[PATCH AUTOSEL 4.19 02/57] gpio: pxa: handle corner case of unprobed device

[PATCH AUTOSEL 4.19 02/57] gpio: pxa: handle corner case of unprobed device

[Sasha Levin]

From: Robert Jarzmik <robert.jarzmik@free.fr>

[ Upstream commit 9ce3ebe973bf4073426f35f282c6b955ed802765 ]

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@free.fr>
Reported-by: Nicolas Chauvet <kwizart@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 eb27fa76e8fc..bcc6be4a5cb2 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -777,6 +777,9 @@ 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);
@@ -795,6 +798,9 @@ 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);
-- 
2.19.1

[PATCH AUTOSEL 4.19 15/57] pinctrl: core: make sure strcmp() doesn't get a null parameter

[Sasha Levin]

From: Yanjiang Jin <yanjiang.jin@hxt-semitech.com>

[ Upstream commit 54a58185bfafb5af5045fb8388c45daa373f90f3 ]

Some drivers, for example, QCOM's qdf2xxx, set groups[gpio].name only
when gpio is valid, and leave invalid gpio names as null.
If we want to access the sys node "pinconf-groups",
pinctrl_get_group_selector() -> get_group_name() may return a null
pointer if group_selector is invalid, then the below Kernel panic
would happen since strcmp() uses this null pointer to do comparison.

 Unable to handle kernel NULL pointer dereference at ss 00000000
el:Internal error: Oops: 9600000[ 143.080279]
SMP
 CPU: 19 PID: 2493 Comm: read_all Tainted: G O
.aarch64 #1
 Hardware name: HXT Semiconductor HXT REP-2 System
 PC is at strcmp+0x18/0x154
 LR is at pinctrl_get_group_selector+0x6c/0xe8
 Process read_all (pid: 2493, stack limit =
 Call trace:
 Exception stack
  strcmp+0x18/0x154
  pin_config_group_get+0x64/0xd8
  pinconf_generic_dump_one+0xd8/0x1c0
  pinconf_generic_dump_pins+0x94/0xc8
  pinconf_groups_show+0xb4/0x104
  seq_read+0x178/0x464
  full_proxy_read+0x6c/0xac
  __vfs_read+0x58/0x178
  vfs_read+0x94/0x164
  SyS_read+0x60/0xc0
  __sys_trace_return+0x0/0x4
 --[ end trace]--
 Kernel panic - not syncing: Fatal exception

Signed-off-by: Yanjiang Jin <yanjiang.jin@hxt-semitech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pinctrl/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index a3dd777e3ce8..c6ff4d5fa482 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -627,7 +627,7 @@ static int pinctrl_generic_group_name_to_selector(struct pinctrl_dev *pctldev,
 	while (selector < ngroups) {
 		const char *gname = ops->get_group_name(pctldev, selector);
 
-		if (!strcmp(function, gname))
+		if (gname && !strcmp(function, gname))
 			return selector;
 
 		selector++;
@@ -743,7 +743,7 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
 	while (group_selector < ngroups) {
 		const char *gname = pctlops->get_group_name(pctldev,
 							    group_selector);
-		if (!strcmp(gname, pin_group)) {
+		if (gname && !strcmp(gname, pin_group)) {
 			dev_dbg(pctldev->dev,
 				"found group selector %u for %s\n",
 				group_selector,
-- 
2.19.1