[PATCH] privates: Clear screen-specific keys during CloseScreen

[Aaron Plattner]

The modesetting driver corrupts memory when used after a server regeneration
because not enough memory is allocated for its pixmap privates.  This happens
because its call to dixRegisterScreenSpecificPrivateKey() does nothing because
key->initialized is still TRUE from the first server generation.  However, the
key is not in the screen's linked list of screen-specific privates because
that's freed and reallocated during the server generation loop in dix_main().

Fix this by clearing the screen-specific keys during CloseScreen, the same way
other privates are cleared during dixResetPrivates().

Finally, add a call to dixFreeScreenSpecificPrivates() for GPU screens.

Signed-off-by: Aaron Plattner <aplattner at nvidia.com>
---
 dix/main.c     |  1 +
 dix/privates.c | 34 +++++++++++++++++++++++-----------
 2 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/dix/main.c b/dix/main.c
index d7a9cdaae8e7..549567660379 100644
--- a/dix/main.c
+++ b/dix/main.c
@@ -339,6 +339,7 @@ dix_main(int argc, char *argv[], char *envp[])
         for (i = screenInfo.numGPUScreens - 1; i >= 0; i--) {
             ScreenPtr pScreen = screenInfo.gpuscreens[i];
             FreeScratchPixmapsForScreen(pScreen);
+            dixFreeScreenSpecificPrivates(pScreen);
             (*pScreen->CloseScreen) (pScreen);
             dixFreePrivates(pScreen->devPrivates, PRIVATE_SCREEN);
             free(pScreen);
diff --git a/dix/privates.c b/dix/privates.c
index e03b2255b7f3..4fd8aeda1202 100644
--- a/dix/privates.c
+++ b/dix/privates.c
@@ -593,6 +593,26 @@ dixLookupPrivateOffset(RESTYPE type)
     return -1;
 }
 
+static void
+FreeKeyLists(DevPrivateSetRec keys[PRIVATE_LAST])
+{
+    DevPrivateType t;
+
+    for (t = PRIVATE_XSELINUX; t < PRIVATE_LAST; t++) {
+        DevPrivateKey key, next;
+
+        for (key = keys[t].key; key; key = next) {
+            next = key->next;
+            key->offset = 0;
+            key->initialized = FALSE;
+            key->size = 0;
+            key->type = 0;
+            if (key->allocated)
+                free(key);
+        }
+    }
+}
+
 /*
  * Screen-specific privates
  */
@@ -642,6 +662,7 @@ dixRegisterScreenSpecificPrivateKey(ScreenPtr pScreen, DevPrivateKey key,
 void
 dixFreeScreenSpecificPrivates(ScreenPtr pScreen)
 {
+    FreeKeyLists(pScreen->screenSpecificPrivates);
 }
 
 /* Initialize screen-specific privates in AddScreen */
@@ -751,18 +772,9 @@ dixResetPrivates(void)
 {
     DevPrivateType t;
 
-    for (t = PRIVATE_XSELINUX; t < PRIVATE_LAST; t++) {
-        DevPrivateKey key, next;
+    FreeKeyLists(global_keys);
 
-        for (key = global_keys[t].key; key; key = next) {
-            next = key->next;
-            key->offset = 0;
-            key->initialized = FALSE;
-            key->size = 0;
-            key->type = 0;
-            if (key->allocated)
-                free(key);
-        }
+    for (t = PRIVATE_XSELINUX; t < PRIVATE_LAST; t++) {
         if (global_keys[t].created) {
             ErrorF("%d %ss still allocated at reset\n",
                    global_keys[t].created, key_names[t]);
-- 
2.5.2