From ea6628e4e2353978af7e3b4ad4fdaab6149acf3d Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Mon, 26 Feb 2024 16:34:47 -0800 Subject: riscv: Fix loading 64-bit NOMMU kernels past the start of RAM [ Upstream commit aea702dde7e9876fb00571a2602f25130847bf0f ] commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") added logic to allow using RAM below the kernel load address. However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the kernel load address. Since that range of memory corresponds to PFNs below ARCH_PFN_OFFSET, mm initialization runs off the beginning of mem_map and corrupts adjacent kernel memory. Fix this by restoring the previous behavior for NOMMU kernels. Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/riscv/mm/init.c') diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index fa34cf55037b..0c00efc75643 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -232,7 +232,7 @@ static void __init setup_bootmem(void) * In 64-bit, any use of __va/__pa before this point is wrong as we * did not know the start of DRAM before. */ - if (IS_ENABLED(CONFIG_64BIT)) + if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base; /* -- cgit v1.2.3