6.8-stable review patch. If anyone has any objections, please let me know.
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From: Samuel Holland samuel.holland@sifive.com
[ 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 samuel.holland@sifive.com Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/include/asm/page.h | 2 +- arch/riscv/mm/init.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 57e887bfa34cb..94b3d6930fc37 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -89,7 +89,7 @@ typedef struct page *pgtable_t; #define PTE_FMT "%08lx" #endif
-#ifdef CONFIG_64BIT +#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) /* * We override this value as its generic definition uses __pa too early in * the boot process (before kernel_map.va_pa_offset is set). diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index fa34cf55037bd..0c00efc75643a 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;
/*