Merge tag 'pm-fixes-for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...

[cascardo/linux.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index ddf8155..4070153 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1692,6 +1692,124 @@ SYSCALL_DEFINE1(umask, int, mask)
        return mask;
 }
 
+#ifdef CONFIG_CHECKPOINT_RESTORE
+static int prctl_set_mm(int opt, unsigned long addr,
+                       unsigned long arg4, unsigned long arg5)
+{
+       unsigned long rlim = rlimit(RLIMIT_DATA);
+       unsigned long vm_req_flags;
+       unsigned long vm_bad_flags;
+       struct vm_area_struct *vma;
+       int error = 0;
+       struct mm_struct *mm = current->mm;
+
+       if (arg4 | arg5)
+               return -EINVAL;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (addr >= TASK_SIZE)
+               return -EINVAL;
+
+       down_read(&mm->mmap_sem);
+       vma = find_vma(mm, addr);
+
+       if (opt != PR_SET_MM_START_BRK && opt != PR_SET_MM_BRK) {
+               /* It must be existing VMA */
+               if (!vma || vma->vm_start > addr)
+                       goto out;
+       }
+
+       error = -EINVAL;
+       switch (opt) {
+       case PR_SET_MM_START_CODE:
+       case PR_SET_MM_END_CODE:
+               vm_req_flags = VM_READ | VM_EXEC;
+               vm_bad_flags = VM_WRITE | VM_MAYSHARE;
+
+               if ((vma->vm_flags & vm_req_flags) != vm_req_flags ||
+                   (vma->vm_flags & vm_bad_flags))
+                       goto out;
+
+               if (opt == PR_SET_MM_START_CODE)
+                       mm->start_code = addr;
+               else
+                       mm->end_code = addr;
+               break;
+
+       case PR_SET_MM_START_DATA:
+       case PR_SET_MM_END_DATA:
+               vm_req_flags = VM_READ | VM_WRITE;
+               vm_bad_flags = VM_EXEC | VM_MAYSHARE;
+
+               if ((vma->vm_flags & vm_req_flags) != vm_req_flags ||
+                   (vma->vm_flags & vm_bad_flags))
+                       goto out;
+
+               if (opt == PR_SET_MM_START_DATA)
+                       mm->start_data = addr;
+               else
+                       mm->end_data = addr;
+               break;
+
+       case PR_SET_MM_START_STACK:
+
+#ifdef CONFIG_STACK_GROWSUP
+               vm_req_flags = VM_READ | VM_WRITE | VM_GROWSUP;
+#else
+               vm_req_flags = VM_READ | VM_WRITE | VM_GROWSDOWN;
+#endif
+               if ((vma->vm_flags & vm_req_flags) != vm_req_flags)
+                       goto out;
+
+               mm->start_stack = addr;
+               break;
+
+       case PR_SET_MM_START_BRK:
+               if (addr <= mm->end_data)
+                       goto out;
+
+               if (rlim < RLIM_INFINITY &&
+                   (mm->brk - addr) +
+                   (mm->end_data - mm->start_data) > rlim)
+                       goto out;
+
+               mm->start_brk = addr;
+               break;
+
+       case PR_SET_MM_BRK:
+               if (addr <= mm->end_data)
+                       goto out;
+
+               if (rlim < RLIM_INFINITY &&
+                   (addr - mm->start_brk) +
+                   (mm->end_data - mm->start_data) > rlim)
+                       goto out;
+
+               mm->brk = addr;
+               break;
+
+       default:
+               error = -EINVAL;
+               goto out;
+       }
+
+       error = 0;
+
+out:
+       up_read(&mm->mmap_sem);
+
+       return error;
+}
+#else /* CONFIG_CHECKPOINT_RESTORE */
+static int prctl_set_mm(int opt, unsigned long addr,
+                       unsigned long arg4, unsigned long arg5)
+{
+       return -EINVAL;
+}
+#endif
+
 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                unsigned long, arg4, unsigned long, arg5)
 {
@@ -1841,6 +1959,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                        else
                                error = PR_MCE_KILL_DEFAULT;
                        break;
+               case PR_SET_MM:
+                       error = prctl_set_mm(arg2, arg3, arg4, arg5);
+                       break;
                default:
                        error = -EINVAL;
                        break;