| Message ID | 20180826184712.GA9330@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/rockchip: Use struct_size() in devm_kzalloc() | expand |
On Sun, Aug 26, 2018 at 11:47 AM, Gustavo A. R. Silva <gustavo@embeddedor.com> 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; > void *entry[]; > }; > > instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > or, like in this particular case: > > size = sizeof(struct foo) + sizeof(void *) * count; > 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); > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > index 1359e5c..cf64e4d 100644 > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > @@ -32,6 +32,7 @@ > #include <linux/of_device.h> > #include <linux/pm_runtime.h> > #include <linux/component.h> > +#include <linux/overflow.h> > > #include <linux/reset.h> > #include <linux/delay.h> > @@ -1561,7 +1562,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) > struct drm_device *drm_dev = data; > struct vop *vop; > struct resource *res; > - size_t alloc_size; > int ret, irq; > > vop_data = of_device_get_match_data(dev); > @@ -1569,8 +1569,8 @@ static int vop_bind(struct device *dev, struct device *master, void *data) > return -ENODEV; > > /* Allocate vop struct and its vop_win array */ > - alloc_size = sizeof(*vop) + sizeof(*vop->win) * vop_data->win_size; > - vop = devm_kzalloc(dev, alloc_size, GFP_KERNEL); > + vop = devm_kzalloc(dev, struct_size(vop, win, vop_data->win_size), > + GFP_KERNEL); > if (!vop) > return -ENOMEM; > > -- > 2.7.4 >
Am Sonntag, 26. August 2018, 20:47:12 CEST schrieb Gustavo A. R. Silva: > 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 = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > or, like in this particular case: > > size = sizeof(struct foo) + sizeof(void *) * count; > 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); > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> applied to drm-misc with Kees' Review Thanks Heiko
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index 1359e5c..cf64e4d 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -32,6 +32,7 @@ #include <linux/of_device.h> #include <linux/pm_runtime.h> #include <linux/component.h> +#include <linux/overflow.h> #include <linux/reset.h> #include <linux/delay.h> @@ -1561,7 +1562,6 @@ static int vop_bind(struct device *dev, struct device *master, void *data) struct drm_device *drm_dev = data; struct vop *vop; struct resource *res; - size_t alloc_size; int ret, irq; vop_data = of_device_get_match_data(dev); @@ -1569,8 +1569,8 @@ static int vop_bind(struct device *dev, struct device *master, void *data) return -ENODEV; /* Allocate vop struct and its vop_win array */ - alloc_size = sizeof(*vop) + sizeof(*vop->win) * vop_data->win_size; - vop = devm_kzalloc(dev, alloc_size, GFP_KERNEL); + vop = devm_kzalloc(dev, struct_size(vop, win, vop_data->win_size), + GFP_KERNEL); if (!vop) return -ENOMEM;
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 = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); or, like in this particular case: size = sizeof(struct foo) + sizeof(void *) * count; 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); This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)