From ba44e5b50873ceea25884af280612e100e151746 Mon Sep 17 00:00:00 2001 From: Dragan Mladjenovic Date: Wed, 22 Jan 2020 17:14:23 +0000 Subject: [PATCH] Add NEWS entry about the change in handling of PT_GNU_STACK on MIPS The change was introduced in: commit 33bc9efd91de1b14354291fc8ebd5bce96379f12 Author: Dragan Mladjenovic Date: Fri Aug 23 16:38:04 2019 +0000 mips: Force RWX stack for hard-float builds that can run on pre-4.8 kernels and probably requires a small explanation. Co-authored-by: Siddhesh Poyarekar --- NEWS | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/NEWS b/NEWS index 44065d9..10814ef 100644 --- a/NEWS +++ b/NEWS @@ -112,6 +112,18 @@ Deprecated and removed features, and other changes affecting compatibility: captured in a dlerror message. In general, this is unsafe because resetting the stack in an arbitrary function call is not possible. +* For MIPS hard-float ABIs, the GNU C Library will be configured to need an + executable stack unless explicitly configured at build time to require + minimum kernel version 4.8 or newer. This is because executing + floating-point branches on a non-executable stack on Linux kernels prior to + 4.8 can lead to application crashes for some MIPS configurations. While + currently PT_GNU_STACK is not widely used on MIPS, future releases of GCC are + expected to enable non-executable stack by default with PT_GNU_STACK by + default and is thus likely to trigger a crash on older kernels. + + The GNU C Library can be built with --enable-kernel=4.8.0 in order to keep a + non-executable stack while dropping support for older kernels. + Changes to build and runtime requirements: * It is no longer necessary to have recent Linux kernel headers to build -- 2.7.4