The arm-smmu driver is unable to allocate the blame for a page fault to a specific device so it calls report_iommu_fault() with the dev argument set to NULL. Normally this doesn't cause anything catastrophic but on a system with the io_page_fault tracepoint enabled this results in a NULL pointer deref (resulting in a fairly spectacular crash on the hardware I'm currently working on).
Fix this by adding logic to the tracepoint to safely propagate NULL. Signed-off-by: Daniel Thompson <[email protected]> --- include/trace/events/iommu.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/trace/events/iommu.h b/include/trace/events/iommu.h index 373007e567cb827458a729b8200bbcc1b7d76912..1315193f13b8812ad4e29e6b0c0c66ca806ce08d 100644 --- a/include/trace/events/iommu.h +++ b/include/trace/events/iommu.h @@ -131,8 +131,8 @@ DECLARE_EVENT_CLASS(iommu_error, TP_ARGS(dev, iova, flags), TP_STRUCT__entry( - __string(device, dev_name(dev)) - __string(driver, dev_driver_string(dev)) + __string(device, dev ? dev_name(dev) : NULL) + __string(driver, dev ? dev_driver_string(dev) : NULL) __field(u64, iova) __field(int, flags) ), --- base-commit: 0f61b1860cc3f52aef9036d7235ed1f017632193 change-id: 20260116-iommu-io_page_fault_null_fix-f81b4e8b5423 Best regards, -- Daniel Thompson <[email protected]>
