linux-kernel - [PATCH] gpiolib: of: fix fallback quirks handling

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]

Message-ID: <20190903231856.GA165165@dtor-ws>
Date:   Tue, 3 Sep 2019 16:18:56 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Andreas Kemnade <andreas@...nade.info>,
        linux-gpio@...r.kernel.org, linux-spi@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] gpiolib: of: fix fallback quirks handling

We should only try to execute fallback quirks handling when previous
call returned -ENOENT, and not when we did not get -EPROBE_DEFER.
The other errors should be treated as hard errors: we did find the GPIO
description, but for some reason we failed to handle it properly.

The fallbacks should only be executed when previous handlers returned
-ENOENT, which means the mapping/description was not found.

Also let's remove the explicit deferral handling when iterating through
GPIO suffixes: it is not needed anymore as we will not be calling
fallbacks for anything but -ENOENT.

Fixes: df451f83e1fc ("gpio: of: fix Freescale SPI CS quirk handling")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/gpio/gpiolib-of.c | 27 +++++++++------------------
 1 file changed, 9 insertions(+), 18 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index b034abe59f28..b45b39c48a34 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -457,36 +457,27 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 
 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
 						&of_flags);
-		/*
-		 * -EPROBE_DEFER in our case means that we found a
-		 * valid GPIO property, but no controller has been
-		 * registered so far.
-		 *
-		 * This means we don't need to look any further for
-		 * alternate name conventions, and we should really
-		 * preserve the return code for our user to be able to
-		 * retry probing later.
-		 */
-		if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
-			return desc;
 
-		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+		if (!IS_ERR(desc) || PTR_ERR(desc) != -ENOENT)
 			break;
 	}
 
-	/* Special handling for SPI GPIOs if used */
-	if (IS_ERR(desc))
+	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
+		/* Special handling for SPI GPIOs if used */
 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
-	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER) {
+	}
+
+	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
 		/* This quirk looks up flags and all */
 		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
 		if (!IS_ERR(desc))
 			return desc;
 	}
 
-	/* Special handling for regulator GPIOs if used */
-	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
+	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
+		/* Special handling for regulator GPIOs if used */
 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
+	}
 
 	if (IS_ERR(desc))
 		return desc;
-- 
2.23.0.187.g17f5b7556c-goog


-- 
Dmitry