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authorQian Cai <cai@gmx.us>2018-12-28 00:36:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:49 -0800
commitfed84c78527009d4f799a3ed9a566502fa026d82 (patch)
treedafd4dfb1c41319e044728c6825fc7c65c5d52d6
parent65c78784135f847e49eb98e6b976e453e71100c3 (diff)
downloadlinux-fed84c78527009d4f799a3ed9a566502fa026d82.tar.bz2
mm/memblock.c: skip kmemleak for kasan_init()
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>
-rw-r--r--arch/arm64/mm/kasan_init.c2
-rw-r--r--include/linux/memblock.h1
-rw-r--r--mm/memblock.c19
3 files changed, 13 insertions, 9 deletions
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 3e142add890b..4b55b15707a3 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 5f74ba623dbd..64c41cf45590 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -319,6 +319,7 @@ 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 f57d7620668b..022d4cbb3618 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 */
@@ -1419,13 +1420,15 @@ 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;
}