[PATCH xserver] xfree86: Wrap RRCrtcIsLeased and RROutputIsLeased to check for DIX structures

[Keith Packard]

Before DIX structures are allocated for crtcs and outputs, we don't
want to call DIX randr code with NULL pointers. This can happen if the
driver sets video modes early in server initialization, which Nouveau
does in zaphod mode.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=106772
Signed-off-by: Keith Packard <keithp at keithp.com>
---
 hw/xfree86/modes/xf86Crtc.c | 42 ++++++++++++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
index 4aa77a244..dd795f983 100644
--- a/hw/xfree86/modes/xf86Crtc.c
+++ b/hw/xfree86/modes/xf86Crtc.c
@@ -174,6 +174,32 @@ xf86CrtcInUse(xf86CrtcPtr crtc)
     return FALSE;
 }
 
+/**
+ * Return whether the crtc is leased by a client
+ */
+
+static Bool
+xf86CrtcIsLeased(xf86CrtcPtr crtc)
+{
+    /* If the DIX structure hasn't been created, it can't have been leased */
+    if (!crtc->randr_crtc)
+        return FALSE;
+    return RRCrtcIsLeased(crtc->randr_crtc);
+}
+
+/**
+ * Return whether the output is leased by a client
+ */
+
+static Bool
+xf86OutputIsLeased(xf86OutputPtr output)
+{
+    /* If the DIX structure hasn't been created, it can't have been leased */
+    if (!output->randr_output)
+        return FALSE;
+    return RROutputIsLeased(output->randr_output);
+}
+
 void
 xf86CrtcSetScreenSubpixelOrder(ScreenPtr pScreen)
 {
@@ -254,7 +280,7 @@ xf86CrtcSetModeTransform(xf86CrtcPtr crtc, DisplayModePtr mode,
     RRTransformRec saved_transform;
     Bool saved_transform_present;
 
-    crtc->enabled = xf86CrtcInUse(crtc) && !RRCrtcIsLeased(crtc->randr_crtc);;
+    crtc->enabled = xf86CrtcInUse(crtc) && !xf86CrtcIsLeased(crtc);
 
     /* We only hit this if someone explicitly sends a "disabled" modeset. */
     if (!crtc->enabled) {
@@ -412,7 +438,7 @@ xf86CrtcSetOrigin(xf86CrtcPtr crtc, int x, int y)
     crtc->x = x;
     crtc->y = y;
 
-    if (RRCrtcIsLeased(crtc->randr_crtc))
+    if (xf86CrtcIsLeased(crtc))
         return;
 
     if (crtc->funcs->set_origin) {
@@ -2656,7 +2682,7 @@ xf86InitialConfiguration(ScrnInfoPtr scrn, Bool canGrow)
 static void
 xf86DisableCrtc(xf86CrtcPtr crtc)
 {
-    if (RRCrtcIsLeased(crtc->randr_crtc))
+    if (xf86CrtcIsLeased(crtc))
         return;
 
     crtc->funcs->dpms(crtc, DPMSModeOff);
@@ -2677,7 +2703,7 @@ xf86PrepareOutputs(ScrnInfoPtr scrn)
     for (o = 0; o < config->num_output; o++) {
         xf86OutputPtr output = config->output[o];
 
-        if (RROutputIsLeased(output->randr_output))
+        if (xf86OutputIsLeased(output))
             continue;
 
 #if RANDR_GET_CRTC_INTERFACE
@@ -2703,7 +2729,7 @@ xf86PrepareCrtcs(ScrnInfoPtr scrn)
         uint32_t desired_outputs = 0, current_outputs = 0;
         int o;
 
-        if (RRCrtcIsLeased(crtc->randr_crtc))
+        if (xf86CrtcIsLeased(crtc))
             continue;
 
         for (o = 0; o < config->num_output; o++) {
@@ -2726,7 +2752,7 @@ xf86PrepareCrtcs(ScrnInfoPtr scrn)
         if (desired_outputs != current_outputs || !desired_outputs)
             xf86DisableCrtc(crtc);
 #else
-        if (RRCrtcIsLeased(crtc->randr_crtc))
+        if (xf86CrtcIsLeased(crtc))
             continue;
 
         xf86DisableCrtc(crtc);
@@ -2964,7 +2990,7 @@ xf86DPMSSet(ScrnInfoPtr scrn, int mode, int flags)
         for (i = 0; i < config->num_output; i++) {
             xf86OutputPtr output = config->output[i];
 
-            if (!RROutputIsLeased(output->randr_output) && output->crtc != NULL)
+            if (!xf86OutputIsLeased(output) && output->crtc != NULL)
                 (*output->funcs->dpms) (output, mode);
         }
     }
@@ -2980,7 +3006,7 @@ xf86DPMSSet(ScrnInfoPtr scrn, int mode, int flags)
         for (i = 0; i < config->num_output; i++) {
             xf86OutputPtr output = config->output[i];
 
-            if (!RROutputIsLeased(output->randr_output) && output->crtc != NULL)
+            if (!xf86OutputIsLeased(output) && output->crtc != NULL)
                 (*output->funcs->dpms) (output, mode);
         }
     }
-- 
2.17.1