From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     gwml@vger.gnuweeb.org, kernel-team@meta.com, w@lwt.eu,
        =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>,
        Willy Tarreau <w@1wt.eu>,
        "Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH nolibc 01/14] tools/nolibc: always disable stack protector for tests
Date:   Mon, 20 Mar 2023 18:11:24 -0700
Message-Id: <20230321011137.51837-1-paulmck@kernel.org>
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From: Thomas Weißschuh <linux@weissschuh.net>

Stack protectors need support from libc.
This support is not provided by nolibc which leads to compiler errors
when stack protectors are enabled by default in a compiler:

      CC      nolibc-test
    /usr/bin/ld: /tmp/ccqbHEPk.o: in function `stat':
    nolibc-test.c:(.text+0x1d1): undefined reference to `__stack_chk_fail'
    /usr/bin/ld: /tmp/ccqbHEPk.o: in function `poll.constprop.0':
    nolibc-test.c:(.text+0x37b): undefined reference to `__stack_chk_fail'
    /usr/bin/ld: /tmp/ccqbHEPk.o: in function `vfprintf.constprop.0':
    nolibc-test.c:(.text+0x712): undefined reference to `__stack_chk_fail'
    /usr/bin/ld: /tmp/ccqbHEPk.o: in function `pad_spc.constprop.0':
    nolibc-test.c:(.text+0x80d): undefined reference to `__stack_chk_fail'
    /usr/bin/ld: /tmp/ccqbHEPk.o: in function `printf':
    nolibc-test.c:(.text+0x8c4): undefined reference to `__stack_chk_fail'
    /usr/bin/ld: /tmp/ccqbHEPk.o:nolibc-test.c:(.text+0x12d4): more undefined references to `__stack_chk_fail' follow
    collect2: error: ld returned 1 exit status

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/nolibc/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 8fe61d3e3cce..874d141da8c4 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for nolibc tests
 include ../../../scripts/Makefile.include
+# We need this for the "cc-option" macro.
+include ../../../build/Build.include
 
 # we're in ".../tools/testing/selftests/nolibc"
 ifeq ($(srctree),)
@@ -72,6 +74,7 @@ endif
 
 CFLAGS_s390 = -m64
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables $(CFLAGS_$(ARCH))
+CFLAGS  += $(call cc-option,-fno-stack-protector)
 LDFLAGS := -s
 
 help:
-- 
2.40.0.rc2