diff options
| -rw-r--r-- | drivers/gpu/drm/drm_drv.c | 34 |
1 files changed, 22 insertions, 12 deletions
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 @@ module_exit(drm_core_exit); /** * 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 @@ static int drm_version(struct drm_device *dev, void *data, 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; } |