On 10/04, jeffxu@xxxxxxxxxxxx wrote:
>
> It is important to note that the CHECKPOINT_RESTORE feature (CRIU) may
> alter the mapping of vdso, vvar, and sigpage during restore
> operations. Consequently, this feature cannot be universally enabled
> across all systems.
Can't review.
But as for uprobes, I'd prefer a simpler patch which doesn't need the new
CONFIG_ and/or kernel boot options, something like the patch below.
And I don't really like the fact that this patch changes the behaviour
of the "generic" _install_special_mapping() helper, but I won't argue.
Oleg.
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -430,6 +430,8 @@ extern unsigned int kobjsize(const void *objp);
#ifdef CONFIG_64BIT
/* VM is sealed, in vm_flags */
#define VM_SEALED _BITUL(63)
+#else
+#define VM_SEALED 0
#endif
/* Bits set in the VMA until the stack is in its final location */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 40ecab0971ff..388373c11593 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1510,7 +1510,7 @@ 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,
&xol_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
