[PATCH v9 5/7] mseal sysmap: uprobe mapping

[jeffxu@chromium.org]

From: Jeff Xu <jeffxu@chromium.org>

Provide support to mseal the uprobe mapping.

Unlike other system mappings, the uprobe mapping is not
established during program startup. However, its lifetime is the same
as the process's lifetime. It could be sealed from creation.

Test was done with perf tool, and observe the uprobe mapping is sealed.

Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kees Cook <kees@kernel.org>
---
 kernel/events/uprobes.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index bf2a87a0a378..98632bc47216 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1683,7 +1683,8 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)
 	}
 
 	vma = _install_special_mapping(mm, area->vaddr, PAGE_SIZE,
-				VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO,
+				VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO|
+				VM_SEALED_SYSMAP,
 				&xol_mapping);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-- 
2.48.1.711.g2feabab25a-goog