From ada00cc8e04f421cce657e8d9f3a439c69437cf4 Mon Sep 17 00:00:00 2001 From: Peter Smith Date: Tue, 10 Dec 2024 13:28:33 +0000 Subject: [PATCH] [buildattr64] Recommend aeabi_pauthabi is only emitted when needed The aeabi_pauthabi subsection is mandatory, which means that if it is present an object consumer is required to understand the contents of the subsection. That makes a relocatable object containing an aeabi_pauthabi subsection with explicit 0 values for the tags less portable than relying on the implicit 0 values when the subsection isn't present. --- buildattr64/buildattr64.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/buildattr64/buildattr64.rst b/buildattr64/buildattr64.rst index cc803ce..e4868ef 100644 --- a/buildattr64/buildattr64.rst +++ b/buildattr64/buildattr64.rst @@ -222,6 +222,8 @@ changes to the content of the document for that release. | | | Clarify that the same attribute with different values is an error. | | | | Rename subsection names to avoid - character which can be difficult | | | | for assemblers to parse as a single token. | + | | | Recommend that aeabi_pauthabi subsection not emitted when pauthabi | + | | | not used. | +------------+---------------------+---------------------------------------------------------------------+ References @@ -940,6 +942,11 @@ While the requirement for the ``FEAT_PAuth`` extension is recorded in the architectural features. The signing schema is software defined with more complex compatibility requirements. +Relocatable objects not using the PAuthABI are recommended not to +output the "aeabi_pauthabi" subsection with explicit values of 0 for +the tags. This permits a relocatable object to be used by an object +consumer that does not implement the "aeabi_pauthabi" subsection. + header contents ^^^^^^^^^^^^^^^