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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/iommu/iommu-debug-pagealloc.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/iommu/iommu-debug-pagealloc.c')
-rw-r--r--drivers/iommu/iommu-debug-pagealloc.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/iommu/iommu-debug-pagealloc.c b/drivers/iommu/iommu-debug-pagealloc.c
new file mode 100644
index 000000000..80164df5b
--- /dev/null
+++ b/drivers/iommu/iommu-debug-pagealloc.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 - Google Inc
+ * Author: Mostafa Saleh <smostafa@google.com>
+ * IOMMU API debug page alloc sanitizer
+ */
+#include <linux/atomic.h>
+#include <linux/iommu.h>
+#include <linux/iommu-debug-pagealloc.h>
+#include <linux/kernel.h>
+#include <linux/page_ext.h>
+#include <linux/page_owner.h>
+
+#include "iommu-priv.h"
+
+static bool needed;
+DEFINE_STATIC_KEY_FALSE(iommu_debug_initialized);
+
+struct iommu_debug_metadata {
+ atomic_t ref;
+};
+
+static __init bool need_iommu_debug(void)
+{
+ return needed;
+}
+
+struct page_ext_operations page_iommu_debug_ops = {
+ .size = sizeof(struct iommu_debug_metadata),
+ .need = need_iommu_debug,
+};
+
+static struct iommu_debug_metadata *get_iommu_data(struct page_ext *page_ext)
+{
+ return page_ext_data(page_ext, &page_iommu_debug_ops);
+}
+
+static void iommu_debug_inc_page(phys_addr_t phys)
+{
+ struct page_ext *page_ext = page_ext_from_phys(phys);
+ struct iommu_debug_metadata *d;
+
+ if (!page_ext)
+ return;
+
+ d = get_iommu_data(page_ext);
+ WARN_ON(atomic_inc_return_relaxed(&d->ref) <= 0);
+ page_ext_put(page_ext);
+}
+
+static void iommu_debug_dec_page(phys_addr_t phys)
+{
+ struct page_ext *page_ext = page_ext_from_phys(phys);
+ struct iommu_debug_metadata *d;
+
+ if (!page_ext)
+ return;
+
+ d = get_iommu_data(page_ext);
+ WARN_ON(atomic_dec_return_relaxed(&d->ref) < 0);
+ page_ext_put(page_ext);
+}
+
+/*
+ * IOMMU page size doesn't have to match the CPU page size. So, we use
+ * the smallest IOMMU page size to refcount the pages in the vmemmap.
+ * That is important as both map and unmap has to use the same page size
+ * to update the refcount to avoid double counting the same page.
+ * And as we can't know from iommu_unmap() what was the original page size
+ * used for map, we just use the minimum supported one for both.
+ */
+static size_t iommu_debug_page_size(struct iommu_domain *domain)
+{
+ return 1UL << __ffs(domain->pgsize_bitmap);
+}
+
+static bool iommu_debug_page_count(const struct page *page)
+{
+ unsigned int ref;
+ struct page_ext *page_ext = page_ext_get(page);
+ struct iommu_debug_metadata *d = get_iommu_data(page_ext);
+
+ ref = atomic_read(&d->ref);
+ page_ext_put(page_ext);
+ return ref != 0;
+}
+
+void __iommu_debug_check_unmapped(const struct page *page, int numpages)
+{
+ while (numpages--) {
+ if (WARN_ON(iommu_debug_page_count(page))) {
+ pr_warn("iommu: Detected page leak!\n");
+ dump_page_owner(page);
+ }
+ page++;
+ }
+}
+
+void __iommu_debug_map(struct iommu_domain *domain, phys_addr_t phys, size_t size)
+{
+ size_t off, end;
+ size_t page_size = iommu_debug_page_size(domain);
+
+ if (WARN_ON(!phys || check_add_overflow(phys, size, &end)))
+ return;
+
+ for (off = 0 ; off < size ; off += page_size)
+ iommu_debug_inc_page(phys + off);
+}
+
+static void __iommu_debug_update_iova(struct iommu_domain *domain,
+ unsigned long iova, size_t size, bool inc)
+{
+ size_t off, end;
+ size_t page_size = iommu_debug_page_size(domain);
+
+ if (WARN_ON(check_add_overflow(iova, size, &end)))
+ return;
+
+ for (off = 0 ; off < size ; off += page_size) {
+ phys_addr_t phys = iommu_iova_to_phys(domain, iova + off);
+
+ if (!phys)
+ continue;
+
+ if (inc)
+ iommu_debug_inc_page(phys);
+ else
+ iommu_debug_dec_page(phys);
+ }
+}
+
+void __iommu_debug_unmap_begin(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ __iommu_debug_update_iova(domain, iova, size, false);
+}
+
+void __iommu_debug_unmap_end(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ size_t unmapped)
+{
+ if ((unmapped == size) || WARN_ON_ONCE(unmapped > size))
+ return;
+
+ /* If unmap failed, re-increment the refcount. */
+ __iommu_debug_update_iova(domain, iova + unmapped,
+ size - unmapped, true);
+}
+
+void iommu_debug_init(void)
+{
+ if (!needed)
+ return;
+
+ pr_info("iommu: Debugging page allocations, expect overhead or disable iommu.debug_pagealloc");
+ static_branch_enable(&iommu_debug_initialized);
+}
+
+static int __init iommu_debug_pagealloc(char *str)
+{
+ return kstrtobool(str, &needed);
+}
+early_param("iommu.debug_pagealloc", iommu_debug_pagealloc);