| Message ID | 20190604233205.GA5377@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | video: fbdev-MMP: Use struct_size() in devm_kzalloc() | expand |
On 6/5/19 1:32 AM, Gustavo A. R. Silva wrote: > 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[]; > }; > > size = sizeof(struct foo) + count * sizeof(struct boo); > instance = devm_kzalloc(dev, size, 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); > > Notice that, in this case, variable size is not necessary, hence it > is removed. > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Patch queued for v5.3, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
diff --git a/drivers/video/fbdev/mmp/hw/mmp_ctrl.c b/drivers/video/fbdev/mmp/hw/mmp_ctrl.c index 87d943f15a12..17174cd7a5bb 100644 --- a/drivers/video/fbdev/mmp/hw/mmp_ctrl.c +++ b/drivers/video/fbdev/mmp/hw/mmp_ctrl.c @@ -433,7 +433,7 @@ static int mmphw_probe(struct platform_device *pdev) { struct mmp_mach_plat_info *mi; struct resource *res; - int ret, i, size, irq; + int ret, i, irq; struct mmphw_path_plat *path_plat; struct mmphw_ctrl *ctrl = NULL; @@ -461,9 +461,9 @@ static int mmphw_probe(struct platform_device *pdev) } /* allocate */ - size = sizeof(struct mmphw_ctrl) + sizeof(struct mmphw_path_plat) * - mi->path_num; - ctrl = devm_kzalloc(&pdev->dev, size, GFP_KERNEL); + ctrl = devm_kzalloc(&pdev->dev, + struct_size(ctrl, path_plats, mi->path_num), + GFP_KERNEL); if (!ctrl) { ret = -ENOMEM; goto failed;
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[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = devm_kzalloc(dev, size, 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); Notice that, in this case, variable size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/video/fbdev/mmp/hw/mmp_ctrl.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)