From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Eric Anholt <eric@anholt.net>, David Airlie <airlied@linux.ie>,
Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] drm/vc4: Use struct_size() in kzalloc()
Date: Wed, 30 Jan 2019 19:00:15 -0600 [thread overview]
Message-ID: <20190131010015.GA32272@embeddedor> (raw)
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;
void *entry[];
};
instance = kzalloc(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 = kzalloc(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/gpu/drm/vc4/vc4_perfmon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c
index 437e7a27f21d..495150415020 100644
--- a/drivers/gpu/drm/vc4/vc4_perfmon.c
+++ b/drivers/gpu/drm/vc4/vc4_perfmon.c
@@ -117,7 +117,7 @@ int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
return -EINVAL;
}
- perfmon = kzalloc(sizeof(*perfmon) + (req->ncounters * sizeof(u64)),
+ perfmon = kzalloc(struct_size(perfmon, counters, req->ncounters),
GFP_KERNEL);
if (!perfmon)
return -ENOMEM;
--
2.20.1
next reply other threads:[~2019-01-31 1:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-31 1:00 Gustavo A. R. Silva [this message]
2019-02-07 22:59 ` [PATCH] drm/vc4: Use struct_size() in kzalloc() Eric Anholt
2019-02-07 22:59 ` Eric Anholt
2019-02-07 23:02 ` Gustavo A. R. Silva
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