Re: [PATCH v2 07/10] arm64: mm: Drop redundant pgd_t* argument from map_mem()
From: Ryan Roberts <ryan.roberts@arm.com>
Date: 2026-01-27 10:10:27
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linux-hardening, lkml
On 26/01/2026 09:26, Ard Biesheuvel wrote:
From: Ard Biesheuvel <ardb@kernel.org> __map_memblock() and map_mem() always operate on swapper_pg_dir, so there is no need to pass around a pgd_t pointer between them. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
nice simplification: Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
quoted hunk ↗ jump to hunk
--- arch/arm64/mm/mmu.c | 25 ++++++++++---------- 1 file changed, 12 insertions(+), 13 deletions(-)diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 377bdc4d84a1..80587cd47ce7 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c@@ -1020,11 +1020,11 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt, flush_tlb_kernel_range(virt, virt + size); } -static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start, - phys_addr_t end, pgprot_t prot, int flags) +static void __init __map_memblock(phys_addr_t start, phys_addr_t end, + pgprot_t prot, int flags) { - early_create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start, - prot, early_pgtable_alloc, flags); + early_create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), + end - start, prot, early_pgtable_alloc, flags); } void __init mark_linear_text_alias_ro(void)@@ -1072,13 +1072,13 @@ static phys_addr_t __init arm64_kfence_alloc_pool(void) return kfence_pool; } -static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) +static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool) { if (!kfence_pool) return; /* KFENCE pool needs page-level mapping. */ - __map_memblock(pgdp, kfence_pool, kfence_pool + KFENCE_POOL_SIZE, + __map_memblock(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, pgprot_tagged(PAGE_KERNEL), NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);@@ -1114,11 +1114,11 @@ bool arch_kfence_init_pool(void) #else /* CONFIG_KFENCE */ static inline phys_addr_t arm64_kfence_alloc_pool(void) { return 0; } -static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) { } +static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool) { } #endif /* CONFIG_KFENCE */ -static void __init map_mem(pgd_t *pgdp) +static void __init map_mem(void) { static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); phys_addr_t kernel_start = __pa_symbol(_text);@@ -1163,7 +1163,7 @@ static void __init map_mem(pgd_t *pgdp) * if MTE is present. Otherwise, it has the same attributes as * PAGE_KERNEL. */ - __map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL), + __map_memblock(start, end, pgprot_tagged(PAGE_KERNEL), flags); }@@ -1177,10 +1177,9 @@ static void __init map_mem(pgd_t *pgdp) * Note that contiguous mappings cannot be remapped in this way, * so we should avoid them here. */ - __map_memblock(pgdp, kernel_start, kernel_end, - PAGE_KERNEL, NO_CONT_MAPPINGS); + __map_memblock(kernel_start, kernel_end, PAGE_KERNEL, NO_CONT_MAPPINGS); memblock_clear_nomap(kernel_start, kernel_end - kernel_start); - arm64_kfence_map_pool(early_kfence_pool, pgdp); + arm64_kfence_map_pool(early_kfence_pool); } void mark_rodata_ro(void)@@ -1402,7 +1401,7 @@ static void __init create_idmap(void) void __init paging_init(void) { - map_mem(swapper_pg_dir); + map_mem(); memblock_allow_resize();