From: Yi Sun <yi.sun@intel.com>
To: vinicius.gomes@intel.com, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: yi.sun@intel.com, gordon.jin@intel.com
Subject: [PATCH v2 2/2] dmaengine: idxd: Fix refcount underflow on module unload
Date: Sat, 7 Jun 2025 21:06:16 +0800 [thread overview]
Message-ID: <20250607130616.514984-3-yi.sun@intel.com> (raw)
In-Reply-To: <20250607130616.514984-1-yi.sun@intel.com>
A recent refactor introduced a misplaced put_device() call, leading to a
reference count underflow during module unload.
There is no need to add additional put_device() calls for idxd groups,
engines, or workqueues. Although commit a409e919ca3 claims:"Note, this
also fixes the missing put_device() for idxd groups, engines, and wqs."
It appears no such omission existed. The required cleanup is already
handled by the call chain:
idxd_unregister_devices() -> device_unregister() -> put_device()
Extend idxd_cleanup() to perform the necessary cleanup, and remove
idxd_cleanup_internals() which was not originally part of the driver
unload path and introduced unintended reference count underflow.
Fixes: a409e919ca32 ("dmaengine: idxd: Refactor remove call with idxd_cleanup() helper")
Signed-off-by: Yi Sun <yi.sun@intel.com>
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 504aca0fd597..a5eabeb6a8bd 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -1321,7 +1321,12 @@ static void idxd_remove(struct pci_dev *pdev)
device_unregister(idxd_confdev(idxd));
idxd_shutdown(pdev);
idxd_device_remove_debugfs(idxd);
- idxd_cleanup(idxd);
+ perfmon_pmu_remove(idxd);
+ idxd_cleanup_interrupts(idxd);
+ if (device_pasid_enabled(idxd))
+ idxd_disable_system_pasid(idxd);
+ if (device_user_pasid_enabled(idxd))
+ idxd_disable_sva(idxd->pdev);
pci_iounmap(pdev, idxd->reg_base);
put_device(idxd_confdev(idxd));
pci_disable_device(pdev);
--
2.43.0
next prev parent reply other threads:[~2025-06-07 13:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-07 13:06 [PATCH v2 0/2] dmaengine: idxd: Fix refcount and cleanup issues on module unload Yi Sun
2025-06-07 13:06 ` [PATCH v2 1/2] dmaengine: idxd: Remove improper idxd_free Yi Sun
2025-06-07 13:06 ` Yi Sun [this message]
2025-06-13 23:20 ` [PATCH v2 2/2] dmaengine: idxd: Fix refcount underflow on module unload Vinicius Costa Gomes
2025-06-14 7:13 ` Yi Sun
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