kmemleak explicitly scans the mem_map through the valid struct page objects. However, memmap_alloc() was also adding this memory to the gray object list, causing it to be scanned twice. Removes memmap_alloc() from the scan list and adds a comment to clarify the behavior. Link: https://lore.kernel.org/lkml/CAOm6qn=FVeTpH54wGDFMHuCOeYtvoTx30ktnv9-w3Nh8RMofEA@xxxxxxxxxxxxxx/ Signed-off-by: Guo Weikang <guoweikang.kernel@xxxxxxxxx> --- v1 -> v2: Fix CI: Recover __earlyonly_bootmem_alloc that is marked with __ref to prevent init section mismatch WARNING. Links: https://lore.kernel.org/oe-kbuild-all/202501021601.jub4p3EM-lkp@xxxxxxxxx/ v2 -> v3: Rebase on latest mm-everything and modified some minor comments. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Links: https://lore.kernel.org/lkml/20250103110150.1352226-1-guoweikang.kernel@xxxxxxxxx/ --- include/linux/memblock.h | 4 ++++ mm/mm_init.c | 8 ++++++-- mm/sparse-vmemmap.c | 5 +++-- 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index dee628350cd1..e79eb6ac516f 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -378,6 +378,10 @@ 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 +/* + * MEMBLOCK_ALLOC_NOLEAKTRACE avoids kmemleak tracing. It implies + * MEMBLOCK_ALLOC_ACCESSIBLE + */ #define MEMBLOCK_ALLOC_NOLEAKTRACE 1 /* We are using top down, so it is safe to use 0 here */ diff --git a/mm/mm_init.c b/mm/mm_init.c index 24b68b425afb..2630cc30147e 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1585,13 +1585,17 @@ void __init *memmap_alloc(phys_addr_t size, phys_addr_t align, { void *ptr; + /* + * Kmemleak will explicitly scan mem_map by traversing all valid + * `struct *page`,so memblock does not need to be added to the scan list. + */ if (exact_nid) ptr = memblock_alloc_exact_nid_raw(size, align, min_addr, - MEMBLOCK_ALLOC_ACCESSIBLE, + MEMBLOCK_ALLOC_NOLEAKTRACE, nid); else ptr = memblock_alloc_try_nid_raw(size, align, min_addr, - MEMBLOCK_ALLOC_ACCESSIBLE, + MEMBLOCK_ALLOC_NOLEAKTRACE, nid); if (ptr && size > 0) diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index cec67c5f37d8..3287ebadd167 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -31,6 +31,8 @@ #include <asm/dma.h> #include <asm/pgalloc.h> +#include "internal.h" + /* * Allocate a block of memory to be used to back the virtual memory map * or to back the page tables that are used to create the mapping. @@ -42,8 +44,7 @@ static void * __ref __earlyonly_bootmem_alloc(int node, unsigned long align, unsigned long goal) { - return memblock_alloc_try_nid_raw(size, align, goal, - MEMBLOCK_ALLOC_ACCESSIBLE, node); + return memmap_alloc(size, align, goal, node, false); } void * __meminit vmemmap_alloc_block(unsigned long size, int node) -- 2.25.1
