diff options
| -rw-r--r-- | arch/um/kernel/skas/mmu.c | 25 |
1 files changed, 2 insertions, 23 deletions
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c index 886ed5e65674..d3fb506d5bd6 100644 --- a/arch/um/kernel/skas/mmu.c +++ b/arch/um/kernel/skas/mmu.c @@ -40,29 +40,8 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm) goto out_free; } - /* - * Ensure the new MM is clean and nothing unwanted is mapped. - * - * TODO: We should clear the memory up to STUB_START to ensure there is - * nothing mapped there, i.e. we (currently) have: - * - * |- user memory -|- unused -|- stub -|- unused -| - * ^ TASK_SIZE ^ STUB_START - * - * Meaning we have two unused areas where we may still have valid - * mappings from our internal clone(). That isn't really a problem as - * userspace is not going to access them, but it is definitely not - * correct. - * - * However, we are "lucky" and if rseq is configured, then on 32 bit - * it will fall into the first empty range while on 64 bit it is going - * to use an anonymous mapping in the second range. As such, things - * continue to work for now as long as we don't start unmapping these - * areas. - * - * Change this to STUB_START once we have a clean userspace. - */ - unmap(new_id, 0, TASK_SIZE); + /* Ensure the new MM is clean and nothing unwanted is mapped */ + unmap(new_id, 0, STUB_START); return 0; |