From: Ran Xiaokai <[email protected]> Introduce kmemleak_no_scan_phys(phys_addr_t), a physical-address variant to kmemleak_no_scan(). This helper marks memory regions as non-scanable using physical addresses directly.
It is specifically designed to prevent kmemleak from accessing pages that have been unmapped by debug_pagealloc after being freed to the buddy allocator. The kexec handover (KHO) subsystem will call this helper to exclude the kho_scratch reservation region from scanning, thereby avoiding fatal page faults during boot when debug_pagealloc=on. Signed-off-by: Ran Xiaokai <[email protected]> --- include/linux/kmemleak.h | 4 ++++ mm/kmemleak.c | 15 ++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h index fbd424b2abb1..e955ad441b8a 100644 --- a/include/linux/kmemleak.h +++ b/include/linux/kmemleak.h @@ -31,6 +31,7 @@ extern void kmemleak_ignore(const void *ptr) __ref; extern void kmemleak_ignore_percpu(const void __percpu *ptr) __ref; extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref; extern void kmemleak_no_scan(const void *ptr) __ref; +extern void kmemleak_no_scan_phys(phys_addr_t phys) __ref; extern void kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp) __ref; extern void kmemleak_free_part_phys(phys_addr_t phys, size_t size) __ref; @@ -113,6 +114,9 @@ static inline void kmemleak_erase(void **ptr) static inline void kmemleak_no_scan(const void *ptr) { } +static inline void kmemleak_no_scan_phys(phys_addr_t phys) +{ +} static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size, gfp_t gfp) { diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 1ac56ceb29b6..b2b8374e19c3 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1058,12 +1058,12 @@ static void object_set_excess_ref(unsigned long ptr, unsigned long excess_ref) * pointer. Such object will not be scanned by kmemleak but references to it * are searched. */ -static void object_no_scan(unsigned long ptr) +static void object_no_scan_flags(unsigned long ptr, unsigned long objflags) { unsigned long flags; struct kmemleak_object *object; - object = find_and_get_object(ptr, 0); + object = __find_and_get_object(ptr, 0, objflags); if (!object) { kmemleak_warn("Not scanning unknown object at 0x%08lx\n", ptr); return; @@ -1328,10 +1328,19 @@ void __ref kmemleak_no_scan(const void *ptr) pr_debug("%s(0x%px)\n", __func__, ptr); if (kmemleak_enabled && ptr && !IS_ERR(ptr)) - object_no_scan((unsigned long)ptr); + object_no_scan_flags((unsigned long)ptr, 0); } EXPORT_SYMBOL(kmemleak_no_scan); +void __ref kmemleak_no_scan_phys(phys_addr_t phys) +{ + pr_debug("%s(%pap)\n", __func__, &phys); + + if (kmemleak_enabled) + object_no_scan_flags((unsigned long)phys, OBJECT_PHYS); +} +EXPORT_SYMBOL(kmemleak_no_scan_phys); + /** * kmemleak_alloc_phys - similar to kmemleak_alloc but taking a physical * address argument -- 2.25.1
