Re: [PATCH 15/20] drm: simplify drm_*_set_unique()

On Fri, Aug 29, 2014 at 12:12:41PM +0200, David Herrmann wrote:

Lets use kasprintf() to avoid pre-allocating the buffer. This is really nothing to optimize for speed and the input is trusted, so kasprintf() is just fine.

Signed-off-by: David Herrmann dh.herrmann@gmail.com

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

---

drivers/gpu/drm/drm_pci.c | 30 ++++++++---------------------- drivers/gpu/drm/drm_platform.c | 31 ++++++++----------------------- 2 files changed, 16 insertions(+), 45 deletions(-)

diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c index 020cfd9..8efea6b 100644 --- a/drivers/gpu/drm/drm_pci.c +++ b/drivers/gpu/drm/drm_pci.c @@ -129,31 +129,17 @@ static int drm_get_pci_domain(struct drm_device *dev)

static int drm_pci_set_busid(struct drm_device *dev, struct drm_master *master) {

• int len, ret;
• master->unique_len = 40;
• master->unique_size = master->unique_len;
• master->unique = kmalloc(master->unique_size, GFP_KERNEL);
• if (master->unique == NULL)

• master->unique = kasprintf(GFP_KERNEL, "pci:%04x:%02x:%02x.%d",

• 			drm_get_pci_domain(dev),
  

• 			dev->pdev->bus->number,
  

• 			PCI_SLOT(dev->pdev->devfn),
  

• 			PCI_FUNC(dev->pdev->devfn));
  

• if (!master->unique) return -ENOMEM;

• len = snprintf(master->unique, master->unique_len,

•        "pci:%04x:%02x:%02x.%d",
  

•        drm_get_pci_domain(dev),
  

•        dev->pdev->bus->number,
  

•        PCI_SLOT(dev->pdev->devfn),
  

•        PCI_FUNC(dev->pdev->devfn));
  

• if (len >= master->unique_len) {

• DRM_ERROR("buffer overflow");
  

• ret = -EINVAL;
  

• goto err;
  

• } else

• master->unique_len = len;
  

• master->unique_len = strlen(master->unique);
• master->unique_size = master->unique_len + 1; return 0;

-err:

• return ret;

}

int drm_pci_set_unique(struct drm_device *dev, diff --git a/drivers/gpu/drm/drm_platform.c b/drivers/gpu/drm/drm_platform.c index d5b76f1..0c09ddd 100644 --- a/drivers/gpu/drm/drm_platform.c +++ b/drivers/gpu/drm/drm_platform.c @@ -70,35 +70,20 @@ err_free:

static int drm_platform_set_busid(struct drm_device *dev, struct drm_master *master) {

• int len, ret, id;
• master->unique_len = 13 + strlen(dev->platformdev->name);
• master->unique_size = master->unique_len;
• master->unique = kmalloc(master->unique_len + 1, GFP_KERNEL);
• if (master->unique == NULL)

• return -ENOMEM;
  

• int id;

  id = dev->platformdev->id;

• /* if only a single instance of the platform device, id will be

• * set to -1.. use 0 instead to avoid a funny looking bus-id:
  

• */
  

• if (id == -1)

• if (id < 0) id = 0;

• len = snprintf(master->unique, master->unique_len,

• 	"platform:%s:%02d", dev->platformdev->name, id);
  

• if (len > master->unique_len) {

• DRM_ERROR("Unique buffer overflowed\n");
  

• ret = -EINVAL;
  

• goto err;
  

• }

• master->unique = kasprintf(GFP_KERNEL, "platform:%s:%02d",

• 				dev->platformdev->name, id);
  

• if (!master->unique)

• return -ENOMEM;
  
  

• master->unique_len = strlen(master->unique);

• master->unique_size = master->unique_len; return 0;

-err:

• return ret;

}

static struct drm_bus drm_platform_bus = {

2.1.0