Linaro-mm-sig

linaro-mm-sig@lists.linaro.org

14 participants
3243 discussions

Re: [PATCH v6 08/12] firmware: qcom: tzmem: export shm_bridge create/delete

by kernel test robot

Hi Amirreza, kernel test robot noticed the following build warnings: [auto build test WARNING on 835244aba90de290b4b0b1fa92b6734f3ee7b3d9] url: https://github.com/intel-lab-lkp/linux/commits/Amirreza-Zarrabi/tee-allow-a… base: 835244aba90de290b4b0b1fa92b6734f3ee7b3d9 patch link: https://lore.kernel.org/r/20250713-qcom-tee-using-tee-ss-without-mem-obj-v6… patch subject: [PATCH v6 08/12] firmware: qcom: tzmem: export shm_bridge create/delete config: arc-randconfig-001-20250714 (https://download.01.org/0day-ci/archive/20250714/202507141458.kBLqFFYk-lkp@…) compiler: arc-linux-gcc (GCC) 8.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250714/202507141458.kBLqFFYk-lkp@…) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp(a)intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202507141458.kBLqFFYk-lkp@intel.com/ All warnings (new ones prefixed by >>): In file included from include/linux/device.h:15, from include/linux/dma-mapping.h:5, from drivers/firmware/qcom/qcom_tzmem.c:10: drivers/firmware/qcom/qcom_tzmem.c: In function 'qcom_tzmem_shm_bridge_create': >> drivers/firmware/qcom/qcom_tzmem.c:139:27: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 4 has type 'phys_addr_t' {aka 'unsigned int'} [-Wformat=] dev_err(qcom_tzmem_dev, "SHM Bridge failed: ret %d paddr 0x%llx, size%zu\n", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/dev_printk.h:110:16: note: in definition of macro 'dev_printk_index_wrap' _p_func(dev, fmt, ##__VA_ARGS__); \ ^~~ include/linux/dev_printk.h:154:49: note: in expansion of macro 'dev_fmt' dev_printk_index_wrap(_dev_err, KERN_ERR, dev, dev_fmt(fmt), ##__VA_ARGS__) ^~~~~~~ drivers/firmware/qcom/qcom_tzmem.c:139:3: note: in expansion of macro 'dev_err' dev_err(qcom_tzmem_dev, "SHM Bridge failed: ret %d paddr 0x%llx, size%zu\n", ^~~~~~~ vim +139 drivers/firmware/qcom/qcom_tzmem.c 110 111 /** 112 * qcom_tzmem_shm_bridge_create() - Create a SHM bridge. 113 * @paddr: Physical address of the memory to share. 114 * @size: Size of the memory to share. 115 * @handle: Handle to the SHM bridge. 116 * 117 * On platforms that support SHM bridge, this function creates a SHM bridge 118 * for the given memory region with QTEE. The handle returned by this function 119 * must be passed to qcom_tzmem_shm_bridge_delete() to free the SHM bridge. 120 * 121 * Return: On success, returns 0; on failure, returns < 0. 122 */ 123 int qcom_tzmem_shm_bridge_create(phys_addr_t paddr, size_t size, u64 *handle) 124 { 125 u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags; 126 int ret; 127 128 if (!qcom_tzmem_using_shm_bridge) 129 return 0; 130 131 pfn_and_ns_perm = paddr | QCOM_SCM_PERM_RW; 132 ipfn_and_s_perm = paddr | QCOM_SCM_PERM_RW; 133 size_and_flags = size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT); 134 135 ret = qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm, 136 size_and_flags, QCOM_SCM_VMID_HLOS, 137 handle); 138 if (ret) { > 139 dev_err(qcom_tzmem_dev, "SHM Bridge failed: ret %d paddr 0x%llx, size%zu\n", 140 ret, paddr, size); 141 142 return ret; 143 } 144 145 return 0; 146 } 147 EXPORT_SYMBOL_GPL(qcom_tzmem_shm_bridge_create); 148 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki

5 months, 1 week

Re: [PATCH v2 2/3] dt-bindings: display: Add Mayqueen Pixpaper e-ink panel

by Krzysztof Kozlowski

On 14/07/2025 04:59, LiangCheng Wang wrote: > The binding is for the Mayqueen Pixpaper e-ink display panel, > controlled via an SPI interface. > > Signed-off-by: LiangCheng Wang <zaq14760(a)gmail.com> <form letter> This is a friendly reminder during the review process. It looks like you received a tag and forgot to add it. If you do not know the process, here is a short explanation: Please add Acked-by/Reviewed-by/Tested-by tags when posting new versions of patchset, under or above your Signed-off-by tag, unless patch changed significantly (e.g. new properties added to the DT bindings). Tag is "received", when provided in a message replied to you on the mailing list. Tools like b4 can help here. However, there's no need to repost patches *only* to add the tags. The upstream maintainer will do that for tags received on the version they apply. Please read: https://elixir.bootlin.com/linux/v6.12-rc3/source/Documentation/process/sub… If a tag was not added on purpose, please state why and what changed. </form letter> Best regards, Krzysztof

5 months, 1 week

Re: [PATCH v2 1/3] dt-bindings: vendor-prefixes: Add Mayqueen name

by Krzysztof Kozlowski

On 14/07/2025 04:59, LiangCheng Wang wrote: > From: Wig Cheng <onlywig(a)gmail.com> > > Mayqueen is a Taiwan-based company primarily focused on the development > of arm64 development boards and e-paper displays. > > Signed-off-by: Wig Cheng <onlywig(a)gmail.com> > --- <form letter> This is a friendly reminder during the review process. It looks like you received a tag and forgot to add it. If you do not know the process, here is a short explanation: Please add Acked-by/Reviewed-by/Tested-by tags when posting new versions of patchset, under or above your Signed-off-by tag, unless patch changed significantly (e.g. new properties added to the DT bindings). Tag is "received", when provided in a message replied to you on the mailing list. Tools like b4 can help here. However, there's no need to repost patches *only* to add the tags. The upstream maintainer will do that for tags received on the version they apply. Please read: https://elixir.bootlin.com/linux/v6.12-rc3/source/Documentation/process/sub… If a tag was not added on purpose, please state why and what changed. </form letter> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> Best regards, Krzysztof

5 months, 1 week

Re: [PATCH v2 0/3] Add support for Mayqueen Pixpaper e-ink panel

by Krzysztof Kozlowski

On 14/07/2025 04:59, LiangCheng Wang wrote: > --- > Changes in v2: > - Reordered patches so that DT bindings come before the driver (suggested by Rob Herring) > - Fixed sparse warning: removed duplicate `.reset` initializer in `pixpaper_plane_funcs` > - Fixed checkpatch issues reported by Media CI: > - Removed unnecessary blank line before closing brace > - Moved opening parentheses up to function call lines (e.g., `DRM_WARN(...)`) > - Fixed alignment of conditionals > - Fixed `dev_warn(` and `drm_universal_plane_init(` formatting > - Thanks to Rob Herring for ack on vendor-prefix patch And what did you do about it? Best regards, Krzysztof

5 months, 1 week

Patch "drm/framebuffer: Acquire internal references on GEM handles" has been added to the 6.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/framebuffer: Acquire internal references on GEM handles to the 6.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-framebuffer-acquire-internal-references-on-gem-handles.patch and it can be found in the queue-6.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From f6bfc9afc7510cb5e6fbe0a17c507917b0120280 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 7 Jul 2025 15:11:55 +0200 Subject: drm/framebuffer: Acquire internal references on GEM handles MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream. Acquire GEM handles in drm_framebuffer_init() and release them in the corresponding drm_framebuffer_cleanup(). Ties the handle's lifetime to the framebuffer. Not all GEM buffer objects have GEM handles. If not set, no refcounting takes place. This is the case for some fbdev emulation. This is not a problem as these GEM objects do not use dma-bufs and drivers will not release them while fbdev emulation is running. Framebuffer flags keep a bit per color plane of which the framebuffer holds a GEM handle reference. As all drivers use drm_framebuffer_init(), they will now all hold dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers"). In the GEM framebuffer helpers, restore the original ref counting on buffer objects. As the helpers for handle refcounting are now no longer called from outside the DRM core, unexport the symbols. v3: - don't mix internal flags with mode flags (Christian) v2: - track framebuffer handle refs by flag - drop gma500 cleanup (Christian) Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") Reported-by: Bert Karwatzki <spasswolf(a)web.de> Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/ Tested-by: Bert Karwatzki <spasswolf(a)web.de> Tested-by: Mario Limonciello <superm1(a)kernel.org> Tested-by: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_framebuffer.c | 31 ++++++++++++++++++++-- drivers/gpu/drm/drm_gem.c | 38 +++++++++++++++++---------- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 ++++------- drivers/gpu/drm/drm_internal.h | 2 - include/drm/drm_framebuffer.h | 7 ++++ 5 files changed, 68 insertions(+), 26 deletions(-) --- a/drivers/gpu/drm/drm_framebuffer.c +++ b/drivers/gpu/drm/drm_framebuffer.c @@ -862,11 +862,23 @@ EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_framebu int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, const struct drm_framebuffer_funcs *funcs) { + unsigned int i; int ret; + bool exists; if (WARN_ON_ONCE(fb->dev != dev || !fb->format)) return -EINVAL; + for (i = 0; i < fb->format->num_planes; i++) { + if (drm_WARN_ON_ONCE(dev, fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i))) + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + if (fb->obj[i]) { + exists = drm_gem_object_handle_get_if_exists_unlocked(fb->obj[i]); + if (exists) + fb->internal_flags |= DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } + INIT_LIST_HEAD(&fb->filp_head); fb->funcs = funcs; @@ -875,7 +887,7 @@ int drm_framebuffer_init(struct drm_devi ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB, false, drm_framebuffer_free); if (ret) - goto out; + goto err; mutex_lock(&dev->mode_config.fb_lock); dev->mode_config.num_fb++; @@ -883,7 +895,16 @@ int drm_framebuffer_init(struct drm_devi mutex_unlock(&dev->mode_config.fb_lock); drm_mode_object_register(dev, &fb->base); -out: + + return 0; + +err: + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) { + drm_gem_object_handle_put_unlocked(fb->obj[i]); + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } return ret; } EXPORT_SYMBOL(drm_framebuffer_init); @@ -960,6 +981,12 @@ EXPORT_SYMBOL(drm_framebuffer_unregister void drm_framebuffer_cleanup(struct drm_framebuffer *fb) { struct drm_device *dev = fb->dev; + unsigned int i; + + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) + drm_gem_object_handle_put_unlocked(fb->obj[i]); + } mutex_lock(&dev->mode_config.fb_lock); list_del(&fb->head); --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -223,23 +223,34 @@ static void drm_gem_object_handle_get(st } /** - * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * drm_gem_object_handle_get_if_exists_unlocked - acquire reference on user-space handle, if any * @obj: GEM object * - * Acquires a reference on the GEM buffer object's handle. Required - * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() - * to release the reference. + * Acquires a reference on the GEM buffer object's handle. Required to keep + * the GEM object alive. Call drm_gem_object_handle_put_if_exists_unlocked() + * to release the reference. Does nothing if the buffer object has no handle. + * + * Returns: + * True if a handle exists, or false otherwise */ -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; guard(mutex)(&dev->object_name_lock); - drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + /* + * First ref taken during GEM object creation, if any. Some + * drivers set up internal framebuffers with GEM objects that + * do not have a GEM handle. Hence, this counter can be zero. + */ + if (!obj->handle_count) + return false; + drm_gem_object_handle_get(obj); + + return true; } -EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); /** * drm_gem_object_handle_free - release resources bound to userspace handles @@ -272,7 +283,7 @@ static void drm_gem_object_exported_dma_ } /** - * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * drm_gem_object_handle_put_unlocked - releases reference on user-space handle * @obj: GEM object * * Releases a reference on the GEM buffer object's handle. Possibly releases @@ -283,14 +294,14 @@ void drm_gem_object_handle_put_unlocked( struct drm_device *dev = obj->dev; bool final = false; - if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) + if (drm_WARN_ON(dev, READ_ONCE(obj->handle_count) == 0)) return; /* - * Must bump handle count first as this may be the last - * ref, in which case the object would disappear before we - * checked for a name - */ + * Must bump handle count first as this may be the last + * ref, in which case the object would disappear before + * we checked for a name. + */ mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { @@ -303,7 +314,6 @@ void drm_gem_object_handle_put_unlocked( if (final) drm_gem_object_put(obj); } -EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_handle_put_unlocked(fb->obj[i]); + drm_gem_object_put(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,10 +182,8 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } - drm_gem_object_handle_get_unlocked(objs[i]); - drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -195,22 +193,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); ret = -EINVAL; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; return 0; -err_gem_object_handle_put_unlocked: +err_gem_object_put: while (i > 0) { --i; - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -161,7 +161,7 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj); void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, --- a/include/drm/drm_framebuffer.h +++ b/include/drm/drm_framebuffer.h @@ -23,6 +23,7 @@ #ifndef __DRM_FRAMEBUFFER_H__ #define __DRM_FRAMEBUFFER_H__ +#include <linux/bits.h> #include <linux/ctype.h> #include <linux/list.h> #include <linux/sched.h> @@ -100,6 +101,8 @@ struct drm_framebuffer_funcs { unsigned num_clips); }; +#define DRM_FRAMEBUFFER_HAS_HANDLE_REF(_i) BIT(0u + (_i)) + /** * struct drm_framebuffer - frame buffer object * @@ -189,6 +192,10 @@ struct drm_framebuffer { */ int flags; /** + * @internal_flags: Framebuffer flags like DRM_FRAMEBUFFER_HAS_HANDLE_REF. + */ + unsigned int internal_flags; + /** * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock. */ struct list_head filp_head; Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.15/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.15/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch queue-6.15/drm-framebuffer-acquire-internal-references-on-gem-handles.patch

5 months, 1 week

Patch "drm/framebuffer: Acquire internal references on GEM handles" has been added to the 6.12-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/framebuffer: Acquire internal references on GEM handles to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-framebuffer-acquire-internal-references-on-gem-handles.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From f6bfc9afc7510cb5e6fbe0a17c507917b0120280 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 7 Jul 2025 15:11:55 +0200 Subject: drm/framebuffer: Acquire internal references on GEM handles MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream. Acquire GEM handles in drm_framebuffer_init() and release them in the corresponding drm_framebuffer_cleanup(). Ties the handle's lifetime to the framebuffer. Not all GEM buffer objects have GEM handles. If not set, no refcounting takes place. This is the case for some fbdev emulation. This is not a problem as these GEM objects do not use dma-bufs and drivers will not release them while fbdev emulation is running. Framebuffer flags keep a bit per color plane of which the framebuffer holds a GEM handle reference. As all drivers use drm_framebuffer_init(), they will now all hold dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers"). In the GEM framebuffer helpers, restore the original ref counting on buffer objects. As the helpers for handle refcounting are now no longer called from outside the DRM core, unexport the symbols. v3: - don't mix internal flags with mode flags (Christian) v2: - track framebuffer handle refs by flag - drop gma500 cleanup (Christian) Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") Reported-by: Bert Karwatzki <spasswolf(a)web.de> Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/ Tested-by: Bert Karwatzki <spasswolf(a)web.de> Tested-by: Mario Limonciello <superm1(a)kernel.org> Tested-by: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_framebuffer.c | 31 ++++++++++++++++++++-- drivers/gpu/drm/drm_gem.c | 38 +++++++++++++++++---------- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 ++++------- drivers/gpu/drm/drm_internal.h | 2 - include/drm/drm_framebuffer.h | 7 ++++ 5 files changed, 68 insertions(+), 26 deletions(-) --- a/drivers/gpu/drm/drm_framebuffer.c +++ b/drivers/gpu/drm/drm_framebuffer.c @@ -860,11 +860,23 @@ void drm_framebuffer_free(struct kref *k int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, const struct drm_framebuffer_funcs *funcs) { + unsigned int i; int ret; + bool exists; if (WARN_ON_ONCE(fb->dev != dev || !fb->format)) return -EINVAL; + for (i = 0; i < fb->format->num_planes; i++) { + if (drm_WARN_ON_ONCE(dev, fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i))) + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + if (fb->obj[i]) { + exists = drm_gem_object_handle_get_if_exists_unlocked(fb->obj[i]); + if (exists) + fb->internal_flags |= DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } + INIT_LIST_HEAD(&fb->filp_head); fb->funcs = funcs; @@ -873,7 +885,7 @@ int drm_framebuffer_init(struct drm_devi ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB, false, drm_framebuffer_free); if (ret) - goto out; + goto err; mutex_lock(&dev->mode_config.fb_lock); dev->mode_config.num_fb++; @@ -881,7 +893,16 @@ int drm_framebuffer_init(struct drm_devi mutex_unlock(&dev->mode_config.fb_lock); drm_mode_object_register(dev, &fb->base); -out: + + return 0; + +err: + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) { + drm_gem_object_handle_put_unlocked(fb->obj[i]); + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } return ret; } EXPORT_SYMBOL(drm_framebuffer_init); @@ -958,6 +979,12 @@ EXPORT_SYMBOL(drm_framebuffer_unregister void drm_framebuffer_cleanup(struct drm_framebuffer *fb) { struct drm_device *dev = fb->dev; + unsigned int i; + + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) + drm_gem_object_handle_put_unlocked(fb->obj[i]); + } mutex_lock(&dev->mode_config.fb_lock); list_del(&fb->head); --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -197,23 +197,34 @@ static void drm_gem_object_handle_get(st } /** - * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * drm_gem_object_handle_get_if_exists_unlocked - acquire reference on user-space handle, if any * @obj: GEM object * - * Acquires a reference on the GEM buffer object's handle. Required - * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() - * to release the reference. + * Acquires a reference on the GEM buffer object's handle. Required to keep + * the GEM object alive. Call drm_gem_object_handle_put_if_exists_unlocked() + * to release the reference. Does nothing if the buffer object has no handle. + * + * Returns: + * True if a handle exists, or false otherwise */ -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; guard(mutex)(&dev->object_name_lock); - drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + /* + * First ref taken during GEM object creation, if any. Some + * drivers set up internal framebuffers with GEM objects that + * do not have a GEM handle. Hence, this counter can be zero. + */ + if (!obj->handle_count) + return false; + drm_gem_object_handle_get(obj); + + return true; } -EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); /** * drm_gem_object_handle_free - release resources bound to userspace handles @@ -246,7 +257,7 @@ static void drm_gem_object_exported_dma_ } /** - * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * drm_gem_object_handle_put_unlocked - releases reference on user-space handle * @obj: GEM object * * Releases a reference on the GEM buffer object's handle. Possibly releases @@ -257,14 +268,14 @@ void drm_gem_object_handle_put_unlocked( struct drm_device *dev = obj->dev; bool final = false; - if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) + if (drm_WARN_ON(dev, READ_ONCE(obj->handle_count) == 0)) return; /* - * Must bump handle count first as this may be the last - * ref, in which case the object would disappear before we - * checked for a name - */ + * Must bump handle count first as this may be the last + * ref, in which case the object would disappear before + * we checked for a name. + */ mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { @@ -277,7 +288,6 @@ void drm_gem_object_handle_put_unlocked( if (final) drm_gem_object_put(obj); } -EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_handle_put_unlocked(fb->obj[i]); + drm_gem_object_put(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,10 +182,8 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } - drm_gem_object_handle_get_unlocked(objs[i]); - drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -195,22 +193,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); ret = -EINVAL; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; return 0; -err_gem_object_handle_put_unlocked: +err_gem_object_put: while (i > 0) { --i; - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -153,7 +153,7 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj); void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, --- a/include/drm/drm_framebuffer.h +++ b/include/drm/drm_framebuffer.h @@ -23,6 +23,7 @@ #ifndef __DRM_FRAMEBUFFER_H__ #define __DRM_FRAMEBUFFER_H__ +#include <linux/bits.h> #include <linux/ctype.h> #include <linux/list.h> #include <linux/sched.h> @@ -100,6 +101,8 @@ struct drm_framebuffer_funcs { unsigned num_clips); }; +#define DRM_FRAMEBUFFER_HAS_HANDLE_REF(_i) BIT(0u + (_i)) + /** * struct drm_framebuffer - frame buffer object * @@ -189,6 +192,10 @@ struct drm_framebuffer { */ int flags; /** + * @internal_flags: Framebuffer flags like DRM_FRAMEBUFFER_HAS_HANDLE_REF. + */ + unsigned int internal_flags; + /** * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock. */ struct list_head filp_head; Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.12/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.12/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch queue-6.12/drm-framebuffer-acquire-internal-references-on-gem-handles.patch

5 months, 1 week

Patch "drm/framebuffer: Acquire internal references on GEM handles" has been added to the 6.6-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/framebuffer: Acquire internal references on GEM handles to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-framebuffer-acquire-internal-references-on-gem-handles.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From f6bfc9afc7510cb5e6fbe0a17c507917b0120280 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 7 Jul 2025 15:11:55 +0200 Subject: drm/framebuffer: Acquire internal references on GEM handles MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream. Acquire GEM handles in drm_framebuffer_init() and release them in the corresponding drm_framebuffer_cleanup(). Ties the handle's lifetime to the framebuffer. Not all GEM buffer objects have GEM handles. If not set, no refcounting takes place. This is the case for some fbdev emulation. This is not a problem as these GEM objects do not use dma-bufs and drivers will not release them while fbdev emulation is running. Framebuffer flags keep a bit per color plane of which the framebuffer holds a GEM handle reference. As all drivers use drm_framebuffer_init(), they will now all hold dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers"). In the GEM framebuffer helpers, restore the original ref counting on buffer objects. As the helpers for handle refcounting are now no longer called from outside the DRM core, unexport the symbols. v3: - don't mix internal flags with mode flags (Christian) v2: - track framebuffer handle refs by flag - drop gma500 cleanup (Christian) Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") Reported-by: Bert Karwatzki <spasswolf(a)web.de> Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/ Tested-by: Bert Karwatzki <spasswolf(a)web.de> Tested-by: Mario Limonciello <superm1(a)kernel.org> Tested-by: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_framebuffer.c | 31 ++++++++++++++++++++-- drivers/gpu/drm/drm_gem.c | 38 +++++++++++++++++---------- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 ++++------- drivers/gpu/drm/drm_internal.h | 2 - include/drm/drm_framebuffer.h | 7 ++++ 5 files changed, 68 insertions(+), 26 deletions(-) --- a/drivers/gpu/drm/drm_framebuffer.c +++ b/drivers/gpu/drm/drm_framebuffer.c @@ -844,11 +844,23 @@ void drm_framebuffer_free(struct kref *k int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb, const struct drm_framebuffer_funcs *funcs) { + unsigned int i; int ret; + bool exists; if (WARN_ON_ONCE(fb->dev != dev || !fb->format)) return -EINVAL; + for (i = 0; i < fb->format->num_planes; i++) { + if (drm_WARN_ON_ONCE(dev, fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i))) + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + if (fb->obj[i]) { + exists = drm_gem_object_handle_get_if_exists_unlocked(fb->obj[i]); + if (exists) + fb->internal_flags |= DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } + INIT_LIST_HEAD(&fb->filp_head); fb->funcs = funcs; @@ -857,7 +869,7 @@ int drm_framebuffer_init(struct drm_devi ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB, false, drm_framebuffer_free); if (ret) - goto out; + goto err; mutex_lock(&dev->mode_config.fb_lock); dev->mode_config.num_fb++; @@ -865,7 +877,16 @@ int drm_framebuffer_init(struct drm_devi mutex_unlock(&dev->mode_config.fb_lock); drm_mode_object_register(dev, &fb->base); -out: + + return 0; + +err: + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) { + drm_gem_object_handle_put_unlocked(fb->obj[i]); + fb->internal_flags &= ~DRM_FRAMEBUFFER_HAS_HANDLE_REF(i); + } + } return ret; } EXPORT_SYMBOL(drm_framebuffer_init); @@ -942,6 +963,12 @@ EXPORT_SYMBOL(drm_framebuffer_unregister void drm_framebuffer_cleanup(struct drm_framebuffer *fb) { struct drm_device *dev = fb->dev; + unsigned int i; + + for (i = 0; i < fb->format->num_planes; i++) { + if (fb->internal_flags & DRM_FRAMEBUFFER_HAS_HANDLE_REF(i)) + drm_gem_object_handle_put_unlocked(fb->obj[i]); + } mutex_lock(&dev->mode_config.fb_lock); list_del(&fb->head); --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -197,23 +197,34 @@ static void drm_gem_object_handle_get(st } /** - * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * drm_gem_object_handle_get_if_exists_unlocked - acquire reference on user-space handle, if any * @obj: GEM object * - * Acquires a reference on the GEM buffer object's handle. Required - * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() - * to release the reference. + * Acquires a reference on the GEM buffer object's handle. Required to keep + * the GEM object alive. Call drm_gem_object_handle_put_if_exists_unlocked() + * to release the reference. Does nothing if the buffer object has no handle. + * + * Returns: + * True if a handle exists, or false otherwise */ -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; guard(mutex)(&dev->object_name_lock); - drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + /* + * First ref taken during GEM object creation, if any. Some + * drivers set up internal framebuffers with GEM objects that + * do not have a GEM handle. Hence, this counter can be zero. + */ + if (!obj->handle_count) + return false; + drm_gem_object_handle_get(obj); + + return true; } -EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); /** * drm_gem_object_handle_free - release resources bound to userspace handles @@ -246,7 +257,7 @@ static void drm_gem_object_exported_dma_ } /** - * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * drm_gem_object_handle_put_unlocked - releases reference on user-space handle * @obj: GEM object * * Releases a reference on the GEM buffer object's handle. Possibly releases @@ -257,14 +268,14 @@ void drm_gem_object_handle_put_unlocked( struct drm_device *dev = obj->dev; bool final = false; - if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) + if (drm_WARN_ON(dev, READ_ONCE(obj->handle_count) == 0)) return; /* - * Must bump handle count first as this may be the last - * ref, in which case the object would disappear before we - * checked for a name - */ + * Must bump handle count first as this may be the last + * ref, in which case the object would disappear before + * we checked for a name. + */ mutex_lock(&dev->object_name_lock); if (--obj->handle_count == 0) { @@ -277,7 +288,6 @@ void drm_gem_object_handle_put_unlocked( if (final) drm_gem_object_put(obj); } -EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_handle_put_unlocked(fb->obj[i]); + drm_gem_object_put(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,10 +182,8 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } - drm_gem_object_handle_get_unlocked(objs[i]); - drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -195,22 +193,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); ret = -EINVAL; - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_handle_put_unlocked; + goto err_gem_object_put; return 0; -err_gem_object_handle_put_unlocked: +err_gem_object_put: while (i > 0) { --i; - drm_gem_object_handle_put_unlocked(objs[i]); + drm_gem_object_put(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -155,7 +155,7 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); -void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +bool drm_gem_object_handle_get_if_exists_unlocked(struct drm_gem_object *obj); void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, --- a/include/drm/drm_framebuffer.h +++ b/include/drm/drm_framebuffer.h @@ -23,6 +23,7 @@ #ifndef __DRM_FRAMEBUFFER_H__ #define __DRM_FRAMEBUFFER_H__ +#include <linux/bits.h> #include <linux/ctype.h> #include <linux/list.h> #include <linux/sched.h> @@ -100,6 +101,8 @@ struct drm_framebuffer_funcs { unsigned num_clips); }; +#define DRM_FRAMEBUFFER_HAS_HANDLE_REF(_i) BIT(0u + (_i)) + /** * struct drm_framebuffer - frame buffer object * @@ -189,6 +192,10 @@ struct drm_framebuffer { */ int flags; /** + * @internal_flags: Framebuffer flags like DRM_FRAMEBUFFER_HAS_HANDLE_REF. + */ + unsigned int internal_flags; + /** * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR * universal plane. Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.6/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.6/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch queue-6.6/drm-framebuffer-acquire-internal-references-on-gem-handles.patch

5 months, 1 week

Patch "drm/gem: Acquire references on GEM handles for framebuffers" has been added to the 6.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/gem: Acquire references on GEM handles for framebuffers to the 6.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch and it can be found in the queue-6.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 5307dce878d4126e1b375587318955bd019c3741 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 30 Jun 2025 10:36:47 +0200 Subject: drm/gem: Acquire references on GEM handles for framebuffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit 5307dce878d4126e1b375587318955bd019c3741 upstream. A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer. This leads to the release of the dma-buf backing the buffer object, if any. [1] Trying to use the framebuffer in further mode-setting operations leads to a segmentation fault. Most easily happens with driver that use shadow planes for vmap-ing the dma-buf during a page flip. An example is shown below. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] <TASK> [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object instance") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag Suggested-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/drm_gem.c#L241 # [1] Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250630084001.293053-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_gem.c | 44 ++++++++++++++++++++++++--- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 +++++---- drivers/gpu/drm/drm_internal.h | 2 + 3 files changed, 51 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -212,6 +212,35 @@ void drm_gem_private_object_fini(struct } EXPORT_SYMBOL(drm_gem_private_object_fini); +static void drm_gem_object_handle_get(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + drm_WARN_ON(dev, !mutex_is_locked(&dev->object_name_lock)); + + if (obj->handle_count++ == 0) + drm_gem_object_get(obj); +} + +/** + * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * @obj: GEM object + * + * Acquires a reference on the GEM buffer object's handle. Required + * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() + * to release the reference. + */ +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + guard(mutex)(&dev->object_name_lock); + + drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + drm_gem_object_handle_get(obj); +} +EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); + /** * drm_gem_object_handle_free - release resources bound to userspace handles * @obj: GEM object to clean up. @@ -242,8 +271,14 @@ static void drm_gem_object_exported_dma_ } } -static void -drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) +/** + * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * @obj: GEM object + * + * Releases a reference on the GEM buffer object's handle. Possibly releases + * the GEM buffer object and associated dma-buf objects. + */ +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; bool final = false; @@ -268,6 +303,7 @@ drm_gem_object_handle_put_unlocked(struc if (final) drm_gem_object_put(obj); } +EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's @@ -389,8 +425,8 @@ drm_gem_handle_create_tail(struct drm_fi int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); - if (obj->handle_count++ == 0) - drm_gem_object_get(obj); + + drm_gem_object_handle_get(obj); /* * Get the user-visible handle using idr. Preload and perform --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_put(fb->obj[i]); + drm_gem_object_handle_put_unlocked(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,8 +182,10 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } + drm_gem_object_handle_get_unlocked(objs[i]); + drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -193,22 +195,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); ret = -EINVAL; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; return 0; -err_gem_object_put: +err_gem_object_handle_put_unlocked: while (i > 0) { --i; - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -161,6 +161,8 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep); Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.15/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.15/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch

5 months, 1 week

Patch "drm/gem: Acquire references on GEM handles for framebuffers" has been added to the 6.12-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/gem: Acquire references on GEM handles for framebuffers to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 5307dce878d4126e1b375587318955bd019c3741 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 30 Jun 2025 10:36:47 +0200 Subject: drm/gem: Acquire references on GEM handles for framebuffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit 5307dce878d4126e1b375587318955bd019c3741 upstream. A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer. This leads to the release of the dma-buf backing the buffer object, if any. [1] Trying to use the framebuffer in further mode-setting operations leads to a segmentation fault. Most easily happens with driver that use shadow planes for vmap-ing the dma-buf during a page flip. An example is shown below. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] <TASK> [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object instance") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag Suggested-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/drm_gem.c#L241 # [1] Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250630084001.293053-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_gem.c | 44 ++++++++++++++++++++++++--- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 +++++---- drivers/gpu/drm/drm_internal.h | 2 + 3 files changed, 51 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -186,6 +186,35 @@ void drm_gem_private_object_fini(struct } EXPORT_SYMBOL(drm_gem_private_object_fini); +static void drm_gem_object_handle_get(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + drm_WARN_ON(dev, !mutex_is_locked(&dev->object_name_lock)); + + if (obj->handle_count++ == 0) + drm_gem_object_get(obj); +} + +/** + * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * @obj: GEM object + * + * Acquires a reference on the GEM buffer object's handle. Required + * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() + * to release the reference. + */ +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + guard(mutex)(&dev->object_name_lock); + + drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + drm_gem_object_handle_get(obj); +} +EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); + /** * drm_gem_object_handle_free - release resources bound to userspace handles * @obj: GEM object to clean up. @@ -216,8 +245,14 @@ static void drm_gem_object_exported_dma_ } } -static void -drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) +/** + * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * @obj: GEM object + * + * Releases a reference on the GEM buffer object's handle. Possibly releases + * the GEM buffer object and associated dma-buf objects. + */ +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; bool final = false; @@ -242,6 +277,7 @@ drm_gem_object_handle_put_unlocked(struc if (final) drm_gem_object_put(obj); } +EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's @@ -363,8 +399,8 @@ drm_gem_handle_create_tail(struct drm_fi int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); - if (obj->handle_count++ == 0) - drm_gem_object_get(obj); + + drm_gem_object_handle_get(obj); /* * Get the user-visible handle using idr. Preload and perform --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_put(fb->obj[i]); + drm_gem_object_handle_put_unlocked(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,8 +182,10 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } + drm_gem_object_handle_get_unlocked(objs[i]); + drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -193,22 +195,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); ret = -EINVAL; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; return 0; -err_gem_object_put: +err_gem_object_handle_put_unlocked: while (i > 0) { --i; - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -153,6 +153,8 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep); Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.12/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.12/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch

5 months, 1 week

Patch "drm/gem: Acquire references on GEM handles for framebuffers" has been added to the 6.6-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled drm/gem: Acquire references on GEM handles for framebuffers to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 5307dce878d4126e1b375587318955bd019c3741 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 30 Jun 2025 10:36:47 +0200 Subject: drm/gem: Acquire references on GEM handles for framebuffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann <tzimmermann(a)suse.de> commit 5307dce878d4126e1b375587318955bd019c3741 upstream. A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer. This leads to the release of the dma-buf backing the buffer object, if any. [1] Trying to use the framebuffer in further mode-setting operations leads to a segmentation fault. Most easily happens with driver that use shadow planes for vmap-ing the dma-buf during a page flip. An example is shown below. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] <TASK> [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object instance") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag Suggested-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/drm_gem.c#L241 # [1] Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Anusha Srivatsa <asrivats(a)redhat.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> Reviewed-by: Christian König <christian.koenig(a)amd.com> Link: https://lore.kernel.org/r/20250630084001.293053-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/gpu/drm/drm_gem.c | 44 ++++++++++++++++++++++++--- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 16 +++++---- drivers/gpu/drm/drm_internal.h | 2 + 3 files changed, 51 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -186,6 +186,35 @@ void drm_gem_private_object_fini(struct } EXPORT_SYMBOL(drm_gem_private_object_fini); +static void drm_gem_object_handle_get(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + drm_WARN_ON(dev, !mutex_is_locked(&dev->object_name_lock)); + + if (obj->handle_count++ == 0) + drm_gem_object_get(obj); +} + +/** + * drm_gem_object_handle_get_unlocked - acquire reference on user-space handles + * @obj: GEM object + * + * Acquires a reference on the GEM buffer object's handle. Required + * to keep the GEM object alive. Call drm_gem_object_handle_put_unlocked() + * to release the reference. + */ +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + + guard(mutex)(&dev->object_name_lock); + + drm_WARN_ON(dev, !obj->handle_count); /* first ref taken in create-tail helper */ + drm_gem_object_handle_get(obj); +} +EXPORT_SYMBOL(drm_gem_object_handle_get_unlocked); + /** * drm_gem_object_handle_free - release resources bound to userspace handles * @obj: GEM object to clean up. @@ -216,8 +245,14 @@ static void drm_gem_object_exported_dma_ } } -static void -drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) +/** + * drm_gem_object_handle_put_unlocked - releases reference on user-space handles + * @obj: GEM object + * + * Releases a reference on the GEM buffer object's handle. Possibly releases + * the GEM buffer object and associated dma-buf objects. + */ +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; bool final = false; @@ -242,6 +277,7 @@ drm_gem_object_handle_put_unlocked(struc if (final) drm_gem_object_put(obj); } +EXPORT_SYMBOL(drm_gem_object_handle_put_unlocked); /* * Called at device or object close to release the file's @@ -363,8 +399,8 @@ drm_gem_handle_create_tail(struct drm_fi int ret; WARN_ON(!mutex_is_locked(&dev->object_name_lock)); - if (obj->handle_count++ == 0) - drm_gem_object_get(obj); + + drm_gem_object_handle_get(obj); /* * Get the user-visible handle using idr. Preload and perform --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -99,7 +99,7 @@ void drm_gem_fb_destroy(struct drm_frame unsigned int i; for (i = 0; i < fb->format->num_planes; i++) - drm_gem_object_put(fb->obj[i]); + drm_gem_object_handle_put_unlocked(fb->obj[i]); drm_framebuffer_cleanup(fb); kfree(fb); @@ -182,8 +182,10 @@ int drm_gem_fb_init_with_funcs(struct dr if (!objs[i]) { drm_dbg_kms(dev, "Failed to lookup GEM object\n"); ret = -ENOENT; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } + drm_gem_object_handle_get_unlocked(objs[i]); + drm_gem_object_put(objs[i]); min_size = (height - 1) * mode_cmd->pitches[i] + drm_format_info_min_pitch(info, i, width) @@ -193,22 +195,22 @@ int drm_gem_fb_init_with_funcs(struct dr drm_dbg_kms(dev, "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", objs[i]->size, min_size, i); - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); ret = -EINVAL; - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; } } ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); if (ret) - goto err_gem_object_put; + goto err_gem_object_handle_put_unlocked; return 0; -err_gem_object_put: +err_gem_object_handle_put_unlocked: while (i > 0) { --i; - drm_gem_object_put(objs[i]); + drm_gem_object_handle_put_unlocked(objs[i]); } return ret; } --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -155,6 +155,8 @@ void drm_sysfs_lease_event(struct drm_de /* drm_gem.c */ int drm_gem_init(struct drm_device *dev); +void drm_gem_object_handle_get_unlocked(struct drm_gem_object *obj); +void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj); int drm_gem_handle_create_tail(struct drm_file *file_priv, struct drm_gem_object *obj, u32 *handlep); Patches currently in stable-queue which might be from tzimmermann(a)suse.de are queue-6.6/drm-gem-fix-race-in-drm_gem_handle_create_tail.patch queue-6.6/drm-gem-acquire-references-on-gem-handles-for-framebuffers.patch

5 months, 1 week

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

Linaro-mm-sig