Lyude Paul
2022-May-05 19:57 UTC
[Nouveau] [PATCH] drm/nouveau: reorder nouveau_drm_device_fini
Hmm, I think we might just need to move the drm_kms_helper_poll_enable() call to the end here instead of all of nouveau_display_init(). I realized this because in nouveau_display_init() it seems that we actually rely on nouveau_display_init() to setup hotplug interrupts - which we do actually need this early on in the driver probe process. That being said though, drm_kms_helper_poll_enable() shouldn't be required for MST short HPD IRQs from working so moving that instead should work. On Wed, 2022-05-04 at 19:18 +0200, Mark Menzynski wrote:> Resources needed for output poll workers are destroyed in > nouveau_fbcon_fini() before output poll workers are cleared in > nouveau_display_fini(). This means there is a time between fbcon_fini > and display_fini, where if output poll happens, it crashes. > > BUG: KASAN: use-after-free in > __drm_fb_helper_initial_config_and_unlock.cold+0x1f3/0x291 > [drm_kms_helper] > > Cc: Ben Skeggs <bskeggs at redhat.com> > Cc: Karol Herbst <kherbst at redhat.com> > Cc: Lyude Paul <lyude at redhat.com> > Cc: David Airlie <airlied at linux.ie> > Cc: Daniel Vetter <daniel at ffwll.ch> > Cc: Sumit Semwal <sumit.semwal at linaro.org> > Cc: "Christian K?nig" <christian.koenig at amd.com> > Cc: dri-devel at lists.freedesktop.org > Cc: nouveau at lists.freedesktop.org > Cc: linux-kernel at vger.kernel.org > Cc: linux-media at vger.kernel.org > Cc: linaro-mm-sig at lists.linaro.org > Signed-off-by: Mark Menzynski <mmenzyns at redhat.com> > --- > ?drivers/gpu/drm/nouveau/nouveau_drm.c | 17 ++++++++--------- > ?1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c > b/drivers/gpu/drm/nouveau/nouveau_drm.c > index 561309d447e0..773efdd20d2f 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_drm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c > @@ -588,12 +588,6 @@ nouveau_drm_device_init(struct drm_device *dev) > ????????if (ret) > ????????????????goto fail_dispctor; > ? > -???????if (dev->mode_config.num_crtc) { > -???????????????ret = nouveau_display_init(dev, false, false); > -???????????????if (ret) > -???????????????????????goto fail_dispinit; > -???????} > - > ????????nouveau_debugfs_init(drm); > ????????nouveau_hwmon_init(dev); > ????????nouveau_svm_init(drm); > @@ -601,6 +595,12 @@ nouveau_drm_device_init(struct drm_device *dev) > ????????nouveau_fbcon_init(dev); > ????????nouveau_led_init(dev); > ? > +???????if (dev->mode_config.num_crtc) { > +???????????????ret = nouveau_display_init(dev, false, false); > +???????????????if (ret) > +???????????????????????goto fail_dispinit; > +???????} > + > ????????if (nouveau_pmops_runtime()) { > ????????????????pm_runtime_use_autosuspend(dev->dev); > ????????????????pm_runtime_set_autosuspend_delay(dev->dev, 5000); > @@ -641,15 +641,14 @@ nouveau_drm_device_fini(struct drm_device *dev) > ????????????????pm_runtime_forbid(dev->dev); > ????????} > ? > +???????if (dev->mode_config.num_crtc) > +???????????????nouveau_display_fini(dev, false, false); > ????????nouveau_led_fini(dev); > ????????nouveau_fbcon_fini(dev); > ????????nouveau_dmem_fini(drm); > ????????nouveau_svm_fini(drm); > ????????nouveau_hwmon_fini(dev); > ????????nouveau_debugfs_fini(drm); > - > -???????if (dev->mode_config.num_crtc) > -???????????????nouveau_display_fini(dev, false, false); > ????????nouveau_display_destroy(dev); > ? > ????????nouveau_accel_fini(drm);-- Cheers, Lyude Paul (she/her) Software Engineer at Red Hat
Mark Menzynski
2022-May-09 13:13 UTC
[Nouveau] [PATCH] drm/nouveau: reorder nouveau_drm_device_fini
I think there are no direct issues with initialization in the state how it is now. I suspect it's because "drm_kms_helper_poll_enable()" starts the first worker thread with a delay, which gives enough time to initialize required resources. I changed the initialization part to keep it consistent with the finish part, which is the one causing troubles. I am not sure where I could move "drm_kms_helper_poll_enable/disable()", since it is defined in "drm/drm_probe_helper.c", which is only included in "nouveau_display.c" and "nouveau_connector.c". Both creating a new function in "nouveau_display.c", and including "probe_helper.h" and using poll_enable in a different file like "nouveau_fbcon.c" seem like too big changes for such small fix. I don't know. Can this new proposed order break something in the finish part as well? Maybe it would be just better to change the order of "nouveau_drm_finish" and keep the current order of "noueau_drm_init"? On Thu, May 5, 2022 at 9:57 PM Lyude Paul <lyude at redhat.com> wrote:> Hmm, I think we might just need to move the drm_kms_helper_poll_enable() > call > to the end here instead of all of nouveau_display_init(). I realized this > because in nouveau_display_init() it seems that we actually rely on > nouveau_display_init() to setup hotplug interrupts - which we do actually > need > this early on in the driver probe process. > > That being said though, drm_kms_helper_poll_enable() shouldn't be required > for > MST short HPD IRQs from working so moving that instead should work. > > On Wed, 2022-05-04 at 19:18 +0200, Mark Menzynski wrote: > > Resources needed for output poll workers are destroyed in > > nouveau_fbcon_fini() before output poll workers are cleared in > > nouveau_display_fini(). This means there is a time between fbcon_fini > > and display_fini, where if output poll happens, it crashes. > > > > BUG: KASAN: use-after-free in > > __drm_fb_helper_initial_config_and_unlock.cold+0x1f3/0x291 > > [drm_kms_helper] > > > > Cc: Ben Skeggs <bskeggs at redhat.com> > > Cc: Karol Herbst <kherbst at redhat.com> > > Cc: Lyude Paul <lyude at redhat.com> > > Cc: David Airlie <airlied at linux.ie> > > Cc: Daniel Vetter <daniel at ffwll.ch> > > Cc: Sumit Semwal <sumit.semwal at linaro.org> > > Cc: "Christian K?nig" <christian.koenig at amd.com> > > Cc: dri-devel at lists.freedesktop.org > > Cc: nouveau at lists.freedesktop.org > > Cc: linux-kernel at vger.kernel.org > > Cc: linux-media at vger.kernel.org > > Cc: linaro-mm-sig at lists.linaro.org > > Signed-off-by: Mark Menzynski <mmenzyns at redhat.com> > > --- > > drivers/gpu/drm/nouveau/nouveau_drm.c | 17 ++++++++--------- > > 1 file changed, 8 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c > > b/drivers/gpu/drm/nouveau/nouveau_drm.c > > index 561309d447e0..773efdd20d2f 100644 > > --- a/drivers/gpu/drm/nouveau/nouveau_drm.c > > +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c > > @@ -588,12 +588,6 @@ nouveau_drm_device_init(struct drm_device *dev) > > if (ret) > > goto fail_dispctor; > > > > - if (dev->mode_config.num_crtc) { > > - ret = nouveau_display_init(dev, false, false); > > - if (ret) > > - goto fail_dispinit; > > - } > > - > > nouveau_debugfs_init(drm); > > nouveau_hwmon_init(dev); > > nouveau_svm_init(drm); > > @@ -601,6 +595,12 @@ nouveau_drm_device_init(struct drm_device *dev) > > nouveau_fbcon_init(dev); > > nouveau_led_init(dev); > > > > + if (dev->mode_config.num_crtc) { > > + ret = nouveau_display_init(dev, false, false); > > + if (ret) > > + goto fail_dispinit; > > + } > > + > > if (nouveau_pmops_runtime()) { > > pm_runtime_use_autosuspend(dev->dev); > > pm_runtime_set_autosuspend_delay(dev->dev, 5000); > > @@ -641,15 +641,14 @@ nouveau_drm_device_fini(struct drm_device *dev) > > pm_runtime_forbid(dev->dev); > > } > > > > + if (dev->mode_config.num_crtc) > > + nouveau_display_fini(dev, false, false); > > nouveau_led_fini(dev); > > nouveau_fbcon_fini(dev); > > nouveau_dmem_fini(drm); > > nouveau_svm_fini(drm); > > nouveau_hwmon_fini(dev); > > nouveau_debugfs_fini(drm); > > - > > - if (dev->mode_config.num_crtc) > > - nouveau_display_fini(dev, false, false); > > nouveau_display_destroy(dev); > > > > nouveau_accel_fini(drm); > > -- > Cheers, > Lyude Paul (she/her) > Software Engineer at Red Hat > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/nouveau/attachments/20220509/26971169/attachment.htm>