Merge tag 'nolibc-20251130-for-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/nolibc/linux-nolibc

Pull nolibc updates from Thomas Weißschuh:

 - Preparations to the use of nolibc in UML:
     - Cleanup of sparse warnings
     - Library mode without _start()
     - More consistency when disabling errno

 - Unconditional installation of all architecture support files

 - Always 64-bit wide ino_t and off_t

 - Various cleanups and bug fixes

* tag 'nolibc-20251130-for-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/nolibc/linux-nolibc: (25 commits)
  selftests/nolibc: error out on linker warnings
  selftests/nolibc: use lld to link loongarch binaries
  tools/nolibc: remove more __nolibc_enosys() fallbacks
  tools/nolibc: remove now superfluous overflow check in llseek
  tools/nolibc: use 64-bit off_t
  tools/nolibc: prefer the llseek syscall
  tools/nolibc: handle 64-bit off_t for llseek
  tools/nolibc: use 64-bit ino_t
  tools/nolibc: avoid using plain integer as NULL pointer
  tools/nolibc: add support for fchdir()
  tools/nolibc: clean up outdated comments in generic arch.h
  tools/nolibc: make the "headers" target install all supported archs
  tools/nolibc: add the more portable inttypes.h
  tools/nolibc: provide the portable sys/select.h
  tools/nolibc: add missing memchr() to string.h
  tools/nolibc: fix misleading help message regarding installation path
  tools/nolibc: add uio.h with readv and writev
  tools/nolibc: add option to disable runtime
  tools/nolibc: use __fallthrough__ rather than fallthrough
  tools/nolibc: implement %m if errno is not defined
  ...

tools/include/nolibc/Makefile

@@ -23,7 +23,7 @@ else
 Q=@
 endif
 
-arch_file := arch-$(ARCH).h
+arch_files := arch.h $(wildcard arch-*.h)
 all_files := \
 		compiler.h \
 		crt.h \
@@ -33,6 +33,7 @@ all_files := \
 		errno.h \
 		fcntl.h \
 		getopt.h \
+		inttypes.h \
 		limits.h \
 		math.h \
 		nolibc.h \
@@ -56,12 +57,14 @@ all_files := \
 		sys/random.h \
 		sys/reboot.h \
 		sys/resource.h \
+		sys/select.h \
 		sys/stat.h \
 		sys/syscall.h \
 		sys/sysmacros.h \
 		sys/time.h \
 		sys/timerfd.h \
 		sys/types.h \
+		sys/uio.h \
 		sys/utsname.h \
 		sys/wait.h \
 		time.h \
@@ -79,7 +82,7 @@ help:
 	@echo "Supported targets under nolibc:"
 	@echo "  all                 call \"headers\""
 	@echo "  clean               clean the sysroot"
-	@echo "  headers             prepare a sysroot in tools/include/nolibc/sysroot"
+	@echo "  headers             prepare a multi-arch sysroot in \$${OUTPUT}sysroot"
 	@echo "  headers_standalone  like \"headers\", and also install kernel headers"
 	@echo "  help                this help"
 	@echo ""
@@ -90,18 +93,11 @@ help:
 	@echo "  OUTPUT  = $(OUTPUT)"
 	@echo ""
 
+# installs headers for all archs at once.
 headers:
-	$(Q)mkdir -p $(OUTPUT)sysroot
-	$(Q)mkdir -p $(OUTPUT)sysroot/include
-	$(Q)cp --parents $(all_files) $(OUTPUT)sysroot/include/
-	$(Q)if [ "$(ARCH)" = "i386" -o "$(ARCH)" = "x86_64" ]; then \
-		cat arch-x86.h;                 \
-	elif [ -e "$(arch_file)" ]; then        \
-		cat $(arch_file);               \
-	else                                    \
-		echo "Fatal: architecture $(ARCH) not yet supported by nolibc." >&2; \
-		exit 1;                         \
-	fi > $(OUTPUT)sysroot/include/arch.h
+	$(Q)mkdir -p "$(OUTPUT)sysroot"
+	$(Q)mkdir -p "$(OUTPUT)sysroot/include"
+	$(Q)cp --parents $(arch_files) $(all_files) "$(OUTPUT)sysroot/include/"
 
 headers_standalone: headers
 	$(Q)$(MAKE) -C $(srctree) headers

tools/include/nolibc/arch-arm.h

@@ -184,6 +184,7 @@
 	_arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -193,5 +194,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_ARM_H */

tools/include/nolibc/arch-arm64.h

@@ -141,6 +141,7 @@
 	_arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -150,4 +151,5 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_ARCH_ARM64_H */

tools/include/nolibc/arch-loongarch.h

@@ -142,6 +142,7 @@
 	_arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -151,5 +152,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_LOONGARCH_H */

tools/include/nolibc/arch-m68k.h

@@ -128,6 +128,7 @@
 	_num;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 void _start(void);
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -137,5 +138,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_M68K_H */

tools/include/nolibc/arch-mips.h

@@ -245,6 +245,7 @@
 
 #endif /* _ABIO32 */
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code, note that it's called __start on MIPS */
 void __start(void);
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __start(void)
@@ -266,5 +267,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector __
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_MIPS_H */

tools/include/nolibc/arch-powerpc.h

@@ -183,6 +183,7 @@
 #endif
 #endif /* !__powerpc64__ */
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -215,5 +216,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 #endif
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_POWERPC_H */

tools/include/nolibc/arch-riscv.h

@@ -139,6 +139,7 @@
 	_arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -152,5 +153,6 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_RISCV_H */

tools/include/nolibc/arch-s390.h

@@ -139,6 +139,7 @@
 	_arg1;								\
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -150,6 +151,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 struct s390_mmap_arg_struct {
 	unsigned long addr;

tools/include/nolibc/arch-sh.h

@@ -140,6 +140,7 @@
 	_ret;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void _start_wrapper(void);
 void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _start_wrapper(void)
@@ -158,5 +159,6 @@ void __attribute__((weak,noreturn)) __nolibc_entrypoint __no_stack_protector _st
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_ARCH_SH_H */

tools/include/nolibc/arch-sparc.h

@@ -152,6 +152,7 @@
 	_arg1;                                                                \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
 {
@@ -169,6 +170,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 static pid_t getpid(void);
 

tools/include/nolibc/arch-x86.h

@@ -157,6 +157,7 @@
 	_eax;							\
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 /*
  * i386 System V ABI mandates:
@@ -176,6 +177,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #else /* !defined(__x86_64__) */
 
@@ -323,6 +325,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	_ret;                                                                 \
 })
 
+#ifndef NOLIBC_NO_RUNTIME
 /* startup code */
 /*
  * x86-64 System V ABI mandates:
@@ -340,6 +343,7 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
 	);
 	__nolibc_entrypoint_epilogue();
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 #define NOLIBC_ARCH_HAS_MEMMOVE
 void *memmove(void *dst, const void *src, size_t len);
@@ -351,7 +355,7 @@ void *memcpy(void *dst, const void *src, size_t len);
 void *memset(void *dst, int c, size_t len);
 
 __asm__ (
-".section .text.nolibc_memmove_memcpy\n"
+".pushsection .text.nolibc_memmove_memcpy\n"
 ".weak memmove\n"
 ".weak memcpy\n"
 "memmove:\n"
@@ -371,8 +375,9 @@ __asm__ (
 	"rep movsb\n\t"
 	"cld\n\t"
 	"retq\n"
+".popsection\n"
 
-".section .text.nolibc_memset\n"
+".pushsection .text.nolibc_memset\n"
 ".weak memset\n"
 "memset:\n"
 	"xchgl %eax, %esi\n\t"
@@ -381,6 +386,7 @@ __asm__ (
 	"rep stosb\n\t"
 	"popq  %rax\n\t"
 	"retq\n"
+".popsection\n"
 );
 
 #endif /* !defined(__x86_64__) */

tools/include/nolibc/arch.h

@@ -3,15 +3,6 @@
  * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
  */
 
-/* Below comes the architecture-specific code. For each architecture, we have
- * the syscall declarations and the _start code definition. This is the only
- * global part. On all architectures the kernel puts everything in the stack
- * before jumping to _start just above us, without any return address (_start
- * is not a function but an entry point). So at the stack pointer we find argc.
- * Then argv[] begins, and ends at the first NULL. Then we have envp which
- * starts and ends with a NULL as well. So envp=argv+argc+1.
- */
-
 #ifndef _NOLIBC_ARCH_H
 #define _NOLIBC_ARCH_H
 

tools/include/nolibc/compiler.h

@@ -41,8 +41,8 @@
 #  define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
 #endif /* __nolibc_has_attribute(no_stack_protector) */
 
-#if __nolibc_has_attribute(fallthrough)
-#  define __nolibc_fallthrough do { } while (0); __attribute__((fallthrough))
+#if __nolibc_has_attribute(__fallthrough__)
+#  define __nolibc_fallthrough do { } while (0); __attribute__((__fallthrough__))
 #else
 #  define __nolibc_fallthrough do { } while (0)
 #endif /* __nolibc_has_attribute(fallthrough) */

tools/include/nolibc/crt.h

@@ -7,6 +7,8 @@
 #ifndef _NOLIBC_CRT_H
 #define _NOLIBC_CRT_H
 
+#ifndef NOLIBC_NO_RUNTIME
+
 #include "compiler.h"
 
 char **environ __attribute__((weak));
@@ -88,4 +90,5 @@ void _start_c(long *sp)
 	exit(exitcode);
 }
 
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_CRT_H */

tools/include/nolibc/dirent.h

@@ -86,9 +86,9 @@ int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
 	 * 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;
+	ret = sys_lseek(fd, ldir->d_off, SEEK_SET);
+	if (ret < 0)
+		return -ret;
 
 	entry->d_ino = ldir->d_ino;
 	/* the destination should always be big enough */

tools/include/nolibc/getopt.h

@@ -78,7 +78,7 @@ int getopt(int argc, char * const argv[], const char *optstring)
 		return '?';
 	}
 	if (optstring[i] == ':') {
-		optarg = 0;
+		optarg = NULL;
 		if (optstring[i + 1] != ':' || __optpos) {
 			optarg = argv[optind++];
 			if (__optpos)

tools/include/nolibc/inttypes.h

@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+
+#include "nolibc.h"

tools/include/nolibc/nolibc.h

@@ -104,11 +104,13 @@
 #include "sys/random.h"
 #include "sys/reboot.h"
 #include "sys/resource.h"
+#include "sys/select.h"
 #include "sys/stat.h"
 #include "sys/syscall.h"
 #include "sys/sysmacros.h"
 #include "sys/time.h"
 #include "sys/timerfd.h"
+#include "sys/uio.h"
 #include "sys/utsname.h"
 #include "sys/wait.h"
 #include "ctype.h"

tools/include/nolibc/stackprotector.h

@@ -9,6 +9,7 @@
 
 #include "compiler.h"
 
+#ifndef NOLIBC_NO_RUNTIME
 #if defined(_NOLIBC_STACKPROTECTOR)
 
 #include "sys.h"
@@ -49,5 +50,6 @@ static __no_stack_protector void __stack_chk_init(void)
 #else /* !defined(_NOLIBC_STACKPROTECTOR) */
 static void __stack_chk_init(void) {}
 #endif /* defined(_NOLIBC_STACKPROTECTOR) */
+#endif /* NOLIBC_NO_RUNTIME */
 
 #endif /* _NOLIBC_STACKPROTECTOR_H */

tools/include/nolibc/std.h

@@ -20,13 +20,13 @@
 
 /* those are commonly provided by sys/types.h */
 typedef unsigned int          dev_t;
-typedef unsigned long         ino_t;
+typedef uint64_t              ino_t;
 typedef unsigned int         mode_t;
 typedef   signed int          pid_t;
 typedef unsigned int          uid_t;
 typedef unsigned int          gid_t;
 typedef unsigned long       nlink_t;
-typedef   signed long         off_t;
+typedef  int64_t              off_t;
 typedef   signed long     blksize_t;
 typedef   signed long      blkcnt_t;
 typedef __kernel_time_t      time_t;

tools/include/nolibc/stdio.h

@@ -321,11 +321,13 @@ int __nolibc_printf(__nolibc_printf_cb cb, intptr_t state, size_t n, const char
 				if (!outstr)
 					outstr="(null)";
 			}
-#ifndef NOLIBC_IGNORE_ERRNO
 			else if (c == 'm') {
+#ifdef NOLIBC_IGNORE_ERRNO
+				outstr = "unknown error";
+#else
 				outstr = strerror(errno);
-			}
 #endif /* NOLIBC_IGNORE_ERRNO */
+			}
 			else if (c == '%') {
 				/* queue it verbatim */
 				continue;
@@ -600,7 +602,11 @@ int sscanf(const char *str, const char *format, ...)
 static __attribute__((unused))
 void perror(const char *msg)
 {
+#ifdef NOLIBC_IGNORE_ERRNO
+	fprintf(stderr, "%s%sunknown error\n", (msg && *msg) ? msg : "", (msg && *msg) ? ": " : "");
+#else
 	fprintf(stderr, "%s%serrno=%d\n", (msg && *msg) ? msg : "", (msg && *msg) ? ": " : "", errno);
+#endif
 }
 
 static __attribute__((unused))

tools/include/nolibc/stdlib.h

@@ -100,6 +100,7 @@ void free(void *ptr)
 	munmap(heap, heap->len);
 }
 
+#ifndef NOLIBC_NO_RUNTIME
 /* getenv() tries to find the environment variable named <name> in the
  * environment array pointed to by global variable "environ" which must be
  * declared as a char **, and must be terminated by a NULL (it is recommended
@@ -122,6 +123,7 @@ char *getenv(const char *name)
 	}
 	return NULL;
 }
+#endif /* NOLIBC_NO_RUNTIME */
 
 static __attribute__((unused))
 void *malloc(size_t len)

tools/include/nolibc/string.h

@@ -93,6 +93,21 @@ void *memset(void *dst, int b, size_t len)
 }
 #endif /* #ifndef NOLIBC_ARCH_HAS_MEMSET */
 
+#ifndef NOLIBC_ARCH_HAS_MEMCHR
+static __attribute__((unused))
+void *memchr(const void *s, int c, size_t len)
+{
+	char *p = (char *)s;
+
+	while (len--) {
+		if (*p == (char)c)
+			return p;
+		p++;
+	}
+	return NULL;
+}
+#endif /* #ifndef NOLIBC_ARCH_HAS_MEMCHR */
+
 static __attribute__((unused))
 char *strchr(const char *s, int c)
 {

tools/include/nolibc/sys.h

@@ -106,7 +106,7 @@ static __attribute__((unused))
 void *sbrk(intptr_t inc)
 {
 	/* first call to find current end */
-	void *ret = sys_brk(0);
+	void *ret = sys_brk(NULL);
 
 	if (ret && sys_brk(ret + inc) == ret + inc)
 		return ret + inc;
@@ -118,6 +118,7 @@ void *sbrk(intptr_t inc)
 
 /*
  * int chdir(const char *path);
+ * int fchdir(int fildes);
  */
 
 static __attribute__((unused))
@@ -132,6 +133,18 @@ int chdir(const char *path)
 	return __sysret(sys_chdir(path));
 }
 
+static __attribute__((unused))
+int sys_fchdir(int fildes)
+{
+	return my_syscall1(__NR_fchdir, fildes);
+}
+
+static __attribute__((unused))
+int fchdir(int fildes)
+{
+	return __sysret(sys_fchdir(fildes));
+}
+
 
 /*
  * int chmod(const char *path, mode_t mode);
@@ -512,6 +525,7 @@ pid_t gettid(void)
 	return sys_gettid();
 }
 
+#ifndef NOLIBC_NO_RUNTIME
 static unsigned long getauxval(unsigned long key);
 
 /*
@@ -523,7 +537,7 @@ int getpagesize(void)
 {
 	return __sysret((int)getauxval(AT_PAGESZ) ?: -ENOENT);
 }
-
+#endif /* NOLIBC_NO_RUNTIME */
 
 /*
  * uid_t getuid(void);
@@ -591,23 +605,20 @@ int link(const char *old, const char *new)
 static __attribute__((unused))
 off_t sys_lseek(int fd, off_t offset, int whence)
 {
-#if defined(__NR_lseek)
-	return my_syscall3(__NR_lseek, fd, offset, whence);
-#else
+#if defined(__NR_llseek)
 	__kernel_loff_t loff = 0;
 	off_t result;
 	int ret;
 
-	/* Only exists on 32bit where nolibc off_t is also 32bit */
-	ret = my_syscall5(__NR_llseek, fd, 0, offset, &loff, whence);
+	ret = my_syscall5(__NR_llseek, fd, offset >> 32, (uint32_t)offset, &loff, whence);
 	if (ret < 0)
 		result = ret;
-	else if (loff != (off_t)loff)
-		result = -EOVERFLOW;
 	else
 		result = loff;
 
 	return result;
+#else
+	return my_syscall3(__NR_lseek, fd, offset, whence);
 #endif
 }
 
@@ -755,51 +766,6 @@ int sched_yield(void)
 }
 
 
-/*
- * int select(int nfds, fd_set *read_fds, fd_set *write_fds,
- *            fd_set *except_fds, struct timeval *timeout);
- */
-
-static __attribute__((unused))
-int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
-{
-#if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect)
-	struct sel_arg_struct {
-		unsigned long n;
-		fd_set *r, *w, *e;
-		struct timeval *t;
-	} arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout };
-	return my_syscall1(__NR_select, &arg);
-#elif defined(__NR__newselect)
-	return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout);
-#elif defined(__NR_select)
-	return my_syscall5(__NR_select, nfds, rfds, wfds, efds, timeout);
-#elif defined(__NR_pselect6)
-	struct timespec t;
-
-	if (timeout) {
-		t.tv_sec  = timeout->tv_sec;
-		t.tv_nsec = timeout->tv_usec * 1000;
-	}
-	return my_syscall6(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
-#else
-	struct __kernel_timespec t;
-
-	if (timeout) {
-		t.tv_sec  = timeout->tv_sec;
-		t.tv_nsec = timeout->tv_usec * 1000;
-	}
-	return my_syscall6(__NR_pselect6_time64, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
-#endif
-}
-
-static __attribute__((unused))
-int select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
-{
-	return __sysret(sys_select(nfds, rfds, wfds, efds, timeout));
-}
-
-
 /*
  * int setpgid(pid_t pid, pid_t pgid);
  */

tools/include/nolibc/sys/auxv.h

@@ -10,6 +10,8 @@
 #ifndef _NOLIBC_SYS_AUXV_H
 #define _NOLIBC_SYS_AUXV_H
 
+#ifndef NOLIBC_NO_RUNTIME
+
 #include "../crt.h"
 
 static __attribute__((unused))
@@ -38,4 +40,5 @@ unsigned long getauxval(unsigned long type)
 	return ret;
 }
 
+#endif /* NOLIBC_NO_RUNTIME */
 #endif /* _NOLIBC_SYS_AUXV_H */

tools/include/nolibc/sys/mman.h

@@ -31,11 +31,6 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
 }
 #endif
 
-/* Note that on Linux, MAP_FAILED is -1 so we can use the generic __sysret()
- * which returns -1 upon error and still satisfy user land that checks for
- * MAP_FAILED.
- */
-
 static __attribute__((unused))
 void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
 {

tools/include/nolibc/sys/reboot.h

@@ -28,7 +28,7 @@ ssize_t sys_reboot(int magic1, int magic2, int cmd, void *arg)
 static __attribute__((unused))
 int reboot(int cmd)
 {
-	return __sysret(sys_reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, 0));
+	return __sysret(sys_reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, NULL));
 }
 
 #endif /* _NOLIBC_SYS_REBOOT_H */

tools/include/nolibc/sys/select.h

@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+
+#include "../nolibc.h"
+
+#ifndef _NOLIBC_SYS_SELECT_H
+#define _NOLIBC_SYS_SELECT_H
+
+#include <linux/time.h>
+#include <linux/unistd.h>
+
+/* commonly an fd_set represents 256 FDs */
+#ifndef FD_SETSIZE
+#define FD_SETSIZE     256
+#endif
+
+#define FD_SETIDXMASK (8 * sizeof(unsigned long))
+#define FD_SETBITMASK (8 * sizeof(unsigned long)-1)
+
+/* for select() */
+typedef struct {
+	unsigned long fds[(FD_SETSIZE + FD_SETBITMASK) / FD_SETIDXMASK];
+} fd_set;
+
+#define FD_CLR(fd, set) do {						\
+		fd_set *__set = (set);					\
+		int __fd = (fd);					\
+		if (__fd >= 0)						\
+			__set->fds[__fd / FD_SETIDXMASK] &=		\
+				~(1U << (__fd & FD_SETBITMASK));	\
+	} while (0)
+
+#define FD_SET(fd, set) do {						\
+		fd_set *__set = (set);					\
+		int __fd = (fd);					\
+		if (__fd >= 0)						\
+			__set->fds[__fd / FD_SETIDXMASK] |=		\
+				1 << (__fd & FD_SETBITMASK);		\
+	} while (0)
+
+#define FD_ISSET(fd, set) ({						\
+			fd_set *__set = (set);				\
+			int __fd = (fd);				\
+		int __r = 0;						\
+		if (__fd >= 0)						\
+			__r = !!(__set->fds[__fd / FD_SETIDXMASK] &	\
+1U << (__fd & FD_SETBITMASK));						\
+		__r;							\
+	})
+
+#define FD_ZERO(set) do {						\
+		fd_set *__set = (set);					\
+		int __idx;						\
+		int __size = (FD_SETSIZE+FD_SETBITMASK) / FD_SETIDXMASK;\
+		for (__idx = 0; __idx < __size; __idx++)		\
+			__set->fds[__idx] = 0;				\
+	} while (0)
+
+/*
+ * int select(int nfds, fd_set *read_fds, fd_set *write_fds,
+ *            fd_set *except_fds, struct timeval *timeout);
+ */
+
+static __attribute__((unused))
+int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
+{
+#if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect)
+	struct sel_arg_struct {
+		unsigned long n;
+		fd_set *r, *w, *e;
+		struct timeval *t;
+	} arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout };
+	return my_syscall1(__NR_select, &arg);
+#elif defined(__NR__newselect)
+	return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout);
+#elif defined(__NR_select)
+	return my_syscall5(__NR_select, nfds, rfds, wfds, efds, timeout);
+#elif defined(__NR_pselect6)
+	struct timespec t;
+
+	if (timeout) {
+		t.tv_sec  = timeout->tv_sec;
+		t.tv_nsec = timeout->tv_usec * 1000;
+	}
+	return my_syscall6(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
+#else
+	struct __kernel_timespec t;
+
+	if (timeout) {
+		t.tv_sec  = timeout->tv_sec;
+		t.tv_nsec = timeout->tv_usec * 1000;
+	}
+	return my_syscall6(__NR_pselect6_time64, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
+#endif
+}
+
+static __attribute__((unused))
+int select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
+{
+	return __sysret(sys_select(nfds, rfds, wfds, efds, timeout));
+}
+
+
+#endif /* _NOLIBC_SYS_SELECT_H */

tools/include/nolibc/sys/uio.h

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * uio for NOLIBC
+ * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
+ * Copyright (C) 2025 Intel Corporation
+ */
+
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
+#ifndef _NOLIBC_SYS_UIO_H
+#define _NOLIBC_SYS_UIO_H
+
+#include "../sys.h"
+#include <linux/uio.h>
+
+
+/*
+ * ssize_t readv(int fd, const struct iovec *iovec, int count);
+ */
+static __attribute__((unused))
+ssize_t sys_readv(int fd, const struct iovec *iovec, int count)
+{
+	return my_syscall3(__NR_readv, fd, iovec, count);
+}
+
+static __attribute__((unused))
+ssize_t readv(int fd, const struct iovec *iovec, int count)
+{
+	return __sysret(sys_readv(fd, iovec, count));
+}
+
+/*
+ * ssize_t writev(int fd, const struct iovec *iovec, int count);
+ */
+static __attribute__((unused))
+ssize_t sys_writev(int fd, const struct iovec *iovec, int count)
+{
+	return my_syscall3(__NR_writev, fd, iovec, count);
+}
+
+static __attribute__((unused))
+ssize_t writev(int fd, const struct iovec *iovec, int count)
+{
+	return __sysret(sys_writev(fd, iovec, count));
+}
+
+
+#endif /* _NOLIBC_SYS_UIO_H */

tools/include/nolibc/sys/wait.h

@@ -65,23 +65,29 @@ pid_t waitpid(pid_t pid, int *status, int options)
 
 	switch (info.si_code) {
 	case 0:
-		*status = 0;
+		if (status)
+			*status = 0;
 		break;
 	case CLD_EXITED:
-		*status = (info.si_status & 0xff) << 8;
+		if (status)
+			*status = (info.si_status & 0xff) << 8;
 		break;
 	case CLD_KILLED:
-		*status = info.si_status & 0x7f;
+		if (status)
+			*status = info.si_status & 0x7f;
 		break;
 	case CLD_DUMPED:
-		*status = (info.si_status & 0x7f) | 0x80;
+		if (status)
+			*status = (info.si_status & 0x7f) | 0x80;
 		break;
 	case CLD_STOPPED:
 	case CLD_TRAPPED:
-		*status = (info.si_status << 8) + 0x7f;
+		if (status)
+			*status = (info.si_status << 8) + 0x7f;
 		break;
 	case CLD_CONTINUED:
-		*status = 0xffff;
+		if (status)
+			*status = 0xffff;
 		break;
 	default:
 		return -1;

tools/include/nolibc/time.h

@@ -89,13 +89,11 @@ int sys_clock_settime(clockid_t clockid, struct timespec *tp)
 {
 #if defined(__NR_clock_settime)
 	return my_syscall2(__NR_clock_settime, clockid, tp);
-#elif defined(__NR_clock_settime64)
+#else
 	struct __kernel_timespec ktp;
 
 	__nolibc_timespec_user_to_kernel(tp, &ktp);
 	return my_syscall2(__NR_clock_settime64, clockid, &ktp);
-#else
-	return __nolibc_enosys(__func__, clockid, tp);
 #endif
 }
 
@@ -111,7 +109,7 @@ int sys_clock_nanosleep(clockid_t clockid, int flags, const struct timespec *rqt
 {
 #if defined(__NR_clock_nanosleep)
 	return my_syscall4(__NR_clock_nanosleep, clockid, flags, rqtp, rmtp);
-#elif defined(__NR_clock_nanosleep_time64)
+#else
 	struct __kernel_timespec krqtp, krmtp;
 	int ret;
 
@@ -120,8 +118,6 @@ int sys_clock_nanosleep(clockid_t clockid, int flags, const struct timespec *rqt
 	if (rmtp)
 		__nolibc_timespec_kernel_to_user(&krmtp, rmtp);
 	return ret;
-#else
-	return __nolibc_enosys(__func__, clockid, flags, rqtp, rmtp);
 #endif
 }
 
@@ -195,7 +191,7 @@ int sys_timer_gettime(timer_t timerid, struct itimerspec *curr_value)
 {
 #if defined(__NR_timer_gettime)
 	return my_syscall2(__NR_timer_gettime, timerid, curr_value);
-#elif defined(__NR_timer_gettime64)
+#else
 	struct __kernel_itimerspec kcurr_value;
 	int ret;
 
@@ -203,8 +199,6 @@ int sys_timer_gettime(timer_t timerid, struct itimerspec *curr_value)
 	__nolibc_timespec_kernel_to_user(&kcurr_value.it_interval, &curr_value->it_interval);
 	__nolibc_timespec_kernel_to_user(&kcurr_value.it_value, &curr_value->it_value);
 	return ret;
-#else
-	return __nolibc_enosys(__func__, timerid, curr_value);
 #endif
 }
 
@@ -220,7 +214,7 @@ int sys_timer_settime(timer_t timerid, int flags,
 {
 #if defined(__NR_timer_settime)
 	return my_syscall4(__NR_timer_settime, timerid, flags, new_value, old_value);
-#elif defined(__NR_timer_settime64)
+#else
 	struct __kernel_itimerspec knew_value, kold_value;
 	int ret;
 
@@ -232,8 +226,6 @@ int sys_timer_settime(timer_t timerid, int flags,
 		__nolibc_timespec_kernel_to_user(&kold_value.it_value, &old_value->it_value);
 	}
 	return ret;
-#else
-	return __nolibc_enosys(__func__, timerid, flags, new_value, old_value);
 #endif
 }
 

tools/include/nolibc/types.h

@@ -70,11 +70,6 @@
 #define DT_LNK         0xa
 #define DT_SOCK        0xc
 
-/* commonly an fd_set represents 256 FDs */
-#ifndef FD_SETSIZE
-#define FD_SETSIZE     256
-#endif
-
 /* PATH_MAX and MAXPATHLEN are often used and found with plenty of different
  * values.
  */
@@ -115,48 +110,6 @@
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
 
-#define FD_SETIDXMASK (8 * sizeof(unsigned long))
-#define FD_SETBITMASK (8 * sizeof(unsigned long)-1)
-
-/* for select() */
-typedef struct {
-	unsigned long fds[(FD_SETSIZE + FD_SETBITMASK) / FD_SETIDXMASK];
-} fd_set;
-
-#define FD_CLR(fd, set) do {						\
-		fd_set *__set = (set);					\
-		int __fd = (fd);					\
-		if (__fd >= 0)						\
-			__set->fds[__fd / FD_SETIDXMASK] &=		\
-				~(1U << (__fd & FD_SETBITMASK));	\
-	} while (0)
-
-#define FD_SET(fd, set) do {						\
-		fd_set *__set = (set);					\
-		int __fd = (fd);					\
-		if (__fd >= 0)						\
-			__set->fds[__fd / FD_SETIDXMASK] |=		\
-				1 << (__fd & FD_SETBITMASK);		\
-	} while (0)
-
-#define FD_ISSET(fd, set) ({						\
-			fd_set *__set = (set);				\
-			int __fd = (fd);				\
-		int __r = 0;						\
-		if (__fd >= 0)						\
-			__r = !!(__set->fds[__fd / FD_SETIDXMASK] &	\
-1U << (__fd & FD_SETBITMASK));						\
-		__r;							\
-	})
-
-#define FD_ZERO(set) do {						\
-		fd_set *__set = (set);					\
-		int __idx;						\
-		int __size = (FD_SETSIZE+FD_SETBITMASK) / FD_SETIDXMASK;\
-		for (__idx = 0; __idx < __size; __idx++)		\
-			__set->fds[__idx] = 0;				\
-	} while (0)
-
 /* for getdents64() */
 struct linux_dirent64 {
 	uint64_t       d_ino;

tools/include/nolibc/unistd.h

@@ -54,7 +54,7 @@ int msleep(unsigned int msecs)
 {
 	struct timeval my_timeval = { msecs / 1000, (msecs % 1000) * 1000 };
 
-	if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+	if (sys_select(0, NULL, NULL, NULL, &my_timeval) < 0)
 		return (my_timeval.tv_sec * 1000) +
 			(my_timeval.tv_usec / 1000) +
 			!!(my_timeval.tv_usec % 1000);
@@ -67,7 +67,7 @@ unsigned int sleep(unsigned int seconds)
 {
 	struct timeval my_timeval = { seconds, 0 };
 
-	if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+	if (sys_select(0, NULL, NULL, NULL, &my_timeval) < 0)
 		return my_timeval.tv_sec + !!my_timeval.tv_usec;
 	else
 		return 0;
@@ -78,7 +78,7 @@ int usleep(unsigned int usecs)
 {
 	struct timeval my_timeval = { usecs / 1000000, usecs % 1000000 };
 
-	return sys_select(0, 0, 0, 0, &my_timeval);
+	return sys_select(0, NULL, NULL, NULL, &my_timeval);
 }
 
 static __attribute__((unused))

tools/testing/selftests/nolibc/Makefile.nolibc

@@ -225,6 +225,7 @@ CFLAGS_mipsn32le = -EL -mabi=n32 -fPIC -march=mips64r2
 CFLAGS_mipsn32be = -EB -mabi=n32 -march=mips64r6
 CFLAGS_mips64le = -EL -mabi=64 -march=mips64r6
 CFLAGS_mips64be = -EB -mabi=64 -march=mips64r2
+CFLAGS_loongarch = $(if $(LLVM),-fuse-ld=lld)
 CFLAGS_sparc32 = $(call cc-option,-m32)
 CFLAGS_sh4 = -ml -m4
 ifeq ($(origin XARCH),command line)

tools/testing/selftests/nolibc/nolibc-test.c

@@ -25,6 +25,7 @@
 #include <sys/sysmacros.h>
 #include <sys/time.h>
 #include <sys/timerfd.h>
+#include <sys/uio.h>
 #include <sys/utsname.h>
 #include <sys/wait.h>
 #include <dirent.h>
@@ -1282,6 +1283,10 @@ int run_syscall(int min, int max)
 	int proc;
 	int test;
 	int tmp;
+	struct iovec iov_one = {
+		.iov_base = &tmp,
+		.iov_len = 1,
+	};
 	int ret = 0;
 	void *p1, *p2;
 	int has_gettid = 1;
@@ -1343,6 +1348,8 @@ 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(fchdir_stdin);      EXPECT_SYSER(1, fchdir(STDIN_FILENO), -1, ENOTDIR); break;
+		CASE_TEST(fchdir_badfd);      EXPECT_SYSER(1, fchdir(-1), -1, EBADF); break;
 		CASE_TEST(file_stream);       EXPECT_SYSZR(1, test_file_stream()); break;
 		CASE_TEST(fork);              EXPECT_SYSZR(1, test_fork(FORK_STANDARD)); break;
 		CASE_TEST(getdents64_root);   EXPECT_SYSNE(1, test_getdents64("/"), -1); break;
@@ -1395,6 +1402,10 @@ int run_syscall(int min, int max)
 		CASE_TEST(waitpid_child);     EXPECT_SYSER(1, waitpid(getpid(), &tmp, WNOHANG), -1, ECHILD); break;
 		CASE_TEST(write_badf);        EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break;
 		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 0)); break;
+		CASE_TEST(readv_badf);        EXPECT_SYSER(1, readv(-1, &iov_one, 1), -1, EBADF); break;
+		CASE_TEST(readv_zero);        EXPECT_SYSZR(1, readv(1, NULL, 0)); break;
+		CASE_TEST(writev_badf);       EXPECT_SYSER(1, writev(-1, &iov_one, 1), -1, EBADF); break;
+		CASE_TEST(writev_zero);       EXPECT_SYSZR(1, writev(1, NULL, 0)); break;
 		CASE_TEST(syscall_noargs);    EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break;
 		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_statx, 0, NULL, 0, 0, NULL), -1, EFAULT); break;
 		CASE_TEST(namespace);         EXPECT_SYSZR(euid0 && proc, test_namespace()); break;
@@ -1540,6 +1551,8 @@ int run_stdlib(int min, int max)
 		CASE_TEST(abs);                     EXPECT_EQ(1, abs(-10), 10); break;
 		CASE_TEST(abs_noop);                EXPECT_EQ(1, abs(10), 10); break;
 		CASE_TEST(difftime);                EXPECT_ZR(1, test_difftime()); break;
+		CASE_TEST(memchr_foobar6_o);        EXPECT_STREQ(1, memchr("foobar", 'o', 6), "oobar"); break;
+		CASE_TEST(memchr_foobar3_b);        EXPECT_STRZR(1, memchr("foobar", 'b', 3)); break;
 
 		case __LINE__:
 			return ret; /* must be last */

tools/testing/selftests/nolibc/run-tests.sh

@@ -169,7 +169,7 @@ test_arch() {
 	cross_compile=$(realpath "${download_location}gcc-${crosstool_version}-nolibc/${ct_arch}-${ct_abi}/bin/${ct_arch}-${ct_abi}-")
 	build_dir="${build_location}/${arch}"
 	if [ "$werror" -ne 0 ]; then
-		CFLAGS_EXTRA="$CFLAGS_EXTRA -Werror"
+		CFLAGS_EXTRA="$CFLAGS_EXTRA -Werror -Wl,--fatal-warnings"
 	fi
 	MAKE=(make -f Makefile.nolibc -j"${nproc}" XARCH="${arch}" CROSS_COMPILE="${cross_compile}" LLVM="${llvm}" O="${build_dir}")