From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>,
Dan Carpenter <dan.carpenter@oracle.com>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH] gpio / ACPI: Prevent potential wrap of GPIO value on OpRegion read
Date: Tue, 1 Apr 2014 13:03:00 +0300 [thread overview]
Message-ID: <1396346580-4857-1-git-send-email-mika.westerberg@linux.intel.com> (raw)
Dan Carpenter's static code checker reports:
The patch 473ed7be0da0: "gpio / ACPI: Add support for ACPI GPIO
operation regions" from Mar 14, 2014, leads to the following static
checker warning:
drivers/gpio/gpiolib-acpi.c:454 acpi_gpio_adr_space_handler()
warn: should 'gpiod_get_raw_value(desc) << i' be a 64 bit type?
This is due the fact that *value is of type u64 and gpiod_get_raw_value()
returns int. Since i can be larger than 31, it is possible that the value
returned gets wrapped.
Fix this by casting the return of gpiod_get_raw_value() to u64 first before
shift.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/gpio/gpiolib-acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index d5be56fe689e..401add28933f 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -451,7 +451,7 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
if (function == ACPI_WRITE)
gpiod_set_raw_value(desc, !!((1 << i) & *value));
else
- *value |= gpiod_get_raw_value(desc) << i;
+ *value |= (u64)gpiod_get_raw_value(desc) << i;
}
out:
--
1.9.1
next reply other threads:[~2014-04-01 10:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-01 10:03 Mika Westerberg [this message]
2014-04-10 16:24 ` [PATCH] gpio / ACPI: Prevent potential wrap of GPIO value on OpRegion read Linus Walleij
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