On Tue, Jan 06, 2026 at 04:21:57PM +0000, Mostafa Saleh wrote:

Add a new config IOMMU_DEBUG_PAGEALLOC, which registers new data to
page_ext.

This config will be used by the IOMMU API to track pages mapped in
the IOMMU to catch drivers trying to free kernel memory that they
still map in their domains, causing all types of memory corruption.

This behaviour is disabled by default and can be enabled using
kernel cmdline iommu.debug_pagealloc.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
---
 .../admin-guide/kernel-parameters.txt         |  9 ++++++
 drivers/iommu/Kconfig                         | 19 +++++++++++
 drivers/iommu/Makefile                        |  1 +
 drivers/iommu/iommu-debug-pagealloc.c         | 32 +++++++++++++++++++
 include/linux/iommu-debug-pagealloc.h         | 17 ++++++++++
 mm/page_ext.c                                 |  4 +++
 6 files changed, 82 insertions(+)
 create mode 100644 drivers/iommu/iommu-debug-pagealloc.c
 create mode 100644 include/linux/iommu-debug-pagealloc.h

Reviewed-by: Pranjal Shrivastava <praan@google.com>
Thanks!