diff --git a/tools/acrn-crashlog/acrnprobe/android_events.c b/tools/acrn-crashlog/acrnprobe/android_events.c
index 47c13db96..471dffd38 100644
--- a/tools/acrn-crashlog/acrnprobe/android_events.c
+++ b/tools/acrn-crashlog/acrnprobe/android_events.c
@@ -32,38 +32,6 @@ static const char *android_img = "/data/android/android.img";
 static const char *android_histpath = "logs/history_event";
 char *loop_dev;
 
-static char *get_line(const char *str, size_t str_size,
-			const char *area, size_t area_size,
-			const char *search_from, size_t *len)
-{
-	char *p;
-	char *match;
-	char *tail;
-	ssize_t search_size = area + area_size - search_from;
-
-	if (search_size < 0 || (size_t)search_size < str_size)
-		return NULL;
-
-	match = memmem(search_from, search_size, str, str_size);
-	if (!match)
-		return NULL;
-	tail = memchr(match + str_size, '\n',
-		      area + area_size - match - str_size);
-	if (!tail)
-		return NULL;
-
-	for (p = match; p >= area; p--) {
-		if (*p == '\n') {
-			*len = tail - p - 1;
-			return (char *)(p + 1);
-		}
-	}
-
-	*len = tail - area;
-	return (char *)area;
-}
-
-
 /* Find the next event that needs to be synced.
  * There is a history_event file in UOS side, it records UOS's events in
  * real-time. Generally, the cursor point to the first unsynchronized line.
@@ -117,8 +85,10 @@ static char *next_vm_event(const char *cursor, const char *data,
 			 * 'type'.
 			 */
 			if (!new || memcmp(new, type + 1, tlen - 1) ||
-			    *(new + tlen - 1) != ' ')
+			    *(new + tlen - 1) != ' ') {
+				free(type);
 				continue;
+			}
 		} else {
 			new = get_line(type, (size_t)tlen, data, dlen,
 				       cursor, &len);
@@ -136,10 +106,11 @@ static char *next_vm_event(const char *cursor, const char *data,
 	return line_to_sync;
 }
 
-#define VMRECORD_HEAD_LINES 6
+#define VMRECORD_HEAD_LINES 7
 #define VMRECORD_TAG_LEN 9
 #define VMRECORD_TAG_WAITING_SYNC	"      <=="
 #define VMRECORD_TAG_NOT_FOUND		"NOT_FOUND"
+#define VMRECORD_TAG_MISS_LOG		"MISS_LOGS"
 #define VMRECORD_TAG_SUCCESS		"         "
 static int generate_log_vmrecord(const char *path)
 {
@@ -148,6 +119,7 @@ static int generate_log_vmrecord(const char *path)
 		" * This file records VM id synced or about to be synched,\n"
 		" * the tag \"<==\" indicates event waiting to sync.\n"
 		" * the tag \"NOT_FOUND\" indicates event not found in UOS.\n"
+		" * the tag \"MISS_LOGS\" indicates event miss logs in UOS.\n"
 		" */\n\n";
 
 	LOGD("Generate (%s)\n", path);
@@ -204,7 +176,12 @@ static int refresh_key_synced_stage1(const struct sender_t *sender,
 			return -1;
 		}
 
-		append_file(log_vmrecordid, log_new);
+		if (append_file(log_vmrecordid, log_new,
+				strnlen(log_new, 64)) < 0) {
+			LOGE("failed to add new record (%s) to (%s)\n",
+			     log_new, log_vmrecordid);
+			return -1;
+		}
 		return 0;
 	}
 
@@ -215,7 +192,8 @@ static int refresh_key_synced_stage1(const struct sender_t *sender,
 
 enum stage2_refresh_type_t {
 	SUCCESS,
-	NOT_FOUND
+	NOT_FOUND,
+	MISS_LOG
 };
 
 static int refresh_key_synced_stage2(char *line, size_t len,
@@ -228,6 +206,8 @@ static int refresh_key_synced_stage2(char *line, size_t len,
 		memcpy(tag, VMRECORD_TAG_SUCCESS, VMRECORD_TAG_LEN);
 	else if (type == NOT_FOUND)
 		memcpy(tag, VMRECORD_TAG_NOT_FOUND, VMRECORD_TAG_LEN);
+	else if (type == MISS_LOG)
+		memcpy(tag, VMRECORD_TAG_MISS_LOG, VMRECORD_TAG_LEN);
 	else
 		return -1;
 
@@ -390,7 +370,7 @@ static void sync_lines_stage2(const struct sender_t *sender,
 	}
 
 	for (record = next_record(recos, recos->begin, &recolen); record;
-	     record = next_record(recos, record, &recolen)) {
+	     record = next_record(recos, record + recolen, &recolen)) {
 		const char * const record_fmt =
 			VM_NAME_FMT ANDROID_KEY_FMT IGN_RESTS;
 		char *hist_line;
@@ -398,6 +378,7 @@ static void sync_lines_stage2(const struct sender_t *sender,
 		char vm_name[32];
 		char vmkey[ANDROID_WORD_LEN];
 		struct vm_t *vm;
+		int res;
 
 		/* VMNAME xxxxxxxxxxxxxxxxxxxx <== */
 		if (str_split_ere(record, recolen,
@@ -421,8 +402,11 @@ static void sync_lines_stage2(const struct sender_t *sender,
 			continue;
 		}
 
-		if (fn(hist_line, len + 1, vm) == VMEVT_HANDLED)
+		res = fn(hist_line, len + 1, vm);
+		if (res == VMEVT_HANDLED)
 			refresh_key_synced_stage2(record, recolen, SUCCESS);
+		else if (res == VMEVT_MISSLOG)
+			refresh_key_synced_stage2(record, recolen, MISS_LOG);
 	}
 
 out:
@@ -454,8 +438,9 @@ static void get_last_line_synced(const struct sender_t *sender)
 			continue;
 
 		snprintf(vm_name, sizeof(vm_name), "%s ", vm->name);
-		ret = file_read_key_value_r(sender->log_vmrecordid, vm_name,
-					    sizeof(vmkey), vmkey);
+		ret = file_read_key_value_r(vmkey, sizeof(vmkey),
+					    sender->log_vmrecordid,
+					    vm_name, strnlen(vm_name, 32));
 		if (ret == -ENOENT) {
 			LOGD("no (%s), will generate\n",
 			     sender->log_vmrecordid);
@@ -536,8 +521,8 @@ static char *setup_loop_dev(void)
 /* This function searches all android vms' new events and call the fn for
  * each event.
  *
- * Note that: fn should return 0 to indicate event has been handled,
- *	      or fn will be called in a time loop until it returns 0.
+ * Note that: fn should return VMEVT_HANDLED to indicate event has been handled.
+ *	      fn will be called in a time loop if it returns VMEVT_DEFER.
  */
 void refresh_vm_history(const struct sender_t *sender,
 		int (*fn)(const char*, size_t, const struct vm_t *))
diff --git a/tools/acrn-crashlog/acrnprobe/history.c b/tools/acrn-crashlog/acrnprobe/history.c
index 831b9e8a6..e40ee9418 100644
--- a/tools/acrn-crashlog/acrnprobe/history.c
+++ b/tools/acrn-crashlog/acrnprobe/history.c
@@ -122,7 +122,6 @@ void hist_raise_event(const char *event, const char *type, const char *log,
 	char eventtime[LONG_TIME_SIZE];
 	struct sender_t *crashlog;
 	int maxlines;
-	int ret;
 	struct history_entry entry = {
 		.event = event,
 		.type = type,
@@ -143,16 +142,13 @@ void hist_raise_event(const char *event, const char *type, const char *log,
 		backup_history();
 	}
 
-	ret = get_current_time_long(eventtime);
-	if (ret <= 0)
+	if (get_current_time_long(eventtime) <= 0)
 		return;
 
 	entry.eventtime = eventtime;
 	entry_to_history_line(&entry, line);
-	ret = append_file(history_file, line);
-	if (ret < 0) {
-		LOGE("append (%s) failed, error (%s)\n", history_file,
-		     strerror(errno));
+	if (append_file(history_file, line, strnlen(line, MAXLINESIZE)) <= 0) {
+		LOGE("failed to append (%s) to (%s)\n", line, history_file);
 		return;
 	}
 }
@@ -235,7 +231,8 @@ static int get_time_from_firstline(char *buffer, size_t size)
 	const char *prefix = "#V1.0 CURRENTUPTIME   ";
 	int len;
 
-	len = file_read_key_value(history_file, prefix, MAXLINESIZE, lasttime);
+	len = file_read_key_value(lasttime, MAXLINESIZE, history_file, prefix,
+				  strlen(prefix));
 	if (len <= 0) {
 		LOGW("failed to read value from %s, error %s\n",
 		      history_file, strerror(-len));
@@ -289,11 +286,12 @@ int prepare_history(void)
 			     strerror(errno));
 			return ret;
 		}
-		ret = append_file(history_file, HISTORY_BLANK_LINE2);
+		ret = append_file(history_file, HISTORY_BLANK_LINE2,
+				  sizeof(HISTORY_BLANK_LINE2) - 1);
 		if (ret < 0) {
 			LOGE("Write (%s, %s) failed, error (%s)\n",
 			     history_file, HISTORY_BLANK_LINE2,
-			     strerror(errno));
+			     strerror(-ret));
 			return ret;
 		}
 		current_lines = count_lines_in_file(history_file);
diff --git a/tools/acrn-crashlog/acrnprobe/include/android_events.h b/tools/acrn-crashlog/acrnprobe/include/android_events.h
index 5dc3e80c8..7dc9d0ba9 100644
--- a/tools/acrn-crashlog/acrnprobe/include/android_events.h
+++ b/tools/acrn-crashlog/acrnprobe/include/android_events.h
@@ -11,7 +11,9 @@ extern char *loop_dev;
 
 #define VMEVT_HANDLED 0
 #define VMEVT_DEFER -1
+#define VMEVT_MISSLOG -2
 
+#define ANDROID_LOGS_DIR "/logs/"
 #define IGN_SPACES "%*[[[:space:]]*]"
 #define IGN_RESTS "%*[[.]*]"
 #define IGN_ONEWORD "%*[[^[:space:]]*]" IGN_SPACES
diff --git a/tools/acrn-crashlog/acrnprobe/property.c b/tools/acrn-crashlog/acrnprobe/property.c
index b1b4d5891..05af6ffe5 100644
--- a/tools/acrn-crashlog/acrnprobe/property.c
+++ b/tools/acrn-crashlog/acrnprobe/property.c
@@ -71,8 +71,9 @@ static int get_buildversion(struct sender_t *sender)
 	char *logbuildid;
 	char *currentbuild = gbuildversion;
 
-	ret = file_read_key_value(OS_VERSION, OS_VERSION_KEY,
-				  sizeof(gbuildversion), gbuildversion);
+	ret = file_read_key_value(gbuildversion, sizeof(gbuildversion),
+				  OS_VERSION, OS_VERSION_KEY,
+				  strlen(OS_VERSION_KEY));
 	if (ret <= 0) {
 		LOGE("failed to get version from %s, error (%s)\n",
 		     OS_VERSION, strerror(-ret));
diff --git a/tools/acrn-crashlog/acrnprobe/sender.c b/tools/acrn-crashlog/acrnprobe/sender.c
index f782e06d6..e43ed1061 100644
--- a/tools/acrn-crashlog/acrnprobe/sender.c
+++ b/tools/acrn-crashlog/acrnprobe/sender.c
@@ -216,13 +216,14 @@ static void telemd_get_log(struct log_t *log, void *data)
 	int res;
 	int i;
 	struct dirent **filelist;
+	struct ac_filter_data acfd = {log->name, log->name_len};
 
 	if (d->srcdir == NULL)
 		goto send_nologs;
 
 	/* search file which use log->name as substring */
 	count = ac_scandir(d->srcdir, &filelist, filter_filename_substr,
-			 log->name, NULL);
+			   &acfd, NULL);
 	if (count < 0) {
 		LOGE("search (%s) in dir (%s) failed\n", log->name, d->srcdir);
 		return;
@@ -544,8 +545,7 @@ static void telemd_send_reboot(void)
 }
 
 static int telemd_new_vmevent(const char *line_to_sync,
-				size_t len __attribute__((unused)),
-				const struct vm_t *vm)
+				size_t len, const struct vm_t *vm)
 {
 	char event[ANDROID_WORD_LEN];
 	char longtime[ANDROID_WORD_LEN];
@@ -589,21 +589,26 @@ static int telemd_new_vmevent(const char *line_to_sync,
 		severity = INFO_SEVERITY;
 
 	/* if line contains log, fill vmlogpath */
-	log = strstr(rest, "/logs/");
+	log = strstr(rest, ANDROID_LOGS_DIR);
 	if (log) {
-		struct sender_t *crashlog;
+		struct sender_t *crashlog = get_sender_by_name("crashlog");
+		const char *logf;
+		size_t logflen;
+		int res;
 
-		crashlog = get_sender_by_name("crashlog");
 		if (!crashlog)
 			return VMEVT_HANDLED;
 
-		res = find_file(crashlog->outdir, log + strlen("/logs/"),
-				2, &vmlogpath, 1);
-		if (res < 0) {
-			LOGE("find (%s) in (%s) failed\n",
-			     log + strlen("/logs/"), crashlog->outdir);
+		logf = log + sizeof(ANDROID_LOGS_DIR) - 1;
+		logflen = &rest[0] + strnlen(rest, PATH_MAX) - logf;
+		res = find_file(crashlog->outdir, logf, logflen, 1,
+				&vmlogpath, 1);
+		if (res == -1) {
+			LOGE("failed to find (%s) in (%s)\n",
+			     logf, crashlog->outdir);
+			return VMEVT_DEFER;
+		} else if (res == 0)
 			return VMEVT_DEFER;
-		}
 	}
 
 	res = asprintf(&class, "%s/%s/%s", vm->name, event, type);
@@ -898,8 +903,7 @@ static void crashlog_send_reboot(void)
 }
 
 static int crashlog_new_vmevent(const char *line_to_sync,
-				size_t len __attribute__((unused)),
-				const struct vm_t *vm)
+				size_t len, const struct vm_t *vm)
 {
 	struct sender_t *crashlog;
 	char event[ANDROID_WORD_LEN];
@@ -980,12 +984,18 @@ static int crashlog_new_vmevent(const char *line_to_sync,
 				ret = VMEVT_DEFER;
 			} else {
 				LOGW("(%s) is missing\n", vmlogpath);
-				ret = VMEVT_HANDLED; /* missing logdir */
+				ret = VMEVT_MISSLOG; /* missing logdir */
 			}
-			res = remove(dir);
-			if (res == -1 && errno != ENOENT)
+			if (remove_r(dir) == -1)
+				LOGE("failed to remove %s (%d)\n", dir, -errno);
+			goto free_dir;
+		}
+		if (cnt == 1) {
+			LOGW("(%s) is empty, will sync it in the next loop\n",
+			     vmlogpath);
+			ret = VMEVT_DEFER;
+			if (remove_r(dir) == -1)
 				LOGE("failed to remove %s (%d)\n", dir, -errno);
-
 			goto free_dir;
 		}
 	}
diff --git a/tools/acrn-crashlog/common/cmdutils.c b/tools/acrn-crashlog/common/cmdutils.c
index 29539c443..e05682587 100644
--- a/tools/acrn-crashlog/common/cmdutils.c
+++ b/tools/acrn-crashlog/common/cmdutils.c
@@ -136,7 +136,7 @@ int exec_out2file(const char *outfile, const char *fmt, ...)
 	if (ret < 0)
 		return ret;
 
-	strtrim(cmd);
+	strtrim(cmd, ret);
 	argc = strcnt(cmd, ' ') + 1;
 
 	argv = (char **)calloc(argc + 1, sizeof(char *));
@@ -171,11 +171,12 @@ int exec_out2file(const char *outfile, const char *fmt, ...)
  * to memory. The memory is allocated by this function and needs to be freed
  * after return.
  *
+ * @param[out] outmem The pointer to command's output.
  * @param fmt Format string of command.
  *
- * @return a pointer to command's output if successful, or NULL if not.
+ * @return the length of command's output if successful, or -1 if not.
  */
-char *exec_out2mem(const char *fmt, ...)
+ssize_t exec_out2mem(char **outmem, const char *fmt, ...)
 {
 	va_list args;
 	char *cmd;
@@ -183,23 +184,25 @@ char *exec_out2mem(const char *fmt, ...)
 	char *out = NULL;
 	char *new;
 	char tmp[1024];
-	int memsize = 0;
-	int newlen = 0;
-	int len = 0;
+	size_t memsize = 0;
+	size_t newlen = 0;
+	ssize_t len = 0;
 	int ret;
 
 	va_start(args, fmt);
 	ret = vasprintf(&cmd, fmt, args);
 	va_end(args);
 	if (ret < 0)
-		return NULL;
+		return -1;
 
 	pp = popen(cmd, "r");
-	if (!pp)
-		goto free_cmd;
+	if (!pp) {
+		free(cmd);
+		return -1;
+	}
 
 	while (fgets(tmp, 1024, pp) != NULL) {
-		newlen += strlen(tmp);
+		newlen += strnlen(tmp, 1024);
 		if (newlen + 1 > memsize) {
 			memsize += 1024;
 			new = realloc(out, memsize);
@@ -208,20 +211,22 @@ char *exec_out2mem(const char *fmt, ...)
 					free(out);
 					out = NULL;
 				}
+				len = -1;
 				goto end;
 			} else {
 				out = new;
 			}
 		}
-		memcpy(out + len, tmp, strlen(tmp) + 1);
+		/* fgets read at most 1023 bytes and plus '\0' */
+		memcpy(out + len, tmp, strnlen(tmp, 1024) + 1);
 
 		len = newlen;
 	}
 
 end:
+	*outmem = out;
 	pclose(pp);
-free_cmd:
 	free(cmd);
 
-	return out;
+	return len;
 }
diff --git a/tools/acrn-crashlog/common/fsutils.c b/tools/acrn-crashlog/common/fsutils.c
index 863027fe2..629d3a876 100644
--- a/tools/acrn-crashlog/common/fsutils.c
+++ b/tools/acrn-crashlog/common/fsutils.c
@@ -32,13 +32,12 @@
 #include <sys/vfs.h>
 #include <sys/wait.h>
 #include <stdlib.h>
+#include <ftw.h>
 #include "fsutils.h"
 #include "cmdutils.h"
 #include "strutils.h"
 #include "log_sys.h"
 
-#define MAX_SEARCH_DIRS 4096
-
 /**
  * Help function to do fclose. In some cases (full partition),
  * file closure could fail, so get error message here.
@@ -81,6 +80,30 @@ int mkdir_p(const char *path)
 	return exec_out2file(NULL, "mkdir -p %s", path);
 }
 
+static int rmfile(const char *path,
+		const struct stat *sbuf __attribute__((unused)),
+		int type __attribute__((unused)),
+		struct FTW *ftwb __attribute__((unused)))
+{
+	if (remove(path) == -1) {
+		LOGE("failed to remove (%s), error (%s)\n", path,
+		     strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+int remove_r(const char *dir)
+{
+	if (!dir)
+		return -1;
+
+	if (nftw(dir, rmfile, 10, FTW_DEPTH | FTW_MOUNT | FTW_PHYS) == -1)
+		return -1;
+
+	return 0;
+}
+
 /**
  * Count file lines.
  * This function defaults to all text files ending with \n.
@@ -141,7 +164,6 @@ char *mm_get_line(struct mm_file_t *mfile, int line)
 struct mm_file_t *mmap_file(const char *path)
 {
 	struct mm_file_t *mfile;
-	int size;
 
 	mfile = malloc(sizeof(struct mm_file_t));
 	if (!mfile) {
@@ -167,8 +189,7 @@ struct mm_file_t *mmap_file(const char *path)
 		     path, strerror(errno));
 		goto close_fd;
 	}
-	size = mfile->size > 0 ? mfile->size : PAGE_SIZE;
-	mfile->begin = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED,
+	mfile->begin = mmap(NULL, mfile->size, PROT_READ|PROT_WRITE, MAP_SHARED,
 			    mfile->fd, 0);
 	if (mfile->begin == MAP_FAILED) {
 		LOGE("mmap (%s) failed, error (%s)\n", path, strerror(errno));
@@ -293,22 +314,18 @@ int do_mv(char *src, char *dest)
  *
  * @return 0 if successful, or a negative errno-style value if not.
  */
-int append_file(char *filename, char *text)
+ssize_t append_file(const char *filename, const char *text, size_t tlen)
 {
-	int fd, res, len;
+	int fd, res;
 
-	if (!filename || !text)
+	if (!filename || !text || !tlen)
 		return -EINVAL;
 
-	len = strlen(text);
-	if (!len)
-		return -EINVAL;
-
-	fd = open(filename, O_RDWR | O_APPEND);
+	fd = open(filename, O_WRONLY | O_APPEND);
 	if (fd < 0)
 		return -errno;
 
-	res = write(fd, text, len);
+	res = write(fd, text, tlen);
 	close(fd);
 
 	return (res == -1 ? -errno : res);
@@ -344,7 +361,7 @@ int replace_file_head(char *filename, char *text)
  * The file is created if it does not exist, otherwise it is truncated.
  *
  * @param filename Path of file.
- * @param text String need to be appended.
+ * @param text String need to be written.
  *
  * @return 0 if successful, or a negative errno-style value if not.
  */
@@ -368,42 +385,6 @@ int overwrite_file(const char *filename, const char *value)
 	return ret;
 }
 
-/**
- * Read line from file descriptor.
- *
- * @param fd File descriptor.
- * @param[out] buffer Content of line.
- *
- * @return length of line if successful, or a negative errno-style value if not.
- */
-int readline(int fd, char buffer[MAXLINESIZE])
-{
-	int size = 0, res;
-	char *pbuffer = &buffer[0];
-
-	/* Read the file until end of line or file */
-	while ((res = read(fd, pbuffer, 1)) == 1 && size < MAXLINESIZE-1) {
-		if (pbuffer[0] == '\n') {
-			buffer[++size] = 0;
-			return size;
-		}
-		pbuffer++;
-		size++;
-	}
-
-	/* Check the last read result */
-	if (res < 0) {
-		/* ernno is checked in the upper layer as we could
-		 * print the filename here
-		 */
-		return res;
-	}
-	/* last line */
-	buffer[size] = 0;
-
-	return size;
-}
-
 /**
  * Read the first line from file.
  *
@@ -414,7 +395,7 @@ int readline(int fd, char buffer[MAXLINESIZE])
  * @return length of string if successful, or a negative errno-style value
  *	   if not.
  */
-int file_read_string(const char *file, char *string, int size)
+ssize_t file_read_string(const char *file, char *string, const int size)
 {
 	FILE *fp;
 	char *res;
@@ -440,7 +421,7 @@ int file_read_string(const char *file, char *string, int size)
 	end = strchr(string, '\n');
 	if (end)
 		*end = 0;
-	return strlen(string);
+	return strnlen(string, size);
 }
 
 /**
@@ -678,89 +659,17 @@ int count_lines_in_file(const char *filename)
 	return ret;
 }
 
-/**
- * Read binary file.
- *
- * @param path File path to read.
- * @param[out] File size being read.
- * @param[out] data File content.
- *
- * @return 0 if successful, or -1 if not.
- */
-int read_full_binary_file(const char *path, unsigned long *size, void **data)
+static ssize_t _file_read_key_value(char *value, const size_t limit,
+				const char *path, const char *key,
+				size_t klen, const char op)
 {
-	FILE *f;
-	long _size;
-	void *buf;
-	int err;
-
-	if (!path || !data || !size) {
-		errno = EINVAL;
-		return -1;
-	}
-
-	f = fopen(path, "rb");
-	if (!f)
-		return -1;
-
-	if (fseek(f, 0, SEEK_END) == -1) {
-		err = errno;
-		goto close;
-	}
-
-	_size = ftell(f);
-	if (_size == -1) {
-		err = errno;
-		goto close;
-	} else if (!_size) {
-		err = ERANGE;
-		goto close;
-	}
-
-	if (fseek(f, 0, SEEK_SET) == -1) {
-		err = errno;
-		goto close;
-	}
-
-	buf = malloc(_size + 10);
-	if (!buf) {
-		err = ENOMEM;
-		goto close;
-	}
-
-	memset(buf, 0, _size + 10);
-	if (fread(buf, 1, _size, f) != (unsigned int)_size) {
-		err = EBADF;
-		goto free;
-	}
-
-	close_file(path, f);
-
-	*data = buf;
-	*size = (unsigned long)_size;
-
-	return 0;
-
-free:
-	free(buf);
-close:
-	close_file(path, f);
-	errno = err;
-	return -1;
-}
-
-static int _file_read_key_value(const char *path, const char op,
-				const char *key, const size_t limit,
-				char *value)
-{
-	int fd;
-	int size;
 	size_t len;
-	char *data;
 	char *msg = NULL;
-	char *end, *start;
+	struct mm_file_t *f = mmap_file(path);
 
-	if (!key || !path) {
+	if (!f)
+		return -errno;
+	if (!key) {
 		errno = EINVAL;
 		return -errno;
 	}
@@ -770,63 +679,47 @@ static int _file_read_key_value(const char *path, const char op,
 		return -errno;
 	}
 
-	size = get_file_size(path);
-	if (size < 0)
-		return size;
-	if (!size) {
-		errno = ENOMSG;
-		return -errno;
-	}
-
-	fd = open(path, O_RDONLY);
-	if (fd < 0)
-		return -errno;
-
-	data = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-	if (data == MAP_FAILED)
-		goto close;
-
 	if (op == 'l')
-		msg = strstr(data, key);
-	else if (op == 'r')
-		msg = strrstr(data, key);
+		msg = get_line(key, klen, f->begin, f->size, f->begin, &len);
+	else if (op == 'r') {
+		char *msg_tmp;
+
+		msg = f->begin;
+		len = 0;
+		while ((msg_tmp = get_line(key, klen, f->begin, f->size,
+					  msg, &len)))
+			msg = msg_tmp + len;
+		if (msg != f->begin)
+			msg -= len;
+		else
+			msg = NULL;
+	}
 	if (!msg) {
 		errno = ENOMSG;
 		goto unmap;
 	}
 
-	start = msg + strlen(key);
-	end = strchr(start, '\n');
-	if (end == NULL)
-		end = data + size;
-
-	len = end - start;
-	len = MIN(len, limit - 1);
-	memcpy(value, start, len);
-	*(value + len) = 0;
-
-	munmap(data, size);
-	close(fd);
+	len = MIN(len - klen, limit - 1);
+	*(char *)mempcpy(value, msg + klen, len) = '\0';
 
+	unmap_file(f);
 	return len;
 
 unmap:
-	munmap(data, size);
-close:
-	close(fd);
+	unmap_file(f);
 	return -errno;
 }
 
-int file_read_key_value(const char *path, const char *key,
-			const size_t limit, char *value)
+ssize_t file_read_key_value(char *value, const size_t limit, const char *path,
+			const char *key, size_t klen)
 {
-	return _file_read_key_value(path, 'l', key, limit, value);
+	return _file_read_key_value(value, limit, path, key, klen, 'l');
 }
 
-int file_read_key_value_r(const char *path, const char *key,
-			const size_t limit, char *value)
+ssize_t file_read_key_value_r(char *value, const size_t limit, const char *path,
+			const char *key, size_t klen)
 {
-	return _file_read_key_value(path, 'r', key, limit, value);
+	return _file_read_key_value(value, limit, path, key, klen, 'r');
 }
 
 /**
@@ -914,41 +807,46 @@ e_free:
 /* filters return zero if the match is successful */
 int filter_filename_substr(const struct dirent *entry, const void *arg)
 {
-	const char *substr = (const char *)arg;
+	struct ac_filter_data *d = (struct ac_filter_data *)arg;
 
-	return !strstr(entry->d_name, substr);
+	return !memmem(entry->d_name, _D_EXACT_NAMLEN(entry), d->str, d->len);
 }
 
 int filter_filename_exactly(const struct dirent *entry, const void *arg)
 {
-	const char *fname = (const char *)arg;
+	struct ac_filter_data *d = (struct ac_filter_data *)arg;
 
-	return strcmp(entry->d_name, fname);
+	return strcmp(entry->d_name, d->str);
 }
 
 int filter_filename_startswith(const struct dirent *entry,
 				const void *arg)
 {
-	const char *str = (const char *)arg;
+	struct ac_filter_data *d = (struct ac_filter_data *)arg;
 
-	return memcmp(entry->d_name, str, strlen(str));
+	if (_D_EXACT_NAMLEN(entry) < d->len)
+		return -1;
+
+	return memcmp(entry->d_name, d->str, d->len);
 }
 
-int dir_contains(const char *dir, const char *filename, const int exact)
+int dir_contains(const char *dir, const char *filename, size_t flen,
+		const int exact)
 {
 	int ret;
 	int i;
 	struct dirent **filelist;
+	struct ac_filter_data acfd = {filename, flen};
 
-	if (!dir || !filename)
+	if (!dir || !filename || !flen)
 		return -1;
 
 	if (exact)
 		ret = ac_scandir(dir, &filelist, filter_filename_exactly,
-			      (const void *)filename, 0);
+				 (const void *)&acfd, 0);
 	else
 		ret = ac_scandir(dir, &filelist, filter_filename_substr,
-			      (const void *)filename, 0);
+				 (const void *)&acfd, 0);
 	if (ret <= 0)
 		return ret;
 
@@ -1008,121 +906,108 @@ free_list:
 	return count;
 }
 
-static int is_subdir(const struct dirent *entry)
-{
-	return (entry->d_type == DT_DIR) &&
-		strcmp(entry->d_name, ".") &&
-		strcmp(entry->d_name, "..");
-}
-
-static void expand_dir(char *_dirs[], int *count, int depth, int max_depth)
-{
-	int files;
-	int i;
-	int res;
-	struct dirent **filelist;
-	char *subdir;
-	char *name;
-	char *current_dir = _dirs[*count - 1];
-
-	if (depth > max_depth)
-		return;
-
-
-	files = scandir(current_dir, &filelist, is_subdir, 0);
-	if (files < 0) {
-		LOGE("lsdir failed, error (%s)\n", strerror(-files));
-		return;
-	}
-
-	for (i = 0; i < files; i++) {
-		if (*count >= MAX_SEARCH_DIRS) {
-			LOGE("too many dirs(%d) under %s\n",
-			     *count, _dirs[0]);
-			goto free;
-		}
-
-		name = filelist[i]->d_name;
-		res = asprintf(&subdir, "%s/%s", current_dir, name);
-		if (res < 0) {
-			LOGE("compute string failed, out of memory\n");
-			goto free;
-		}
-
-		_dirs[*count] = subdir;
-		(*count)++;
-		expand_dir(_dirs, count, depth++, max_depth);
-	}
-free:
-	for (i = 0; i < files; i++)
-		free(filelist[i]);
-	free(filelist);
-}
-
 /**
  * Find target file in specified dir.
  *
  * @param dir Where to start search.
  * @param target_file Target file to search.
- * @param depth File's depth in the directory tree.
+ * @param tflen The length of target_file.
+ * @param depth Descend at most depth of directories below the starting dir.
  * @param path[out] Searched file path in given dir.
  * @param limit The number of files uplayer want to get.
  *
  * @return the count of searched files on success, or -1 on error.
  */
-int find_file(const char *dir, char *target_file, int depth, char *path[],
-		int limit)
+int find_file(const char *dir, const char *target_file, size_t tflen,
+		int depth, char *path[], int limit)
 {
-	int i, ret;
-	int count = 0;
-	char *_dirs[MAX_SEARCH_DIRS];
-	int dirs;
+	int wdepth = 0;
+	int found = 0;
+	char wdir[PATH_MAX];
+	DIR **dp;
 
-	if (depth < 1 || !dir || !target_file || !path || limit <= 0)
+	if (!dir || !target_file || !tflen || !path || limit <= 0)
 		return -1;
-
-	ret = asprintf(&_dirs[0], "%s", dir);
-	if (ret < 0) {
-		LOGE("compute string failed, out of memory\n");
+	if (!memccpy(wdir, dir, 0, PATH_MAX))
+		return -1;
+	dp = calloc(depth + 1, sizeof(DIR *));
+	if (!dp) {
+		LOGE("out of memory\n");
 		return -1;
 	}
-	dirs = 1;
 
-	/* expand all dirs */
-	expand_dir(_dirs, &dirs, 1, depth);
-	for (i = 0; i < dirs; i++) {
-		if (count >= limit)
-			goto free;
+	while (wdepth >= 0) {
+		struct dirent *dirp;
 
-		ret = dir_contains(_dirs[i], target_file, 1);
-		if (ret == 1) {
-			ret = asprintf(&path[count++], "%s/%s",
-				       _dirs[i], target_file);
-			if (ret < 0) {
-				LOGE("compute string failed, out of memory\n");
-				ret = -1;
-				goto fail;
+		if (!dp[wdepth]) {
+			/* new stream */
+			dp[wdepth] = opendir(wdir);
+			if (!dp[wdepth]) {
+				LOGE("failed to opendir (%s), error (%s)\n",
+				     wdir, strerror(errno));
+				goto fail_open;
+			}
+		}
+
+		while (!(errno = 0) && (dirp = readdir(dp[wdepth]))) {
+			if (!strcmp(dirp->d_name, ".") ||
+			    !strcmp(dirp->d_name, ".."))
+				continue;
+
+			if (!strcmp(dirp->d_name, target_file)) {
+				if (asprintf(&path[found], "%s/%s", wdir,
+				    dirp->d_name) == -1) {
+					LOGE("out of memory\n");
+					goto fail_read;
+				}
+				if (++found == limit)
+					goto end;
+			}
+
+			if (dirp->d_type == DT_DIR && wdepth < depth) {
+				/* search in subdir */
+				*(char *)
+				mempcpy(mempcpy(wdir + strnlen(wdir, PATH_MAX),
+					"/", 1),
+					dirp->d_name,
+					strnlen(dirp->d_name, NAME_MAX)) = '\0';
+				wdepth++;
+				break;
+			}
+		}
+		if (!dirp) {
+			if (!errno) {
+				/* meet the end of stream, back to the parent */
+				char *p;
+
+				closedir(dp[wdepth]);
+				dp[wdepth--] = NULL;
+				p = strrchr(wdir, '/');
+				if (p)
+					*p = '\0';
+			} else {
+				LOGE("failed to readdir, (%s)\n",
+				     strerror(errno));
+				goto fail_read;
 			}
-		} else if (ret < 0) {
-			LOGE("dir_contains failed\n");
-			ret = -1;
-			goto fail;
 		}
 	}
+end:
+	while (wdepth >= 0)
+		closedir(dp[wdepth--]);
+	free(dp);
+	return found;
 
-free:
-	for (i = 0; i < dirs; i++)
-		free(_dirs[i]);
-
-	return count;
-fail:
-	for (i = 0; i < dirs; i++)
-		free(_dirs[i]);
-
-	for (i = 0; i < count; i++)
-		free(path[i]);
-
-	return ret;
+fail_read:
+	LOGE("failed to search in dir %s\n", wdir);
+	closedir(dp[wdepth]);
+fail_open:
+	while (wdepth)
+		closedir(dp[--wdepth]);
+	while (found)
+		free(path[--found]);
+	free(dp);
+	return -1;
 }
 
 int read_file(const char *path, unsigned long *size, void **data)
@@ -1214,6 +1099,7 @@ int config_fmt_to_files(const char *file_fmt, char ***out)
 	int ret = 0;
 	struct dirent **filelist;
 	char **out_array;
+	struct ac_filter_data acfd;
 
 	if (!file_fmt || !out)
 		return -1;
@@ -1247,14 +1133,15 @@ int config_fmt_to_files(const char *file_fmt, char ***out)
 	*p = '\0';
 	file_prefix = p + 1;
 	p = strrchr(file_prefix, '[');
-	if (p) {
-		*p = '\0';
-	} else {
+	if (!p) {
 		ret = -1;
 		LOGE("unsupported formats (%s)\n", dir);
 		goto free_dir;
 	}
 
+	*p = '\0';
+	acfd.str = file_prefix;
+	acfd.len = p - file_prefix;
 
 	if (!directory_exists(dir)) {
 		ret = 0;
@@ -1276,7 +1163,7 @@ int config_fmt_to_files(const char *file_fmt, char ***out)
 
 	/* get all files which start with prefix */
 	count = ac_scandir(dir, &filelist, filter_filename_startswith,
-			   file_prefix, alphasort);
+			   &acfd, alphasort);
 	if (count < 0) {
 		ret = -1;
 		LOGE("failed to ac_scandir\n");
diff --git a/tools/acrn-crashlog/common/include/cmdutils.h b/tools/acrn-crashlog/common/include/cmdutils.h
index fe1898916..8248e7fa5 100644
--- a/tools/acrn-crashlog/common/include/cmdutils.h
+++ b/tools/acrn-crashlog/common/include/cmdutils.h
@@ -5,4 +5,4 @@
 
 int execv_out2file(char * const argv[], const char *outfile);
 int exec_out2file(const char *outfile, const char *fmt, ...);
-char *exec_out2mem(const char *fmt, ...);
+ssize_t exec_out2mem(char **outmem, const char *fmt, ...);
diff --git a/tools/acrn-crashlog/common/include/fsutils.h b/tools/acrn-crashlog/common/include/fsutils.h
index d0f676a2f..ef0148531 100644
--- a/tools/acrn-crashlog/common/include/fsutils.h
+++ b/tools/acrn-crashlog/common/include/fsutils.h
@@ -43,6 +43,11 @@ struct mm_file_t {
 	int size;
 };
 
+struct ac_filter_data {
+	const char *str;
+	size_t len;
+};
+
 static inline int file_exists(const char *filename)
 {
 	struct stat info;
@@ -72,18 +77,17 @@ static inline int get_file_size(const char *filepath)
 
 char *mm_get_line(struct mm_file_t *mfile, int line);
 int mkdir_p(const char *path);
+int remove_r(const char *dir);
 int mm_count_lines(struct mm_file_t *mfile);
 struct mm_file_t *mmap_file(const char *path);
 void unmap_file(struct mm_file_t *mfile);
 int do_copy_tail(const char *src, const char *dest, int limit);
 int do_mv(char *src, char *dest);
-int append_file(char *filename, char *text);
-int mm_replace_str_line(struct mm_file_t *mfile, char *replace,
-			int line);
+ssize_t append_file(const char *filename, const char *text, size_t tlen);
 int replace_file_head(char *filename, char *text);
 int overwrite_file(const char *filename, const char *value);
 int readline(int fd, char buffer[MAXLINESIZE]);
-int file_read_string(const char *file, char *string, int size);
+ssize_t file_read_string(const char *file, char *string, const int size);
 void file_reset_init(const char *filename);
 int file_read_int(const char *filename, unsigned int *pcurrent);
 int file_update_int(const char *filename, unsigned int current,
@@ -93,10 +97,10 @@ int space_available(const char *path, int quota);
 int count_lines_in_file(const char *filename);
 int read_full_binary_file(const char *path, unsigned long *size,
 			void **data);
-int file_read_key_value(const char *path, const char *key,
-			const size_t limit, char *value);
-int file_read_key_value_r(const char *path, const char *key,
-			const size_t limit, char *value);
+ssize_t file_read_key_value(char *value, const size_t limit, const char *path,
+			const char *key, size_t klen);
+ssize_t file_read_key_value_r(char *value, const size_t limit, const char *path,
+			const char *key, size_t klen);
 int ac_scandir(const char *dirp, struct dirent ***namelist,
 		int (*filter)(const struct dirent *, const void *),
 		const void *farg,
@@ -106,10 +110,10 @@ int filter_filename_substr(const struct dirent *entry, const void *arg);
 int filter_filename_exactly(const struct dirent *entry, const void *arg);
 int filter_filename_startswith(const struct dirent *entry,
 					const void *arg);
-int dir_contains(const char *dir, const char *filename, int exact);
+int dir_contains(const char *dir, const char *filename, size_t flen, int exact);
 int lsdir(const char *dir, char *fullname[], int limit);
-int find_file(const char *dir, char *target_file, int depth, char *path[],
-		int limit);
+int find_file(const char *dir, const char *target_file, size_t tflen,
+		int depth, char *path[], int limit);
 int read_file(const char *path, unsigned long *size, void **data);
 int is_ac_filefmt(const char *file_fmt);
 int config_fmt_to_files(const char *file_fmt, char ***out);
diff --git a/tools/acrn-crashlog/common/include/log_sys.h b/tools/acrn-crashlog/common/include/log_sys.h
index 7fa4b8171..c03abe982 100644
--- a/tools/acrn-crashlog/common/include/log_sys.h
+++ b/tools/acrn-crashlog/common/include/log_sys.h
@@ -6,42 +6,43 @@
 #ifndef __LOG_SYS_H__
 #define __LOG_SYS_H__
 
-#include <stdarg.h>
 #include <syslog.h>
+#include <systemd/sd-journal.h>
 
-void do_log(int level,
-#ifdef DEBUG_ACRN_CRASHLOG
-		const char *func, int line,
-#endif
-		...);
+void debug_log(int level, const char *func, int line, ...);
 
-#define MAX_LOG_LEN 1024
 #define LOG_LEVEL LOG_WARNING
 
 #ifdef DEBUG_ACRN_CRASHLOG
 #define LOGE(...) \
-		do_log(LOG_ERR, __func__, __LINE__,  __VA_ARGS__)
+		debug_log(LOG_ERR, __func__, __LINE__,  __VA_ARGS__)
 
 #define LOGW(...) \
-		do_log(LOG_WARNING, __func__, __LINE__, __VA_ARGS__)
+		debug_log(LOG_WARNING, __func__, __LINE__, __VA_ARGS__)
 
 #define LOGI(...) \
-		do_log(LOG_INFO, __func__, __LINE__, __VA_ARGS__)
+		debug_log(LOG_INFO, __func__, __LINE__, __VA_ARGS__)
 
 #define LOGD(...) \
-		do_log(LOG_DEBUG, __func__, __LINE__, __VA_ARGS__)
+		debug_log(LOG_DEBUG, __func__, __LINE__, __VA_ARGS__)
 #else
+#define ac_log(level, ...) \
+	do { \
+		if (level <= LOG_LEVEL) \
+			sd_journal_print(level, __VA_ARGS__); \
+	} while (0)
+
 #define LOGE(...) \
-		do_log(LOG_ERR, __VA_ARGS__)
+		ac_log(LOG_ERR, __VA_ARGS__)
 
 #define LOGW(...) \
-		do_log(LOG_WARNING, __VA_ARGS__)
+		ac_log(LOG_WARNING, __VA_ARGS__)
 
 #define LOGI(...) \
-		do_log(LOG_INFO, __VA_ARGS__)
+		ac_log(LOG_INFO, __VA_ARGS__)
 
 #define LOGD(...) \
-		do_log(LOG_DEBUG, __VA_ARGS__)
+		ac_log(LOG_DEBUG, __VA_ARGS__)
 #endif
 
 #endif
diff --git a/tools/acrn-crashlog/common/include/strutils.h b/tools/acrn-crashlog/common/include/strutils.h
index faf3da101..d5ac2cb55 100644
--- a/tools/acrn-crashlog/common/include/strutils.h
+++ b/tools/acrn-crashlog/common/include/strutils.h
@@ -9,10 +9,12 @@
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 #define s_not_expect(res, size) (res < 0 || (size_t)res >= size)
 
+char *get_line(const char *str, size_t str_size,
+		const char *area, size_t area_size,
+		const char *search_from, size_t *len);
 ssize_t strlinelen(const char *str, size_t size);
 char *strrstr(const char *s, const char *str);
-char *next_line(char *buf);
-char *strtrim(char *str);
+char *strtrim(char *str, size_t len);
 int strcnt(char *str, char c);
 int str_split_ere(const char *str, size_t slen,
 		const char *fmt, size_t flen, ...);
diff --git a/tools/acrn-crashlog/common/log_sys.c b/tools/acrn-crashlog/common/log_sys.c
index 98f0d7f0a..44006d9e7 100644
--- a/tools/acrn-crashlog/common/log_sys.c
+++ b/tools/acrn-crashlog/common/log_sys.c
@@ -4,46 +4,35 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-#include <systemd/sd-journal.h>
+#include <stdarg.h>
 #include "log_sys.h"
 
-void do_log(const int level,
-#ifdef DEBUG_ACRN_CRASHLOG
-			const char *func, const int line,
-#endif
-			...)
+void debug_log(const int level, const char *func, const int line, ...)
 {
 	va_list args;
 	char *fmt;
-	char log[MAX_LOG_LEN];
-	int n = 0;
-#ifdef DEBUG_ACRN_CRASHLOG
-	const char header_fmt[] = "<%-20s%5d>: ";
-#endif
+	char *head;
+	char *msg;
 
 	if (level > LOG_LEVEL)
 		return;
 
-#ifdef DEBUG_ACRN_CRASHLOG
 	va_start(args, line);
-#else
-	va_start(args, level);
-#endif
 	fmt = va_arg(args, char *);
 	if (!fmt)
 		return;
-
-#ifdef DEBUG_ACRN_CRASHLOG
-	/* header */
-	n = snprintf(log, sizeof(log), header_fmt, func, line);
-	if (n < 0 || (size_t)n >= sizeof(log))
-		n = 0;
-#endif
-	/* msg */
-	vsnprintf(log + n, sizeof(log) - (size_t)n, fmt, args);
-	log[sizeof(log) - 1] = 0;
+	if (vasprintf(&msg, fmt, args) == -1)
+		return;
 	va_end(args);
 
-	sd_journal_print(level, "%s", log);
+	if (asprintf(&head, "<%-20s%5d>: ", func, line) == -1) {
+		free(msg);
+		return;
+	}
+
+	sd_journal_print(level, "%s%s", head, msg);
+	free(msg);
+	free(head);
 }
diff --git a/tools/acrn-crashlog/common/strutils.c b/tools/acrn-crashlog/common/strutils.c
index eb68377fb..9b6bbffb4 100644
--- a/tools/acrn-crashlog/common/strutils.c
+++ b/tools/acrn-crashlog/common/strutils.c
@@ -11,6 +11,62 @@
 #include "log_sys.h"
 #include "fsutils.h"
 
+/**
+ * Find the first line containing specified string in given area.
+ *
+ * @param str A pointer to the string contained by target line.
+ * @param str_size String length of str.
+ * @param area A pointer to the area where target line may be located.
+ *             This pointer will be returned if the specified string is in
+ *             the first line of area (There is not '\n' located between area
+ *             and the head of searched string).
+ * @param area_size String length of area.
+ * @param search_from A pointer where searching starts. It should be greater
+ *                    than or equal to area, and less than area + area_size.
+ * @param[out] len The length of target line (excludes \n), it only be modified
+ *             when function returns successfully.
+ *
+ * @return a pointer to the head of target line within area (it may be greater
+ *         than search_from).
+ *         NULL will be returned if the specified string is not found in
+ *         any lines (lines must end with '\n'. It means the real searching
+ *         scope is from search_from to the last '\n' in area).
+ */
+char *get_line(const char *str, size_t str_size,
+		const char *area, size_t area_size,
+		const char *search_from, size_t *len)
+{
+	char *p;
+	char *match;
+	char *tail;
+	ssize_t search_size = area + area_size - search_from;
+
+	if (!str || !str_size || !area || !area_size || !search_from || !len)
+		return NULL;
+
+	if (search_from < area || search_from >= area + area_size ||
+	    (size_t)search_size < str_size)
+		return NULL;
+
+	match = memmem(search_from, search_size, str, str_size);
+	if (!match)
+		return NULL;
+	tail = memchr(match + str_size, '\n',
+		      area + area_size - match - str_size);
+	if (!tail)
+		return NULL;
+
+	for (p = match; p >= area; p--) {
+		if (*p == '\n') {
+			*len = tail - p - 1;
+			return (char *)(p + 1);
+		}
+	}
+
+	*len = tail - area;
+	return (char *)area;
+}
+
 /**
  * Get the length of line.
  *
@@ -57,54 +113,32 @@ char *strrstr(const char *s, const char *substr)
 	return NULL;
 }
 
-char *next_line(char *buf)
+char *strtrim(char *str, size_t len)
 {
+	size_t h_del = 0;
+	size_t reserve;
 	char *p;
 
-	p  = strchr(buf, '\n');
-	/* if meet end of buf, the return value is also NULL */
-	if (p)
-		return p + 1;
+	if (!len)
+		return str;
 
-	return NULL;
-}
+	for (p = str; p < str + len && *p == ' '; p++)
+		h_del++;
 
-static char *strtriml(char *str)
-{
-	char *p = str;
-
-	while (*p == ' ')
-		p++;
-	return memmove(str, p, strlen(p) + 1);
-}
-
-static char *strtrimr(char *str)
-{
-	size_t len;
-	char *end;
-
-	len = strlen(str);
-	if (len > 0) {
-		end = str + strlen(str) - 1;
-		while (*end == ' ' && end >= str) {
-			*end = 0;
-			end--;
-		}
+	reserve = len - h_del;
+	if (!reserve) {
+		*str = '\0';
+		return str;
 	}
 
+	for (p = str + len - 1; p >= str && *p == ' '; p--)
+		reserve--;
+
+	memmove(str, str + h_del, reserve);
+	*(str + reserve) = '\0';
 	return str;
 }
 
-char *strtrim(char *str)
-{
-	if (str) {
-		strtrimr(str);
-		return strtriml(str);
-	}
-
-	return NULL;
-}
-
 int strcnt(char *str, char c)
 {
 	int cnt = 0;
diff --git a/tools/acrn-crashlog/usercrash/crash_dump.c b/tools/acrn-crashlog/usercrash/crash_dump.c
index c5d948c64..a941c1047 100644
--- a/tools/acrn-crashlog/usercrash/crash_dump.c
+++ b/tools/acrn-crashlog/usercrash/crash_dump.c
@@ -129,12 +129,11 @@ static int get_backtrace(int pid, int fd, int sig, const char *comm)
 			return -1;
 		}
 	}
-	membkt = exec_out2mem(GET_GDB_INFO, format);
-	if (!membkt) {
+	len = exec_out2mem(&membkt, GET_GDB_INFO, format);
+	if (len <= 0) {
 		LOGE("get gdb info failed\n");
 		return -1;
 	}
-	len = strlen(membkt);
 	ret = write(fd, membkt, len);
 	free(membkt);
 	if (ret != len) {