This is a note to let you know that I've just added the patch titled
dmaengine: idxd: Move dma_free_coherent() out of spinlocked context
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-idxd-move-dma_free_coherent-out-of-spinloc.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 936bcdb644a572504a83e703d28db08feccdd72b
Author: Rex Zhang <rex.zhang@xxxxxxxxx>
Date: Tue Dec 12 10:21:58 2023 +0800
dmaengine: idxd: Move dma_free_coherent() out of spinlocked context
[ Upstream commit e271c0ba3f919c48e90c64b703538fbb7865cb63 ]
Task may be rescheduled within dma_free_coherent(). So dma_free_coherent()
can't be called between spin_lock() and spin_unlock() to avoid Call Trace:
Call Trace:
<TASK>
dump_stack_lvl+0x37/0x50
__might_resched+0x16a/0x1c0
vunmap+0x2c/0x70
__iommu_dma_free+0x96/0x100
idxd_device_evl_free+0xd5/0x100 [idxd]
device_release_driver_internal+0x197/0x200
unbind_store+0xa1/0xb0
kernfs_fop_write_iter+0x120/0x1c0
vfs_write+0x2d3/0x400
ksys_write+0x63/0xe0
do_syscall_64+0x44/0xa0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Move it out of the context.
Fixes: 244da66cda35 ("dmaengine: idxd: setup event log configuration")
Signed-off-by: Rex Zhang <rex.zhang@xxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Link: https://lore.kernel.org/r/20231212022158.358619-2-rex.zhang@xxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 8f754f922217..fa0f880beae6 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -802,6 +802,9 @@ static int idxd_device_evl_setup(struct idxd_device *idxd)
static void idxd_device_evl_free(struct idxd_device *idxd)
{
+ void *evl_log;
+ unsigned int evl_log_size;
+ dma_addr_t evl_dma;
union gencfg_reg gencfg;
union genctrl_reg genctrl;
struct device *dev = &idxd->pdev->dev;
@@ -822,11 +825,15 @@ static void idxd_device_evl_free(struct idxd_device *idxd)
iowrite64(0, idxd->reg_base + IDXD_EVLCFG_OFFSET);
iowrite64(0, idxd->reg_base + IDXD_EVLCFG_OFFSET + 8);
- dma_free_coherent(dev, evl->log_size, evl->log, evl->dma);
bitmap_free(evl->bmap);
+ evl_log = evl->log;
+ evl_log_size = evl->log_size;
+ evl_dma = evl->dma;
evl->log = NULL;
evl->size = IDXD_EVL_SIZE_MIN;
spin_unlock(&evl->lock);
+
+ dma_free_coherent(dev, evl_log_size, evl_log, evl_dma);
}
static void idxd_group_config_write(struct idxd_group *group)
