summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/prctl.h12
-rw-r--r--kernel/sys.c121
2 files changed, 133 insertions, 0 deletions
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index a3baeb2..7ddc7f1 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -102,4 +102,16 @@
#define PR_MCE_KILL_GET 34
+/*
+ * Tune up process memory map specifics.
+ */
+#define PR_SET_MM 35
+# define PR_SET_MM_START_CODE 1
+# define PR_SET_MM_END_CODE 2
+# define PR_SET_MM_START_DATA 3
+# define PR_SET_MM_END_DATA 4
+# define PR_SET_MM_START_STACK 5
+# define PR_SET_MM_START_BRK 6
+# define PR_SET_MM_BRK 7
+
#endif /* _LINUX_PRCTL_H */
diff --git a/kernel/sys.c b/kernel/sys.c
index ddf8155..4070153 100644
--- 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;
OpenPOWER on IntegriCloud