From 75516c75a72b5629736c611cf45058d95978a9f2 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Fri, 23 Apr 2021 18:51:34 +0100 Subject: arm64: doc: Add brk/mmap/mremap() to the Tagged Address ABI Exceptions Prior to commit dcde237319e6 ("mm: Avoid creating virtual address aliases in brk()/mmap()/mremap()"), the kernel allowed tagged addresses to be passed to the brk/mmap/mremap() syscalls. This relaxation was tightened in 5.6 (backported to stable 5.4) but the tagged-address-abi.rst document was only partially updated. Signed-off-by: Catalin Marinas Fixes: dcde237319e6 ("mm: Avoid creating virtual address aliases in brk()/mmap()/mremap()") Reported-by: Peter Maydell Cc: Will Deacon Cc: Vincenzo Frascino Link: https://lore.kernel.org/r/20210423175134.14838-1-catalin.marinas@arm.com Signed-off-by: Catalin Marinas --- Documentation/arm64/tagged-address-abi.rst | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/arm64') diff --git a/Documentation/arm64/tagged-address-abi.rst b/Documentation/arm64/tagged-address-abi.rst index cbc4d4500241..459e6b66ff68 100644 --- a/Documentation/arm64/tagged-address-abi.rst +++ b/Documentation/arm64/tagged-address-abi.rst @@ -113,6 +113,12 @@ ABI relaxation: - ``shmat()`` and ``shmdt()``. +- ``brk()`` (since kernel v5.6). + +- ``mmap()`` (since kernel v5.6). + +- ``mremap()``, the ``new_address`` argument (since kernel v5.6). + Any attempt to use non-zero tagged pointers may result in an error code being returned, a (fatal) signal being raised, or other modes of failure. -- cgit v1.2.3-59-g8ed1b