riscv: mm: Fixup compat arch_get_mmap_end

When the task is in COMPAT mode, the arch_get_mmap_end should be 2GB,
not TASK_SIZE_64. The TASK_SIZE has contained is_compat_mode()
detection, so change the definition of STACK_TOP_MAX to TASK_SIZE
directly.

Cc: [email protected]
Fixes: add2cc6 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <[email protected]>
Signed-off-by: Guo Ren <[email protected]>
Reviewed-by: Leonardo Bras <[email protected]>
Reviewed-by: Charlie Jenkins <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: guoren83

arch/riscv/include/asm/processor.h

@@ -16,7 +16,7 @@
 
 #ifdef CONFIG_64BIT
 #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
-#define STACK_TOP_MAX		TASK_SIZE_64
+#define STACK_TOP_MAX		TASK_SIZE
 
 #define arch_get_mmap_end(addr, len, flags)			\
 ({								\