kbuild: Fix '-S -c' in x86 stack protector scripts

After a recent change in clang to stop consuming all instances of '-S'
and '-c' [1], the stack protector scripts break due to the kernel's use
of -Werror=unused-command-line-argument to catch cases where flags are
not being properly consumed by the compiler driver:

  $ echo | clang -o - -x c - -S -c -Werror=unused-command-line-argument
  clang: error: argument unused during compilation: '-c' [-Werror,-Wunused-command-line-argument]

This results in CONFIG_STACKPROTECTOR getting disabled because
CONFIG_CC_HAS_SANE_STACKPROTECTOR is no longer set.

'-c' and '-S' both instruct the compiler to stop at different stages of
the pipeline ('-S' after compiling, '-c' after assembling), so having
them present together in the same command makes little sense. In this
case, the test wants to stop before assembling because it is looking at
the textual assembly output of the compiler for either '%fs' or '%gs',
so remove '-c' from the list of arguments to resolve the error.

All versions of GCC continue to work after this change, along with
versions of clang that do or do not contain the change mentioned above.

Cc: stable@vger.kernel.org
Fixes: 4f7fd4d7a791 ("[PATCH] Add the -fstack-protector option to the CFLAGS")
Fixes: 60a5317ff0f4 ("x86: implement x86_32 stack protector")
Link: https://github.com/llvm/llvm-project/commit/6461e537815f7fa68cef06842505353cf5600e9c
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/scripts/gcc-x86_32-has-stack-protector.sh b/scripts/gcc-x86_32-has-stack-protector.sh
index 825c75c5b715051405905c599ff0e7b9f19a9106..9459ca4f0f11fb28d807d1e0bacee3f63bb27062 100755 (executable)
--- a/scripts/gcc-x86_32-has-stack-protector.sh
+++ b/scripts/gcc-x86_32-has-stack-protector.sh
@@ -5,4 +5,4 @@
 # -mstack-protector-guard-reg, added by
 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81708
 
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -m32 -O0 -fstack-protector -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard - -o - 2> /dev/null | grep -q "%fs"
+echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m32 -O0 -fstack-protector -mstack-protector-guard-reg=fs -mstack-protector-guard-symbol=__stack_chk_guard - -o - 2> /dev/null | grep -q "%fs"

diff --git a/scripts/gcc-x86_64-has-stack-protector.sh b/scripts/gcc-x86_64-has-stack-protector.sh
index 75e4e22b986adcfd07197777c5d59d5601d3c920..f680bb01aeeb30fcf3fe44289f2db4b4c8158d63 100755 (executable)
--- a/scripts/gcc-x86_64-has-stack-protector.sh
+++ b/scripts/gcc-x86_64-has-stack-protector.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 
-echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -m64 -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs"
+echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -m64 -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs"