[PATCH] kbuild: dummy-tools: adjust to stricter stackprotector check

From: Michal Kubecek <mkubecek@suse.cz>
To: Masahiro Yamada <masahiroy@kernel.org>, linux-kbuild@vger.kernel.org
Cc: Michal Marek <michal.lkml@markovi.net>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] kbuild: dummy-tools: adjust to stricter stackprotector check
Date: Sat, 15 May 2021 12:11:13 +0200	[thread overview]
Message-ID: <13e53f8f5dab1e3e070b4cb34bbe8b89f85f5326.1621076083.git.mkubecek@suse.cz> (raw)

Commit 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular
percpu variable") modified the stackprotector check on 32-bit x86 to check
if gcc supports using %fs as canary. Adjust dummy-tools gcc script to pass
this new test by returning "%fs" rather than "%gs" if it detects
-mstack-protector-guard-reg=fs on command line.

Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
 scripts/dummy-tools/gcc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/scripts/dummy-tools/gcc b/scripts/dummy-tools/gcc
index f6d543725f1e..b2483149bbe5 100755
--- a/scripts/dummy-tools/gcc
+++ b/scripts/dummy-tools/gcc
@@ -76,7 +76,11 @@ fi
 if arg_contain -S "$@"; then
 	# For scripts/gcc-x86-*-has-stack-protector.sh
 	if arg_contain -fstack-protector "$@"; then
-		echo "%gs"
+		if arg_contain -mstack-protector-guard-reg=fs "$@"; then
+			echo "%fs"
+		else
+			echo "%gs"
+		fi
 		exit 0
 	fi
 
-- 
2.31.1

