From: Catalin Marinas <catalin.marinas@xxxxxxx> Subject: mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a physical address to a virtual one using __va(). However, such physical addresses may sometimes be located in highmem and using __va() is incorrect, leading to inconsistent object tracking in kmemleak. The following functions have been added to the kmemleak API and they take a physical address as the object pointer. They only perform the corresponding action if the address has a lowmem mapping: kmemleak_alloc_phys kmemleak_free_part_phys kmemleak_not_leak_phys kmemleak_ignore_phys The affected calling places have been updated to use the new kmemleak API. Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@xxxxxxx Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Reported-by: Vignesh R <vigneshr@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/dev-tools/kmemleak.rst | 9 ++++ include/linux/kmemleak.h | 18 +++++++++ mm/bootmem.c | 6 +-- mm/cma.c | 2 - mm/kmemleak.c | 47 +++++++++++++++++++++++++ mm/memblock.c | 8 ++-- mm/nobootmem.c | 2 - 7 files changed, 83 insertions(+), 9 deletions(-) diff -puN Documentation/dev-tools/kmemleak.rst~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping Documentation/dev-tools/kmemleak.rst --- a/Documentation/dev-tools/kmemleak.rst~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/Documentation/dev-tools/kmemleak.rst @@ -162,6 +162,15 @@ See the include/linux/kmemleak.h header - ``kmemleak_alloc_recursive`` - as kmemleak_alloc but checks the recursiveness - ``kmemleak_free_recursive`` - as kmemleak_free but checks the recursiveness +The following functions take a physical address as the object pointer +and only perform the corresponding action if the address has a lowmem +mapping: + +- ``kmemleak_alloc_phys`` +- ``kmemleak_free_part_phys`` +- ``kmemleak_not_leak_phys`` +- ``kmemleak_ignore_phys`` + Dealing with false positives/negatives -------------------------------------- diff -puN include/linux/kmemleak.h~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping include/linux/kmemleak.h --- a/include/linux/kmemleak.h~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/include/linux/kmemleak.h @@ -38,6 +38,11 @@ extern void kmemleak_not_leak(const void extern void kmemleak_ignore(const void *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_alloc_phys(phys_addr_t phys, size_t size, int min_count, + gfp_t gfp) __ref; +extern void kmemleak_free_part_phys(phys_addr_t phys, size_t size) __ref; +extern void kmemleak_not_leak_phys(phys_addr_t phys) __ref; +extern void kmemleak_ignore_phys(phys_addr_t phys) __ref; static inline void kmemleak_alloc_recursive(const void *ptr, size_t size, int min_count, unsigned long flags, @@ -106,6 +111,19 @@ static inline void kmemleak_erase(void * static inline void kmemleak_no_scan(const void *ptr) { } +static inline void kmemleak_alloc_phys(phys_addr_t phys, size_t size, + int min_count, gfp_t gfp) +{ +} +static inline void kmemleak_free_part_phys(phys_addr_t phys, size_t size) +{ +} +static inline void kmemleak_not_leak_phys(phys_addr_t phys) +{ +} +static inline void kmemleak_ignore_phys(phys_addr_t phys) +{ +} #endif /* CONFIG_DEBUG_KMEMLEAK */ diff -puN mm/bootmem.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping mm/bootmem.c --- a/mm/bootmem.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/mm/bootmem.c @@ -155,7 +155,7 @@ void __init free_bootmem_late(unsigned l { unsigned long cursor, end; - kmemleak_free_part(__va(physaddr), size); + kmemleak_free_part_phys(physaddr, size); cursor = PFN_UP(physaddr); end = PFN_DOWN(physaddr + size); @@ -399,7 +399,7 @@ void __init free_bootmem_node(pg_data_t { unsigned long start, end; - kmemleak_free_part(__va(physaddr), size); + kmemleak_free_part_phys(physaddr, size); start = PFN_UP(physaddr); end = PFN_DOWN(physaddr + size); @@ -420,7 +420,7 @@ void __init free_bootmem(unsigned long p { unsigned long start, end; - kmemleak_free_part(__va(physaddr), size); + kmemleak_free_part_phys(physaddr, size); start = PFN_UP(physaddr); end = PFN_DOWN(physaddr + size); diff -puN mm/cma.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping mm/cma.c --- a/mm/cma.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/mm/cma.c @@ -336,7 +336,7 @@ int __init cma_declare_contiguous(phys_a * kmemleak scans/reads tracked objects for pointers to other * objects but this address isn't mapped and accessible */ - kmemleak_ignore(phys_to_virt(addr)); + kmemleak_ignore_phys(addr); base = addr; } diff -puN mm/kmemleak.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping mm/kmemleak.c --- a/mm/kmemleak.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/mm/kmemleak.c @@ -90,6 +90,8 @@ #include <linux/cache.h> #include <linux/percpu.h> #include <linux/hardirq.h> +#include <linux/bootmem.h> +#include <linux/pfn.h> #include <linux/mmzone.h> #include <linux/slab.h> #include <linux/thread_info.h> @@ -1121,6 +1123,51 @@ void __ref kmemleak_no_scan(const void * } EXPORT_SYMBOL(kmemleak_no_scan); +/** + * kmemleak_alloc_phys - similar to kmemleak_alloc but taking a physical + * address argument + */ +void __ref kmemleak_alloc_phys(phys_addr_t phys, size_t size, int min_count, + gfp_t gfp) +{ + if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn) + kmemleak_alloc(__va(phys), size, min_count, gfp); +} +EXPORT_SYMBOL(kmemleak_alloc_phys); + +/** + * kmemleak_free_part_phys - similar to kmemleak_free_part but taking a + * physical address argument + */ +void __ref kmemleak_free_part_phys(phys_addr_t phys, size_t size) +{ + if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn) + kmemleak_free_part(__va(phys), size); +} +EXPORT_SYMBOL(kmemleak_free_part_phys); + +/** + * kmemleak_not_leak_phys - similar to kmemleak_not_leak but taking a physical + * address argument + */ +void __ref kmemleak_not_leak_phys(phys_addr_t phys) +{ + if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn) + kmemleak_not_leak(__va(phys)); +} +EXPORT_SYMBOL(kmemleak_not_leak_phys); + +/** + * kmemleak_ignore_phys - similar to kmemleak_ignore but taking a physical + * address argument + */ +void __ref kmemleak_ignore_phys(phys_addr_t phys) +{ + if (!IS_ENABLED(CONFIG_HIGHMEM) || PHYS_PFN(phys) < max_low_pfn) + kmemleak_ignore(__va(phys)); +} +EXPORT_SYMBOL(kmemleak_ignore_phys); + /* * Update an object's checksum and return true if it was modified. */ diff -puN mm/memblock.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping mm/memblock.c --- a/mm/memblock.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/mm/memblock.c @@ -723,7 +723,7 @@ int __init_memblock memblock_free(phys_a (unsigned long long)base + size - 1, (void *)_RET_IP_); - kmemleak_free_part(__va(base), size); + kmemleak_free_part_phys(base, size); return memblock_remove_range(&memblock.reserved, base, size); } @@ -1152,7 +1152,7 @@ static phys_addr_t __init memblock_alloc * The min_count is set to 0 so that memblock allocations are * never reported as leaks. */ - kmemleak_alloc(__va(found), size, 0, 0); + kmemleak_alloc_phys(found, size, 0, 0); return found; } return 0; @@ -1399,7 +1399,7 @@ void __init __memblock_free_early(phys_a memblock_dbg("%s: [%#016llx-%#016llx] %pF\n", __func__, (u64)base, (u64)base + size - 1, (void *)_RET_IP_); - kmemleak_free_part(__va(base), size); + kmemleak_free_part_phys(base, size); memblock_remove_range(&memblock.reserved, base, size); } @@ -1419,7 +1419,7 @@ void __init __memblock_free_late(phys_ad memblock_dbg("%s: [%#016llx-%#016llx] %pF\n", __func__, (u64)base, (u64)base + size - 1, (void *)_RET_IP_); - kmemleak_free_part(__va(base), size); + kmemleak_free_part_phys(base, size); cursor = PFN_UP(base); end = PFN_DOWN(base + size); diff -puN mm/nobootmem.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping mm/nobootmem.c --- a/mm/nobootmem.c~mm-kmemleak-avoid-using-__va-on-addresses-that-dont-have-a-lowmem-mapping +++ a/mm/nobootmem.c @@ -84,7 +84,7 @@ void __init free_bootmem_late(unsigned l { unsigned long cursor, end; - kmemleak_free_part(__va(addr), size); + kmemleak_free_part_phys(addr, size); cursor = PFN_UP(addr); end = PFN_DOWN(addr + size); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
