From f6e6c57f2e100813be6d5882060fef81cb6f32de Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:06 +0900 Subject: [PATCH 1/8] arm64: mm: remove unreachable invalid range check in kasan_init_shadow() kasan_init_shadow() maps each memblock region with for_each_mem_range() and breaks the loop when start >= end. for_each_mem_range() never returns an invalid range, so start < end always. Therefore the start >= end check is unreachable, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: Andrey Ryabinin Link: https://patch.msgid.link/20260630150413.1718632-2-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/arm64/mm/kasan_init.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 3fcad956fdf7..45fbdce684c8 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -353,9 +353,6 @@ static void __init kasan_init_shadow(void) void *start = (void *)__phys_to_virt(pa_start); void *end = (void *)__phys_to_virt(pa_end); - if (start >= end) - break; - kasan_map_populate((unsigned long)kasan_mem_to_shadow(start), (unsigned long)kasan_mem_to_shadow(end), early_pfn_to_nid(virt_to_pfn(start))); From 68d3b7d58237b8794d9343210d4c90b8381cfa96 Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:07 +0900 Subject: [PATCH 2/8] LoongArch: remove unreachable invalid range check in kasan_init() kasan_init() populates the linear mapping shadow with for_each_mem_range() and breaks the loop when start >= end. for_each_mem_range() never returns an invalid range, so start < end always. Therefore the start >= end check is unreachable, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: Andrey Ryabinin Link: https://patch.msgid.link/20260630150413.1718632-3-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/loongarch/mm/kasan_init.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/loongarch/mm/kasan_init.c b/arch/loongarch/mm/kasan_init.c index 0fc02ca06457..92ca0ba86406 100644 --- a/arch/loongarch/mm/kasan_init.c +++ b/arch/loongarch/mm/kasan_init.c @@ -305,9 +305,6 @@ void __init kasan_init(void) void *start = (void *)phys_to_virt(pa_start); void *end = (void *)phys_to_virt(pa_end); - if (start >= end) - break; - kasan_map_populate((unsigned long)mem_to_shadow(start), (unsigned long)mem_to_shadow(end), NUMA_NO_NODE); } From 99e60ebe108817fd48791f2cb81f1e672ad8285b Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:08 +0900 Subject: [PATCH 3/8] riscv: remove unreachable invalid range check in create_linear_mapping_page_table() create_linear_mapping_page_table() iterates memblock regions with for_each_mem_range() and breaks the loop when start >= end. for_each_mem_range() never returns an invalid range, so start < end always. Therefore the start >= end check is unreachable, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: Charlie Jenkins Tested-by: Charlie Jenkins Link: https://patch.msgid.link/20260630150413.1718632-4-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/riscv/mm/init.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 5b1b3c88b4d1..eb93c2ac05a6 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1229,8 +1229,6 @@ static void __init create_linear_mapping_page_table(void) /* Map all memory banks in the linear mapping */ for_each_mem_range(i, &start, &end) { - if (start >= end) - break; if (start <= __pa(PAGE_OFFSET) && __pa(PAGE_OFFSET) < end) start = __pa(PAGE_OFFSET); From 8008f6995d0c0cf22e7b4d60e95fe14085c10f35 Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:09 +0900 Subject: [PATCH 4/8] riscv: remove unreachable invalid range check in kasan_init() kasan_init() populates the linear mapping shadow with for_each_mem_range() and breaks the loop when start >= end. for_each_mem_range() never returns an invalid range, so start < end always. Therefore the start >= end check is unreachable, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: Charlie Jenkins Tested-by: Charlie Jenkins Reviewed-by: Andrey Ryabinin Link: https://patch.msgid.link/20260630150413.1718632-5-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/riscv/mm/kasan_init.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c index c4a2a9e5586e..1f3aa9611187 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -512,9 +512,6 @@ void __init kasan_init(void) void *start = (void *)__va(p_start); void *end = (void *)__va(p_end); - if (start >= end) - break; - kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end)); } From 3db1a9ccf9290ea3fe01aadf3bd743ef7032b24a Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:10 +0900 Subject: [PATCH 5/8] ARM: remove unreachable invalid range check in kasan_init() kasan_init() maps each memblock region with for_each_mem_range(), which guarantees pa_start < pa_end. Then it skips any region with pa_start >= arm_lowmem_limit, so pa_start < arm_lowmem_limit is guaranteed as well. When pa_end <= arm_lowmem_limit, pa_start < pa_end means start < end, so the start >= end check is unreachable. When pa_end > arm_lowmem_limit, end is clamped to __va(arm_lowmem_limit), and pa_start < arm_lowmem_limit means start < end, so the check is unreachable as well. No functional change. Signed-off-by: Sang-Heon Jeon Link: https://patch.msgid.link/20260630150413.1718632-6-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/arm/mm/kasan_init.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c index c6625e808bf8..1f7c74c5df9e 100644 --- a/arch/arm/mm/kasan_init.c +++ b/arch/arm/mm/kasan_init.c @@ -262,12 +262,6 @@ void __init kasan_init(void) &pa_start, &pa_end, &arm_lowmem_limit); end = __va(arm_lowmem_limit); } - if (start >= end) { - pr_info("Skipping invalid memory block %pa-%pa (virtual %p-%p)\n", - &pa_start, &pa_end, start, end); - continue; - } - create_mapping(start, end); } From 21e95a4b6f34770571eeeaa6adb535efba1b7281 Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:11 +0900 Subject: [PATCH 6/8] powerpc64/kasan: Remove unreachable invalid range check in kasan_init_phys_region() kasan_init() maps each memblock region with for_each_mem_range() and passes it to kasan_init_phys_region(), which does nothing when start >= end. for_each_mem_range() never returns an invalid range, so start < end always. Therefore the start >= end check is unreachable, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Link: https://patch.msgid.link/20260630150413.1718632-7-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- arch/powerpc/mm/kasan/init_book3e_64.c | 3 --- arch/powerpc/mm/kasan/init_book3s_64.c | 3 --- 2 files changed, 6 deletions(-) diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c b/arch/powerpc/mm/kasan/init_book3e_64.c index 0d3a73d6d4b0..0ed372fb8b09 100644 --- a/arch/powerpc/mm/kasan/init_book3e_64.c +++ b/arch/powerpc/mm/kasan/init_book3e_64.c @@ -68,9 +68,6 @@ static void __init kasan_init_phys_region(void *start, void *end) unsigned long k_start, k_end, k_cur; void *va; - if (start >= end) - return; - k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE); k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE); diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c b/arch/powerpc/mm/kasan/init_book3s_64.c index dcafa641804c..ccfbfb894637 100644 --- a/arch/powerpc/mm/kasan/init_book3s_64.c +++ b/arch/powerpc/mm/kasan/init_book3s_64.c @@ -24,9 +24,6 @@ static void __init kasan_init_phys_region(void *start, void *end) unsigned long k_start, k_end, k_cur; void *va; - if (start >= end) - return; - k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE); k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE); From c6af91e48594191f62ad3c1fcc8269b1eb539ef8 Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:12 +0900 Subject: [PATCH 7/8] mm: remove unnecessary empty range check in early_calculate_totalpages() early_calculate_totalpages() iterates the memory ranges with for_each_mem_pfn_range() and calls node_set_state(nid, N_MEMORY) only when end_pfn - start_pfn is non-zero. for_each_mem_pfn_range() never returns an empty range, so start_pfn < end_pfn always. Therefore the check is unnecessary, so remove it. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: Mike Rapoport (Microsoft) Link: https://patch.msgid.link/20260630150413.1718632-8-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- mm/mm_init.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/mm/mm_init.c b/mm/mm_init.c index 0f64909e8d20..17498a13eb99 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -332,8 +332,7 @@ static unsigned long __init early_calculate_totalpages(void) unsigned long pages = end_pfn - start_pfn; totalpages += pages; - if (pages) - node_set_state(nid, N_MEMORY); + node_set_state(nid, N_MEMORY); } return totalpages; } From 2db44dc8bdd3cfc933a3193724f4d38b03e35b80 Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Wed, 1 Jul 2026 00:04:13 +0900 Subject: [PATCH 8/8] mm/hugetlb: remove unnecessary empty range check in hugetlb_bootmem_set_nodes() hugetlb_bootmem_set_nodes() iterates the memory ranges with for_each_mem_pfn_range() and calls node_set(nid, hugetlb_bootmem_nodes) only when end_pfn > start_pfn. for_each_mem_pfn_range() never returns an empty range, so start_pfn < end_pfn always. Therefore the check is unnecessary, so remove it. start_pfn and end_pfn are no longer used, so remove the local variables. No functional change. Signed-off-by: Sang-Heon Jeon Reviewed-by: David Hildenbrand (Arm) Link: https://patch.msgid.link/20260630150413.1718632-9-ekffu200098@gmail.com Signed-off-by: Mike Rapoport (Microsoft) --- mm/hugetlb.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 571212b80835..4f7020962486 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4444,15 +4444,12 @@ hugetlb_early_param("default_hugepagesz", default_hugepagesz_setup); void __init hugetlb_bootmem_set_nodes(void) { int i, nid; - unsigned long start_pfn, end_pfn; if (!nodes_empty(hugetlb_bootmem_nodes)) return; - for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { - if (end_pfn > start_pfn) - node_set(nid, hugetlb_bootmem_nodes); - } + for_each_mem_pfn_range(i, MAX_NUMNODES, NULL, NULL, &nid) + node_set(nid, hugetlb_bootmem_nodes); } void __init hugetlb_bootmem_alloc(void)