emacs: Do not use SIGSTKSZ

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/emacs/emacs_27.2.bb

@@ -4,8 +4,9 @@ HOMEPAGE = "https://www.gnu.org/software/emacs/"
 LICENSE = "GPLv3"
 LIC_FILES_CHKSUM = "file://COPYING;md5=1ebbd3e34237af26da5dc08a4e440464"
 
-SRC_URI = "https://ftp.gnu.org/pub/gnu/emacs/emacs-${PV}.tar.xz"
-
+SRC_URI = "https://ftp.gnu.org/pub/gnu/emacs/emacs-${PV}.tar.xz \
+           file://emacs-glibc-2.34.patch \
+          "
 SRC_URI_append_class-target = " file://usemake-docfile-native.patch"
 
 SRC_URI[sha256sum] = "b4a7cc4e78e63f378624e0919215b910af5bb2a0afc819fad298272e9f40c1b9"

meta-oe/recipes-support/emacs/files/emacs-glibc-2.34.patch

@@ -0,0 +1,40 @@
+From f97e07ea807cc6d38774a3888a15091b20645ac6 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Tue, 9 Mar 2021 11:22:59 -0800
+Subject: [PATCH] Port alternate signal stack to upcoming glibc 2.34
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+* src/sysdep.c (sigsegv_stack): Increase size to 64 KiB and align
+it to max_align_t.  This copies from Gnulib’s c-stack.c, and works
+around a portability bug in draft glibc 2.34, which no longer
+defines SIGSTKSZ when _GNU_SOURCE is defined.
+---
+ src/sysdep.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/src/sysdep.c b/src/sysdep.c
+index 941b4e2fa2..24d8832b2f 100644
+--- a/src/sysdep.c
++++ b/src/sysdep.c
+@@ -1785,7 +1785,15 @@ handle_arith_signal (int sig)
+ 
+ /* Alternate stack used by SIGSEGV handler below.  */
+ 
+-static unsigned char sigsegv_stack[SIGSTKSZ];
++/* Storage for the alternate signal stack.
++   64 KiB is not too large for Emacs, and is large enough
++   for all known platforms.  Smaller sizes may run into trouble.
++   For example, libsigsegv 2.6 through 2.8 have a bug where some
++   architectures use more than the Linux default of an 8 KiB alternate
++   stack when deciding if a fault was caused by stack overflow.  */
++static max_align_t sigsegv_stack[(64 * 1024
++				  + sizeof (max_align_t) - 1)
++				 / sizeof (max_align_t)];
+ 
+ 
+ /* Return true if SIGINFO indicates a stack overflow.  */
+-- 
+2.29.2
+