[PATCH v2 nolibc 01/15] tools/nolibc: tests: use volatile to force stack smashing

[PATCH v2 nolibc 01/15] tools/nolibc: tests: use volatile to force stack smashing

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

Use a volatile pointer to write outside the buffer so the compiler can't
optimize it away.

Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/lkml/c0584807-511c-4496-b062-1263ea38f349@p183/
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/nolibc-test.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 21bacc928bf7..47013b78972e 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -667,17 +667,13 @@ int run_stdlib(int min, int max)
 	return ret;
 }
 
-#if defined(__clang__)
-__attribute__((optnone))
-#elif defined(__GNUC__)
-__attribute__((optimize("O0")))
-#endif
 static int smash_stack(void)
 {
 	char buf[100];
+	volatile char *ptr = buf;
 
 	for (size_t i = 0; i < 200; i++)
-		buf[i] = 'P';
+		ptr[i] = 'P';
 
 	return 1;
 }
-- 
2.40.1

[PATCH v2 nolibc 02/15] tools/nolibc: tests: fix build on non-c99 compliant compilers

[Paul E. McKenney]

From: Willy Tarreau <w@1wt.eu>

Commit 9735716830f2 ("tools/nolibc: tests: add test for -fstack-protector")
brought a declaration inside the initialization statement of a for loop,
which breaks the build on compilers that do not default to c99
compatibility, making it more difficult to validate that the lib still
builds on such compilers. The fix is trivial, so let's move the
declaration to the variables block of the function instead. No backport
is needed.

Cc: 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/nolibc-test.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 47013b78972e..6f2f109569a3 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -671,8 +671,9 @@ static int smash_stack(void)
 {
 	char buf[100];
 	volatile char *ptr = buf;
+	size_t i;
 
-	for (size_t i = 0; i < 200; i++)
+	for (i = 0; i < 200; i++)
 		ptr[i] = 'P';
 
 	return 1;
-- 
2.40.1

[PATCH v2 nolibc 03/15] tools/nolibc: fix build of the test case using glibc

[Paul E. McKenney]

From: Willy Tarreau <w@1wt.eu>

Some extra tests for various integer types and limits were added by
commit d1209597ff00 ("tools/nolibc: add tests for the integer limits
in stdint.h"), but we forgot to retest with glibc. Stddef and stdint
are now needed for the program to build there.

Cc: Vincent Dagonneau <v@vda.io>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 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 6f2f109569a3..1bafbd8da6af 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -34,6 +34,8 @@
 #include <sched.h>
 #include <signal.h>
 #include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <unistd.h>
 #endif
 #endif
-- 
2.40.1

[PATCH v2 nolibc 04/15] tools/nolibc: add libc-test binary

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

This can be used to easily compare the behavior of nolibc to the system
libc.

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/.gitignore | 1 +
 tools/testing/selftests/nolibc/Makefile   | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/tools/testing/selftests/nolibc/.gitignore b/tools/testing/selftests/nolibc/.gitignore
index 4696df589d68..52f613cdad54 100644
--- a/tools/testing/selftests/nolibc/.gitignore
+++ b/tools/testing/selftests/nolibc/.gitignore
@@ -1,4 +1,5 @@
 /initramfs/
+/libc-test
 /nolibc-test
 /run.out
 /sysroot/
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index bbce57420465..0cbe13809b37 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -94,6 +94,7 @@ help:
 	@echo "  help         this help"
 	@echo "  sysroot      create the nolibc sysroot here (uses \$$ARCH)"
 	@echo "  nolibc-test  build the executable (uses \$$CC and \$$CROSS_COMPILE)"
+	@echo "  libc-test    build an executable using the compiler's default libc instead"
 	@echo "  run-user     runs the executable under QEMU (uses \$$ARCH, \$$TEST)"
 	@echo "  initramfs    prepare the initramfs with nolibc-test"
 	@echo "  defconfig    create a fresh new default config (uses \$$ARCH)"
@@ -128,6 +129,9 @@ nolibc-test: nolibc-test.c sysroot/$(ARCH)/include
 	$(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \
 	  -nostdlib -static -Isysroot/$(ARCH)/include $< -lgcc
 
+libc-test: nolibc-test.c
+	$(QUIET_CC)$(CC) -o $@ $<
+
 # qemu user-land test
 run-user: nolibc-test
 	$(Q)qemu-$(QEMU_ARCH) ./nolibc-test > "$(CURDIR)/run.out" || :
@@ -159,6 +163,8 @@ clean:
 	$(Q)rm -rf sysroot
 	$(call QUIET_CLEAN, nolibc-test)
 	$(Q)rm -f nolibc-test
+	$(call QUIET_CLEAN, libc-test)
+	$(Q)rm -f libc-test
 	$(call QUIET_CLEAN, initramfs)
 	$(Q)rm -rf initramfs
 	$(call QUIET_CLEAN, run.out)
-- 
2.40.1

[PATCH v2 nolibc 05/15] tools/nolibc: add wrapper for memfd_create

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

This is useful for users and will also be used by a future testcase.

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/include/nolibc/sys.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 5d624dc63a42..bea9760dbd16 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -1365,6 +1365,29 @@ ssize_t write(int fd, const void *buf, size_t count)
 	return ret;
 }
 
+
+/*
+ * int memfd_create(const char *name, unsigned int flags);
+ */
+
+static __attribute__((unused))
+int sys_memfd_create(const char *name, unsigned int flags)
+{
+	return my_syscall2(__NR_memfd_create, name, flags);
+}
+
+static __attribute__((unused))
+int memfd_create(const char *name, unsigned int flags)
+{
+	ssize_t ret = sys_memfd_create(name, flags);
+
+	if (ret < 0) {
+		SET_ERRNO(-ret);
+		ret = -1;
+	}
+	return ret;
+}
+
 /* make sure to include all global symbols */
 #include "nolibc.h"
 
-- 
2.40.1

[PATCH nolibc 0/15] nolibc updates for v6.5]

[Paul E. McKenney]

Hello!

This series contains nolibc updates for v6.5:

1.	tools/nolibc: tests: use volatile to force stack smashing,
	courtesy of Thomas Weißschuh.

2.	tools/nolibc: tests: fix build on non-c99 compliant compilers,
	courtesy of Willy Tarreau.

3.	tools/nolibc: fix build of the test case using glibc, courtesy
	of Willy Tarreau.

4.	tools/nolibc: add libc-test binary, courtesy of
	Thomas Weißschuh.

5.	tools/nolibc: add wrapper for memfd_create, courtesy of
	Thomas Weißschuh.

6.	tools/nolibc: implement fd-based FILE streams, courtesy of
	Thomas Weißschuh.

7.	tools/nolibc: add testcases for vfprintf, courtesy of
	Thomas Weißschuh.

8.	tools/nolibc: Fix build of stdio.h due to header ordering,
	courtesy of Mark Brown.

9.	tools/nolibc: use standard __asm__ statements, courtesy of
	Thomas Weißschuh.

10.	tools/nolibc: use __inline__ syntax, courtesy of
	Thomas Weißschuh.

11.	tools/nolibc: use C89 comment syntax, courtesy of
	Thomas Weißschuh.

12.	tools/nolibc: validate C89 compatibility, courtesy of
	Thomas Weißschuh.

13.	tools/nolibc: s390: provide custom implementation for sys_fork,
	courtesy of Thomas Weißschuh.

14.	tools/nolibc: add testcase for fork()/waitpid(), courtesy of
	Thomas Weißschuh.

15.	tools/nolibc: remove LINUX_REBOOT_ constants, courtesy of
	Thomas Weißschuh.

						Thanx, Paul

------------------------------------------------------------------------

 b/tools/include/nolibc/arch-aarch64.h          |   32 +++---
 b/tools/include/nolibc/arch-arm.h              |   44 ++++----
 b/tools/include/nolibc/arch-i386.h             |   40 ++++----
 b/tools/include/nolibc/arch-loongarch.h        |   38 +++----
 b/tools/include/nolibc/arch-mips.h             |   56 +++++------
 b/tools/include/nolibc/arch-riscv.h            |   40 ++++----
 b/tools/include/nolibc/arch-s390.h             |    2 
 b/tools/include/nolibc/arch-x86_64.h           |   34 +++---
 b/tools/include/nolibc/nolibc.h                |    2 
 b/tools/include/nolibc/stackprotector.h        |    4 
 b/tools/include/nolibc/stdio.h                 |   95 +++++++++++++------
 b/tools/include/nolibc/stdlib.h                |   18 +--
 b/tools/include/nolibc/string.h                |    4 
 b/tools/include/nolibc/sys.h                   |   23 ++++
 b/tools/include/nolibc/types.h                 |    8 -
 b/tools/testing/selftests/nolibc/.gitignore    |    1 
 b/tools/testing/selftests/nolibc/Makefile      |    6 +
 b/tools/testing/selftests/nolibc/nolibc-test.c |    8 -
 tools/include/nolibc/arch-s390.h               |    9 +
 tools/include/nolibc/sys.h                     |   11 +-
 tools/testing/selftests/nolibc/Makefile        |    2 
 tools/testing/selftests/nolibc/nolibc-test.c   |  125 +++++++++++++++++++++++--
 22 files changed, 391 insertions(+), 211 deletions(-)

[PATCH v2 nolibc 06/15] tools/nolibc: implement fd-based FILE streams

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

This enables the usage of the stream APIs with arbitrary filedescriptors.

It will be used by a future testcase.

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/include/nolibc/stdio.h | 95 ++++++++++++++++++++++++++----------
 1 file changed, 68 insertions(+), 27 deletions(-)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 6cbbb52836a0..0eef91daf289 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -21,17 +21,75 @@
 #define EOF (-1)
 #endif
 
-/* just define FILE as a non-empty type */
+/* just define FILE as a non-empty type. The value of the pointer gives
+ * the FD: FILE=~fd for fd>=0 or NULL for fd<0. This way positive FILE
+ * are immediately identified as abnormal entries (i.e. possible copies
+ * of valid pointers to something else).
+ */
 typedef struct FILE {
 	char dummy[1];
 } FILE;
 
-/* We define the 3 common stdio files as constant invalid pointers that
- * are easily recognized.
- */
-static __attribute__((unused)) FILE* const stdin  = (FILE*)-3;
-static __attribute__((unused)) FILE* const stdout = (FILE*)-2;
-static __attribute__((unused)) FILE* const stderr = (FILE*)-1;
+static __attribute__((unused)) FILE* const stdin  = (FILE*)(intptr_t)~STDIN_FILENO;
+static __attribute__((unused)) FILE* const stdout = (FILE*)(intptr_t)~STDOUT_FILENO;
+static __attribute__((unused)) FILE* const stderr = (FILE*)(intptr_t)~STDERR_FILENO;
+
+/* provides a FILE* equivalent of fd. The mode is ignored. */
+static __attribute__((unused))
+FILE *fdopen(int fd, const char *mode __attribute__((unused)))
+{
+	if (fd < 0) {
+		SET_ERRNO(EBADF);
+		return NULL;
+	}
+	return (FILE*)(intptr_t)~fd;
+}
+
+/* provides the fd of stream. */
+static __attribute__((unused))
+int fileno(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	if (i >= 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+	return ~i;
+}
+
+/* flush a stream. */
+static __attribute__((unused))
+int fflush(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	/* NULL is valid here. */
+	if (i > 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+
+	/* Don't do anything, nolibc does not support buffering. */
+	return 0;
+}
+
+/* flush a stream. */
+static __attribute__((unused))
+int fclose(FILE *stream)
+{
+	intptr_t i = (intptr_t)stream;
+
+	if (i >= 0) {
+		SET_ERRNO(EBADF);
+		return -1;
+	}
+
+	if (close(~i))
+		return EOF;
+
+	return 0;
+}
 
 /* getc(), fgetc(), getchar() */
 
@@ -41,14 +99,8 @@ static __attribute__((unused))
 int fgetc(FILE* stream)
 {
 	unsigned char ch;
-	int fd;
 
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
-
-	if (read(fd, &ch, 1) <= 0)
+	if (read(fileno(stream), &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
@@ -68,14 +120,8 @@ static __attribute__((unused))
 int fputc(int c, FILE* stream)
 {
 	unsigned char ch = c;
-	int fd;
-
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
 
-	if (write(fd, &ch, 1) <= 0)
+	if (write(fileno(stream), &ch, 1) <= 0)
 		return EOF;
 	return ch;
 }
@@ -96,12 +142,7 @@ static __attribute__((unused))
 int _fwrite(const void *buf, size_t size, FILE *stream)
 {
 	ssize_t ret;
-	int fd;
-
-	if (stream < stdin || stream > stderr)
-		return EOF;
-
-	fd = 3 + (long)stream;
+	int fd = fileno(stream);
 
 	while (size) {
 		ret = write(fd, buf, size);
-- 
2.40.1

[PATCH v2 nolibc 07/15] tools/nolibc: add testcases for vfprintf

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

vfprintf() is complex and so far did not have proper tests.

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/nolibc-test.c | 86 ++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 1bafbd8da6af..888da60eb5ba 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -20,6 +20,7 @@
 #include <linux/reboot.h>
 #include <sys/io.h>
 #include <sys/ioctl.h>
+#include <sys/mman.h>
 #include <sys/mount.h>
 #include <sys/reboot.h>
 #include <sys/stat.h>
@@ -669,6 +670,90 @@ int run_stdlib(int min, int max)
 	return ret;
 }
 
+#define EXPECT_VFPRINTF(c, expected, fmt, ...)				\
+	ret += expect_vfprintf(llen, c, expected, fmt, ##__VA_ARGS__)
+
+static int expect_vfprintf(int llen, size_t c, const char *expected, const char *fmt, ...)
+{
+	int ret, fd, w, r;
+	char buf[100];
+	FILE *memfile;
+	va_list args;
+
+	fd = memfd_create("vfprintf", 0);
+	if (fd == -1) {
+		pad_spc(llen, 64, "[FAIL]\n");
+		return 1;
+	}
+
+	memfile = fdopen(fd, "w+");
+	if (!memfile) {
+		pad_spc(llen, 64, "[FAIL]\n");
+		return 1;
+	}
+
+	va_start(args, fmt);
+	w = vfprintf(memfile, fmt, args);
+	va_end(args);
+
+	if (w != c) {
+		llen += printf(" written(%d) != %d", w, (int) c);
+		pad_spc(llen, 64, "[FAIL]\n");
+		return 1;
+	}
+
+	fflush(memfile);
+	lseek(fd, 0, SEEK_SET);
+
+	r = read(fd, buf, sizeof(buf) - 1);
+	buf[r] = '\0';
+
+	fclose(memfile);
+
+	if (r != w) {
+		llen += printf(" written(%d) != read(%d)", w, r);
+		pad_spc(llen, 64, "[FAIL]\n");
+		return 1;
+	}
+
+	llen += printf(" \"%s\" = \"%s\"", expected, buf);
+	ret = strncmp(expected, buf, c);
+
+	pad_spc(llen, 64, ret ? "[FAIL]\n" : " [OK]\n");
+	return ret;
+}
+
+static int run_vfprintf(int min, int max)
+{
+	int test;
+	int tmp;
+	int ret = 0;
+	void *p1, *p2;
+
+	for (test = min; test >= 0 && test <= max; test++) {
+		int llen = 0; // line length
+
+		/* avoid leaving empty lines below, this will insert holes into
+		 * test numbers.
+		 */
+		switch (test + __LINE__ + 1) {
+		CASE_TEST(empty);        EXPECT_VFPRINTF(0, "", ""); break;
+		CASE_TEST(simple);       EXPECT_VFPRINTF(3, "foo", "foo"); break;
+		CASE_TEST(string);       EXPECT_VFPRINTF(3, "foo", "%s", "foo"); break;
+		CASE_TEST(number);       EXPECT_VFPRINTF(4, "1234", "%d", 1234); break;
+		CASE_TEST(negnumber);    EXPECT_VFPRINTF(5, "-1234", "%d", -1234); break;
+		CASE_TEST(unsigned);     EXPECT_VFPRINTF(5, "12345", "%u", 12345); break;
+		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 __LINE__:
+			return ret; /* must be last */
+		/* note: do not set any defaults so as to permit holes above */
+		}
+	}
+	return ret;
+}
+
 static int smash_stack(void)
 {
 	char buf[100];
@@ -777,6 +862,7 @@ static const struct test test_names[] = {
 	/* add new tests here */
 	{ .name = "syscall",    .func = run_syscall    },
 	{ .name = "stdlib",     .func = run_stdlib     },
+	{ .name = "vfprintf",   .func = run_vfprintf   },
 	{ .name = "protection", .func = run_protection },
 	{ 0 }
 };
-- 
2.40.1

[PATCH v2 nolibc 08/15] tools/nolibc: Fix build of stdio.h due to header ordering

[Paul E. McKenney]

From: Mark Brown <broonie@kernel.org>

When we added fd based file streams we created references to STx_FILENO in
stdio.h but these constants are declared in unistd.h which is the last file
included by the top level nolibc.h meaning those constants are not defined
when we try to build stdio.h. This causes programs using nolibc.h to fail
to build.

Reorder the headers to avoid this issue.

Fixes: d449546c957f ("tools/nolibc: implement fd-based FILE streams")
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/include/nolibc/nolibc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 04739a6293c4..05a228a6ee78 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -99,11 +99,11 @@
 #include "sys.h"
 #include "ctype.h"
 #include "signal.h"
+#include "unistd.h"
 #include "stdio.h"
 #include "stdlib.h"
 #include "string.h"
 #include "time.h"
-#include "unistd.h"
 #include "stackprotector.h"
 
 /* Used by programs to avoid std includes */
-- 
2.40.1

[PATCH v2 nolibc 09/15] tools/nolibc: use standard __asm__ statements

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

Most of the code was migrated to C99-conformant __asm__ statements
before. It seems string.h was missed.

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/include/nolibc/string.h                | 4 ++--
 tools/testing/selftests/nolibc/nolibc-test.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index fffdaf6ff467..0c2e06c7c477 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -90,7 +90,7 @@ void *memset(void *dst, int b, size_t len)
 
 	while (len--) {
 		/* prevent gcc from recognizing memset() here */
-		asm volatile("");
+		__asm__ volatile("");
 		*(p++) = b;
 	}
 	return dst;
@@ -139,7 +139,7 @@ size_t strlen(const char *str)
 	size_t len;
 
 	for (len = 0; str[len]; len++)
-		asm("");
+		__asm__("");
 	return len;
 }
 
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 888da60eb5ba..e692be98973a 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -984,7 +984,7 @@ int main(int argc, char **argv, char **envp)
 #else
 		else if (ioperm(0x501, 1, 1) == 0)
 #endif
-			asm volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0));
+			__asm__ volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0));
 		/* if it does nothing, fall back to the regular panic */
 #endif
 	}
-- 
2.40.1

[PATCH v2 nolibc 10/15] tools/nolibc: use __inline__ syntax

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

When building in strict C89 mode the "inline" keyword is unknown.
While "__inline__" is non-standard it is used by the kernel headers
themselves.
So the used compilers would have to support it or the users shim it with
a #define.

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/include/nolibc/stdlib.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 894c955d027e..902162f80337 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -102,7 +102,7 @@ char *_getenv(const char *name, char **environ)
 	return NULL;
 }
 
-static inline __attribute__((unused,always_inline))
+static __inline__ __attribute__((unused,always_inline))
 char *getenv(const char *name)
 {
 	extern char **environ;
@@ -231,7 +231,7 @@ int utoh_r(unsigned long in, char *buffer)
 /* converts unsigned long <in> to an hex string using the static itoa_buffer
  * and returns the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *utoh(unsigned long in)
 {
 	utoh_r(in, itoa_buffer);
@@ -293,7 +293,7 @@ int itoa_r(long in, char *buffer)
 /* for historical compatibility, same as above but returns the pointer to the
  * buffer.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *ltoa_r(long in, char *buffer)
 {
 	itoa_r(in, buffer);
@@ -303,7 +303,7 @@ char *ltoa_r(long in, char *buffer)
 /* converts long integer <in> to a string using the static itoa_buffer and
  * returns the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *itoa(long in)
 {
 	itoa_r(in, itoa_buffer);
@@ -313,7 +313,7 @@ char *itoa(long in)
 /* converts long integer <in> to a string using the static itoa_buffer and
  * returns the pointer to that string. Same as above, for compatibility.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *ltoa(long in)
 {
 	itoa_r(in, itoa_buffer);
@@ -323,7 +323,7 @@ char *ltoa(long in)
 /* converts unsigned long integer <in> to a string using the static itoa_buffer
  * and returns the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *utoa(unsigned long in)
 {
 	utoa_r(in, itoa_buffer);
@@ -367,7 +367,7 @@ int u64toh_r(uint64_t in, char *buffer)
 /* converts uint64_t <in> to an hex string using the static itoa_buffer and
  * returns the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *u64toh(uint64_t in)
 {
 	u64toh_r(in, itoa_buffer);
@@ -429,7 +429,7 @@ int i64toa_r(int64_t in, char *buffer)
 /* converts int64_t <in> to a string using the static itoa_buffer and returns
  * the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *i64toa(int64_t in)
 {
 	i64toa_r(in, itoa_buffer);
@@ -439,7 +439,7 @@ char *i64toa(int64_t in)
 /* converts uint64_t <in> to a string using the static itoa_buffer and returns
  * the pointer to that string.
  */
-static inline __attribute__((unused))
+static __inline__ __attribute__((unused))
 char *u64toa(uint64_t in)
 {
 	u64toa_r(in, itoa_buffer);
-- 
2.40.1

[PATCH v2 nolibc 11/15] tools/nolibc: use C89 comment syntax

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

Most of nolibc is already using C89 comments.

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/include/nolibc/arch-aarch64.h          | 32 +++++------
 tools/include/nolibc/arch-arm.h              | 44 +++++++--------
 tools/include/nolibc/arch-i386.h             | 40 +++++++-------
 tools/include/nolibc/arch-loongarch.h        | 38 ++++++-------
 tools/include/nolibc/arch-mips.h             | 56 ++++++++++----------
 tools/include/nolibc/arch-riscv.h            | 40 +++++++-------
 tools/include/nolibc/arch-s390.h             |  2 +-
 tools/include/nolibc/arch-x86_64.h           | 34 ++++++------
 tools/include/nolibc/stackprotector.h        |  4 +-
 tools/include/nolibc/sys.h                   |  8 +--
 tools/testing/selftests/nolibc/nolibc-test.c | 12 ++---
 11 files changed, 155 insertions(+), 155 deletions(-)

diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h
index 383baddef701..76ef26520c85 100644
--- a/tools/include/nolibc/arch-aarch64.h
+++ b/tools/include/nolibc/arch-aarch64.h
@@ -176,24 +176,24 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
-		"ldr x0, [sp]\n"     // argc (x0) was in the stack
-		"add x1, sp, 8\n"    // argv (x1) = sp
-		"lsl x2, x0, 3\n"    // envp (x2) = 8*argc ...
-		"add x2, x2, 8\n"    //           + 8 (skip null)
-		"add x2, x2, x1\n"   //           + argv
-		"adrp x3, environ\n"          // x3 = &environ (high bits)
-		"str x2, [x3, #:lo12:environ]\n" // store envp into environ
-		"mov x4, x2\n"       // search for auxv (follows NULL after last env)
+		"ldr x0, [sp]\n"     /* argc (x0) was in the stack                          */
+		"add x1, sp, 8\n"    /* argv (x1) = sp                                      */
+		"lsl x2, x0, 3\n"    /* envp (x2) = 8*argc ...                              */
+		"add x2, x2, 8\n"    /*           + 8 (skip null)                           */
+		"add x2, x2, x1\n"   /*           + argv                                    */
+		"adrp x3, environ\n"          /* x3 = &environ (high bits)                  */
+		"str x2, [x3, #:lo12:environ]\n" /* store envp into environ                 */
+		"mov x4, x2\n"       /* search for auxv (follows NULL after last env)       */
 		"0:\n"
-		"ldr x5, [x4], 8\n"  // x5 = *x4; x4 += 8
-		"cbnz x5, 0b\n"      // and stop at NULL after last env
-		"adrp x3, _auxv\n"   // x3 = &_auxv (high bits)
-		"str x4, [x3, #:lo12:_auxv]\n" // store x4 into _auxv
-		"and sp, x1, -16\n"  // sp must be 16-byte aligned in the callee
-		"bl main\n"          // main() returns the status code, we'll exit with it.
-		"mov x8, 93\n"       // NR_exit == 93
+		"ldr x5, [x4], 8\n"  /* x5 = *x4; x4 += 8                                   */
+		"cbnz x5, 0b\n"      /* and stop at NULL after last env                     */
+		"adrp x3, _auxv\n"   /* x3 = &_auxv (high bits)                             */
+		"str x4, [x3, #:lo12:_auxv]\n" /* store x4 into _auxv                       */
+		"and sp, x1, -16\n"  /* sp must be 16-byte aligned in the callee            */
+		"bl main\n"          /* main() returns the status code, we'll exit with it. */
+		"mov x8, 93\n"       /* NR_exit == 93                                       */
 		"svc #0\n"
 	);
 	__builtin_unreachable();
 }
-#endif // _NOLIBC_ARCH_AARCH64_H
+#endif /* _NOLIBC_ARCH_AARCH64_H */
diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index 42499f23e73c..2eab1aef321b 100644
--- a/tools/include/nolibc/arch-arm.h
+++ b/tools/include/nolibc/arch-arm.h
@@ -203,34 +203,34 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
-		"pop {%r0}\n"                 // argc was in the stack
-		"mov %r1, %sp\n"              // argv = sp
+		"pop {%r0}\n"                 /* argc was in the stack                               */
+		"mov %r1, %sp\n"              /* argv = sp                                           */
 
-		"add %r2, %r0, $1\n"          // envp = (argc + 1) ...
-		"lsl %r2, %r2, $2\n"          //        * 4        ...
-		"add %r2, %r2, %r1\n"         //        + argv
-		"ldr %r3, 1f\n"               // r3 = &environ (see below)
-		"str %r2, [r3]\n"             // store envp into environ
+		"add %r2, %r0, $1\n"          /* envp = (argc + 1) ...                               */
+		"lsl %r2, %r2, $2\n"          /*        * 4        ...                               */
+		"add %r2, %r2, %r1\n"         /*        + argv                                       */
+		"ldr %r3, 1f\n"               /* r3 = &environ (see below)                           */
+		"str %r2, [r3]\n"             /* store envp into environ                             */
 
-		"mov r4, r2\n"                // search for auxv (follows NULL after last env)
+		"mov r4, r2\n"                /* search for auxv (follows NULL after last env)       */
 		"0:\n"
-		"mov r5, r4\n"                // r5 = r4
-		"add r4, r4, #4\n"            // r4 += 4
-		"ldr r5,[r5]\n"               // r5 = *r5 = *(r4-4)
-		"cmp r5, #0\n"                // and stop at NULL after last env
+		"mov r5, r4\n"                /* r5 = r4                                             */
+		"add r4, r4, #4\n"            /* r4 += 4                                             */
+		"ldr r5,[r5]\n"               /* r5 = *r5 = *(r4-4)                                  */
+		"cmp r5, #0\n"                /* and stop at NULL after last env                     */
 		"bne 0b\n"
-		"ldr %r3, 2f\n"               // r3 = &_auxv (low bits)
-		"str r4, [r3]\n"              // store r4 into _auxv
+		"ldr %r3, 2f\n"               /* r3 = &_auxv (low bits)                              */
+		"str r4, [r3]\n"              /* store r4 into _auxv                                 */
 
-		"mov %r3, $8\n"               // AAPCS : sp must be 8-byte aligned in the
-		"neg %r3, %r3\n"              //         callee, and bl doesn't push (lr=pc)
-		"and %r3, %r3, %r1\n"         // so we do sp = r1(=sp) & r3(=-8);
-		"mov %sp, %r3\n"              //
+		"mov %r3, $8\n"               /* AAPCS : sp must be 8-byte aligned in the            */
+		"neg %r3, %r3\n"              /*         callee, and bl doesn't push (lr=pc)         */
+		"and %r3, %r3, %r1\n"         /* so we do sp = r1(=sp) & r3(=-8);                    */
+		"mov %sp, %r3\n"
 
-		"bl main\n"                   // main() returns the status code, we'll exit with it.
-		"movs r7, $1\n"               // NR_exit == 1
+		"bl main\n"                   /* main() returns the status code, we'll exit with it. */
+		"movs r7, $1\n"               /* NR_exit == 1                                        */
 		"svc $0x00\n"
-		".align 2\n"                  // below are the pointers to a few variables
+		".align 2\n"                  /* below are the pointers to a few variables           */
 		"1:\n"
 		".word environ\n"
 		"2:\n"
@@ -239,4 +239,4 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_ARM_H
+#endif /* _NOLIBC_ARCH_ARM_H */
diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h
index 2d98d78fd3f3..7c41897a08ce 100644
--- a/tools/include/nolibc/arch-i386.h
+++ b/tools/include/nolibc/arch-i386.h
@@ -194,31 +194,31 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protec
 {
 	__asm__ volatile (
 #ifdef NOLIBC_STACKPROTECTOR
-		"call __stack_chk_init\n"   // initialize stack protector
+		"call __stack_chk_init\n"   /* initialize stack protector                    */
 #endif
-		"pop %eax\n"                // argc   (first arg, %eax)
-		"mov %esp, %ebx\n"          // argv[] (second arg, %ebx)
-		"lea 4(%ebx,%eax,4),%ecx\n" // then a NULL then envp (third arg, %ecx)
-		"mov %ecx, environ\n"       // save environ
-		"xor %ebp, %ebp\n"          // zero the stack frame
-		"mov %ecx, %edx\n"          // search for auxv (follows NULL after last env)
+		"pop %eax\n"                /* argc   (first arg, %eax)                      */
+		"mov %esp, %ebx\n"          /* argv[] (second arg, %ebx)                     */
+		"lea 4(%ebx,%eax,4),%ecx\n" /* then a NULL then envp (third arg, %ecx)       */
+		"mov %ecx, environ\n"       /* save environ                                  */
+		"xor %ebp, %ebp\n"          /* zero the stack frame                          */
+		"mov %ecx, %edx\n"          /* search for auxv (follows NULL after last env) */
 		"0:\n"
-		"add $4, %edx\n"            // search for auxv using edx, it follows the
-		"cmp -4(%edx), %ebp\n"      // ... NULL after last env (ebp is zero here)
+		"add $4, %edx\n"            /* search for auxv using edx, it follows the     */
+		"cmp -4(%edx), %ebp\n"      /* ... NULL after last env (ebp is zero here)    */
 		"jnz 0b\n"
-		"mov %edx, _auxv\n"         // save it into _auxv
-		"and $-16, %esp\n"          // x86 ABI : esp must be 16-byte aligned before
-		"sub $4, %esp\n"            // the call instruction (args are aligned)
-		"push %ecx\n"               // push all registers on the stack so that we
-		"push %ebx\n"               // support both regparm and plain stack modes
+		"mov %edx, _auxv\n"         /* save it into _auxv                            */
+		"and $-16, %esp\n"          /* x86 ABI : esp must be 16-byte aligned before  */
+		"sub $4, %esp\n"            /* the call instruction (args are aligned)       */
+		"push %ecx\n"               /* push all registers on the stack so that we    */
+		"push %ebx\n"               /* support both regparm and plain stack modes    */
 		"push %eax\n"
-		"call main\n"               // main() returns the status code in %eax
-		"mov %eax, %ebx\n"          // retrieve exit code (32-bit int)
-		"movl $1, %eax\n"           // NR_exit == 1
-		"int $0x80\n"               // exit now
-		"hlt\n"                     // ensure it does not
+		"call main\n"               /* main() returns the status code in %eax        */
+		"mov %eax, %ebx\n"          /* retrieve exit code (32-bit int)               */
+		"movl $1, %eax\n"           /* NR_exit == 1                                  */
+		"int $0x80\n"               /* exit now                                      */
+		"hlt\n"                     /* ensure it does not                            */
 	);
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_I386_H
+#endif /* _NOLIBC_ARCH_I386_H */
diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index 029ee3cd6baf..ec3b46a991a9 100644
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/tools/include/nolibc/arch-loongarch.h
@@ -158,7 +158,7 @@ const unsigned long *_auxv __attribute__((weak));
 #define LONG_ADDI    "addi.w"
 #define LONG_SLL     "slli.w"
 #define LONG_BSTRINS "bstrins.w"
-#else // __loongarch_grlen == 64
+#else /* __loongarch_grlen == 64 */
 #define LONGLOG      "3"
 #define SZREG        "8"
 #define REG_L        "ld.d"
@@ -173,28 +173,28 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
-		REG_L        " $a0, $sp, 0\n"         // argc (a0) was in the stack
-		LONG_ADDI    " $a1, $sp, "SZREG"\n"   // argv (a1) = sp + SZREG
-		LONG_SLL     " $a2, $a0, "LONGLOG"\n" // envp (a2) = SZREG*argc ...
-		LONG_ADDI    " $a2, $a2, "SZREG"\n"   //             + SZREG (skip null)
-		LONG_ADD     " $a2, $a2, $a1\n"       //             + argv
+		REG_L        " $a0, $sp, 0\n"         /* argc (a0) was in the stack                          */
+		LONG_ADDI    " $a1, $sp, "SZREG"\n"   /* argv (a1) = sp + SZREG                              */
+		LONG_SLL     " $a2, $a0, "LONGLOG"\n" /* envp (a2) = SZREG*argc ...                          */
+		LONG_ADDI    " $a2, $a2, "SZREG"\n"   /*             + SZREG (skip null)                     */
+		LONG_ADD     " $a2, $a2, $a1\n"       /*             + argv                                  */
 
-		"move          $a3, $a2\n"            // iterate a3 over envp to find auxv (after NULL)
-		"0:\n"                                // do {
-		REG_L        " $a4, $a3, 0\n"         //   a4 = *a3;
-		LONG_ADDI    " $a3, $a3, "SZREG"\n"   //   a3 += sizeof(void*);
-		"bne           $a4, $zero, 0b\n"      // } while (a4);
-		"la.pcrel      $a4, _auxv\n"          // a4 = &_auxv
-		LONG_S       " $a3, $a4, 0\n"         // store a3 into _auxv
+		"move          $a3, $a2\n"            /* iterate a3 over envp to find auxv (after NULL)      */
+		"0:\n"                                /* do {                                                */
+		REG_L        " $a4, $a3, 0\n"         /*   a4 = *a3;                                         */
+		LONG_ADDI    " $a3, $a3, "SZREG"\n"   /*   a3 += sizeof(void*);                              */
+		"bne           $a4, $zero, 0b\n"      /* } while (a4);                                       */
+		"la.pcrel      $a4, _auxv\n"          /* a4 = &_auxv                                         */
+		LONG_S       " $a3, $a4, 0\n"         /* store a3 into _auxv                                 */
 
-		"la.pcrel      $a3, environ\n"        // a3 = &environ
-		LONG_S       " $a2, $a3, 0\n"         // store envp(a2) into environ
-		LONG_BSTRINS " $sp, $zero, 3, 0\n"    // sp must be 16-byte aligned
-		"bl            main\n"                // main() returns the status code, we'll exit with it.
-		"li.w          $a7, 93\n"             // NR_exit == 93
+		"la.pcrel      $a3, environ\n"        /* a3 = &environ                                       */
+		LONG_S       " $a2, $a3, 0\n"         /* store envp(a2) into environ                         */
+		LONG_BSTRINS " $sp, $zero, 3, 0\n"    /* sp must be 16-byte aligned                          */
+		"bl            main\n"                /* main() returns the status code, we'll exit with it. */
+		"li.w          $a7, 93\n"             /* NR_exit == 93                                       */
 		"syscall       0\n"
 	);
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_LOONGARCH_H
+#endif /* _NOLIBC_ARCH_LOONGARCH_H */
diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index bf83432d23ed..8822f150e72f 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -183,42 +183,42 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void)
 {
 	__asm__ volatile (
-		//".set nomips16\n"
+		/*".set nomips16\n"*/
 		".set push\n"
 		".set    noreorder\n"
 		".option pic0\n"
-		//".ent __start\n"
-		//"__start:\n"
-		"lw $a0,($sp)\n"        // argc was in the stack
-		"addiu  $a1, $sp, 4\n"  // argv = sp + 4
-		"sll $a2, $a0, 2\n"     // a2 = argc * 4
-		"add   $a2, $a2, $a1\n" // envp = argv + 4*argc ...
-		"addiu $a2, $a2, 4\n"   //        ... + 4
-		"lui $a3, %hi(environ)\n"     // load environ into a3 (hi)
-		"addiu $a3, %lo(environ)\n"   // load environ into a3 (lo)
-		"sw $a2,($a3)\n"              // store envp(a2) into environ
-
-		"move $t0, $a2\n"             // iterate t0 over envp, look for NULL
-		"0:"                          // do {
-		"lw $a3, ($t0)\n"             //   a3=*(t0);
-		"bne $a3, $0, 0b\n"           // } while (a3);
-		"addiu $t0, $t0, 4\n"         // delayed slot: t0+=4;
-		"lui $a3, %hi(_auxv)\n"       // load _auxv into a3 (hi)
-		"addiu $a3, %lo(_auxv)\n"     // load _auxv into a3 (lo)
-		"sw $t0, ($a3)\n"             // store t0 into _auxv
+		/*".ent __start\n"*/
+		/*"__start:\n"*/
+		"lw $a0,($sp)\n"        /* argc was in the stack                               */
+		"addiu  $a1, $sp, 4\n"  /* argv = sp + 4                                       */
+		"sll $a2, $a0, 2\n"     /* a2 = argc * 4                                       */
+		"add   $a2, $a2, $a1\n" /* envp = argv + 4*argc ...                            */
+		"addiu $a2, $a2, 4\n"   /*        ... + 4                                      */
+		"lui $a3, %hi(environ)\n"     /* load environ into a3 (hi)                     */
+		"addiu $a3, %lo(environ)\n"   /* load environ into a3 (lo)                     */
+		"sw $a2,($a3)\n"              /* store envp(a2) into environ                   */
+
+		"move $t0, $a2\n"             /* iterate t0 over envp, look for NULL           */
+		"0:"                          /* do {                                          */
+		"lw $a3, ($t0)\n"             /*   a3=*(t0);                                   */
+		"bne $a3, $0, 0b\n"           /* } while (a3);                                 */
+		"addiu $t0, $t0, 4\n"         /* delayed slot: t0+=4;                          */
+		"lui $a3, %hi(_auxv)\n"       /* load _auxv into a3 (hi)                       */
+		"addiu $a3, %lo(_auxv)\n"     /* load _auxv into a3 (lo)                       */
+		"sw $t0, ($a3)\n"             /* store t0 into _auxv                           */
 
 		"li $t0, -8\n"
-		"and $sp, $sp, $t0\n"   // sp must be 8-byte aligned
-		"addiu $sp,$sp,-16\n"   // the callee expects to save a0..a3 there!
-		"jal main\n"            // main() returns the status code, we'll exit with it.
-		"nop\n"                 // delayed slot
-		"move $a0, $v0\n"       // retrieve 32-bit exit code from v0
-		"li $v0, 4001\n"        // NR_exit == 4001
+		"and $sp, $sp, $t0\n"   /* sp must be 8-byte aligned                           */
+		"addiu $sp,$sp,-16\n"   /* the callee expects to save a0..a3 there!            */
+		"jal main\n"            /* main() returns the status code, we'll exit with it. */
+		"nop\n"                 /* delayed slot                                        */
+		"move $a0, $v0\n"       /* retrieve 32-bit exit code from v0                   */
+		"li $v0, 4001\n"        /* NR_exit == 4001                                     */
 		"syscall\n"
-		//".end __start\n"
+		/*".end __start\n"*/
 		".set pop\n"
 	);
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_MIPS_H
+#endif /* _NOLIBC_ARCH_MIPS_H */
diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index e197fcb10ac0..0d5f15fdedc4 100644
--- a/tools/include/nolibc/arch-riscv.h
+++ b/tools/include/nolibc/arch-riscv.h
@@ -181,28 +181,28 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 		".option norelax\n"
 		"lla   gp, __global_pointer$\n"
 		".option pop\n"
-		"lw    a0, 0(sp)\n"          // argc (a0) was in the stack
-		"add   a1, sp, "SZREG"\n"    // argv (a1) = sp
-		"slli  a2, a0, "PTRLOG"\n"   // envp (a2) = SZREG*argc ...
-		"add   a2, a2, "SZREG"\n"    //             + SZREG (skip null)
-		"add   a2,a2,a1\n"           //             + argv
-
-		"add   a3, a2, zero\n"       // iterate a3 over envp to find auxv (after NULL)
-		"0:\n"                       // do {
-		"ld    a4, 0(a3)\n"          //   a4 = *a3;
-		"add   a3, a3, "SZREG"\n"    //   a3 += sizeof(void*);
-		"bne   a4, zero, 0b\n"       // } while (a4);
-		"lui   a4, %hi(_auxv)\n"     // a4 = &_auxv (high bits)
-		"sd    a3, %lo(_auxv)(a4)\n" // store a3 into _auxv
-
-		"lui a3, %hi(environ)\n"     // a3 = &environ (high bits)
-		"sd a2,%lo(environ)(a3)\n"   // store envp(a2) into environ
-		"andi  sp,a1,-16\n"          // sp must be 16-byte aligned
-		"call  main\n"               // main() returns the status code, we'll exit with it.
-		"li a7, 93\n"                // NR_exit == 93
+		"lw    a0, 0(sp)\n"          /* argc (a0) was in the stack                          */
+		"add   a1, sp, "SZREG"\n"    /* argv (a1) = sp                                      */
+		"slli  a2, a0, "PTRLOG"\n"   /* envp (a2) = SZREG*argc ...                          */
+		"add   a2, a2, "SZREG"\n"    /*             + SZREG (skip null)                     */
+		"add   a2,a2,a1\n"           /*             + argv                                  */
+
+		"add   a3, a2, zero\n"       /* iterate a3 over envp to find auxv (after NULL)      */
+		"0:\n"                       /* do {                                                */
+		"ld    a4, 0(a3)\n"          /*   a4 = *a3;                                         */
+		"add   a3, a3, "SZREG"\n"    /*   a3 += sizeof(void*);                              */
+		"bne   a4, zero, 0b\n"       /* } while (a4);                                       */
+		"lui   a4, %hi(_auxv)\n"     /* a4 = &_auxv (high bits)                             */
+		"sd    a3, %lo(_auxv)(a4)\n" /* store a3 into _auxv                                 */
+
+		"lui a3, %hi(environ)\n"     /* a3 = &environ (high bits)                           */
+		"sd a2,%lo(environ)(a3)\n"   /* store envp(a2) into environ                         */
+		"andi  sp,a1,-16\n"          /* sp must be 16-byte aligned                          */
+		"call  main\n"               /* main() returns the status code, we'll exit with it. */
+		"li a7, 93\n"                /* NR_exit == 93                                       */
 		"ecall\n"
 	);
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_RISCV_H
+#endif /* _NOLIBC_ARCH_RISCV_H */
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index 6b0e54ed543d..c62ee2472407 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -223,4 +223,4 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
 	return (void *)my_syscall1(__NR_mmap, &args);
 }
 #define sys_mmap sys_mmap
-#endif // _NOLIBC_ARCH_S390_H
+#endif /* _NOLIBC_ARCH_S390_H */
diff --git a/tools/include/nolibc/arch-x86_64.h b/tools/include/nolibc/arch-x86_64.h
index f7f2a11d4c3b..d98f6c89d143 100644
--- a/tools/include/nolibc/arch-x86_64.h
+++ b/tools/include/nolibc/arch-x86_64.h
@@ -194,27 +194,27 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
 #ifdef NOLIBC_STACKPROTECTOR
-		"call __stack_chk_init\n"   // initialize stack protector
+		"call __stack_chk_init\n"   /* initialize stack protector                          */
 #endif
-		"pop %rdi\n"                // argc   (first arg, %rdi)
-		"mov %rsp, %rsi\n"          // argv[] (second arg, %rsi)
-		"lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx)
-		"mov %rdx, environ\n"       // save environ
-		"xor %ebp, %ebp\n"          // zero the stack frame
-		"mov %rdx, %rax\n"          // search for auxv (follows NULL after last env)
+		"pop %rdi\n"                /* argc   (first arg, %rdi)                            */
+		"mov %rsp, %rsi\n"          /* argv[] (second arg, %rsi)                           */
+		"lea 8(%rsi,%rdi,8),%rdx\n" /* then a NULL then envp (third arg, %rdx)             */
+		"mov %rdx, environ\n"       /* save environ                                        */
+		"xor %ebp, %ebp\n"          /* zero the stack frame                                */
+		"mov %rdx, %rax\n"          /* search for auxv (follows NULL after last env)       */
 		"0:\n"
-		"add $8, %rax\n"            // search for auxv using rax, it follows the
-		"cmp -8(%rax), %rbp\n"      // ... NULL after last env (rbp is zero here)
+		"add $8, %rax\n"            /* search for auxv using rax, it follows the           */
+		"cmp -8(%rax), %rbp\n"      /* ... NULL after last env (rbp is zero here)          */
 		"jnz 0b\n"
-		"mov %rax, _auxv\n"         // save it into _auxv
-		"and $-16, %rsp\n"          // x86 ABI : esp must be 16-byte aligned before call
-		"call main\n"               // main() returns the status code, we'll exit with it.
-		"mov %eax, %edi\n"          // retrieve exit code (32 bit)
-		"mov $60, %eax\n"           // NR_exit == 60
-		"syscall\n"                 // really exit
-		"hlt\n"                     // ensure it does not return
+		"mov %rax, _auxv\n"         /* save it into _auxv                                  */
+		"and $-16, %rsp\n"          /* x86 ABI : esp must be 16-byte aligned before call   */
+		"call main\n"               /* main() returns the status code, we'll exit with it. */
+		"mov %eax, %edi\n"          /* retrieve exit code (32 bit)                         */
+		"mov $60, %eax\n"           /* NR_exit == 60                                       */
+		"syscall\n"                 /* really exit                                         */
+		"hlt\n"                     /* ensure it does not return                           */
 	);
 	__builtin_unreachable();
 }
 
-#endif // _NOLIBC_ARCH_X86_64_H
+#endif /* _NOLIBC_ARCH_X86_64_H */
diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
index d119cbbbc256..77e5251c4490 100644
--- a/tools/include/nolibc/stackprotector.h
+++ b/tools/include/nolibc/stackprotector.h
@@ -48,6 +48,6 @@ void __stack_chk_init(void)
 	/* a bit more randomness in case getrandom() fails */
 	__stack_chk_guard ^= (uintptr_t) &__stack_chk_guard;
 }
-#endif // defined(NOLIBC_STACKPROTECTOR)
+#endif /* defined(NOLIBC_STACKPROTECTOR) */
 
-#endif // _NOLIBC_STACKPROTECTOR_H
+#endif /* _NOLIBC_STACKPROTECTOR_H */
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index bea9760dbd16..1b9b91cd8b57 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -12,15 +12,15 @@
 
 /* system includes */
 #include <asm/unistd.h>
-#include <asm/signal.h>  // for SIGCHLD
+#include <asm/signal.h>  /* for SIGCHLD */
 #include <asm/ioctls.h>
 #include <asm/mman.h>
 #include <linux/fs.h>
 #include <linux/loop.h>
 #include <linux/time.h>
 #include <linux/auxvec.h>
-#include <linux/fcntl.h> // for O_* and AT_*
-#include <linux/stat.h>  // for statx()
+#include <linux/fcntl.h> /* for O_* and AT_* */
+#include <linux/stat.h>  /* for statx() */
 
 #include "arch.h"
 #include "errno.h"
@@ -322,7 +322,7 @@ static __attribute__((noreturn,unused))
 void sys_exit(int status)
 {
 	my_syscall1(__NR_exit, status & 255);
-	while(1); // shut the "noreturn" warnings.
+	while(1); /* shut the "noreturn" warnings. */
 }
 
 static __attribute__((noreturn,unused))
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index e692be98973a..f06b38cfe38a 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 
 #define _GNU_SOURCE
 
@@ -46,8 +46,8 @@ char **environ;
 
 /* definition of a series of tests */
 struct test {
-	const char *name;              // test name
-	int (*func)(int min, int max); // handler
+	const char *name;              /* test name */
+	int (*func)(int min, int max); /* handler */
 };
 
 #ifndef _NOLIBC_STDLIB_H
@@ -494,7 +494,7 @@ int run_syscall(int min, int max)
 	euid0 = geteuid() == 0;
 
 	for (test = min; test >= 0 && test <= max; test++) {
-		int llen = 0; // line length
+		int llen = 0; /* line length */
 
 		/* avoid leaving empty lines below, this will insert holes into
 		 * test numbers.
@@ -584,7 +584,7 @@ int run_stdlib(int min, int max)
 	void *p1, *p2;
 
 	for (test = min; test >= 0 && test <= max; test++) {
-		int llen = 0; // line length
+		int llen = 0; /* line length */
 
 		/* avoid leaving empty lines below, this will insert holes into
 		 * test numbers.
@@ -731,7 +731,7 @@ static int run_vfprintf(int min, int max)
 	void *p1, *p2;
 
 	for (test = min; test >= 0 && test <= max; test++) {
-		int llen = 0; // line length
+		int llen = 0; /* line length */
 
 		/* avoid leaving empty lines below, this will insert holes into
 		 * test numbers.
-- 
2.40.1

[PATCH v2 nolibc 12/15] tools/nolibc: validate C89 compatibility

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

To make sure no non-compatible changes are introduced accidentally
validate the language standard when building the tests.

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 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 0cbe13809b37..423d22f353a0 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -83,7 +83,7 @@ CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
-CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
+CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \
 		$(call cc-option,-fno-stack-protector) \
 		$(CFLAGS_STKP_$(ARCH)) $(CFLAGS_$(ARCH))
 LDFLAGS := -s
-- 
2.40.1

[PATCH v2 nolibc 13/15] tools/nolibc: s390: provide custom implementation for sys_fork

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

On s390 the first two arguments to the clone() syscall are swapped,
as documented in clone(2).

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/include/nolibc/arch-s390.h | 9 +++++++++
 tools/include/nolibc/sys.h       | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index c62ee2472407..a738e7f3f8e8 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -5,6 +5,7 @@
 
 #ifndef _NOLIBC_ARCH_S390_H
 #define _NOLIBC_ARCH_S390_H
+#include <asm/signal.h>
 #include <asm/unistd.h>
 
 /* The struct returned by the stat() syscall, equivalent to stat64(). The
@@ -223,4 +224,12 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
 	return (void *)my_syscall1(__NR_mmap, &args);
 }
 #define sys_mmap sys_mmap
+
+static __attribute__((unused))
+pid_t sys_fork(void)
+{
+	return my_syscall5(__NR_clone, 0, SIGCHLD, 0, 0, 0);
+}
+#define sys_fork sys_fork
+
 #endif /* _NOLIBC_ARCH_S390_H */
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 1b9b91cd8b57..60dffb1cbf96 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -336,6 +336,7 @@ void exit(int status)
  * pid_t fork(void);
  */
 
+#ifndef sys_fork
 static __attribute__((unused))
 pid_t sys_fork(void)
 {
@@ -351,6 +352,7 @@ pid_t sys_fork(void)
 #error Neither __NR_clone nor __NR_fork defined, cannot implement sys_fork()
 #endif
 }
+#endif
 
 static __attribute__((unused))
 pid_t fork(void)
-- 
2.40.1

[PATCH v2 nolibc 14/15] tools/nolibc: add testcase for fork()/waitpid()

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

On s390 the arguments to clone() which is used by fork() are different
than other archs.
Make sure everything works correctly.

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/nolibc-test.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index f06b38cfe38a..f042a6436b6b 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -474,6 +474,25 @@ static int test_getpagesize(void)
 	return !c;
 }
 
+static int test_fork(void)
+{
+	int status;
+	pid_t pid = fork();
+
+	switch (pid) {
+	case -1:
+		return 1;
+
+	case 0:
+		exit(123);
+
+	default:
+		pid = waitpid(pid, &status, 0);
+
+		return pid == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 123;
+	}
+}
+
 /* Run syscall tests between IDs <min> and <max>.
  * Return 0 on success, non-zero on failure.
  */
@@ -530,6 +549,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(dup3_0);            tmp = dup3(0, 100, 0);  EXPECT_SYSNE(1, tmp, -1); close(tmp); break;
 		CASE_TEST(dup3_m1);           tmp = dup3(-1, 100, 0); EXPECT_SYSER(1, tmp, -1, EBADF); if (tmp != -1) close(tmp); break;
 		CASE_TEST(execve_root);       EXPECT_SYSER(1, execve("/", (char*[]){ [0] = "/", [1] = NULL }, NULL), -1, EACCES); break;
+		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(gettimeofday_null); EXPECT_SYSZR(1, gettimeofday(NULL, NULL)); break;
-- 
2.40.1

[PATCH v2 nolibc 15/15] tools/nolibc: remove LINUX_REBOOT_ constants

[Paul E. McKenney]

From: Thomas Weißschuh <linux@weissschuh.net>

The same constants and some more have been exposed to userspace via
linux/reboot.h for a long time.

To avoid conflicts and trim down nolibc a bit drop the custom
definitions.

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/include/nolibc/sys.h   | 1 +
 tools/include/nolibc/types.h | 8 --------
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 60dffb1cbf96..d5792a5de70b 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -21,6 +21,7 @@
 #include <linux/auxvec.h>
 #include <linux/fcntl.h> /* for O_* and AT_* */
 #include <linux/stat.h>  /* for statx() */
+#include <linux/reboot.h> /* for LINUX_REBOOT_* */
 
 #include "arch.h"
 #include "errno.h"
diff --git a/tools/include/nolibc/types.h b/tools/include/nolibc/types.h
index aedd7d9e3f64..15b0baffd336 100644
--- a/tools/include/nolibc/types.h
+++ b/tools/include/nolibc/types.h
@@ -86,14 +86,6 @@
 #define SEEK_CUR       1
 #define SEEK_END       2
 
-/* cmd for reboot() */
-#define LINUX_REBOOT_MAGIC1         0xfee1dead
-#define LINUX_REBOOT_MAGIC2         0x28121969
-#define LINUX_REBOOT_CMD_HALT       0xcdef0123
-#define LINUX_REBOOT_CMD_POWER_OFF  0x4321fedc
-#define LINUX_REBOOT_CMD_RESTART    0x01234567
-#define LINUX_REBOOT_CMD_SW_SUSPEND 0xd000fce2
-
 /* Macros used on waitpid()'s return status */
 #define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
 #define WIFEXITED(status)   (((status) & 0x7f) == 0)
-- 
2.40.1