Hi Sudeep,
On Tue, Apr 20, 2021 at 3:53 PM Sudeep Holla sudeep.holla@arm.com wrote:
Gentle Ping! There is boot failure because of this issue with linux-next on few arm platforms with non PCIe efifb. Please review and get the fix merged ASAP so the testing on these platforms can continue with linux-next.
It was merged in drm-tip as d510c88cfbb2 ("efifb: Check efifb_pci_dev before using it").
Kai-Heng
On Thu, Apr 15, 2021 at 11:22:24AM +0100, Sudeep Holla wrote:
Commit a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") added runtime pm calls to probe and remove routines to ensure the PCI device for efifb stays in D0 state. However not ever efifb is based on PCI device and efifb_pci_dev can be NULL if that is the case.
In such cases, we will get a boot splat like below due to NULL dereference: -->8 Console: switching to colour frame buffer device 240x67 fb0: EFI VGA frame buffer device Unable to handle kernel NULL pointer dereference at virtual address 0000000000000270 Mem abort info: ESR = 0x96000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [0000000000000270] user address but active_mm is swapper Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc7-next-20210413 #1 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) pc : pm_runtime_drop_link+0x12c/0x338 lr : efifb_probe+0x7bc/0x7f0 Call trace: pm_runtime_drop_link+0x12c/0x338 efifb_probe+0x7bc/0x7f0 platform_probe+0x68/0xd8 really_probe+0xe4/0x3a8 driver_probe_device+0x64/0xc8 device_driver_attach+0x74/0x80 __driver_attach+0x64/0xf0 bus_for_each_dev+0x70/0xc0 driver_attach+0x24/0x30 bus_add_driver+0x150/0x1f8 driver_register+0x64/0x120 __platform_driver_register+0x28/0x38 efifb_driver_init+0x1c/0x28 do_one_initcall+0x48/0x2b0 kernel_init_freeable+0x1e8/0x258 kernel_init+0x14/0x118 ret_from_fork+0x10/0x30 Code: 88027c01 35ffffa2 17fff706 f9800051 (885f7c40) ---[ end trace 17d8da630bf8ff77 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b -->8
Fix the issue by checking for non-NULL efifb_pci_dev before dereferencing for runtime pm calls in probe and remove routines.
Fixes: a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") Cc: Kai-Heng Feng kai.heng.feng@canonical.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Peter Jones pjones@redhat.com Signed-off-by: Sudeep Holla sudeep.holla@arm.com
drivers/video/fbdev/efifb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c index f58a545b3bf3..8ea8f079cde2 100644 --- a/drivers/video/fbdev/efifb.c +++ b/drivers/video/fbdev/efifb.c @@ -575,7 +575,8 @@ static int efifb_probe(struct platform_device *dev) goto err_fb_dealoc; } fb_info(info, "%s frame buffer device\n", info->fix.id);
pm_runtime_get_sync(&efifb_pci_dev->dev);
if (efifb_pci_dev)pm_runtime_get_sync(&efifb_pci_dev->dev); return 0;err_fb_dealoc: @@ -602,7 +603,8 @@ static int efifb_remove(struct platform_device *pdev) unregister_framebuffer(info); sysfs_remove_groups(&pdev->dev.kobj, efifb_groups); framebuffer_release(info);
pm_runtime_put(&efifb_pci_dev->dev);
if (efifb_pci_dev)pm_runtime_put(&efifb_pci_dev->dev); return 0;}
2.25.1
-- Regards, Sudeep