drm: replace DRM_COPY macro w/ a function
Don't inline it; the compiler can figure it out. Comments added that are
based upon my interpretation of the code. Hopefully they're correct. :)
Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 43297ca..ec0e3ae 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -368,14 +368,25 @@
/**
* Copy and IOCTL return string to user space
*/
-#define DRM_COPY(name, value) \
- len = strlen(value); \
- if (len > name##_len) len = name##_len; \
- name##_len = strlen(value); \
- if (len && name) { \
- if (copy_to_user(name, value, len)) \
- return -EFAULT; \
- }
+static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
+{
+ int len;
+
+ /* don't overflow userbuf */
+ len = strlen(value);
+ if (len > *buf_len)
+ len = *buf_len;
+
+ /* let userspace know exact length of driver value (which could be
+ * larger than the userspace-supplied buffer) */
+ *buf_len = strlen(value);
+
+ /* finally, try filling in the userbuf */
+ if (len && buf)
+ if (copy_to_user(buf, value, len))
+ return -EFAULT;
+ return 0;
+}
/**
* Get version information
@@ -392,14 +403,13 @@
struct drm_file *file_priv)
{
struct drm_version *version = data;
- int len;
version->version_major = dev->driver->major;
version->version_minor = dev->driver->minor;
version->version_patchlevel = dev->driver->patchlevel;
- DRM_COPY(version->name, dev->driver->name);
- DRM_COPY(version->date, dev->driver->date);
- DRM_COPY(version->desc, dev->driver->desc);
+ drm_copy_field(version->name, &version->name_len, dev->driver->name);
+ drm_copy_field(version->date, &version->date_len, dev->driver->date);
+ drm_copy_field(version->desc, &version->desc_len, dev->driver->desc);
return 0;
}