From: Sergei Trofimovich <slyfox@gentoo.org>
Date: Fri, 15 May 2020 23:11:54 +0000 (+0100)
Subject: sys-libs/glibc: avoid GPREL overflow on ia64, bug #723268
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=f43c7cd9e5a92d784af5e21ba22083cdb70c0e51;p=gentoo.git

sys-libs/glibc: avoid GPREL overflow on ia64, bug #723268

-fno-common had unintended side-effect to optimise more
accesses to global variables as module-local via GPREL22
relocations. Unfortunately glibc is large enough to overflow
GPREL22 offset.

Let's add a -fcommon workaround back to pessimize code slightly
that refers module-local globals. We'll need an equivalen of
-fPIC to do it consistently.

Bug: https://bugs.gentoo.org/723268
Package-Manager: Portage-2.3.99, Repoman-2.3.22
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---

diff --git a/sys-libs/glibc/glibc-2.30-r8.ebuild b/sys-libs/glibc/glibc-2.30-r8.ebuild
index aea0098e69f7..0421d5e61db1 100644
--- a/sys-libs/glibc/glibc-2.30-r8.ebuild
+++ b/sys-libs/glibc/glibc-2.30-r8.ebuild
@@ -305,6 +305,12 @@ setup_target_flags() {
 				einfo "Auto adding -march=${t} to CFLAGS_x86 #185404 (ABI=${ABI})"
 			fi
 		;;
+		ia64)
+			# Workaround GPREL22 overflow by slightly pessimizing global
+			# references to go via 64-bit relocations instead of 22-bit ones.
+			# This allows building glibc on ia64 without an overflow: #723268
+			append-flags -fcommon
+		;;
 		mips)
 			# The mips abi cannot support the GNU style hashes. #233233
 			filter-ldflags -Wl,--hash-style=gnu -Wl,--hash-style=both
diff --git a/sys-libs/glibc/glibc-2.31-r3.ebuild b/sys-libs/glibc/glibc-2.31-r3.ebuild
index c05055b8811e..5580625ba6d0 100644
--- a/sys-libs/glibc/glibc-2.31-r3.ebuild
+++ b/sys-libs/glibc/glibc-2.31-r3.ebuild
@@ -299,6 +299,12 @@ setup_target_flags() {
 				einfo "Auto adding -march=${t} to CFLAGS_x86 #185404 (ABI=${ABI})"
 			fi
 		;;
+		ia64)
+			# Workaround GPREL22 overflow by slightly pessimizing global
+			# references to go via 64-bit relocations instead of 22-bit ones.
+			# This allows building glibc on ia64 without an overflow: #723268
+			append-flags -fcommon
+		;;
 		mips)
 			# The mips abi cannot support the GNU style hashes. #233233
 			filter-ldflags -Wl,--hash-style=gnu -Wl,--hash-style=both
diff --git a/sys-libs/glibc/glibc-9999.ebuild b/sys-libs/glibc/glibc-9999.ebuild
index bba57f5d6075..2355e5bce34e 100644
--- a/sys-libs/glibc/glibc-9999.ebuild
+++ b/sys-libs/glibc/glibc-9999.ebuild
@@ -298,6 +298,12 @@ setup_target_flags() {
 				einfo "Auto adding -march=${t} to CFLAGS_x86 #185404 (ABI=${ABI})"
 			fi
 		;;
+		ia64)
+			# Workaround GPREL22 overflow by slightly pessimizing global
+			# references to go via 64-bit relocations instead of 22-bit ones.
+			# This allows building glibc on ia64 without an overflow: #723268
+			append-flags -fcommon
+		;;
 		mips)
 			# The mips abi cannot support the GNU style hashes. #233233
 			filter-ldflags -Wl,--hash-style=gnu -Wl,--hash-style=both