7 @@ 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 +4778,7 @@ 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 +5010,9 @@ 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 +5079,9 @@ 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)
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