diff options
author | Himanshu Madhani <himanshu.madhani@oracle.com> | 2025-07-08 22:25:30 +0000 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2025-07-10 23:41:08 +0200 |
commit | 68ea85df15d111d82fc474cbe104174791169355 (patch) | |
tree | 37debc5017299a084aed7409a9e26e0cfed47476 | |
parent | d7b8f8e20813f0179d8ef519541a3527e7661d3a (diff) |
PCI/MSI: Prevent recursive locking in pci_msix_write_tph_tag()
pci_msix_write_tph_tag() takes the per device MSI descriptor mutex and then
invokes msi_domain_get_virq(), which takes the same mutex again. That
obviously results in a system hang which is exposed by a softlockup or
lockdep warning.
Move the lock guard after the invocation of msi_domain_get_virq() to fix
this.
[ tglx: Massage changelog by adding a proper explanation and removing the
not really useful stacktrace ]
Fixes: d5124a9957b2 ("PCI/MSI: Provide a sane mechanism for TPH")
Reported-by: Jorge Lopez <jorge.jo.lopez@oracle.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jorge Lopez <jorge.jo.lopez@oracle.com>
Link: https://lore.kernel.org/all/20250708222530.1041477-1-himanshu.madhani@oracle.com
-rw-r--r-- | drivers/pci/msi/msi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c index 6ede55a7c5e6..d686488f4111 100644 --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -934,10 +934,12 @@ int pci_msix_write_tph_tag(struct pci_dev *pdev, unsigned int index, u16 tag) if (!pdev->msix_enabled) return -ENXIO; - guard(msi_descs_lock)(&pdev->dev); virq = msi_get_virq(&pdev->dev, index); if (!virq) return -ENXIO; + + guard(msi_descs_lock)(&pdev->dev); + /* * This is a horrible hack, but short of implementing a PCI * specific interrupt chip callback and a huge pile of |