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From:   Jianlin Lv <iecedge@gmail.com>
To:     akpm@linux-foundation.org, yejiajian2018@email.szu.edu.cn,
        caoyixuan2019@email.szu.edu.cn, seanga2@gmail.com,
        zhangyinan2019@email.szu.edu.cn, zhaochongxi2019@email.szu.edu.cn
Cc:     iecedge@gmail.com, jianlv@ebay.com, linux-kernel@vger.kernel.org
Subject: [PATCH] tools/vm/page_owner_sort: free memory before exit
Date:   Mon, 19 Dec 2022 16:49:17 +0000
Message-Id: <20221219164917.14132-1-iecedge@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Although when a process terminates, the kernel will removes memory
associated with that process, It's neither good style nor proper design
to leave it to kernel.
This patch free allocated memory before process exit.

Signed-off-by: Jianlin Lv <iecedge@gmail.com>
---
 tools/vm/page_owner_sort.c | 65 ++++++++++++++++++++++++++------------
 1 file changed, 45 insertions(+), 20 deletions(-)

diff --git a/tools/vm/page_owner_sort.c b/tools/vm/page_owner_sort.c
index ce860ab94162..7c2ac124cdc8 100644
--- a/tools/vm/page_owner_sort.c
+++ b/tools/vm/page_owner_sort.c
@@ -246,15 +246,16 @@ static int search_pattern(regex_t *pattern, char *pattern_str, char *buf)
 	return 0;
 }
 
-static void check_regcomp(regex_t *pattern, const char *regex)
+static bool check_regcomp(regex_t *pattern, const char *regex)
 {
 	int err;
 
 	err = regcomp(pattern, regex, REG_EXTENDED | REG_NEWLINE);
 	if (err != 0 || pattern->re_nsub != 1) {
 		fprintf(stderr, "Invalid pattern %s code %d\n", regex, err);
-		exit(1);
+		return false;
 	}
+	return true;
 }
 
 static char **explode(char sep, const char *str, int *size)
@@ -494,28 +495,28 @@ static bool is_need(char *buf)
 	return true;
 }
 
-static void add_list(char *buf, int len, char *ext_buf)
+static bool add_list(char *buf, int len, char *ext_buf)
 {
 	if (list_size != 0 &&
 		len == list[list_size-1].len &&
 		memcmp(buf, list[list_size-1].txt, len) == 0) {
 		list[list_size-1].num++;
 		list[list_size-1].page_num += get_page_num(buf);
-		return;
+		return true;
 	}
 	if (list_size == max_size) {
 		fprintf(stderr, "max_size too small??\n");
-		exit(1);
+		return false;
 	}
 	if (!is_need(buf))
-		return;
+		return true;
 	list[list_size].pid = get_pid(buf);
 	list[list_size].tgid = get_tgid(buf);
 	list[list_size].comm = get_comm(buf);
 	list[list_size].txt = malloc(len+1);
 	if (!list[list_size].txt) {
 		fprintf(stderr, "Out of memory\n");
-		exit(1);
+		return false;
 	}
 	memcpy(list[list_size].txt, buf, len);
 	list[list_size].txt[len] = 0;
@@ -534,6 +535,7 @@ static void add_list(char *buf, int len, char *ext_buf)
 		printf("loaded %d\r", list_size);
 		fflush(stdout);
 	}
+	return true;
 }
 
 static bool parse_cull_args(const char *arg_str)
@@ -790,12 +792,19 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	check_regcomp(&order_pattern, "order\\s*([0-9]*),");
-	check_regcomp(&pid_pattern, "pid\\s*([0-9]*),");
-	check_regcomp(&tgid_pattern, "tgid\\s*([0-9]*) ");
-	check_regcomp(&comm_pattern, "tgid\\s*[0-9]*\\s*\\((.*)\\),\\s*ts");
-	check_regcomp(&ts_nsec_pattern, "ts\\s*([0-9]*)\\s*ns,");
-	check_regcomp(&free_ts_nsec_pattern, "free_ts\\s*([0-9]*)\\s*ns");
+	if (!check_regcomp(&order_pattern, "order\\s*([0-9]*),"))
+		goto out_order;
+	if (!check_regcomp(&pid_pattern, "pid\\s*([0-9]*),"))
+		goto out_pid;
+	if (!check_regcomp(&tgid_pattern, "tgid\\s*([0-9]*) "))
+		goto out_tgid;
+	if (!check_regcomp(&comm_pattern, "tgid\\s*[0-9]*\\s*\\((.*)\\),\\s*ts"))
+		goto out_comm;
+	if (!check_regcomp(&ts_nsec_pattern, "ts\\s*([0-9]*)\\s*ns,"))
+		goto out_ts;
+	if (!check_regcomp(&free_ts_nsec_pattern, "free_ts\\s*([0-9]*)\\s*ns"))
+		goto out_free_ts;
+
 	fstat(fileno(fin), &st);
 	max_size = st.st_size / 100; /* hack ... */
 
@@ -804,7 +813,7 @@ int main(int argc, char **argv)
 	ext_buf = malloc(BUF_SIZE);
 	if (!list || !buf || !ext_buf) {
 		fprintf(stderr, "Out of memory\n");
-		exit(1);
+		goto out_free;
 	}
 
 	for ( ; ; ) {
@@ -812,7 +821,8 @@ int main(int argc, char **argv)
 
 		if (buf_len < 0)
 			break;
-		add_list(buf, buf_len, ext_buf);
+		if (!add_list(buf, buf_len, ext_buf))
+			goto out_free;
 	}
 
 	printf("loaded %d\n", list_size);
@@ -862,11 +872,26 @@ int main(int argc, char **argv)
 			fprintf(fout, "\n");
 		}
 	}
-	regfree(&order_pattern);
-	regfree(&pid_pattern);
-	regfree(&tgid_pattern);
-	regfree(&comm_pattern);
-	regfree(&ts_nsec_pattern);
+
+out_free:
+	if (ext_buf)
+		free(ext_buf);
+	if (buf)
+		free(buf);
+	if (list)
+		free(list);
+out_free_ts:
 	regfree(&free_ts_nsec_pattern);
+out_ts:
+	regfree(&ts_nsec_pattern);
+out_comm:
+	regfree(&comm_pattern);
+out_tgid:
+	regfree(&tgid_pattern);
+out_pid:
+	regfree(&pid_pattern);
+out_order:
+	regfree(&order_pattern);
+
 	return 0;
 }
-- 
2.25.1