> Subject: [RFC PATCH] drm/i915: i915 null pointer dereference You can remove the RFC patch this patch LGTM from a solution standpoint. You need to modify the subject to drm/i915/gt : Check set_default_submission() before deferencing it. Ill be resending this patch to get results from LGCI. After which this can be merged.
Otherwise this LGTM, Reviewed-by: Suraj Kandpal <[email protected]> > > When the i915 driver firmware binaries are not present, the > set_default_submission pointer is not set. This pointer is dereferenced during > suspend anyways. > > Add a check to make sure it is set before dereferencing. > > # echo +20 > /sys/class/rtc/rtc0/wakealarm && echo mem > > /sys/power/state > [ 23.289926] PM: suspend entry (deep) > [ 23.293558] Filesystems sync: 0.000 seconds > [ 23.298010] Freezing user space processes > [ 23.302771] Freezing user space processes completed (elapsed 0.000 > seconds) > [ 23.309766] OOM killer disabled. > [ 23.313027] Freezing remaining freezable tasks > [ 23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 > seconds) > [ 23.342038] serial 00:05: disabled > [ 23.345719] serial 00:02: disabled > [ 23.349342] serial 00:01: disabled > [ 23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache > [ 23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache > [ 23.361635] ata1.00: Entering standby power mode > [ 23.368863] ata2.00: Entering standby power mode > [ 23.445187] BUG: kernel NULL pointer dereference, address: > 0000000000000000 > [ 23.452194] #PF: supervisor instruction fetch in kernel mode > [ 23.457896] #PF: error_code(0x0010) - not-present page > [ 23.463065] PGD 0 P4D 0 > [ 23.465640] Oops: Oops: 0010 [#1] SMP NOPTI > [ 23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S > W 6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary) > [ 23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN > [ 23.496511] Workqueue: async async_run_entry_fn > [ 23.501087] RIP: 0010:0x0 > [ 23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6. > [ 23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246 > [ 23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: > 000000000000000f > [ 23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: > ffff9f428290e000 > [ 23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: > 00000000ffffffff > [ 23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: > ffff9f42829070f8 > [ 23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: > ffff9f4282906b68 > [ 23.551457] FS: 0000000000000000(0000) GS:ffff9f466b2cf000(0000) > knlGS:0000000000000000 > [ 23.559588] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: > 0000000000f70ef0 > [ 23.572539] PKRU: 55555554 > [ 23.575281] Call Trace: > [ 23.577770] <TASK> > [ 23.579905] intel_engines_reset_default_submission+0x42/0x60 > [ 23.585695] __intel_gt_unset_wedged+0x191/0x200 > [ 23.590360] intel_gt_unset_wedged+0x20/0x40 > [ 23.594675] gt_sanitize+0x15e/0x170 > [ 23.598290] i915_gem_suspend_late+0x6b/0x180 > [ 23.602692] i915_drm_suspend_late+0x35/0xf0 > [ 23.607008] ? __pfx_pci_pm_suspend_late+0x10/0x10 > [ 23.611843] dpm_run_callback+0x78/0x1c0 > [ 23.615817] device_suspend_late+0xde/0x2e0 > [ 23.620037] async_suspend_late+0x18/0x30 > [ 23.624082] async_run_entry_fn+0x25/0xa0 > [ 23.628129] process_one_work+0x15b/0x380 > [ 23.632182] worker_thread+0x2a5/0x3c0 > [ 23.635973] ? __pfx_worker_thread+0x10/0x10 > [ 23.640279] kthread+0xf6/0x1f0 > [ 23.643464] ? __pfx_kthread+0x10/0x10 > [ 23.647263] ? __pfx_kthread+0x10/0x10 > [ 23.651045] ret_from_fork+0x131/0x190 > [ 23.654837] ? __pfx_kthread+0x10/0x10 > [ 23.658634] ret_from_fork_asm+0x1a/0x30 > [ 23.662597] </TASK> > [ 23.664826] Modules linked in: > [ 23.667914] CR2: 0000000000000000 > [ 23.671271] ------------[ cut here ]------------ > > Signed-off-by: Rahul Bukte <[email protected]> > --- > drivers/gpu/drm/i915/gt/intel_engine_cs.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > index b721bbd23356..ce8cdd517daa 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > @@ -1969,7 +1969,8 @@ void > intel_engines_reset_default_submission(struct intel_gt *gt) > if (engine->sanitize) > engine->sanitize(engine); > > - engine->set_default_submission(engine); > + if (engine->set_default_submission) > + engine->set_default_submission(engine); > } > } > > -- > 2.43.0
