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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: tglx@linutronix.de, Enrico Weigelt <info@metux.net>,
	Kate Stewart <kstewart@linuxfoundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] mm, vmpressure: Fix a signedness bug in vmpressure_register_event()
Date: Wed, 25 Sep 2019 11:04:49 +0000	[thread overview]
Message-ID: <20190925110449.GO3264@mwanda> (raw)

The "mode" and "level" variables are enums and in this context GCC will
treat them as unsigned ints so the error handling is never triggered.

I also removed the bogus initializer because it isn't required any more
and it's sort of confusing.

Fixes: 3cadfa2b9497 ("mm/vmpressure.c: convert to use match_string() helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 mm/vmpressure.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index f3b50811497a..fe077500cf20 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -362,7 +362,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
 	struct vmpressure_event *ev;
 	enum vmpressure_modes mode = VMPRESSURE_NO_PASSTHROUGH;
-	enum vmpressure_levels level = -1;
+	enum vmpressure_levels level;
 	char *spec, *spec_orig;
 	char *token;
 	int ret = 0;
@@ -376,7 +376,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	/* Find required level */
 	token = strsep(&spec, ",");
 	level = match_string(vmpressure_str_levels, VMPRESSURE_NUM_LEVELS, token);
-	if (level < 0) {
+	if ((int)level < 0) {
 		ret = level;
 		goto out;
 	}
@@ -385,7 +385,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	token = strsep(&spec, ",");
 	if (token) {
 		mode = match_string(vmpressure_str_modes, VMPRESSURE_NUM_MODES, token);
-		if (mode < 0) {
+		if ((int)mode < 0) {
 			ret = mode;
 			goto out;
 		}
-- 
2.20.1

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: tglx@linutronix.de, Enrico Weigelt <info@metux.net>,
	Kate Stewart <kstewart@linuxfoundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] mm, vmpressure: Fix a signedness bug in vmpressure_register_event()
Date: Wed, 25 Sep 2019 14:04:49 +0300	[thread overview]
Message-ID: <20190925110449.GO3264@mwanda> (raw)

The "mode" and "level" variables are enums and in this context GCC will
treat them as unsigned ints so the error handling is never triggered.

I also removed the bogus initializer because it isn't required any more
and it's sort of confusing.

Fixes: 3cadfa2b9497 ("mm/vmpressure.c: convert to use match_string() helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 mm/vmpressure.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index f3b50811497a..fe077500cf20 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -362,7 +362,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
 	struct vmpressure_event *ev;
 	enum vmpressure_modes mode = VMPRESSURE_NO_PASSTHROUGH;
-	enum vmpressure_levels level = -1;
+	enum vmpressure_levels level;
 	char *spec, *spec_orig;
 	char *token;
 	int ret = 0;
@@ -376,7 +376,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	/* Find required level */
 	token = strsep(&spec, ",");
 	level = match_string(vmpressure_str_levels, VMPRESSURE_NUM_LEVELS, token);
-	if (level < 0) {
+	if ((int)level < 0) {
 		ret = level;
 		goto out;
 	}
@@ -385,7 +385,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 	token = strsep(&spec, ",");
 	if (token) {
 		mode = match_string(vmpressure_str_modes, VMPRESSURE_NUM_MODES, token);
-		if (mode < 0) {
+		if ((int)mode < 0) {
 			ret = mode;
 			goto out;
 		}
-- 
2.20.1



             reply	other threads:[~2019-09-25 11:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-25 11:04 Dan Carpenter [this message]
2019-09-25 11:04 ` [PATCH] mm, vmpressure: Fix a signedness bug in vmpressure_register_event() Dan Carpenter
2019-09-25 13:07 ` Andy Shevchenko
2019-09-25 13:07   ` Andy Shevchenko
2019-09-26 19:04 ` David Rientjes
2019-09-26 19:04   ` David Rientjes
2019-09-28 21:23 ` Andrew Morton
2019-09-28 21:23   ` Andrew Morton
2019-09-28 21:47   ` Matthew Wilcox
2019-09-28 21:47     ` Matthew Wilcox
2019-09-28 22:04     ` Andrew Morton
2019-09-28 22:04       ` Andrew Morton
2019-10-01  7:20   ` Dan Carpenter
2019-10-01  7:20     ` Dan Carpenter

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