linux-kernel - [PATCH] gpio: pxa: handle corner case of unprobed device

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-next>] [day] [month] [year] [list]

Date:   Sat, 25 Aug 2018 10:44:17 +0200
From:   Robert Jarzmik <robert.jarzmik@...e.fr>
To:     Robert Jarzmik <robert.jarzmik@...e.fr>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] gpio: pxa: handle corner case of unprobed device

In the corner case where the gpio driver probe fails, for whatever
reason, the suspend and resume handlers will still be called as they
have to be registered as syscore operations. This applies as well when
no probe was called while the driver has been built in the kernel.

Nicolas tracked this in :
https://bugzilla.kernel.org/show_bug.cgi?id=200905

Therefore, add a failsafe in these function, and test if a proper probe
succeeded and the driver is functional.

Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
Reported-by: Nicolas Chauvet <kwizart@...il.com>
---
 drivers/gpio/gpio-pxa.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index c18712dabf93..bfe4c5c9f41c 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -776,6 +776,9 @@ static int pxa_gpio_suspend(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return 0;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		c->saved_gplr = readl_relaxed(c->regbase + GPLR_OFFSET);
 		c->saved_gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);
@@ -794,6 +797,9 @@ static void pxa_gpio_resume(void)
 	struct pxa_gpio_bank *c;
 	int gpio;
 
+	if (!pchip)
+		return;
+
 	for_each_gpio_bank(gpio, c, pchip) {
 		/* restore level with set/clear */
 		writel_relaxed(c->saved_gplr, c->regbase + GPSR_OFFSET);
-- 
2.11.0