The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 59df44bfb0ca4c3ee1f1c3c5d0ee8e314844799e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023100755-chevron-epilogue-4117@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

59df44bfb0ca ("iommu/vt-d: Avoid memory allocation in iommu_suspend()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 59df44bfb0ca4c3ee1f1c3c5d0ee8e314844799e Mon Sep 17 00:00:00 2001 From: Zhang Rui rui.zhang@intel.com Date: Mon, 25 Sep 2023 20:04:17 +0800 Subject: [PATCH] iommu/vt-d: Avoid memory allocation in iommu_suspend()

The iommu_suspend() syscore suspend callback is invoked with IRQ disabled. Allocating memory with the GFP_KERNEL flag may re-enable IRQs during the suspend callback, which can cause intermittent suspend/hibernation problems with the following kernel traces:

Calling iommu_suspend+0x0/0x1d0 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 15 at kernel/time/timekeeping.c:868 ktime_get+0x9b/0xb0 ... CPU: 0 PID: 15 Comm: rcu_preempt Tainted: G U E 6.3-intel #r1 RIP: 0010:ktime_get+0x9b/0xb0 ... Call Trace: <IRQ> tick_sched_timer+0x22/0x90 ? __pfx_tick_sched_timer+0x10/0x10 __hrtimer_run_queues+0x111/0x2b0 hrtimer_interrupt+0xfa/0x230 __sysvec_apic_timer_interrupt+0x63/0x140 sysvec_apic_timer_interrupt+0x7b/0xa0 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1f/0x30 ... ------------[ cut here ]------------ Interrupts enabled after iommu_suspend+0x0/0x1d0 WARNING: CPU: 0 PID: 27420 at drivers/base/syscore.c:68 syscore_suspend+0x147/0x270 CPU: 0 PID: 27420 Comm: rtcwake Tainted: G U W E 6.3-intel #r1 RIP: 0010:syscore_suspend+0x147/0x270 ... Call Trace: <TASK> hibernation_snapshot+0x25b/0x670 hibernate+0xcd/0x390 state_store+0xcf/0xe0 kobj_attr_store+0x13/0x30 sysfs_kf_write+0x3f/0x50 kernfs_fop_write_iter+0x128/0x200 vfs_write+0x1fd/0x3c0 ksys_write+0x6f/0xf0 __x64_sys_write+0x1d/0x30 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc

Given that only 4 words memory is needed, avoid the memory allocation in iommu_suspend().

CC: stable@kernel.org Fixes: 33e07157105e ("iommu/vt-d: Avoid GFP_ATOMIC where it is not needed") Signed-off-by: Zhang Rui rui.zhang@intel.com Tested-by: Ooi, Chin Hao chin.hao.ooi@intel.com Link: https://lore.kernel.org/r/20230921093956.234692-1-rui.zhang@intel.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20230925120417.55977-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 5db283c17e0d..3685ba90ec88 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2998,13 +2998,6 @@ static int iommu_suspend(void) struct intel_iommu *iommu = NULL; unsigned long flag;

- for_each_active_iommu(iommu, drhd) { - iommu->iommu_state = kcalloc(MAX_SR_DMAR_REGS, sizeof(u32), - GFP_KERNEL); - if (!iommu->iommu_state) - goto nomem; - } - iommu_flush_all();

for_each_active_iommu(iommu, drhd) { @@ -3024,12 +3017,6 @@ static int iommu_suspend(void) raw_spin_unlock_irqrestore(&iommu->register_lock, flag); } return 0; - -nomem: - for_each_active_iommu(iommu, drhd) - kfree(iommu->iommu_state); - - return -ENOMEM; }

static void iommu_resume(void) @@ -3061,9 +3048,6 @@ static void iommu_resume(void)

raw_spin_unlock_irqrestore(&iommu->register_lock, flag); } - - for_each_active_iommu(iommu, drhd) - kfree(iommu->iommu_state); }

static struct syscore_ops iommu_syscore_ops = { diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index c18fb699c87a..7dac94f62b4e 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -681,7 +681,7 @@ struct intel_iommu { struct iopf_queue *iopf_queue; unsigned char iopfq_name[16]; struct q_inval *qi; /* Queued invalidation info */ - u32 *iommu_state; /* Store iommu states between suspend and resume.*/ + u32 iommu_state[MAX_SR_DMAR_REGS]; /* Store iommu states between suspend and resume.*/

#ifdef CONFIG_IRQ_REMAP struct ir_table *ir_table; /* Interrupt remapping info */