| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <19bde085588.1b451560725069.154128025837198067@linux.beauty>
Date: Wed, 21 Jan 2026 08:50:46 +0800
From: Li Chen <me@...ux.beauty>
To: "Dave Airlie" <airlied@...il.com>
Cc: "Lyude Paul" <lyude@...hat.com>, "Danilo Krummrich" <dakr@...nel.org>,
"Maarten Lankhorst" <maarten.lankhorst@...ux.intel.com>,
"Maxime Ripard" <mripard@...nel.org>,
"Thomas Zimmermann" <tzimmermann@...e.de>,
"Simona Vetter" <simona@...ll.ch>,
"dri-devel" <dri-devel@...ts.freedesktop.org>,
"nouveau" <nouveau@...ts.freedesktop.org>,
"linux-kernel" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] nouveau: pci: quiesce GPU on shutdown
Hi Dave,
> On Tue, 20 Jan 2026 at 22:15, Li Chen <me@...ux.beauty> wrote:
> >
> > Kexec reboot does not reset PCI devices.
> > Invoking the full DRM/TTM teardown from ->shutdown can trigger WARNs when
> > userspace still holds DRM file descriptors.
> >
> > Quiesce the GPU through the suspend path and then power down the PCI
> > function so the next kernel can re-initialize the device from a consistent
> > state.
> >
> > WARNING: drivers/gpu/drm/drm_mode_config.c:578 at drm_mode_config_cleanup+0x2e7/0x300, CPU#2: kexec/1300
> > Call Trace:
> > <TASK>
> > ? srso_return_thunk+0x5/0x5f
> > ? enable_work+0x3a/0x100
> > nouveau_display_destroy+0x39/0x70 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > nouveau_drm_device_fini+0x7b/0x1f0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > nouveau_drm_shutdown+0x52/0xc0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > pci_device_shutdown+0x35/0x60
> > device_shutdown+0x11c/0x1b0
> > kernel_kexec+0x13a/0x160
> > __do_sys_reboot+0x209/0x240
> > do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? __rtnl_unlock+0x37/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? netdev_run_todo+0x63/0x570
> > ? netif_change_flags+0x54/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? devinet_ioctl+0x1e5/0x790
> > ? srso_return_thunk+0x5/0x5f
> > ? inet_ioctl+0x1e9/0x200
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x7d/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x23b/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? put_user_ifreq+0x7a/0x90
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x107/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? exc_page_fault+0x7e/0x1a0
> > entry_SYSCALL_64_after_hwframe+0x76/0x7e
> >
> > nouveau 0000:26:00.0: [drm] drm_WARN_ON(!list_empty(&fb->filp_head))
> > WARNING: drivers/gpu/drm/drm_framebuffer.c:833 at drm_framebuffer_free+0x73/0xa0, CPU#2: kexec/1300
> > Call Trace:
> > <TASK>
> > drm_mode_config_cleanup+0x248/0x300
> > ? __pfx___drm_printfn_dbg+0x10/0x10
> > ? drm_mode_config_cleanup+0x1dc/0x300
> > nouveau_display_destroy+0x39/0x70 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > nouveau_drm_device_fini+0x7b/0x1f0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > nouveau_drm_shutdown+0x52/0xc0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > pci_device_shutdown+0x35/0x60
> > device_shutdown+0x11c/0x1b0
> > kernel_kexec+0x13a/0x160
> > __do_sys_reboot+0x209/0x240
> > do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? __rtnl_unlock+0x37/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? netdev_run_todo+0x63/0x570
> > ? netif_change_flags+0x54/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? devinet_ioctl+0x1e5/0x790
> > ? srso_return_thunk+0x5/0x5f
> > ? inet_ioctl+0x1e9/0x200
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x7d/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x23b/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? put_user_ifreq+0x7a/0x90
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x107/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? exc_page_fault+0x7e/0x1a0
> > entry_SYSCALL_64_after_hwframe+0x76/0x7e
> >
> > WARNING: include/drm/ttm/ttm_resource.h:406 at nouveau_ttm_fini+0x257/0x270 [nouveau], CPU#2: kexec/1300
> > Call Trace:
> > <TASK>
> > nouveau_drm_device_fini+0x93/0x1f0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > nouveau_drm_shutdown+0x52/0xc0 [nouveau c19e0da7fd83583a023f855c510d9a3903808734]
> > pci_device_shutdown+0x35/0x60
> > device_shutdown+0x11c/0x1b0
> > kernel_kexec+0x13a/0x160
> > __do_sys_reboot+0x209/0x240
> > do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? __rtnl_unlock+0x37/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? netdev_run_todo+0x63/0x570
> > ? netif_change_flags+0x54/0x70
> > ? srso_return_thunk+0x5/0x5f
> > ? devinet_ioctl+0x1e5/0x790
> > ? srso_return_thunk+0x5/0x5f
> > ? inet_ioctl+0x1e9/0x200
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x7d/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x23b/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? put_user_ifreq+0x7a/0x90
> > ? srso_return_thunk+0x5/0x5f
> > ? sock_do_ioctl+0x107/0x130
> > ? srso_return_thunk+0x5/0x5f
> > ? __x64_sys_ioctl+0x97/0xe0
> > ? srso_return_thunk+0x5/0x5f
> > ? do_syscall_64+0x81/0x610
> > ? srso_return_thunk+0x5/0x5f
> > ? exc_page_fault+0x7e/0x1a0
> > entry_SYSCALL_64_after_hwframe+0x76/0x7e
> >
> > Signed-off-by: Li Chen <me@...ux.beauty>
> > ---
> > drivers/gpu/drm/nouveau/nouveau_drm.c | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> > index 1527b801f013..50384462723b 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> > @@ -1079,6 +1079,29 @@ nouveau_pmops_resume(struct device *dev)
> > return ret;
> > }
> >
> > +static void
> > +nouveau_drm_shutdown(struct pci_dev *pdev)
> > +{
> > + struct nouveau_drm *drm = pci_get_drvdata(pdev);
> > + int ret;
> > +
> > + if (!drm)
> > + return;
> > +
> > + if (drm->dev->switch_power_state == DRM_SWITCH_POWER_OFF ||
> > + drm->dev->switch_power_state == DRM_SWITCH_POWER_DYNAMIC_OFF)
> > + return;
> > +
> > + ret = nouveau_do_suspend(drm, false);
> > + if (ret)
> > + NV_ERROR(drm, "shutdown suspend failed with: %d\n", ret);
> > +
> > + pci_save_state(pdev);
> > + pci_disable_device(pdev);
> > + pci_set_power_state(pdev, PCI_D3hot);
> > + usleep_range(200, 400);\
>
> Why is this needed? it at least needs a comment.
This patch is needed for kexec/KHO/LUO reboot: firmware reset is skipped, so the GPU may remain in an active/DMA
state and the next kernel can fail to re-init nouveau. We can’t call the full DRM/TTM teardown from ->shutdown() because
userspace may still hold DRM fds during shutdown, which triggers WARNs.
So the shutdown hook reuses the suspend/quiesce path (safe with open fds) and then powers down the PCI function (D3hot)
to leave the device in a consistent state for the next kernel.
Regards,
Li
Powered by blists - more mailing lists