+ elf-document-some-de-facto-pt_-abi-quirks.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: ELF: document some de-facto PT_* ABI quirks
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     elf-document-some-de-facto-pt_-abi-quirks.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/elf-document-some-de-facto-pt_-abi-quirks.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Alexey Dobriyan <adobriyan@gmail.com>
Subject: ELF: document some de-facto PT_* ABI quirks
Date: Sun, 26 Mar 2023 19:49:49 +0300

Turns out rules about PT_INTERP, PT_GNU_STACK and PT_GNU_PROPERTY
program headers are slightly different.

Link: https://lkml.kernel.org/r/c4233c97-306c-4db8-9667-34fc31ec4aed@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/ELF/ELF.rst   |   32 ++++++++++++++++++++++++++++++++
 Documentation/ELF/index.rst |   10 ++++++++++
 Documentation/index.rst     |    1 +
 3 files changed, 43 insertions(+)

--- /dev/null
+++ a/Documentation/ELF/ELF.rst
@@ -0,0 +1,32 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================================
+Linux-specific ELF idiosyncrasies
+=================================
+
+Definitions
+===========
+
+"First" program header is the one with the smallest offset in the file:
+e_phoff. "Last" program header is the one with the biggest offset:
+e_phoff + (e_phnum - 1) * sizeof(Elf_Phdr).
+
+PT_INTERP
+=========
+
+First PT_INTERP program header is used to locate the filename of ELF
+interpreter. Other PT_INTERP headers are ignored (since Linux 2.4.11).
+
+PT_GNU_STACK
+============
+
+Last PT_GNU_STACK program header defines userspace stack executability
+(since Linux 2.6.6). Other PT_GNU_STACK headers are ignored.
+
+PT_GNU_PROPERTY
+===============
+
+ELF interpreter's last PT_GNU_PROPERTY program header is used (since
+Linux 5.8). If interpreter doesn't have one, then the last PT_GNU_PROPERTY
+program header of an executable is used. Other PT_GNU_PROPERTY headers
+are ignored.
--- /dev/null
+++ a/Documentation/ELF/index.rst
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===
+ELF
+===
+
+.. toctree::
+   :maxdepth: 1
+
+   ELF
--- a/Documentation/index.rst~elf-document-some-de-facto-pt_-abi-quirks
+++ a/Documentation/index.rst
@@ -113,6 +113,7 @@ to ReStructured Text format, or are simp
    :maxdepth: 1
 
    staging/index
+   ELF/index
 
 
 Translations
_

Patches currently in -mm which might be from adobriyan@gmail.com are

mm-uninline-kstrdup.patch
elf-fix-all-elf-typos.patch
elf-document-some-de-facto-pt_-abi-quirks.patch