From db735fc4036bbe1fbe606819b5f0ff26cc76cdff Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Tue, 21 Jan 2020 11:18:48 -0800 Subject: drm/msm: Set dma maximum segment size for mdss Turning on CONFIG_DMA_API_DEBUG_SG results in the following error: [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536] [ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318 [ 12.102655] Modules linked in: joydev [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2 [ 12.112450] Hardware name: Google Cheza (rev3+) (DT) [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO) [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318 [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318 [ 12.131487] sp : ffffff800cc3ba80 [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000 [ 12.140395] x27: 0000000000000004 x26: 0000000000000004 [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000 [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000 [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090 [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000 [ 12.167749] x17: 0000000000000000 x16: 0000000000000000 [ 12.173218] x15: 0000000000000000 x14: 0720072007200720 [ 12.178689] x13: 0720072007200720 x12: 0720072007200720 [ 12.184161] x11: 0720072007200720 x10: 0720072007200720 [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000 [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000 [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734 [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240 [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400 [ 12.217006] Call trace: [ 12.219535] debug_dma_map_sg+0x1dc/0x318 [ 12.223671] get_pages+0x19c/0x20c [ 12.227177] msm_gem_fault+0x64/0xfc [ 12.230874] __do_fault+0x3c/0x140 [ 12.234383] __handle_mm_fault+0x70c/0xdb8 [ 12.238603] handle_mm_fault+0xac/0xc4 [ 12.242473] do_page_fault+0x1bc/0x3d4 [ 12.246342] do_translation_fault+0x54/0x88 [ 12.250652] do_mem_abort+0x60/0xf0 [ 12.254250] el0_da+0x20/0x24 [ 12.257317] irq event stamp: 67260 [ 12.260828] hardirqs last enabled at (67259): [] console_unlock+0x214/0x608 [ 12.269693] hardirqs last disabled at (67260): [] do_debug_exception+0x5c/0x178 [ 12.278820] softirqs last enabled at (67256): [] __do_softirq+0x4d4/0x520 [ 12.287510] softirqs last disabled at (67249): [] irq_exit+0xa8/0x100 [ 12.295742] ---[ end trace e63cfc40c313ffab ]--- The root of the problem is that the default segment size for sgt is (UINT_MAX & PAGE_MASK), and the default segment size for device dma is 64K. As such, if you compare the 2, you would deduce that the sg segment will overflow the device's capacity. In reality, the hardware can accommodate the larger sg segments, it's just not initializing its max segment properly. This patch initializes the max segment size for the mdss device, which gets rid of that pesky warning. Reported-by: Stephen Boyd Tested-by: Stephen Boyd Tested-by: Sai Prakash Ranjan Reviewed-by: Rob Clark Signed-off-by: Sean Paul Signed-off-by: Douglas Anderson Link: https://patchwork.freedesktop.org/patch/msgid/20200121111813.REPOST.1.I92c66a35fb13f368095b05287bdabdbe88ca6922@changeid --- drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index f50fefb87040..c80ddd7019b5 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -441,6 +441,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv) if (ret) goto err_msm_uninit; + if (!dev->dma_parms) { + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), + GFP_KERNEL); + if (!dev->dma_parms) + return -ENOMEM; + } + dma_set_max_seg_size(dev, DMA_BIT_MASK(32)); + msm_gem_shrinker_init(ddev); switch (get_mdp_ver(pdev)) { -- cgit v1.2.3 From 4b848f20eda5974020f043ca14bacf7a7e634fc8 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Sun, 2 Feb 2020 14:21:33 +0100 Subject: drm/vgem: Close use-after-free race in vgem_gem_create There's two references floating around here (for the object reference, not the handle_count reference, that's a different thing): - The temporary reference held by vgem_gem_create, acquired by creating the object and released by calling drm_gem_object_put_unlocked. - The reference held by the object handle, created by drm_gem_handle_create. This one generally outlives the function, except if a 2nd thread races with a GEM_CLOSE ioctl call. So usually everything is correct, except in that race case, where the access to gem_object->size could be looking at freed data already. Which again isn't a real problem (userspace shot its feet off already with the race, we could return garbage), but maybe someone can exploit this as an information leak. Cc: Dan Carpenter Cc: Hillf Danton Reported-by: syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Cc: Emil Velikov Cc: Daniel Vetter Cc: Sean Paul Cc: Chris Wilson Cc: Eric Anholt Cc: Sam Ravnborg Cc: Rob Clark Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20200202132133.1891846-1-daniel.vetter@ffwll.ch --- drivers/gpu/drm/vgem/vgem_drv.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c index 5bd60ded3d81..909eba43664a 100644 --- a/drivers/gpu/drm/vgem/vgem_drv.c +++ b/drivers/gpu/drm/vgem/vgem_drv.c @@ -196,9 +196,10 @@ static struct drm_gem_object *vgem_gem_create(struct drm_device *dev, return ERR_CAST(obj); ret = drm_gem_handle_create(file, &obj->base, handle); - drm_gem_object_put_unlocked(&obj->base); - if (ret) + if (ret) { + drm_gem_object_put_unlocked(&obj->base); return ERR_PTR(ret); + } return &obj->base; } @@ -221,7 +222,9 @@ static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev, args->size = gem_object->size; args->pitch = pitch; - DRM_DEBUG("Created object of size %lld\n", size); + drm_gem_object_put_unlocked(gem_object); + + DRM_DEBUG("Created object of size %llu\n", args->size); return 0; } -- cgit v1.2.3 From e1cf35b94c5fd122a8780587559fc6da9fc2dd12 Mon Sep 17 00:00:00 2001 From: Mauro Rossi Date: Mon, 3 Feb 2020 22:31:13 +0100 Subject: drm/edid: fix building error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes the following building error: CC [M]  drivers/gpu/drm/drm_edid.o ~/pie-x86_kernel/kernel/drivers/gpu/drm/drm_edid.c: In function 'cea_mode_alternate_timings': ~/pie-x86_kernel/kernel/drivers/gpu/drm/drm_edid.c:3275:2: error: call to '__compiletime_assert_3282' declared with attribute error: BUILD_BUG_ON failed: cea_mode_for_vic(8)->vtotal != 262 || cea_mode_for_vic(9)->vtotal != 262 || cea_mode_for_vic(12)->vtotal != 262 || cea_mode_for_vic(13)->vtotal != 262 || cea_mode_for_vic(23)->vtotal != 312 || cea_mode_for_vic(24)->vtotal != 312 || cea_mode_for_vic(27)->vtotal != 312 || cea_mode_for_vic(28)->vtotal != 312 make[4]: *** [~/pie-x86_kernel/kernel/scripts/Makefile.build:265: drivers/gpu/drm/drm_edid.o] Error 1 Fixes: 7befe621ff81 ("drm/edid: Abstract away cea_edid_modes[]") Signed-off-by: Mauro Rossi Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200203213113.28183-1-issor.oruam@gmail.com --- drivers/gpu/drm/drm_edid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 99769d6c9f84..805fb004c8eb 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -3211,7 +3211,7 @@ static u8 *drm_find_cea_extension(const struct edid *edid) return cea; } -static const struct drm_display_mode *cea_mode_for_vic(u8 vic) +static __always_inline const struct drm_display_mode *cea_mode_for_vic(u8 vic) { BUILD_BUG_ON(1 + ARRAY_SIZE(edid_cea_modes_1) - 1 != 127); BUILD_BUG_ON(193 + ARRAY_SIZE(edid_cea_modes_193) - 1 != 219); -- cgit v1.2.3