NetBSD Problem Report #57405

From www@netbsd.org  Sat May 13 10:28:48 2023
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Date: Sat, 13 May 2023 10:28:46 +0000 (UTC)
From: campbell+netbsd@mumble.net
Reply-To: campbell+netbsd@mumble.net
To: gnats-bugs@NetBSD.org
Subject: clang build has been broken on aarch64 since binutils 2.39 update
X-Send-Pr-Version: www-1.0

>Number:         57405
>Category:       toolchain
>Synopsis:       clang build has been broken on aarch64 since binutils 2.39 update
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 13 10:30:01 +0000 2023
>Last-Modified:  Sat May 13 11:00:05 +0000 2023
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The NetLD Foundation
>Environment:
>Description:
build_install ===> compat       (with: BOOTSTRAP_SUBDIRS=../../../lib)
build_install ===> compat/dirshack
build_install ===> compat/arm/eabi
build_install ===> compat/arm/eabi/../../../lib
dependall-csu ===> compat/arm/eabi/../../../lib
dependall ===> compat/arm/eabi/../../../lib/csu
install-csu ===> compat/arm/eabi/../../../lib
install ===> compat/arm/eabi/../../../lib/csu
dependall-libc ===> compat/arm/eabi/../../../lib
dependall ===> compat/arm/eabi/../../../lib/libc
      build  libc/libc.so.12.220.link
/home/riastradh/netbsd/current/src/../obj.arm64-clang/tooldir/aarch64--netbsd/bin/ld: warning: -z relro ignored
aarch64--netbsd-clang: error: linker command failed with exit code 1 (use -v to see invocation)                

This warning appears to be new, arising from this change to ignore the `-z relro' option:

http://cvsweb.netbsd.org/bsdweb.cgi/src/external/gpl3/binutils/dist/ld/emultempl/elf.em.diff?r1=1.2&r2=1.3&only_with_tag=MAIN

       else if (strcmp (optarg, "nocopyreloc") == 0)
-	link_info.nocopyreloc = TRUE;
+	link_info.nocopyreloc = true;
+EOF
+if test -n "$COMMONPAGESIZE"; then
+fragment <<EOF
       else if (strcmp (optarg, "relro") == 0)
-	link_info.relro = TRUE;
+	link_info.relro = true;
       else if (strcmp (optarg, "norelro") == 0)
-	link_info.relro = FALSE;
+	link_info.relro = false;
+EOF
+fi
+fragment <<EOF
       else if (strcmp (optarg, "separate-code") == 0)

I'm not sure if relro is expected to work, now or ever, on 32-bit arm, but `-z relro' is passed only if MKRELRO is not `no':

https://nxr.netbsd.org/xref/src/share/mk/bsd.sys.mk?r=1.313#140

    140 .if ${MKRELRO:Uno} != "no"
    141 LDFLAGS+=	-Wl,-z,relro
    142 .endif

And bsd.own.mk enables MKRELRO by default on aarch64 and disables it by default on 32-bit arm:

https://nxr.netbsd.org/xref/src/share/mk/bsd.own.mk?r=1.1318#1138

   1137 #
   1138 # RELRO is enabled on i386, amd64, and aarch64 by default
   1139 #
   1140 .if ${MACHINE} == "i386" || \
   1141     ${MACHINE} == "amd64" || \
   1142     ${MACHINE_ARCH:Maarch64*}
   1143 MKRELRO?=	partial
   1144 .else
   1145 MKRELRO?=	no
   1146 .endif

So presumably relro should be disabled during the 32-bit compat library builds.  But it must be enabled if the build fails this way.  Perhaps we need to manually override it somewhere in the makefile magic under src/compat.
>How-To-Repeat:
./build.sh -c clang -m evbarm64 release
>Fix:
Yes, please!

>Audit-Trail:
From: Taylor R Campbell <campbell+netbsd@mumble.net>
To: gnats-bugs@netbsd.org
Cc: 
Subject: Re: toolchain/57405: clang build has been broken on aarch64 since binutils 2.39 update
Date: Sat, 13 May 2023 10:39:51 +0000

 And this only happens in the clang build because 32-bit compat
 libraries are only enabled in the clang build for now:

 https://nxr.netbsd.org/xref/src/compat/archdirs.mk?r=1.14#31

      31 .if ${ACTIVE_CC} == "clang"
      32 .if (${MACHINE_ARCH} == "aarch64")
      33 ARCHDIR_SUBDIR+= arm/eabi
      34 ARCHDIR_SUBDIR+= arm/eabihf
      35 .elif (${MACHINE_ARCH} == "aarch64eb")
      36 ARCHDIR_SUBDIR+= arm/eabi
      37 .endif
      38 .endif

 (That they have to be disabled in the gcc build is a different bug for
 other reasons I don't remember; someone should file a separate PR for
 that.)

From: "Taylor R Campbell" <riastradh@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/57405 CVS commit: src
Date: Sat, 13 May 2023 10:56:55 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Sat May 13 10:56:55 UTC 2023

 Modified Files:
 	src/compat/arm/eabi: bsd.eabi.mk
 	src/compat/arm/eabihf: bsd.eabihf.mk
 	src/share/mk: bsd.own.mk

 Log Message:
 compat: Disable relro in 32-bit arm compat.

 Not supported by binutils:

 ld: warning: -z relro ignored

 PR toolchain/57405


 To generate a diff of this commit:
 cvs rdiff -u -r1.6 -r1.7 src/compat/arm/eabi/bsd.eabi.mk
 cvs rdiff -u -r1.4 -r1.5 src/compat/arm/eabihf/bsd.eabihf.mk
 cvs rdiff -u -r1.1318 -r1.1319 src/share/mk/bsd.own.mk

 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.

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