i915 driver fails on i686 userspace + x86_64 kernel

[Pavel Roskin]

Hi Chris,

It's almost certainly stack corruption.  This "patch" fixes X for me.
The first DRM_IOCTL_MODE_GETCONNECTOR in sna_output_init() must be
overwriting the implied memory bounds.

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index 28151ab..dac834f 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -2588,6 +2588,7 @@ sna_output_init(ScrnInfoPtr scrn, struct sna_mode *mode, 
int num)
        struct sna *sna = to_sna(scrn);
        xf86OutputPtr output;
        struct drm_mode_get_connector conn;
+       int enc_protect[16];
        struct drm_mode_get_encoder enc;
        struct drm_mode_modeinfo dummy;
        struct sna_output *sna_output;
@@ -2600,6 +2601,7 @@ sna_output_init(ScrnInfoPtr scrn, struct sna_mode *mode, 
int num)

        VG_CLEAR(conn);
        VG_CLEAR(enc);
+       &enc_protect;

        conn.connector_id = mode->kmode->connectors[num];
        conn.count_props = 0;

-- 
Regards,
Pavel Roskin