Merge tag 'linux_kselftest-nolibc-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull nolibc updates from Shuah Khan:
 "Highlights:

   - Clang support (including LTO)

  Other Changes:

   - stdbool.h support

   - argc/argv/envp arguments for constructors

   - Small #include ordering fix"

* tag 'linux_kselftest-nolibc-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
  tools/nolibc: x86_64: use local label in memcpy/memmove
  tools/nolibc: stackprotector: mark implicitly used symbols as used
  tools/nolibc: crt: mark _start_c() as used
  selftests/nolibc: run-tests.sh: allow building through LLVM
  selftests/nolibc: use correct clang target for s390/systemz
  selftests/nolibc: don't use libgcc when building with clang
  selftests/nolibc: run-tests.sh: avoid overwriting CFLAGS_EXTRA
  selftests/nolibc: add cc-option compatible with clang cross builds
  selftests/nolibc: add support for LLVM= parameter
  selftests/nolibc: determine $(srctree) first
  selftests/nolibc: avoid passing NULL to printf("%s")
  selftests/nolibc: report failure if no testcase passed
  tools/nolibc: compiler: use attribute((naked)) if available
  tools/nolibc: move entrypoint specifics to compiler.h
  tools/nolibc: compiler: introduce __nolibc_has_attribute()
  tools/nolibc: powerpc: limit stack-protector workaround to GCC
  tools/nolibc: mips: load current function to $t9
  tools/nolibc: arm: use clang-compatible asm syntax
  tools/nolibc: pass argc, argv and envp to constructors
  tools/nolibc: add stdbool.h header
  ...

3 files changed, 45 insertions, 21 deletions

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 3fbabab46958..8de98ea7af80 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -1,19 +1,21 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for nolibc tests
-include ../../../scripts/Makefile.include
-include ../../../scripts/utilities.mak
-# We need this for the "cc-option" macro.
-include ../../../build/Build.include
+# we're in ".../tools/testing/selftests/nolibc"
+ifeq ($(srctree),)
+srctree := $(patsubst %/tools/testing/selftests/,%,$(dir $(CURDIR)))
+endif
+
+include $(srctree)/tools/scripts/utilities.mak
+# We need this for the "__cc-option" macro.
+include $(srctree)/scripts/Makefile.compiler
 
 ifneq ($(O),)
 ifneq ($(call is-absolute,$(O)),y)
 $(error Only absolute O= parameters are supported)
 endif
-endif
-
-# we're in ".../tools/testing/selftests/nolibc"
-ifeq ($(srctree),)
-srctree := $(patsubst %/tools/testing/selftests/,%,$(dir $(CURDIR)))
+objtree := $(O)
+else
+objtree ?= $(srctree)
 endif
 
 ifeq ($(ARCH),)
@@ -21,7 +23,7 @@ include $(srctree)/scripts/subarch.include
 ARCH = $(SUBARCH)
 endif
 
-objtree ?= $(srctree)
+cc-option = $(call __cc-option, $(CC),$(CLANG_CROSS_FLAGS),$(1),$(2))
 
 # XARCH extends the kernel's ARCH with a few variants of the same
 # architecture that only differ by the configuration, the toolchain
@@ -155,9 +157,22 @@ CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 -W -Wall -Wex
 		$(CFLAGS_$(XARCH)) $(CFLAGS_STACKPROTECTOR) $(CFLAGS_EXTRA)
 LDFLAGS :=
 
+LIBGCC := -lgcc
+
+ifneq ($(LLVM),)
+# Not needed for clang
+LIBGCC :=
+endif
+
+# Modify CFLAGS based on LLVM=
+include $(srctree)/tools/scripts/Makefile.include
+
+# GCC uses "s390", clang "systemz"
+CLANG_CROSS_FLAGS := $(subst --target=s390-linux,--target=systemz-linux,$(CLANG_CROSS_FLAGS))
+
 REPORT  ?= awk '/\[OK\][\r]*$$/{p++} /\[FAIL\][\r]*$$/{if (!f) printf("\n"); f++; print;} /\[SKIPPED\][\r]*$$/{s++} \
 		END{ printf("\n%3d test(s): %3d passed, %3d skipped, %3d failed => status: ", p+s+f, p, s, f); \
-		if (f) printf("failure\n"); else if (s) printf("warning\n"); else printf("success\n");; \
+		if (f || !p) printf("failure\n"); else if (s) printf("warning\n"); else printf("success\n");; \
 		printf("\nSee all results in %s\n", ARGV[1]); }'
 
 help:
@@ -204,11 +219,11 @@ sysroot/$(ARCH)/include:
 ifneq ($(NOLIBC_SYSROOT),0)
 nolibc-test: nolibc-test.c nolibc-test-linkage.c sysroot/$(ARCH)/include
 	$(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \
-	  -nostdlib -nostdinc -static -Isysroot/$(ARCH)/include nolibc-test.c nolibc-test-linkage.c -lgcc
+	  -nostdlib -nostdinc -static -Isysroot/$(ARCH)/include nolibc-test.c nolibc-test-linkage.c $(LIBGCC)
 else
 nolibc-test: nolibc-test.c nolibc-test-linkage.c
 	$(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \
-	  -nostdlib -static -include $(srctree)/tools/include/nolibc/nolibc.h nolibc-test.c nolibc-test-linkage.c -lgcc
+	  -nostdlib -static -include $(srctree)/tools/include/nolibc/nolibc.h nolibc-test.c nolibc-test-linkage.c $(LIBGCC)
 endif
 
 libc-test: nolibc-test.c nolibc-test-linkage.c
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 093d0512f4c5..6fba7025c5e3 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -542,7 +542,7 @@ int expect_strzr(const char *expr, int llen)
 {
 	int ret = 0;
 
-	llen += printf(" = <%s> ", expr);
+	llen += printf(" = <%s> ", expr ? expr : "(null)");
 	if (expr) {
 		ret = 1;
 		result(llen, FAIL);
@@ -561,7 +561,7 @@ int expect_strnz(const char *expr, int llen)
 {
 	int ret = 0;
 
-	llen += printf(" = <%s> ", expr);
+	llen += printf(" = <%s> ", expr ? expr : "(null)");
 	if (!expr) {
 		ret = 1;
 		result(llen, FAIL);
@@ -686,9 +686,10 @@ static void constructor1(void)
 }
 
 __attribute__((constructor))
-static void constructor2(void)
+static void constructor2(int argc, char **argv, char **envp)
 {
-	constructor_test_value *= 2;
+	if (argc && argv && envp)
+		constructor_test_value *= 2;
 }
 
 int run_startup(int min, int max)
diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index 0446e6326a40..e7ecda4ae796 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -15,10 +15,11 @@ download_location="${cache_dir}/crosstools/"
 build_location="$(realpath "${cache_dir}"/nolibc-tests/)"
 perform_download=0
 test_mode=system
-CFLAGS_EXTRA="-Werror"
+werror=1
+llvm=
 archs="i386 x86_64 arm64 arm mips32le mips32be ppc ppc64 ppc64le riscv s390 loongarch"
 
-TEMP=$(getopt -o 'j:d:c:b:a:m:peh' -n "$0" -- "$@")
+TEMP=$(getopt -o 'j:d:c:b:a:m:pelh' -n "$0" -- "$@")
 
 eval set -- "$TEMP"
 unset TEMP
@@ -42,6 +43,7 @@ Options:
  -b [DIR]       Build location (default: ${build_location})
  -m [MODE]      Test mode user/system (default: ${test_mode})
  -e             Disable -Werror
+ -l             Build with LLVM/clang
 EOF
 }
 
@@ -69,7 +71,10 @@ while true; do
 			test_mode="$2"
 			shift 2; continue ;;
 		'-e')
-			CFLAGS_EXTRA=""
+			werror=0
+			shift; continue ;;
+		'-l')
+			llvm=1
 			shift; continue ;;
 		'-h')
 			print_usage
@@ -140,7 +145,10 @@ test_arch() {
 	ct_abi=$(crosstool_abi "$1")
 	cross_compile=$(realpath "${download_location}gcc-${crosstool_version}-nolibc/${ct_arch}-${ct_abi}/bin/${ct_arch}-${ct_abi}-")
 	build_dir="${build_location}/${arch}"
-	MAKE=(make -j"${nproc}" XARCH="${arch}" CROSS_COMPILE="${cross_compile}" O="${build_dir}")
+	if [ "$werror" -ne 0 ]; then
+		CFLAGS_EXTRA="$CFLAGS_EXTRA -Werror"
+	fi
+	MAKE=(make -j"${nproc}" XARCH="${arch}" CROSS_COMPILE="${cross_compile}" LLVM="${llvm}" O="${build_dir}")
 
 	mkdir -p "$build_dir"
 	if [ "$test_mode" = "system" ] && [ ! -f "${build_dir}/.config" ]; then