From 9099daed9c6991a512c1f74b92ec49daf9408cda Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 11 Oct 2016 13:55:11 -0700 Subject: [PATCH] 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@arm.com Signed-off-by: Catalin Marinas Reported-by: Vignesh R Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 --git a/Documentation/dev-tools/kmemleak.rst b/Documentation/dev-tools/kmemleak.rst index 1788722d5495..b2391b829169 100644 --- a/Documentation/dev-tools/kmemleak.rst +++ b/Documentation/dev-tools/kmemleak.rst @@ -162,6 +162,15 @@ See the include/linux/kmemleak.h header for the functions prototype. - ``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 --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h index 4894c6888bc6..1c2a32829620 100644 --- a/include/linux/kmemleak.h +++ b/include/linux/kmemleak.h @@ -38,6 +38,11 @@ extern void kmemleak_not_leak(const void *ptr) __ref; 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 **ptr) 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 --git a/mm/bootmem.c b/mm/bootmem.c index a869f84f44d3..e8a55a3c9feb 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -155,7 +155,7 @@ void __init free_bootmem_late(unsigned long physaddr, unsigned long size) { 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 *pgdat, unsigned long physaddr, { 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 physaddr, unsigned long size) { 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 --git a/mm/cma.c b/mm/cma.c index bd0e1412475e..384c2cb51b56 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -336,7 +336,7 @@ int __init cma_declare_contiguous(phys_addr_t base, * 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 --git a/mm/kmemleak.c b/mm/kmemleak.c index 086292f7c59d..a5e453cf05c4 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -90,6 +90,8 @@ #include #include #include +#include +#include #include #include #include @@ -1121,6 +1123,51 @@ void __ref kmemleak_no_scan(const void *ptr) } 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 --git a/mm/memblock.c b/mm/memblock.c index c8dfa430342b..7608bc305936 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -723,7 +723,7 @@ int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size) (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_range_nid(phys_addr_t size, * 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_addr_t base, phys_addr_t size) 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_addr_t base, phys_addr_t size) 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 --git a/mm/nobootmem.c b/mm/nobootmem.c index ba609b684d7a..487dad610731 100644 --- a/mm/nobootmem.c +++ b/mm/nobootmem.c @@ -84,7 +84,7 @@ void __init free_bootmem_late(unsigned long addr, unsigned long size) { 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);