From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Lee Jones <lee.jones@linaro.org>,
Linus Walleij <linus.walleij@linaro.org>
Cc: linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH 2/2] mfd: sm501: Use struct_size() in devm_kzalloc()
Date: Tue, 22 Jan 2019 10:58:20 -0600 [thread overview]
Message-ID: <4e25a7933cc9876b24fa3322637a22df7475bc40.1548175934.git.gustavo@embeddedor.com> (raw)
In-Reply-To: <cover.1548175934.git.gustavo@embeddedor.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = devm_kzalloc(dev, sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/mfd/sm501.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index e0173bf4b0dc..d217debf382e 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -1142,8 +1142,7 @@ static int sm501_register_gpio_i2c_instance(struct sm501_devdata *sm,
return -ENOMEM;
/* Create a gpiod lookup using gpiochip-local offsets */
- lookup = devm_kzalloc(&pdev->dev,
- sizeof(*lookup) + 3 * sizeof(struct gpiod_lookup),
+ lookup = devm_kzalloc(&pdev->dev, struct_size(lookup, table, 3),
GFP_KERNEL);
if (!lookup)
return -ENOMEM;
--
2.20.1
next prev parent reply other threads:[~2019-01-22 16:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-22 16:55 [PATCH 0/2] Fix NULL pointer dereference and use struct_size() Gustavo A. R. Silva
2019-01-22 16:56 ` [PATCH 1/2] mfd: sm501: Fix potential NULL pointer dereference Gustavo A. R. Silva
2019-01-30 13:35 ` Lee Jones
2019-01-31 0:16 ` Gustavo A. R. Silva
2019-01-22 16:58 ` Gustavo A. R. Silva [this message]
2019-01-30 13:35 ` [PATCH 2/2] mfd: sm501: Use struct_size() in devm_kzalloc() Lee Jones
2019-01-26 13:20 ` [PATCH 0/2] Fix NULL pointer dereference and use struct_size() Linus Walleij
2019-01-26 13:49 ` Gustavo A. R. Silva
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