linux-kernel - [PATCH 7/8] backlight: lm3630a_bl: Remove invalid checks for unsigned int

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 24 Jun 2020 15:57:20 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     daniel.thompson@...aro.org, jingoohan1@...il.com,
        dri-devel@...ts.freedesktop.org, linux-fbdev@...r.kernel.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Lee Jones <lee.jones@...aro.org>, stable@...r.kernel.org,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Daniel Jeong <gshark.jeong@...il.com>,
        LDD MLP <ldd-mlp@...t.ti.com>
Subject: [PATCH 7/8] backlight: lm3630a_bl: Remove invalid checks for unsigned int < 0

unsigned ints 'sources' and 'bank' cannot be less than LM3630A_SINK_0 (0)
and LM3630A_BANK_0 (0) respecitively, so change the logic to only check
for thier two possible valid values.

Fixes W=1 warnings:

 drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_led_sources’:
 drivers/video/backlight/lm3630a_bl.c:394:18: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
 394 | if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
 | ^
 drivers/video/backlight/lm3630a_bl.c: In function ‘lm3630a_parse_bank’:
 drivers/video/backlight/lm3630a_bl.c:415:11: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
 415 | if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
 | ^

Cc: <stable@...r.kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Cc: Daniel Jeong <gshark.jeong@...il.com>
Cc: LDD MLP <ldd-mlp@...t.ti.com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
 drivers/video/backlight/lm3630a_bl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index ee320883b7108..e88a2b0e59046 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -391,7 +391,7 @@ static int lm3630a_parse_led_sources(struct fwnode_handle *node,
 		return ret;
 
 	for (i = 0; i < num_sources; i++) {
-		if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
+		if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
 			return -EINVAL;
 
 		ret |= BIT(sources[i]);
@@ -412,7 +412,7 @@ static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
 	if (ret)
 		return ret;
 
-	if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
+	if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
 		return -EINVAL;
 
 	led_sources = lm3630a_parse_led_sources(node, BIT(bank));
-- 
2.25.1