4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit fed84c78527009d4f799a3ed9a566502fa026d82 ]
Kmemleak does not play well with KASAN (tested on both HPE Apollo 70 and Huawei TaiShan 2280 aarch64 servers).
After calling start_kernel()->setup_arch()->kasan_init(), kmemleak early log buffer went from something like 280 to 260000 which caused kmemleak disabled and crash dump memory reservation failed. The multitude of kmemleak_alloc() calls is from nested loops while KASAN is setting up full memory mappings, so let early kmemleak allocations skip those memblock_alloc_internal() calls came from kasan_init() given that those early KASAN memory mappings should not reference to other memory. Hence, no kmemleak false positives.
kasan_init kasan_map_populate [1] kasan_pgd_populate [2] kasan_pud_populate [3] kasan_pmd_populate [4] kasan_pte_populate [5] kasan_alloc_zeroed_page memblock_alloc_try_nid memblock_alloc_internal kmemleak_alloc
[1] for_each_memblock(memory, reg) [2] while (pgdp++, addr = next, addr != end) [3] while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))) [4] while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))) [5] while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)))
Link: http://lkml.kernel.org/r/1543442925-17794-1-git-send-email-cai@gmx.us Signed-off-by: Qian Cai cai@gmx.us Acked-by: Catalin Marinas catalin.marinas@arm.com Cc: Michal Hocko mhocko@suse.com Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: Alexander Potapenko glider@google.com Cc: Dmitry Vyukov dvyukov@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/mm/kasan_init.c | 2 +- include/linux/memblock.h | 1 + mm/memblock.c | 19 +++++++++++-------- 3 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 63527e585aac..fcb2ca30b6f1 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -39,7 +39,7 @@ static phys_addr_t __init kasan_alloc_zeroed_page(int node) { void *p = memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE, __pa(MAX_DMA_ADDRESS), - MEMBLOCK_ALLOC_ACCESSIBLE, node); + MEMBLOCK_ALLOC_KASAN, node); return __pa(p); }
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index aee299a6aa76..3ef3086ed52f 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -320,6 +320,7 @@ static inline int memblock_get_region_node(const struct memblock_region *r) /* Flags for memblock allocation APIs */ #define MEMBLOCK_ALLOC_ANYWHERE (~(phys_addr_t)0) #define MEMBLOCK_ALLOC_ACCESSIBLE 0 +#define MEMBLOCK_ALLOC_KASAN 1
/* We are using top down, so it is safe to use 0 here */ #define MEMBLOCK_LOW_LIMIT 0 diff --git a/mm/memblock.c b/mm/memblock.c index 81ae63ca78d0..f45a049532fe 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -262,7 +262,8 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size, phys_addr_t kernel_end, ret;
/* pump up @end */ - if (end == MEMBLOCK_ALLOC_ACCESSIBLE) + if (end == MEMBLOCK_ALLOC_ACCESSIBLE || + end == MEMBLOCK_ALLOC_KASAN) end = memblock.current_limit;
/* avoid allocating the first page */ @@ -1412,13 +1413,15 @@ again: done: ptr = phys_to_virt(alloc);
- /* - * The min_count is set to 0 so that bootmem allocated blocks - * are never reported as leaks. This is because many of these blocks - * are only referred via the physical address which is not - * looked up by kmemleak. - */ - kmemleak_alloc(ptr, size, 0, 0); + /* Skip kmemleak for kasan_init() due to high volume. */ + if (max_addr != MEMBLOCK_ALLOC_KASAN) + /* + * The min_count is set to 0 so that bootmem allocated + * blocks are never reported as leaks. This is because many + * of these blocks are only referred via the physical + * address which is not looked up by kmemleak. + */ + kmemleak_alloc(ptr, size, 0, 0);
return ptr; }