From 24981fa336b61f2c5b305ab62e571c7196323cfb Mon Sep 17 00:00:00 2001 From: =?utf8?q?Michel=20D=C3=A4nzer?= Date: Wed, 16 Jun 2021 12:46:51 +0200 Subject: [PATCH] drm/amdgpu: Call drm_framebuffer_init last for framebuffer init MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Once drm_framebuffer_init has returned 0, the framebuffer is hooked up to the reference counting machinery and can no longer be destroyed with a simple kfree. Therefore, it must be called last. If drm_framebuffer_init returns 0 but its caller then returns non-0, there will likely be memory corruption fireworks down the road. The following lead me to this fix: [ 12.891228] kernel BUG at lib/list_debug.c:25! [...] [ 12.891263] RIP: 0010:__list_add_valid+0x4b/0x70 [...] [ 12.891324] Call Trace: [ 12.891330] drm_framebuffer_init+0xb5/0x100 [drm] [ 12.891378] amdgpu_display_gem_fb_verify_and_init+0x47/0x120 [amdgpu] [ 12.891592] ? amdgpu_display_user_framebuffer_create+0x10d/0x1f0 [amdgpu] [ 12.891794] amdgpu_display_user_framebuffer_create+0x126/0x1f0 [amdgpu] [ 12.891995] drm_internal_framebuffer_create+0x378/0x3f0 [drm] [ 12.892036] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm] [ 12.892075] drm_mode_addfb2+0x34/0xd0 [drm] [ 12.892115] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm] [ 12.892153] drm_ioctl_kernel+0xe2/0x150 [drm] [ 12.892193] drm_ioctl+0x3da/0x460 [drm] [ 12.892232] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm] [ 12.892274] amdgpu_drm_ioctl+0x43/0x80 [amdgpu] [ 12.892475] __se_sys_ioctl+0x72/0xc0 [ 12.892483] do_syscall_64+0x33/0x40 [ 12.892491] entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: f258907fdd835e "drm/amdgpu: Verify bo size can fit framebuffer size on init." Signed-off-by: Michel Dänzer Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c index 2b6a66c..8e5a7ac 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c @@ -1046,11 +1046,12 @@ int amdgpu_display_gem_fb_init(struct drm_device *dev, rfb->base.obj[0] = obj; drm_helper_mode_fill_fb_struct(dev, &rfb->base, mode_cmd); - ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs); + + ret = amdgpu_display_framebuffer_init(dev, rfb, mode_cmd, obj); if (ret) goto err; - ret = amdgpu_display_framebuffer_init(dev, rfb, mode_cmd, obj); + ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs); if (ret) goto err; @@ -1070,9 +1071,6 @@ int amdgpu_display_gem_fb_verify_and_init( rfb->base.obj[0] = obj; drm_helper_mode_fill_fb_struct(dev, &rfb->base, mode_cmd); - ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs); - if (ret) - goto err; /* Verify that the modifier is supported. */ if (!drm_any_plane_has_format(dev, mode_cmd->pixel_format, mode_cmd->modifier[0])) { @@ -1088,6 +1086,10 @@ int amdgpu_display_gem_fb_verify_and_init( if (ret) goto err; + ret = drm_framebuffer_init(dev, &rfb->base, &amdgpu_fb_funcs); + if (ret) + goto err; + return 0; err: drm_dbg_kms(dev, "Failed to verify and init gem fb: %d\n", ret); -- 2.7.4