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

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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>
This commit is contained in:
Zhang Rui 2023-09-25 20:04:17 +08:00 committed by Joerg Roedel
parent c7bd8a1f45
commit 59df44bfb0
2 changed files with 1 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/iommu/intel/iommu.c
View File

@ -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 = {

2
drivers/iommu/intel/iommu.h
View File

@ -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 */