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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/iommu/iommu-debug-pagealloc.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/iommu/iommu-debug-pagealloc.c')
| -rw-r--r-- | drivers/iommu/iommu-debug-pagealloc.c | 164 |
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); |
