From cd88ee3d68f305c27018820adaaf3050b6e134b1 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Fri, 20 Jul 2018 12:48:02 +0200
Subject: drm/cirrus: Use drm_framebuffer_put to avoid kernel oops in clean-up
References: bsc#1101822
Git-commit: abf7b30d7f61d981bfcca65d1e8331b27021b475
Patch-mainline: v4.20-rc1
In the Cirrus driver, the regular clean-up code also performs the clean-up
of a failed initialization. If the fbdev's framebuffer was not initialized,
the clean-up will fail within drm_framebuffer_unregister_private. Booting
with cirrus.bpp=16 triggers this bug.
The framebuffer is currently stored directly within struct cirrus_fbdev. To
fix the bug, we turn it into a pointer that is only set for initialized
framebuffers. The fbdev's clean-up code skips uninitialized framebuffers.
The memory for struct drm_framebuffer is allocated dynamically. This requires
additional error handling within cirrusfb_create. The framebuffer clean-up is
now performed by drm_framebuffer_put, which also frees the data strcuture's
memory.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1101822
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/cirrus/cirrus_drv.h | 2 -
drivers/gpu/drm/cirrus/cirrus_fbdev.c | 49 ++++++++++++++++++++--------------
drivers/gpu/drm/cirrus/cirrus_mode.c | 2 -
3 files changed, 32 insertions(+), 21 deletions(-)
--- a/drivers/gpu/drm/cirrus/cirrus_drv.h
+++ b/drivers/gpu/drm/cirrus/cirrus_drv.h
@@ -152,7 +152,7 @@ struct cirrus_device {
struct cirrus_fbdev {
struct drm_fb_helper helper;
- struct cirrus_framebuffer gfb;
+ struct cirrus_framebuffer *gfb;
void *sysram;
int size;
int x1, y1, x2, y2; /* dirty rect */
--- a/drivers/gpu/drm/cirrus/cirrus_fbdev.c
+++ b/drivers/gpu/drm/cirrus/cirrus_fbdev.c
@@ -22,14 +22,14 @@ static void cirrus_dirty_update(struct c
struct drm_gem_object *obj;
struct cirrus_bo *bo;
int src_offset, dst_offset;
- int bpp = afbdev->gfb.base.format->cpp[0];
+ int bpp = afbdev->gfb->base.format->cpp[0];
int ret = -EBUSY;
bool unmap = false;
bool store_for_later = false;
int x2, y2;
unsigned long flags;
- obj = afbdev->gfb.obj;
+ obj = afbdev->gfb->obj;
bo = gem_to_cirrus_bo(obj);
/*
@@ -82,7 +82,7 @@ static void cirrus_dirty_update(struct c
}
for (i = y; i < y + height; i++) {
/* assume equal stride for now */
- src_offset = dst_offset = i * afbdev->gfb.base.pitches[0] + (x * bpp);
+ src_offset = dst_offset = i * afbdev->gfb->base.pitches[0] + (x * bpp);
memcpy_toio(bo->kmap.virtual + src_offset, afbdev->sysram + src_offset, width * bpp);
}
@@ -165,7 +165,7 @@ static int cirrusfb_create(struct drm_fb
container_of(helper, struct cirrus_fbdev, helper);
struct cirrus_device *cdev = gfbdev->helper.dev->dev_private;
struct fb_info *info;
- struct drm_framebuffer *fb;
+ struct cirrus_framebuffer *fb;
struct drm_mode_fb_cmd2 mode_cmd;
void *sysram;
struct drm_gem_object *gobj = NULL;
@@ -192,33 +192,36 @@ static int cirrusfb_create(struct drm_fb
return -ENOMEM;
info = drm_fb_helper_alloc_fbi(helper);
- if (IS_ERR(info))
- return PTR_ERR(info);
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
+ goto err_vfree;
+ }
info->par = gfbdev;
- ret = cirrus_framebuffer_init(cdev->dev, &gfbdev->gfb, &mode_cmd, gobj);
+ fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+ if (!fb) {
+ ret = -ENOMEM;
+ goto err_drm_gem_object_put_unlocked;
+ }
+
+ ret = cirrus_framebuffer_init(cdev->dev, fb, &mode_cmd, gobj);
if (ret)
- return ret;
+ goto err_kfree;
gfbdev->sysram = sysram;
gfbdev->size = size;
-
- fb = &gfbdev->gfb.base;
- if (!fb) {
- DRM_INFO("fb is NULL\n");
- return -EINVAL;
- }
+ gfbdev->gfb = fb;
/* setup helper */
- gfbdev->helper.fb = fb;
+ gfbdev->helper.fb = &fb->base;
strcpy(info->fix.id, "cirrusdrmfb");
info->flags = FBINFO_DEFAULT;
info->fbops = &cirrusfb_ops;
- drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
+ drm_fb_helper_fill_fix(info, fb->base.pitches[0], fb->base.format->depth);
drm_fb_helper_fill_var(info, &gfbdev->helper, sizes->fb_width,
sizes->fb_height);
@@ -238,16 +241,24 @@ static int cirrusfb_create(struct drm_fb
DRM_INFO("fb mappable at 0x%lX\n", info->fix.smem_start);
DRM_INFO("vram aper at 0x%lX\n", (unsigned long)info->fix.smem_start);
DRM_INFO("size %lu\n", (unsigned long)info->fix.smem_len);
- DRM_INFO("fb depth is %d\n", fb->format->depth);
- DRM_INFO(" pitch is %d\n", fb->pitches[0]);
+ DRM_INFO("fb depth is %d\n", fb->base.format->depth);
+ DRM_INFO(" pitch is %d\n", fb->base.pitches[0]);
return 0;
+
+err_kfree:
+ kfree(fb);
+err_drm_gem_object_put_unlocked:
+ drm_gem_object_put_unlocked(gobj);
+err_vfree:
+ vfree(sysram);
+ return ret;
}
static int cirrus_fbdev_destroy(struct drm_device *dev,
struct cirrus_fbdev *gfbdev)
{
- struct cirrus_framebuffer *gfb = &gfbdev->gfb;
+ struct cirrus_framebuffer *gfb = gfbdev->gfb;
drm_fb_helper_unregister_fbi(&gfbdev->helper);
--- a/drivers/gpu/drm/cirrus/cirrus_mode.c
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@@ -133,7 +133,7 @@ static int cirrus_crtc_do_set_base(struc
return ret;
}
- if (&cdev->mode_info.gfbdev->gfb == cirrus_fb) {
+ if (cdev->mode_info.gfbdev->gfb == cirrus_fb) {
/* if pushing console in kmap it */
ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
if (ret)