From e23d6ba5029bc555974ee2461130a1b67c5224a7 Mon Sep 17 00:00:00 2001 From: Rex Zhang Date: Tue, 12 Dec 2023 10:21:58 +0800 Subject: [PATCH] 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: 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 Reviewed-by: Dave Jiang Reviewed-by: Fenghua Yu Link: https://lore.kernel.org/r/20231212022158.358619-2-rex.zhang@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/idxd/device.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c index 8f754f9..fa0f880 100644 --- a/drivers/dma/idxd/device.c +++ b/drivers/dma/idxd/device.c @@ -802,6 +802,9 @@ err_bmap: 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) -- 2.7.4