From 0de64754a55470adb0a870f3105c8922334bb6fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 21:10:42 +0100
Subject: [PATCH 01/26] tools/nolibc: add prototypes for non-static functions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

With -Wmissing-prototypes the compiler will warn about non-static
functions which don't have a prototype defined.
This warning doesn't make much sense for nolibc itself but for user code
it is still useful.
To pacify the compiler add prototypes next to the function definitions,
similar to how it is handled elsewhere in the kernel.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-1-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/arch-mips.h      | 1 +
 tools/include/nolibc/crt.h            | 2 ++
 tools/include/nolibc/signal.h         | 1 +
 tools/include/nolibc/stackprotector.h | 2 ++
 tools/include/nolibc/stdlib.h         | 1 +
 tools/include/nolibc/string.h         | 4 ++++
 6 files changed, 11 insertions(+)

diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index 1791a8ce58da..753a8ed2cf69 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -179,6 +179,7 @@
 })
 
 /* startup code, note that it's called __start on MIPS */
+void __start(void);
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __start(void)
 {
 	__asm__ volatile (
diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h
index bbcd5fd09806..c4b10103bbec 100644
--- a/tools/include/nolibc/crt.h
+++ b/tools/include/nolibc/crt.h
@@ -10,6 +10,7 @@
 char **environ __attribute__((weak));
 const unsigned long *_auxv __attribute__((weak));
 
+void _start(void);
 static void __stack_chk_init(void);
 static void exit(int);
 
@@ -22,6 +23,7 @@ extern void (*const __init_array_end[])(int, char **, char**) __attribute__((wea
 extern void (*const __fini_array_start[])(void) __attribute__((weak));
 extern void (*const __fini_array_end[])(void) __attribute__((weak));
 
+void _start_c(long *sp);
 __attribute__((weak,used))
 void _start_c(long *sp)
 {
diff --git a/tools/include/nolibc/signal.h b/tools/include/nolibc/signal.h
index 137552216e46..cdcc5904c51e 100644
--- a/tools/include/nolibc/signal.h
+++ b/tools/include/nolibc/signal.h
@@ -13,6 +13,7 @@
 #include "sys.h"
 
 /* This one is not marked static as it's needed by libgcc for divide by zero */
+int raise(int signal);
 __attribute__((weak,unused,section(".text.nolibc_raise")))
 int raise(int signal)
 {
diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
index 1d0d5259ec41..c71a2c257177 100644
--- a/tools/include/nolibc/stackprotector.h
+++ b/tools/include/nolibc/stackprotector.h
@@ -18,6 +18,7 @@
  * triggering stack protector errors themselves
  */
 
+void __stack_chk_fail(void);
 __attribute__((weak,used,noreturn,section(".text.nolibc_stack_chk")))
 void __stack_chk_fail(void)
 {
@@ -28,6 +29,7 @@ void __stack_chk_fail(void)
 	for (;;);
 }
 
+void __stack_chk_fail_local(void);
 __attribute__((weak,noreturn,section(".text.nolibc_stack_chk")))
 void __stack_chk_fail_local(void)
 {
diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 75aa273c23a6..86ad378ab1ea 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -30,6 +30,7 @@ static __attribute__((unused)) char itoa_buffer[21];
  */
 
 /* must be exported, as it's used by libgcc for various divide functions */
+void abort(void);
 __attribute__((weak,unused,noreturn,section(".text.nolibc_abort")))
 void abort(void)
 {
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index 9ec9c24f38c0..ba84ab700e30 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -32,6 +32,7 @@ int memcmp(const void *s1, const void *s2, size_t n)
 /* might be ignored by the compiler without -ffreestanding, then found as
  * missing.
  */
+void *memmove(void *dst, const void *src, size_t len);
 __attribute__((weak,unused,section(".text.nolibc_memmove")))
 void *memmove(void *dst, const void *src, size_t len)
 {
@@ -56,6 +57,7 @@ void *memmove(void *dst, const void *src, size_t len)
 
 #ifndef NOLIBC_ARCH_HAS_MEMCPY
 /* must be exported, as it's used by libgcc on ARM */
+void *memcpy(void *dst, const void *src, size_t len);
 __attribute__((weak,unused,section(".text.nolibc_memcpy")))
 void *memcpy(void *dst, const void *src, size_t len)
 {
@@ -73,6 +75,7 @@ void *memcpy(void *dst, const void *src, size_t len)
 /* might be ignored by the compiler without -ffreestanding, then found as
  * missing.
  */
+void *memset(void *dst, int b, size_t len);
 __attribute__((weak,unused,section(".text.nolibc_memset")))
 void *memset(void *dst, int b, size_t len)
 {
@@ -124,6 +127,7 @@ char *strcpy(char *dst, const char *src)
  * thus itself, hence the asm() statement below that's meant to disable this
  * confusing practice.
  */
+size_t strlen(const char *str);
 __attribute__((weak,unused,section(".text.nolibc_strlen")))
 size_t strlen(const char *str)
 {

From 69ccba67d7cd9d92f313164eb00606b553a6d188 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 21:10:43 +0100
Subject: [PATCH 02/26] selftests/nolibc: ignore -Wmissing-prototypes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

To make sure nolibc itself is compatible with -Wmissing-prototypes the
compiler flag should be enabled when building nolibc-test.
However some of its functions are non-static to ease debugging [0],
triggering the compiler warning.

Disable the warning inside nolibc-test while still enabling it for
nolibc itself.

[0] https://lore.kernel.org/lkml/ZMjM0UPRAqoC+goY@1wt.eu/

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-2-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 0e0e3b48a8c3..f162793b162f 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -43,6 +43,8 @@
 #endif
 #endif
 
+#pragma GCC diagnostic ignored "-Wmissing-prototypes"
+
 #include "nolibc-test-linkage.h"
 
 /* for the type of int_fast16_t and int_fast32_t, musl differs from glibc and nolibc */

From 4da4e35e9d7ebcf575e02791fa3b1784bd0765a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 21:10:44 +0100
Subject: [PATCH 03/26] selftests/nolibc: enable -Wmissing-prototypes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

User code may want to use this compiler flag.
Make sure it is supported by nolibc.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-prototype-v1-3-e1afc5c1999a@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 7d14a7c0cb62..f867ebe3474e 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -164,7 +164,7 @@ CFLAGS_mips32le = -EL -mabi=32 -fPIC
 CFLAGS_mips32be = -EB -mabi=32
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 -W -Wall -Wextra \
-		$(call cc-option,-fno-stack-protector) \
+		$(call cc-option,-fno-stack-protector) $(call cc-option,-Wmissing-prototypes) \
 		$(CFLAGS_$(XARCH)) $(CFLAGS_STACKPROTECTOR) $(CFLAGS_EXTRA)
 LDFLAGS :=
 

From cfb1bfe9535a74f01a6b9df9fbf1cf0608d13786 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Tue, 28 Jan 2025 22:22:46 +0100
Subject: [PATCH 04/26] tools/nolibc: make signature of ioctl() more flexible
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

POSIX defines the signature of ioctl() as follows,
to allow passing a pointer or integer without casting:
	int ioctl(int fildes, int request, ... /* arg */);

Nolibc ioctl() expects a pointer, forcing the user to manually cast.
Using va_arg to make the signature more flexible would work but seems to
prevent inlining of the function. Instead use a macro. "fd" and "req"
will still be typechecked through sys_ioctl().

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys.h | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index d4a5c2399a66..8c0a55bc9dc3 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -532,20 +532,16 @@ uid_t getuid(void)
 
 
 /*
- * int ioctl(int fd, unsigned long req, void *value);
+ * int ioctl(int fd, unsigned long cmd, ... arg);
  */
 
 static __attribute__((unused))
-int sys_ioctl(int fd, unsigned long req, void *value)
+long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
 {
-	return my_syscall3(__NR_ioctl, fd, req, value);
+	return my_syscall3(__NR_ioctl, fd, cmd, arg);
 }
 
-static __attribute__((unused))
-int ioctl(int fd, unsigned long req, void *value)
-{
-	return __sysret(sys_ioctl(fd, req, value));
-}
+#define ioctl(fd, cmd, arg) __sysret(sys_ioctl(fd, cmd, (unsigned long)(arg)))
 
 /*
  * int kill(pid_t pid, int signal);

From e16214dc1fbfa7ad6b6d2d8b4dcf05a7b3e5eb45 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 08:37:37 +0100
Subject: [PATCH 05/26] selftests/nolibc: drop mips32be EXTRACONFIG
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

kbuild already contains logic to merge predefines snippets into a
defconfig file. For MIPS a snippet for big-endian is already provided.

Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-1-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index f867ebe3474e..5e2abc3493de 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -82,7 +82,7 @@ DEFCONFIG_x86        = defconfig
 DEFCONFIG_arm64      = defconfig
 DEFCONFIG_arm        = multi_v7_defconfig
 DEFCONFIG_mips32le   = malta_defconfig
-DEFCONFIG_mips32be   = malta_defconfig
+DEFCONFIG_mips32be   = malta_defconfig generic/eb.config
 DEFCONFIG_ppc        = pmac32_defconfig
 DEFCONFIG_ppc64      = powernv_be_defconfig
 DEFCONFIG_ppc64le    = powernv_defconfig
@@ -93,7 +93,6 @@ DEFCONFIG_s390       = defconfig
 DEFCONFIG_loongarch  = defconfig
 DEFCONFIG            = $(DEFCONFIG_$(XARCH))
 
-EXTRACONFIG_mips32be = -d CONFIG_CPU_LITTLE_ENDIAN -e CONFIG_CPU_BIG_ENDIAN
 EXTRACONFIG           = $(EXTRACONFIG_$(XARCH))
 
 # optional tests to run (default = all)

From a75b763b51ee259b5c6dd3725b5fe515548917fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 08:37:38 +0100
Subject: [PATCH 06/26] selftests/nolibc: drop call to prepare target
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The "prepare" target does not need to be run manually.
kbuild knows when to use it on its own and the target is not even
documented.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-2-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 5e2abc3493de..60e422fc6b07 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -263,7 +263,7 @@ initramfs: nolibc-test
 	$(Q)cp nolibc-test initramfs/init
 
 defconfig:
-	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare
+	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG)
 	$(Q)if [ -n "$(EXTRACONFIG)" ]; then \
 		$(srctree)/scripts/config --file $(objtree)/.config $(EXTRACONFIG); \
 		$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) olddefconfig < /dev/null; \

From 25d5ef9e7c55fa6f997a53eced9a33a982c9421b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 08:37:39 +0100
Subject: [PATCH 07/26] selftests/nolibc: drop call to mrproper target
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"mrproper" unnecessarily cleans a lot of files.
kbuild is smart enough to handle changed configurations,
so the cleanup is not necessary and only leads to excessive rebuilds.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-3-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 60e422fc6b07..4e075fda9e99 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -263,7 +263,7 @@ initramfs: nolibc-test
 	$(Q)cp nolibc-test initramfs/init
 
 defconfig:
-	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG)
+	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(DEFCONFIG)
 	$(Q)if [ -n "$(EXTRACONFIG)" ]; then \
 		$(srctree)/scripts/config --file $(objtree)/.config $(EXTRACONFIG); \
 		$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) olddefconfig < /dev/null; \

From d7d271ec30dd02bb9c695233e7fc04a6c728f467 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 08:37:40 +0100
Subject: [PATCH 08/26] selftests/nolibc: execute defconfig before other
 targets
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Some targets use the test kernel configuration.
Executing defconfig in the same make invocation as those targets results
in errors as the configuration may be in an inconsistent state during
reconfiguration.
Avoid this by introducing ordering dependencies between the defconfig
and some other targets.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-4-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 4e075fda9e99..983985b7529b 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -219,7 +219,7 @@ all: run
 
 sysroot: sysroot/$(ARCH)/include
 
-sysroot/$(ARCH)/include:
+sysroot/$(ARCH)/include: | defconfig
 	$(Q)rm -rf sysroot/$(ARCH) sysroot/sysroot
 	$(QUIET_MKDIR)mkdir -p sysroot
 	$(Q)$(MAKE) -C $(srctree) outputmakefile
@@ -269,10 +269,10 @@ defconfig:
 		$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) olddefconfig < /dev/null; \
 	fi
 
-kernel:
+kernel: | defconfig
 	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) < /dev/null
 
-kernel-standalone: initramfs
+kernel-standalone: initramfs | defconfig
 	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs < /dev/null
 
 # run the tests after building the kernel

From c1f4a7a84037249d086a4114c0c4332a260e9091 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 23 Jan 2025 08:37:41 +0100
Subject: [PATCH 09/26] selftests/nolibc: always keep test kernel configuration
 up to date
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Avoid using a stale test kernel configuration by always synchronizing
it to the current source tree.
kbuild is smart enough to avoid spurious rebuilds.

Shuffle the code around a bit to keep all the commands with side-effects
together.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250123-nolibc-config-v2-5-5701c35995d6@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/run-tests.sh | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index 9c5160c53881..bc4e92b4f1b9 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -157,10 +157,6 @@ test_arch() {
 	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 "${build_dir}/.config" ]; then
-		swallow_output "${MAKE[@]}" defconfig
-	fi
 	case "$test_mode" in
 		'system')
 			test_target=run
@@ -173,6 +169,9 @@ test_arch() {
 			exit 1
 	esac
 	printf '%-15s' "$arch:"
+
+	mkdir -p "$build_dir"
+	swallow_output "${MAKE[@]}" defconfig
 	swallow_output "${MAKE[@]}" CFLAGS_EXTRA="$CFLAGS_EXTRA" "$test_target" V=1
 	cp run.out run.out."${arch}"
 	"${MAKE[@]}" report | grep passed

From dde5625d4d75787a59e95f4d7d6983714bfc14c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas.weissschuh@linutronix.de>
Date: Sun, 9 Feb 2025 14:25:45 +0100
Subject: [PATCH 10/26] tools/nolibc: add support for sys_llseek()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Not all architectures have the old sys_lseek(), notably riscv32.
Implement lseek() in terms of sys_llseek() in that case.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250209-nolibc-dir-v2-1-57cc1da8558b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys.h | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 8c0a55bc9dc3..8f44c33b1213 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -597,10 +597,37 @@ off_t sys_lseek(int fd, off_t offset, int whence)
 #endif
 }
 
+static __attribute__((unused))
+int sys_llseek(int fd, unsigned long offset_high, unsigned long offset_low,
+	       __kernel_loff_t *result, int whence)
+{
+#ifdef __NR_llseek
+	return my_syscall5(__NR_llseek, fd, offset_high, offset_low, result, whence);
+#else
+	return __nolibc_enosys(__func__, fd, offset_high, offset_low, result, whence);
+#endif
+}
+
 static __attribute__((unused))
 off_t lseek(int fd, off_t offset, int whence)
 {
-	return __sysret(sys_lseek(fd, offset, whence));
+	__kernel_loff_t loff = 0;
+	off_t result;
+	int ret;
+
+	result = sys_lseek(fd, offset, whence);
+	if (result == -ENOSYS) {
+		/* Only exists on 32bit where nolibc off_t is also 32bit */
+		ret = sys_llseek(fd, 0, offset, &loff, whence);
+		if (ret < 0)
+			result = ret;
+		else if (loff != (off_t)loff)
+			result = -EOVERFLOW;
+		else
+			result = loff;
+	}
+
+	return __sysret(result);
 }
 
 

From 665fa8dea90d9fbc0e7137c7e1315d6f7e15757e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas.weissschuh@linutronix.de>
Date: Sun, 9 Feb 2025 14:25:46 +0100
Subject: [PATCH 11/26] tools/nolibc: add support for directory access
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add an implementation for directory access operations.
To keep nolibc itself allocation-free, a "DIR *" does not point to any
data, but directly encodes a filedescriptor number, equivalent to "FILE *".
Without any per-directory storage it is not possible to implement
readdir() POSIX confirming. Instead only readdir_r() is provided.
While readdir_r() is deprecated in glibc, the reasons for that are
not applicable to nolibc.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250209-nolibc-dir-v2-2-57cc1da8558b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/Makefile                |  1 +
 tools/include/nolibc/dirent.h                | 98 ++++++++++++++++++++
 tools/include/nolibc/nolibc.h                |  1 +
 tools/testing/selftests/nolibc/nolibc-test.c | 39 ++++++++
 4 files changed, 139 insertions(+)
 create mode 100644 tools/include/nolibc/dirent.h

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index a1f55fb24bb3..dceec0e1a135 100644
--- a/tools/include/nolibc/Makefile
+++ b/tools/include/nolibc/Makefile
@@ -29,6 +29,7 @@ all_files := \
 		compiler.h \
 		crt.h \
 		ctype.h \
+		dirent.h \
 		errno.h \
 		nolibc.h \
 		signal.h \
diff --git a/tools/include/nolibc/dirent.h b/tools/include/nolibc/dirent.h
new file mode 100644
index 000000000000..c5c30d0dd680
--- /dev/null
+++ b/tools/include/nolibc/dirent.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Directory access for NOLIBC
+ * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
+ */
+
+#ifndef _NOLIBC_DIRENT_H
+#define _NOLIBC_DIRENT_H
+
+#include "stdint.h"
+#include "types.h"
+
+#include <linux/limits.h>
+
+struct dirent {
+	ino_t	d_ino;
+	char	d_name[NAME_MAX + 1];
+};
+
+/* See comment of FILE in stdio.h */
+typedef struct {
+	char dummy[1];
+} DIR;
+
+static __attribute__((unused))
+DIR *fdopendir(int fd)
+{
+	if (fd < 0) {
+		SET_ERRNO(EBADF);
+		return NULL;
+	}
+	return (DIR *)(intptr_t)~fd;
+}
+
+static __attribute__((unused))
+DIR *opendir(const char *name)
+{
+	int fd;
+
+	fd = open(name, O_RDONLY);
+	if (fd == -1)
+		return NULL;
+	return fdopendir(fd);
+}
+
+static __attribute__((unused))
+int closedir(DIR *dirp)
+{
+	intptr_t i = (intptr_t)dirp;
+
+	if (i >= 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+	return close(~i);
+}
+
+static __attribute__((unused))
+int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
+{
+	char buf[sizeof(struct linux_dirent64) + NAME_MAX + 1];
+	struct linux_dirent64 *ldir = (void *)buf;
+	intptr_t i = (intptr_t)dirp;
+	int fd, ret;
+
+	if (i >= 0)
+		return EBADF;
+
+	fd = ~i;
+
+	ret = sys_getdents64(fd, ldir, sizeof(buf));
+	if (ret < 0)
+		return -ret;
+	if (ret == 0) {
+		*result = NULL;
+		return 0;
+	}
+
+	/*
+	 * getdents64() returns as many entries as fit the buffer.
+	 * readdir() can only return one entry at a time.
+	 * Make sure the non-returned ones are not skipped.
+	 */
+	ret = lseek(fd, ldir->d_off, SEEK_SET);
+	if (ret == -1)
+		return errno;
+
+	entry->d_ino = ldir->d_ino;
+	/* the destination should always be big enough */
+	strlcpy(entry->d_name, ldir->d_name, sizeof(entry->d_name));
+	*result = entry;
+	return 0;
+}
+
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
+#endif /* _NOLIBC_DIRENT_H */
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 92436b1e4441..05d92afedb72 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -105,6 +105,7 @@
 #include "string.h"
 #include "time.h"
 #include "stackprotector.h"
+#include "dirent.h"
 
 /* Used by programs to avoid std includes */
 #define NOLIBC
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index f162793b162f..798fbdcd3ff8 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -769,6 +769,44 @@ int test_getdents64(const char *dir)
 	return ret;
 }
 
+static int test_dirent(void)
+{
+	int comm = 0, cmdline = 0;
+	struct dirent dirent, *result;
+	DIR *dir;
+	int ret;
+
+	dir = opendir("/proc/self");
+	if (!dir)
+		return 1;
+
+	while (1) {
+		errno = 0;
+		ret = readdir_r(dir, &dirent, &result);
+		if (ret != 0)
+			return 1;
+		if (!result)
+			break;
+
+		if (strcmp(dirent.d_name, "comm") == 0)
+			comm++;
+		else if (strcmp(dirent.d_name, "cmdline") == 0)
+			cmdline++;
+	}
+
+	if (errno)
+		return 1;
+
+	ret = closedir(dir);
+	if (ret)
+		return 1;
+
+	if (comm != 1 || cmdline != 1)
+		return 1;
+
+	return 0;
+}
+
 int test_getpagesize(void)
 {
 	int x = getpagesize();
@@ -1061,6 +1099,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(fork);              EXPECT_SYSZR(1, test_fork()); break;
 		CASE_TEST(getdents64_root);   EXPECT_SYSNE(1, test_getdents64("/"), -1); break;
 		CASE_TEST(getdents64_null);   EXPECT_SYSER(1, test_getdents64("/dev/null"), -1, ENOTDIR); break;
+		CASE_TEST(directories);       EXPECT_SYSZR(proc, test_dirent()); break;
 		CASE_TEST(gettimeofday_tv);   EXPECT_SYSZR(1, gettimeofday(&tv, NULL)); break;
 		CASE_TEST(gettimeofday_tv_tz);EXPECT_SYSZR(1, gettimeofday(&tv, &tz)); break;
 		CASE_TEST(getpagesize);       EXPECT_SYSZR(1, test_getpagesize()); break;

From 16681bea9a80080765c98b545ad74c17de2d513c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Tue, 11 Feb 2025 12:03:52 +0100
Subject: [PATCH 12/26] selftests/nolibc: split up architecture list in
 run-tests.sh
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The list is getting overly long and any modifications introduce a lot of
noise and are prone to conflicts. Split the string into a bash array
and break that into multiple lines.

Link: https://lore.kernel.org/r/20250211-nolibc-test-archs-v1-1-8e55aa3369cf@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/run-tests.sh | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index bc4e92b4f1b9..6db011152768 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -17,7 +17,16 @@ perform_download=0
 test_mode=system
 werror=1
 llvm=
-archs="i386 x86_64 arm64 arm mips32le mips32be ppc ppc64 ppc64le riscv32 riscv64 s390 loongarch"
+all_archs=(
+	i386 x86_64
+	arm64 arm
+	mips32le mips32be
+	ppc ppc64 ppc64le
+	riscv32 riscv64
+	s390
+	loongarch
+)
+archs="${all_archs[@]}"
 
 TEMP=$(getopt -o 'j:d:c:b:a:m:pelh' -n "$0" -- "$@")
 

From 00ddf4cc9756b4974e6c1d61ae22ae5dcdf29084 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Wed, 12 Feb 2025 19:01:01 +0100
Subject: [PATCH 13/26] selftests/nolibc: only run constructor tests on nolibc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The nolibc testsuite can be run against other libcs to test for
interoperability. Some aspects of the constructor execution are not
standardized and musl does not provide all tested feature, for one it
does not provide arguments to the constructors, anymore?

Skip the constructor tests on non-nolibc configurations.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250212-nolibc-test-constructor-v1-1-c963875b3da4@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 798fbdcd3ff8..94db506eca90 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -738,9 +738,9 @@ int run_startup(int min, int max)
 		CASE_TEST(environ_HOME);     EXPECT_PTRNZ(1, getenv("HOME")); break;
 		CASE_TEST(auxv_addr);        EXPECT_PTRGT(test_auxv != (void *)-1, test_auxv, brk); break;
 		CASE_TEST(auxv_AT_UID);      EXPECT_EQ(1, getauxval(AT_UID), getuid()); break;
-		CASE_TEST(constructor);      EXPECT_EQ(1, constructor_test_value, 2); break;
+		CASE_TEST(constructor);      EXPECT_EQ(is_nolibc, constructor_test_value, 2); break;
 		CASE_TEST(linkage_errno);    EXPECT_PTREQ(1, linkage_test_errno_addr(), &errno); break;
-		CASE_TEST(linkage_constr);   EXPECT_EQ(1, linkage_test_constructor_test_value, 6); break;
+		CASE_TEST(linkage_constr);   EXPECT_EQ(is_nolibc, linkage_test_constructor_test_value, 6); break;
 		case __LINE__:
 			return ret; /* must be last */
 		/* note: do not set any defaults so as to permit holes above */

From 3d1e67c615cb5487ee89ff6afdbfe7b9d09baf8b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 6 Feb 2025 08:10:26 +0100
Subject: [PATCH 14/26] selftests/nolibc: rename s390 to s390x
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Support for 32-bit s390 is about to be added.
As "s39032" would look horrible, use the another naming scheme.
32-bit s390 is "s390" and 64-bit s390 is "s390x",
similar to how it is handled in various toolchain components.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250206-nolibc-s390-v2-1-991ad97e3d58@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile     | 11 ++++++-----
 tools/testing/selftests/nolibc/run-tests.sh |  3 ++-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 983985b7529b..97e08b92bee3 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -54,6 +54,7 @@ ARCH_mips32le    = mips
 ARCH_mips32be    = mips
 ARCH_riscv32     = riscv
 ARCH_riscv64     = riscv
+ARCH_s390x       = s390
 ARCH            := $(or $(ARCH_$(XARCH)),$(XARCH))
 
 # kernel image names by architecture
@@ -70,7 +71,7 @@ IMAGE_ppc64le    = arch/powerpc/boot/zImage
 IMAGE_riscv      = arch/riscv/boot/Image
 IMAGE_riscv32    = arch/riscv/boot/Image
 IMAGE_riscv64    = arch/riscv/boot/Image
-IMAGE_s390       = arch/s390/boot/bzImage
+IMAGE_s390x      = arch/s390/boot/bzImage
 IMAGE_loongarch  = arch/loongarch/boot/vmlinuz.efi
 IMAGE            = $(objtree)/$(IMAGE_$(XARCH))
 IMAGE_NAME       = $(notdir $(IMAGE))
@@ -89,7 +90,7 @@ DEFCONFIG_ppc64le    = powernv_defconfig
 DEFCONFIG_riscv      = defconfig
 DEFCONFIG_riscv32    = rv32_defconfig
 DEFCONFIG_riscv64    = defconfig
-DEFCONFIG_s390       = defconfig
+DEFCONFIG_s390x      = defconfig
 DEFCONFIG_loongarch  = defconfig
 DEFCONFIG            = $(DEFCONFIG_$(XARCH))
 
@@ -112,7 +113,7 @@ QEMU_ARCH_ppc64le    = ppc64
 QEMU_ARCH_riscv      = riscv64
 QEMU_ARCH_riscv32    = riscv32
 QEMU_ARCH_riscv64    = riscv64
-QEMU_ARCH_s390       = s390x
+QEMU_ARCH_s390x      = s390x
 QEMU_ARCH_loongarch  = loongarch64
 QEMU_ARCH            = $(QEMU_ARCH_$(XARCH))
 
@@ -140,7 +141,7 @@ QEMU_ARGS_ppc64le    = -M powernv -append "console=hvc0 panic=-1 $(TEST:%=NOLIBC
 QEMU_ARGS_riscv      = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_riscv32    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_riscv64    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
-QEMU_ARGS_s390       = -M s390-ccw-virtio -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_s390x      = -M s390-ccw-virtio -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_loongarch  = -M virt -append "console=ttyS0,115200 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS            = -m 1G $(QEMU_ARGS_$(XARCH)) $(QEMU_ARGS_BIOS) $(QEMU_ARGS_EXTRA)
 
@@ -158,7 +159,7 @@ CFLAGS_i386 = $(call cc-option,-m32)
 CFLAGS_ppc = -m32 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64 = -m64 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64le = -m64 -mlittle-endian -mno-vsx $(call cc-option,-mabi=elfv2)
-CFLAGS_s390 = -m64
+CFLAGS_s390x = -m64
 CFLAGS_mips32le = -EL -mabi=32 -fPIC
 CFLAGS_mips32be = -EB -mabi=32
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index 6db011152768..b1706ac4def5 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -23,7 +23,7 @@ all_archs=(
 	mips32le mips32be
 	ppc ppc64 ppc64le
 	riscv32 riscv64
-	s390
+	s390x
 	loongarch
 )
 archs="${all_archs[@]}"
@@ -109,6 +109,7 @@ crosstool_arch() {
 	riscv) echo riscv64;;
 	loongarch) echo loongarch64;;
 	mips*) echo mips;;
+	s390*) echo s390;;
 	*) echo "$1";;
 	esac
 }

From 9c812b01f13d37410ea103e00bc47e5e0f6d2bad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 6 Feb 2025 08:10:27 +0100
Subject: [PATCH 15/26] tools/nolibc: add support for 32-bit s390
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

32-bit s390 is very close to the existing 64-bit implementation.

Some special handling is necessary as there is neither LLVM nor
QEMU support. Also the kernel itself can not build natively for 32-bit
s390, so instead the test program is executed with a 64-bit kernel.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250206-nolibc-s390-v2-2-991ad97e3d58@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/arch-s390.h            | 5 +++++
 tools/include/nolibc/arch.h                 | 2 +-
 tools/testing/selftests/nolibc/Makefile     | 5 +++++
 tools/testing/selftests/nolibc/run-tests.sh | 6 +++++-
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index f9ab83a219b8..acfee7e9d5e2 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -143,8 +143,13 @@
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
 	__asm__ volatile (
+#ifdef __s390x__
 		"lgr	%r2, %r15\n"          /* save stack pointer to %r2, as arg1 of _start_c */
 		"aghi	%r15, -160\n"         /* allocate new stackframe                        */
+#else
+		"lr	%r2, %r15\n"
+		"ahi	%r15, -96\n"
+#endif
 		"xc	0(8,%r15), 0(%r15)\n" /* clear backchain                                */
 		"brasl	%r14, _start_c\n"     /* transfer to c runtime                          */
 	);
diff --git a/tools/include/nolibc/arch.h b/tools/include/nolibc/arch.h
index c8f4e5d3add9..8a2c143c0fba 100644
--- a/tools/include/nolibc/arch.h
+++ b/tools/include/nolibc/arch.h
@@ -29,7 +29,7 @@
 #include "arch-powerpc.h"
 #elif defined(__riscv)
 #include "arch-riscv.h"
-#elif defined(__s390x__)
+#elif defined(__s390x__) || defined(__s390__)
 #include "arch-s390.h"
 #elif defined(__loongarch__)
 #include "arch-loongarch.h"
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 97e08b92bee3..14fc8c7e7c30 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -72,6 +72,7 @@ IMAGE_riscv      = arch/riscv/boot/Image
 IMAGE_riscv32    = arch/riscv/boot/Image
 IMAGE_riscv64    = arch/riscv/boot/Image
 IMAGE_s390x      = arch/s390/boot/bzImage
+IMAGE_s390       = arch/s390/boot/bzImage
 IMAGE_loongarch  = arch/loongarch/boot/vmlinuz.efi
 IMAGE            = $(objtree)/$(IMAGE_$(XARCH))
 IMAGE_NAME       = $(notdir $(IMAGE))
@@ -91,6 +92,7 @@ DEFCONFIG_riscv      = defconfig
 DEFCONFIG_riscv32    = rv32_defconfig
 DEFCONFIG_riscv64    = defconfig
 DEFCONFIG_s390x      = defconfig
+DEFCONFIG_s390       = defconfig compat.config
 DEFCONFIG_loongarch  = defconfig
 DEFCONFIG            = $(DEFCONFIG_$(XARCH))
 
@@ -114,6 +116,7 @@ QEMU_ARCH_riscv      = riscv64
 QEMU_ARCH_riscv32    = riscv32
 QEMU_ARCH_riscv64    = riscv64
 QEMU_ARCH_s390x      = s390x
+QEMU_ARCH_s390       = s390x
 QEMU_ARCH_loongarch  = loongarch64
 QEMU_ARCH            = $(QEMU_ARCH_$(XARCH))
 
@@ -142,6 +145,7 @@ QEMU_ARGS_riscv      = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_T
 QEMU_ARGS_riscv32    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_riscv64    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_s390x      = -M s390-ccw-virtio -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_s390       = -M s390-ccw-virtio -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_loongarch  = -M virt -append "console=ttyS0,115200 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS            = -m 1G $(QEMU_ARGS_$(XARCH)) $(QEMU_ARGS_BIOS) $(QEMU_ARGS_EXTRA)
 
@@ -160,6 +164,7 @@ CFLAGS_ppc = -m32 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64 = -m64 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64le = -m64 -mlittle-endian -mno-vsx $(call cc-option,-mabi=elfv2)
 CFLAGS_s390x = -m64
+CFLAGS_s390 = -m31
 CFLAGS_mips32le = -EL -mabi=32 -fPIC
 CFLAGS_mips32be = -EB -mabi=32
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index b1706ac4def5..d716124f5e82 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -23,7 +23,7 @@ all_archs=(
 	mips32le mips32be
 	ppc ppc64 ppc64le
 	riscv32 riscv64
-	s390x
+	s390x s390
 	loongarch
 )
 archs="${all_archs[@]}"
@@ -179,6 +179,10 @@ test_arch() {
 			exit 1
 	esac
 	printf '%-15s' "$arch:"
+	if [ "$arch" = "s390" ] && ([ "$llvm" = "1" ] || [ "$test_mode" = "user" ]); then
+		echo "Unsupported configuration"
+		return
+	fi
 
 	mkdir -p "$build_dir"
 	swallow_output "${MAKE[@]}" defconfig

From 22edf1f8d4dc4e506efa83a3647c9f00d1eadd77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Sun, 9 Feb 2025 21:27:12 +0100
Subject: [PATCH 16/26] tools/nolibc: add support for [v]sscanf()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

These functions are used often, also in selftests.
sscanf() itself is also used by kselftest.h itself.

The implementation is limited and only supports numeric arguments.

Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-1-c29dea32f1cd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/stdio.h                 | 98 ++++++++++++++++++++
 tools/testing/selftests/nolibc/nolibc-test.c | 68 ++++++++++++++
 2 files changed, 166 insertions(+)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 3892034198dd..a403351dbf60 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -349,6 +349,104 @@ int printf(const char *fmt, ...)
 	return ret;
 }
 
+static __attribute__((unused))
+int vsscanf(const char *str, const char *format, va_list args)
+{
+	uintmax_t uval;
+	intmax_t ival;
+	int base;
+	char *endptr;
+	int matches;
+	int lpref;
+
+	matches = 0;
+
+	while (1) {
+		if (*format == '%') {
+			/* start of pattern */
+			lpref = 0;
+			format++;
+
+			if (*format == 'l') {
+				/* same as in printf() */
+				lpref = 1;
+				format++;
+				if (*format == 'l') {
+					lpref = 2;
+					format++;
+				}
+			}
+
+			if (*format == '%') {
+				/* literal % */
+				if ('%' != *str)
+					goto done;
+				str++;
+				format++;
+				continue;
+			} else if (*format == 'd') {
+				ival = strtoll(str, &endptr, 10);
+				if (lpref == 0)
+					*va_arg(args, int *) = ival;
+				else if (lpref == 1)
+					*va_arg(args, long *) = ival;
+				else if (lpref == 2)
+					*va_arg(args, long long *) = ival;
+			} else if (*format == 'u' || *format == 'x' || *format == 'X') {
+				base = *format == 'u' ? 10 : 16;
+				uval = strtoull(str, &endptr, base);
+				if (lpref == 0)
+					*va_arg(args, unsigned int *) = uval;
+				else if (lpref == 1)
+					*va_arg(args, unsigned long *) = uval;
+				else if (lpref == 2)
+					*va_arg(args, unsigned long long *) = uval;
+			} else if (*format == 'p') {
+				*va_arg(args, void **) = (void *)strtoul(str, &endptr, 16);
+			} else {
+				SET_ERRNO(EILSEQ);
+				goto done;
+			}
+
+			format++;
+			str = endptr;
+			matches++;
+
+		} else if (*format == '\0') {
+			goto done;
+		} else if (isspace(*format)) {
+			/* skip spaces in format and str */
+			while (isspace(*format))
+				format++;
+			while (isspace(*str))
+				str++;
+		} else if (*format == *str) {
+			/* literal match */
+			format++;
+			str++;
+		} else {
+			if (!matches)
+				matches = EOF;
+			goto done;
+		}
+	}
+
+done:
+	return matches;
+}
+
+static __attribute__((unused, format(scanf, 2, 3)))
+int sscanf(const char *str, const char *format, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, format);
+	ret = vsscanf(str, format, args);
+	va_end(args);
+	return ret;
+}
+
 static __attribute__((unused))
 void perror(const char *msg)
 {
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 94db506eca90..79c3e6a845f3 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1325,6 +1325,73 @@ static int expect_vfprintf(int llen, int c, const char *expected, const char *fm
 	return ret;
 }
 
+static int test_scanf(void)
+{
+	unsigned long long ull;
+	unsigned long ul;
+	unsigned int u;
+	long long ll;
+	long l;
+	void *p;
+	int i;
+
+	/* return __LINE__ to point to the specific failure */
+
+	/* test EOF */
+	if (sscanf("", "foo") != EOF)
+		return __LINE__;
+
+	/* test simple literal without placeholder */
+	if (sscanf("foo", "foo") != 0)
+		return __LINE__;
+
+	/* test single placeholder */
+	if (sscanf("123", "%d", &i) != 1)
+		return __LINE__;
+
+	if (i != 123)
+		return __LINE__;
+
+	/* test multiple place holders and separators */
+	if (sscanf("a123b456c0x90", "a%db%uc%p", &i, &u, &p) != 3)
+		return __LINE__;
+
+	if (i != 123)
+		return __LINE__;
+
+	if (u != 456)
+		return __LINE__;
+
+	if (p != (void *)0x90)
+		return __LINE__;
+
+	/* test space handling */
+	if (sscanf("a    b1", "a b%d", &i) != 1)
+		return __LINE__;
+
+	if (i != 1)
+		return __LINE__;
+
+	/* test literal percent */
+	if (sscanf("a%1", "a%%%d", &i) != 1)
+		return __LINE__;
+
+	if (i != 1)
+		return __LINE__;
+
+	/* test stdint.h types */
+	if (sscanf("1|2|3|4|5|6",
+		   "%d|%ld|%lld|%u|%lu|%llu",
+		   &i, &l, &ll, &u, &ul, &ull) != 6)
+		return __LINE__;
+
+	if (i != 1 || l != 2 || ll != 3 ||
+	    u != 4 || ul != 5 || ull != 6)
+		return __LINE__;
+
+	return 0;
+}
+
 static int run_vfprintf(int min, int max)
 {
 	int test;
@@ -1346,6 +1413,7 @@ static int run_vfprintf(int min, int max)
 		CASE_TEST(char);         EXPECT_VFPRINTF(1, "c", "%c", 'c'); break;
 		CASE_TEST(hex);          EXPECT_VFPRINTF(1, "f", "%x", 0xf); break;
 		CASE_TEST(pointer);      EXPECT_VFPRINTF(3, "0x1", "%p", (void *) 0x1); break;
+		CASE_TEST(scanf);        EXPECT_ZR(1, test_scanf()); break;
 		case __LINE__:
 			return ret; /* must be last */
 		/* note: do not set any defaults so as to permit holes above */

From 3bd53b2fa57d9472d3af63b3f4d26023ba07b579 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Sun, 9 Feb 2025 21:27:13 +0100
Subject: [PATCH 17/26] Revert "selftests: kselftest: Fix build failure with
 NOLIBC"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This reverts commit 16767502aa990cca2cb7d1372b31d328c4c85b40.

Nolibc gained support for uname(2) and sscanf(3) which are the
dependencies of ksft_min_kernel_version().

So re-enable support for ksft_min_kernel_version() under nolibc.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-2-c29dea32f1cd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/kselftest.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index cdf91b0ca40f..c3b6d2604b1e 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -444,10 +444,6 @@ static inline __noreturn __printf(1, 2) void ksft_exit_skip(const char *msg, ...
 static inline int ksft_min_kernel_version(unsigned int min_major,
 					  unsigned int min_minor)
 {
-#ifdef NOLIBC
-	ksft_print_msg("NOLIBC: Can't check kernel version: Function not implemented\n");
-	return 0;
-#else
 	unsigned int major, minor;
 	struct utsname info;
 
@@ -455,7 +451,6 @@ static inline int ksft_min_kernel_version(unsigned int min_major,
 		ksft_exit_fail_msg("Can't parse kernel version\n");
 
 	return major > min_major || (major == min_major && minor >= min_minor);
-#endif
 }
 
 #endif /* __KSELFTEST_H */

From f8bedb30d66b467fffdb38d8e7265b7be23cfa38 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Sat, 1 Mar 2025 12:23:59 +0100
Subject: [PATCH 18/26] selftests/nolibc: explicitly enable ARM mode
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The default could also be -mthumb.

Explicitly use -marm to keep everything predictable.

Tested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250301-nolibc-armthumb-v1-1-d1f04abb5f6d@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 14fc8c7e7c30..1dd2841a5fe7 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -160,6 +160,7 @@ Q=@
 endif
 
 CFLAGS_i386 = $(call cc-option,-m32)
+CFLAGS_arm = -marm
 CFLAGS_ppc = -m32 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64 = -m64 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64le = -m64 -mlittle-endian -mno-vsx $(call cc-option,-mabi=elfv2)

From cb839e0cc881b4abd4a2e64cd06c2e313987a189 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Sat, 1 Mar 2025 12:24:00 +0100
Subject: [PATCH 19/26] selftests/nolibc: add armthumb configuration
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

While nolibc does support ARM Thumb instructions,
that support was not tested specifically.

Add a new test configuration for it.

Tested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250301-nolibc-armthumb-v1-2-d1f04abb5f6d@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/Makefile     | 6 ++++++
 tools/testing/selftests/nolibc/run-tests.sh | 5 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 1dd2841a5fe7..58bcbbd029bc 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -47,6 +47,7 @@ XARCH_riscv      = riscv64
 XARCH            = $(or $(XARCH_$(ARCH)),$(ARCH))
 
 # map from user input variants to their kernel supported architectures
+ARCH_armthumb    = arm
 ARCH_ppc         = powerpc
 ARCH_ppc64       = powerpc
 ARCH_ppc64le     = powerpc
@@ -63,6 +64,7 @@ IMAGE_x86_64     = arch/x86/boot/bzImage
 IMAGE_x86        = arch/x86/boot/bzImage
 IMAGE_arm64      = arch/arm64/boot/Image
 IMAGE_arm        = arch/arm/boot/zImage
+IMAGE_armthumb   = arch/arm/boot/zImage
 IMAGE_mips32le   = vmlinuz
 IMAGE_mips32be   = vmlinuz
 IMAGE_ppc        = vmlinux
@@ -83,6 +85,7 @@ DEFCONFIG_x86_64     = defconfig
 DEFCONFIG_x86        = defconfig
 DEFCONFIG_arm64      = defconfig
 DEFCONFIG_arm        = multi_v7_defconfig
+DEFCONFIG_armthumb   = multi_v7_defconfig
 DEFCONFIG_mips32le   = malta_defconfig
 DEFCONFIG_mips32be   = malta_defconfig generic/eb.config
 DEFCONFIG_ppc        = pmac32_defconfig
@@ -107,6 +110,7 @@ QEMU_ARCH_x86_64     = x86_64
 QEMU_ARCH_x86        = x86_64
 QEMU_ARCH_arm64      = aarch64
 QEMU_ARCH_arm        = arm
+QEMU_ARCH_armthumb   = arm
 QEMU_ARCH_mips32le   = mipsel  # works with malta_defconfig
 QEMU_ARCH_mips32be  = mips
 QEMU_ARCH_ppc        = ppc
@@ -136,6 +140,7 @@ QEMU_ARGS_x86_64     = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(
 QEMU_ARGS_x86        = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_arm64      = -M virt -cpu cortex-a53 -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_arm        = -M virt -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_armthumb   = -M virt -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_mips32le   = -M malta -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_mips32be   = -M malta -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_ppc        = -M g3beige -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
@@ -161,6 +166,7 @@ endif
 
 CFLAGS_i386 = $(call cc-option,-m32)
 CFLAGS_arm = -marm
+CFLAGS_armthumb = -mthumb -march=armv6t2
 CFLAGS_ppc = -m32 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64 = -m64 -mbig-endian -mno-vsx $(call cc-option,-mmultiple)
 CFLAGS_ppc64le = -m64 -mlittle-endian -mno-vsx $(call cc-option,-mabi=elfv2)
diff --git a/tools/testing/selftests/nolibc/run-tests.sh b/tools/testing/selftests/nolibc/run-tests.sh
index d716124f5e82..0299a0912d40 100755
--- a/tools/testing/selftests/nolibc/run-tests.sh
+++ b/tools/testing/selftests/nolibc/run-tests.sh
@@ -19,7 +19,7 @@ werror=1
 llvm=
 all_archs=(
 	i386 x86_64
-	arm64 arm
+	arm64 arm armthumb
 	mips32le mips32be
 	ppc ppc64 ppc64le
 	riscv32 riscv64
@@ -103,6 +103,7 @@ fi
 crosstool_arch() {
 	case "$1" in
 	arm64) echo aarch64;;
+	armthumb) echo arm;;
 	ppc) echo powerpc;;
 	ppc64) echo powerpc64;;
 	ppc64le) echo powerpc64;;
@@ -116,7 +117,7 @@ crosstool_arch() {
 
 crosstool_abi() {
 	case "$1" in
-	arm) echo linux-gnueabi;;
+	arm | armthumb) echo linux-gnueabi;;
 	*) echo linux;;
 	esac
 }

From b2edaad7f5192a79384b7d0bec62312b668da463 Mon Sep 17 00:00:00 2001
From: Louis Taylor <louis@kragniz.eu>
Date: Thu, 6 Mar 2025 18:41:18 +0000
Subject: [PATCH 20/26] tools/nolibc: add support for openat(2)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

openat is useful to avoid needing to construct relative paths, so expose
a wrapper for using it directly.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-1-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys.h                   | 25 ++++++++++++++++++++
 tools/testing/selftests/nolibc/nolibc-test.c | 17 +++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 8f44c33b1213..3cd938f9abda 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -765,6 +765,31 @@ int mount(const char *src, const char *tgt,
 	return __sysret(sys_mount(src, tgt, fst, flags, data));
 }
 
+/*
+ * int openat(int dirfd, const char *path, int flags[, mode_t mode]);
+ */
+
+static __attribute__((unused))
+int sys_openat(int dirfd, const char *path, int flags, mode_t mode)
+{
+	return my_syscall4(__NR_openat, dirfd, path, flags, mode);
+}
+
+static __attribute__((unused))
+int openat(int dirfd, const char *path, int flags, ...)
+{
+	mode_t mode = 0;
+
+	if (flags & O_CREAT) {
+		va_list args;
+
+		va_start(args, flags);
+		mode = va_arg(args, mode_t);
+		va_end(args);
+	}
+
+	return __sysret(sys_openat(dirfd, path, flags, mode));
+}
 
 /*
  * int open(const char *path, int flags[, mode_t mode]);
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 79c3e6a845f3..e8faddcecf9d 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1028,6 +1028,22 @@ int test_rlimit(void)
 	return 0;
 }
 
+int test_openat(void)
+{
+	int dev, null;
+
+	dev = openat(AT_FDCWD, "/dev", O_DIRECTORY);
+	if (dev < 0)
+		return -1;
+
+	null = openat(dev, "null", O_RDONLY);
+	close(dev);
+	if (null < 0)
+		return -1;
+
+	close(null);
+	return 0;
+}
 
 /* Run syscall tests between IDs <min> and <max>.
  * Return 0 on success, non-zero on failure.
@@ -1116,6 +1132,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(mmap_munmap_good);  EXPECT_SYSZR(1, test_mmap_munmap()); break;
 		CASE_TEST(open_tty);          EXPECT_SYSNE(1, tmp = open("/dev/null", 0), -1); if (tmp != -1) close(tmp); break;
 		CASE_TEST(open_blah);         EXPECT_SYSER(1, tmp = open("/proc/self/blah", 0), -1, ENOENT); if (tmp != -1) close(tmp); break;
+		CASE_TEST(openat_dir);        EXPECT_SYSZR(1, test_openat()); break;
 		CASE_TEST(pipe);              EXPECT_SYSZR(1, test_pipe()); break;
 		CASE_TEST(poll_null);         EXPECT_SYSZR(1, poll(NULL, 0, 0)); break;
 		CASE_TEST(poll_stdout);       EXPECT_SYSNE(1, ({ struct pollfd fds = { 1, POLLOUT, 0}; poll(&fds, 1, 0); }), -1); break;

From fbd4f52f5bf76e6ef63d7ebee16d404c6c8cfebb Mon Sep 17 00:00:00 2001
From: Louis Taylor <louis@kragniz.eu>
Date: Thu, 6 Mar 2025 18:41:19 +0000
Subject: [PATCH 21/26] tools/nolibc: always use openat(2) instead of open(2)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

All architectures support openat, so we don't need to make its use
conditional.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-2-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 3cd938f9abda..a8dca5ac6542 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -798,13 +798,7 @@ int openat(int dirfd, const char *path, int flags, ...)
 static __attribute__((unused))
 int sys_open(const char *path, int flags, mode_t mode)
 {
-#ifdef __NR_openat
 	return my_syscall4(__NR_openat, AT_FDCWD, path, flags, mode);
-#elif defined(__NR_open)
-	return my_syscall3(__NR_open, path, flags, mode);
-#else
-	return __nolibc_enosys(__func__, path, flags, mode);
-#endif
 }
 
 static __attribute__((unused))

From 90e1f9f7440cba79716a9d5b0c9df2ce6a661197 Mon Sep 17 00:00:00 2001
From: Louis Taylor <louis@kragniz.eu>
Date: Thu, 6 Mar 2025 18:41:20 +0000
Subject: [PATCH 22/26] tools/nolibc: process open() vararg as mode_t
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

openat() uses mode_t for this, so also update open() to be consistent.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-3-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/sys.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index a8dca5ac6542..5d8adc778575 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -810,7 +810,7 @@ int open(const char *path, int flags, ...)
 		va_list args;
 
 		va_start(args, flags);
-		mode = va_arg(args, int);
+		mode = va_arg(args, mode_t);
 		va_end(args);
 	}
 

From 00e03fea969efd46b104acd271e7f7e08e7c23bf Mon Sep 17 00:00:00 2001
From: Louis Taylor <louis@kragniz.eu>
Date: Thu, 6 Mar 2025 18:41:21 +0000
Subject: [PATCH 23/26] tools/nolibc: drop outdated example from overview
 comment
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This behaviour was changed in commit a7604ba149e7 ("tools/nolibc/sys:
make open() take a vararg on the 3rd argument").

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-4-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/include/nolibc/nolibc.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 05d92afedb72..70872401aca8 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -31,8 +31,7 @@
  *   - The third level is the libc call definition. It exposes the lower raw
  *     sys_<name>() calls in a way that looks like what a libc usually does,
  *     takes care of specific input values, and of setting errno upon error.
- *     There can be minor variations compared to standard libc calls. For
- *     example the open() call always takes 3 args here.
+ *     There can be minor variations compared to standard libc calls.
  *
  * The errno variable is declared static and unused. This way it can be
  * optimized away if not used. However this means that a program made of

From 6e406202a44a1a37176da0333cec10d5320c4b33 Mon Sep 17 00:00:00 2001
From: Louis Taylor <louis@kragniz.eu>
Date: Thu, 6 Mar 2025 18:41:22 +0000
Subject: [PATCH 24/26] selftests/nolibc: use O_RDONLY flag instead of 0
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This doesn't matter much, but is what the standard says.

Signed-off-by: Louis Taylor <louis@kragniz.eu>
Link: https://lore.kernel.org/r/20250306184147.208723-5-louis@kragniz.eu
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index e8faddcecf9d..a5abf16dbfe0 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1130,8 +1130,8 @@ int run_syscall(int min, int max)
 		CASE_TEST(mmap_bad);          EXPECT_PTRER(1, mmap(NULL, 0, PROT_READ, MAP_PRIVATE, 0, 0), MAP_FAILED, EINVAL); break;
 		CASE_TEST(munmap_bad);        EXPECT_SYSER(1, munmap(NULL, 0), -1, EINVAL); break;
 		CASE_TEST(mmap_munmap_good);  EXPECT_SYSZR(1, test_mmap_munmap()); break;
-		CASE_TEST(open_tty);          EXPECT_SYSNE(1, tmp = open("/dev/null", 0), -1); if (tmp != -1) close(tmp); break;
-		CASE_TEST(open_blah);         EXPECT_SYSER(1, tmp = open("/proc/self/blah", 0), -1, ENOENT); if (tmp != -1) close(tmp); break;
+		CASE_TEST(open_tty);          EXPECT_SYSNE(1, tmp = open("/dev/null", O_RDONLY), -1); if (tmp != -1) close(tmp); break;
+		CASE_TEST(open_blah);         EXPECT_SYSER(1, tmp = open("/proc/self/blah", O_RDONLY), -1, ENOENT); if (tmp != -1) close(tmp); break;
 		CASE_TEST(openat_dir);        EXPECT_SYSZR(1, test_openat()); break;
 		CASE_TEST(pipe);              EXPECT_SYSZR(1, test_pipe()); break;
 		CASE_TEST(poll_null);         EXPECT_SYSZR(1, poll(NULL, 0, 0)); break;

From a782d45c867ca92edc50e54715a71124bec1dd11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date: Thu, 6 Mar 2025 22:52:39 +0100
Subject: [PATCH 25/26] selftests/nolibc: stop testing constructor order
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The execution order of constructors in undefined and depends on the
toolchain.  While recent toolchains seems to have a stable order, it
doesn't work for older ones and may also change at any time.

Stop validating the order and instead only validate that all
constructors are executed.

Reported-by: Willy Tarreau <w@1wt.eu>
Closes: https://lore.kernel.org/lkml/20250301110735.GA18621@1wt.eu/
Link: https://lore.kernel.org/r/20250306-nolibc-constructor-order-v1-1-68fd161cc5ec@weissschuh.net
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/nolibc-test-linkage.c | 6 +++---
 tools/testing/selftests/nolibc/nolibc-test.c         | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test-linkage.c b/tools/testing/selftests/nolibc/nolibc-test-linkage.c
index 5ff4c8a1db2a..a7ca8325863f 100644
--- a/tools/testing/selftests/nolibc/nolibc-test-linkage.c
+++ b/tools/testing/selftests/nolibc/nolibc-test-linkage.c
@@ -11,16 +11,16 @@ void *linkage_test_errno_addr(void)
 	return &errno;
 }
 
-int linkage_test_constructor_test_value;
+int linkage_test_constructor_test_value = 0;
 
 __attribute__((constructor))
 static void constructor1(void)
 {
-	linkage_test_constructor_test_value = 2;
+	linkage_test_constructor_test_value |= 1 << 0;
 }
 
 __attribute__((constructor))
 static void constructor2(void)
 {
-	linkage_test_constructor_test_value *= 3;
+	linkage_test_constructor_test_value |= 1 << 1;
 }
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index a5abf16dbfe0..5884a891c491 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -692,14 +692,14 @@ int expect_strtox(int llen, void *func, const char *input, int base, intmax_t ex
 __attribute__((constructor))
 static void constructor1(void)
 {
-	constructor_test_value = 1;
+	constructor_test_value |= 1 << 0;
 }
 
 __attribute__((constructor))
 static void constructor2(int argc, char **argv, char **envp)
 {
 	if (argc && argv && envp)
-		constructor_test_value *= 2;
+		constructor_test_value |= 1 << 1;
 }
 
 int run_startup(int min, int max)
@@ -738,9 +738,9 @@ int run_startup(int min, int max)
 		CASE_TEST(environ_HOME);     EXPECT_PTRNZ(1, getenv("HOME")); break;
 		CASE_TEST(auxv_addr);        EXPECT_PTRGT(test_auxv != (void *)-1, test_auxv, brk); break;
 		CASE_TEST(auxv_AT_UID);      EXPECT_EQ(1, getauxval(AT_UID), getuid()); break;
-		CASE_TEST(constructor);      EXPECT_EQ(is_nolibc, constructor_test_value, 2); break;
+		CASE_TEST(constructor);      EXPECT_EQ(is_nolibc, constructor_test_value, 0x3); break;
 		CASE_TEST(linkage_errno);    EXPECT_PTREQ(1, linkage_test_errno_addr(), &errno); break;
-		CASE_TEST(linkage_constr);   EXPECT_EQ(is_nolibc, linkage_test_constructor_test_value, 6); break;
+		CASE_TEST(linkage_constr);   EXPECT_EQ(1, linkage_test_constructor_test_value, 0x3); break;
 		case __LINE__:
 			return ret; /* must be last */
 		/* note: do not set any defaults so as to permit holes above */

From bceb73904c855c78402dca94c82915f078f259dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas.weissschuh@linutronix.de>
Date: Fri, 7 Mar 2025 13:43:23 +0100
Subject: [PATCH 26/26] tools/nolibc: don't use asm/ UAPI headers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The asm/ and asm-generic/ namespaces are implementation details of the UAPI
headers and not meant for direct usage.

Use the equivalent headers from the linux/ namespace instead.

While at it also drop the duplicate include of linux/signal.h from sys.h.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250307-nolibc-asm-headers-v2-1-e2a734f25d22@linutronix.de
---
 tools/include/nolibc/arch-s390.h | 4 ++--
 tools/include/nolibc/errno.h     | 2 +-
 tools/include/nolibc/sys.h       | 9 ++++-----
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index acfee7e9d5e2..df4c3cc713ac 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -5,8 +5,8 @@
 
 #ifndef _NOLIBC_ARCH_S390_H
 #define _NOLIBC_ARCH_S390_H
-#include <asm/signal.h>
-#include <asm/unistd.h>
+#include <linux/signal.h>
+#include <linux/unistd.h>
 
 #include "compiler.h"
 #include "crt.h"
diff --git a/tools/include/nolibc/errno.h b/tools/include/nolibc/errno.h
index a44486ff0477..1d8d8033e8ff 100644
--- a/tools/include/nolibc/errno.h
+++ b/tools/include/nolibc/errno.h
@@ -7,7 +7,7 @@
 #ifndef _NOLIBC_ERRNO_H
 #define _NOLIBC_ERRNO_H
 
-#include <asm/errno.h>
+#include <linux/errno.h>
 
 #ifndef NOLIBC_IGNORE_ERRNO
 #define SET_ERRNO(v) do { errno = (v); } while (0)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 5d8adc778575..08c1c074bec8 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -10,10 +10,10 @@
 #include "std.h"
 
 /* system includes */
-#include <asm/unistd.h>
-#include <asm/signal.h>  /* for SIGCHLD */
-#include <asm/ioctls.h>
-#include <asm/mman.h>
+#include <linux/unistd.h>
+#include <linux/signal.h>  /* for SIGCHLD */
+#include <linux/termios.h>
+#include <linux/mman.h>
 #include <linux/fs.h>
 #include <linux/loop.h>
 #include <linux/time.h>
@@ -23,7 +23,6 @@
 #include <linux/prctl.h>
 #include <linux/resource.h>
 #include <linux/utsname.h>
-#include <linux/signal.h>
 
 #include "arch.h"
 #include "errno.h"