Unverified Commit 49a0a373 authored by Alexandre Ghiti's avatar Alexandre Ghiti Committed by Palmer Dabbelt
Browse files

riscv: Check the virtual alignment before choosing a map size 



We used to only check the alignment of the physical address to decide
which mapping would fit for a certain region of the linear mapping, but
it is not enough since the virtual address must also be aligned, so check
that too.

Fixes: 3335068f ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Reported-by: default avatarSong Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/linux-riscv/tencent_7C3B580B47C1B17C16488EC1@qq.com/


Signed-off-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230607125851.63370-1-alexghiti@rivosinc.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 25abe0db

arch/riscv/mm/init.c

+7 −6
Original line number Diff line number Diff line
@@ -660,18 +660,19 @@ void __init create_pgd_mapping(pgd_t *pgdp, 
	create_pgd_next_mapping(nextp, va, pa, sz, prot);

}



static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)

static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va,

				      phys_addr_t size)

{

	if (!(base & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE)

	if (!(pa & (PGDIR_SIZE - 1)) && !(va & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE)

		return PGDIR_SIZE;



	if (!(base & (P4D_SIZE - 1)) && size >= P4D_SIZE)

	if (!(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)

		return P4D_SIZE;



	if (!(base & (PUD_SIZE - 1)) && size >= PUD_SIZE)

	if (!(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)

		return PUD_SIZE;



	if (!(base & (PMD_SIZE - 1)) && size >= PMD_SIZE)

	if (!(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)

		return PMD_SIZE;



	return PAGE_SIZE;
@@ -1177,7 +1178,7 @@ static void __init create_linear_mapping_range(phys_addr_t start, 
	for (pa = start; pa < end; pa += map_size) {

		va = (uintptr_t)__va(pa);

		map_size = fixed_map_size ? fixed_map_size :

					    best_map_size(pa, end - pa);

					    best_map_size(pa, va, end - pa);



		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,

				   pgprot_from_va(va));