[PATCH v6 09/11] arm64: update Documentation/arm64/tagged-pointers.txt

Andrey Konovalov
2018-08-30T11:41:14Z

Add a note that work on passing tagged user pointers to the kernel via
syscalls has started, but might not be complete yet.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
Documentation/arm64/tagged-pointers.txt | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt
index a25a99e82bb1..361481283f00 100644
--- a/Documentation/arm64/tagged-pointers.txt
+++ b/Documentation/arm64/tagged-pointers.txt
@@ -35,8 +35,9 @@ Using non-zero address tags in any of these locations may result in an
error code being returned, a (fatal) signal being raised, or other modes
of failure.

-For these reasons, passing non-zero address tags to the kernel via
-system calls is forbidden, and using a non-zero address tag for sp is
+Some initial work for supporting non-zero address tags passed to the
+kernel via system calls has been done, but the kernel doesn't provide
+any guarantees at this point. Using a non-zero address tag for sp is
strongly discouraged.

Programs maintaining a frame pointer and frame records that use non-zero
--
2.19.0.rc0.228.g281dcd1b4d0-goog