riscv: Make sure the linear mapping does not use the kernel mapping

For 64-bit kernel, the end of the address space is occupied by the kernel mapping and currently, the functions to populate the kernel page tables (i.e. create_p*d_mapping) do not override existing mapping so we must make sure the linear mapping does not map memory in the kernel mapping by clipping the memory above the memory limit. Signed-off-by: Alexandre Ghiti <[email protected]> Fixes: c9811e3 ("riscv: Add mem kernel parameter support") Signed-off-by: Palmer Dabbelt <[email protected]>
linux-surface · Jul 23, 2021 · c99127c · c99127c
1 parent c09dc9e
commit c99127c
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
@@ -717,6 +717,8 @@ static void __init setup_vm_final(void)
 		if (start <= __pa(PAGE_OFFSET) &&
 		    __pa(PAGE_OFFSET) < end)
 			start = __pa(PAGE_OFFSET);
+		if (end >= __pa(PAGE_OFFSET) + memory_limit)
+			end = __pa(PAGE_OFFSET) + memory_limit;
 
 		map_size = best_map_size(start, end - start);
 		for (pa = start; pa < end; pa += map_size) {