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Diffstat (limited to 'bsd-core/drm_auth.c')
-rw-r--r--bsd-core/drm_auth.c17
1 files changed, 6 insertions, 11 deletions
diff --git a/bsd-core/drm_auth.c b/bsd-core/drm_auth.c
index 0b411d14..a03cc918 100644
--- a/bsd-core/drm_auth.c
+++ b/bsd-core/drm_auth.c
@@ -116,25 +116,20 @@ int DRM(getmagic)(DRM_IOCTL_ARGS)
{
static drm_magic_t sequence = 0;
drm_auth_t auth;
- static DRM_SPINTYPE lock;
- static int first = 1;
DRM_DEVICE;
DRM_PRIV;
- if (first) {
- DRM_SPININIT(lock, "drm getmagic");
- first = 0;
- }
-
/* Find unique magic */
if (priv->magic) {
auth.magic = priv->magic;
} else {
do {
- DRM_SPINLOCK(&lock);
- if (!sequence) ++sequence; /* reserve 0 */
- auth.magic = sequence++;
- DRM_SPINUNLOCK(&lock);
+ int old = sequence;
+
+ auth.magic = old+1;
+
+ if (!atomic_cmpset_int(&sequence, old, auth.magic))
+ continue;
} while (DRM(find_file)(dev, auth.magic));
priv->magic = auth.magic;
DRM(add_magic)(dev, priv, auth.magic);