[1/4] trace-cmd: Internal refactoring of pid address map logic

Commit Message

Tzvetomir Stoyanov (VMware) Aug. 7, 2020, 12:06 p.m. UTC

Make functions for collecting file to memory map of a PID non static,
so they can be reused in the trace-cmd application context. Created new
file trace-obj-debug.c with these functions.

Signed-off-by: Tzvetomir Stoyanov (VMware) <[e-mail]>
---
 tracecmd/Makefile              |   1 +
 tracecmd/include/trace-local.h |  19 +++--
 tracecmd/trace-obj-debug.c     | 138 +++++++++++++++++++++++++++++++++
 tracecmd/trace-record.c        | 107 +------------------------
 4 files changed, 152 insertions(+), 113 deletions(-)
 create mode 100644 tracecmd/trace-obj-debug.c

Patch

diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index 5e59adf8..f9435558 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -31,6 +31,7 @@  TRACE_CMD_OBJS += trace-show.o
 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
 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 d148aa16..c5c225e0 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -178,14 +178,6 @@  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 opt_list {
 	struct opt_list *next;
 	const char	*option;
@@ -314,4 +306,15 @@  void *malloc_or_die(unsigned int size); /* Can be overridden */
 void __noreturn __die(const char *fmt, ...);
 void __noreturn _vdie(const char *fmt, va_list ap);
 
+/* --- Debug symbols--- */
+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;
+};
+int trace_debug_get_filemap(struct pid_addr_maps **file_maps, int pid);
+void trace_debug_free_filemap(struct pid_addr_maps *maps);
+
 #endif /* __TRACE_LOCAL_H */
diff --git a/tracecmd/trace-obj-debug.c b/tracecmd/trace-obj-debug.c
new file mode 100644
index 00000000..9aa9baae
--- /dev/null
+++ b/tracecmd/trace-obj-debug.c
@@ -0,0 +1,138 @@ 
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2020, VMware, Tzvetomir Stoyanov <[e-mail]>
+ *
+ */
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "trace-local.h"
+
+#define _STRINGIFY(x) #x
+#define STRINGIFY(x) _STRINGIFY(x)
+int trace_debug_get_filemap(struct pid_addr_maps **pid_maps, int pid)
+{
+	struct pid_addr_maps *maps = *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 = *pid_maps;
+		*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 (*pid_maps != maps) {
+			m = *pid_maps;
+			while (m) {
+				if (m->next == maps) {
+					m->next = maps->next;
+					break;
+				}
+				m = m->next;
+			}
+		} else
+			*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 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);
+}
+
+void trace_debug_free_filemap(struct pid_addr_maps *maps)
+{
+	struct pid_addr_maps *del;
+
+	while (maps) {
+		del = maps;
+		maps = maps->next;
+		procmap_free(del);
+	}
+}
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index bd004574..a48475b3 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -1080,109 +1080,6 @@  static char *make_pid_filter(struct buffer_instance *instance,
 	return filter;
 }
 
-#define _STRINGIFY(x) #x
-#define STRINGIFY(x) _STRINGIFY(x)
-
-static int get_pid_addr_maps(struct buffer_instance *instance, int pid)
-{
-	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 buffer_instance *instance;
@@ -1194,7 +1091,7 @@  static void get_filter_pid_maps(void)
 		for (p = instance->filter_pids; p; p = p->next) {
 			if (p->exclude)
 				continue;
-			get_pid_addr_maps(instance, p->pid);
+			trace_debug_get_filemap(&instance->pid_maps, p->pid);
 		}
 	}
 }
@@ -1524,7 +1421,7 @@  static void ptrace_wait(enum trace_type type)
 			case PTRACE_EVENT_EXIT:
 				instance = get_intance_fpid(pid);
 				if (instance && instance->get_procmap)
-					get_pid_addr_maps(instance, pid);
+					trace_debug_get_filemap(&instance->pid_maps, pid);
 				ptrace(PTRACE_GETEVENTMSG, pid, NULL, &cstatus);
 				ptrace(PTRACE_DETACH, pid, NULL, NULL);
 				break;