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  tools/nolibc: clean up outdated comments in generic arch.h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
  ...

34 files changed, 275 insertions, 162 deletions

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index 143c2d2c2ba6..8118e22844f1 100644
--- a/tools/include/nolibc/Makefile
+++ b/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
diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index 1f66e7e5a444..251c42579028 100644
--- a/tools/include/nolibc/arch-arm.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-arm64.h b/tools/include/nolibc/arch-arm64.h
index 02a3f74c8ec8..080a55a7144e 100644
--- a/tools/include/nolibc/arch-arm64.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index 5511705303ea..c894176c3f89 100644
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-m68k.h b/tools/include/nolibc/arch-m68k.h
index 6dac1845f298..2a4fbada5e79 100644
--- a/tools/include/nolibc/arch-m68k.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index 0cbac63b249a..a72506ceec6b 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-powerpc.h b/tools/include/nolibc/arch-powerpc.h
index 204564bbcd32..e0c7e0b81f7c 100644
--- a/tools/include/nolibc/arch-powerpc.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index 885383a86c38..1c00cacf57e1 100644
--- a/tools/include/nolibc/arch-riscv.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index 0a39bee261b9..74125a254ce3 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/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;
diff --git a/tools/include/nolibc/arch-sh.h b/tools/include/nolibc/arch-sh.h
index a96b8914607e..7a421197d104 100644
--- a/tools/include/nolibc/arch-sh.h
+++ b/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 */
diff --git a/tools/include/nolibc/arch-sparc.h b/tools/include/nolibc/arch-sparc.h
index ca420d843e25..2ebb5686e105 100644
--- a/tools/include/nolibc/arch-sparc.h
+++ b/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);
 
diff --git a/tools/include/nolibc/arch-x86.h b/tools/include/nolibc/arch-x86.h
index d3efc0c3b8ad..f6c43ac5377b 100644
--- a/tools/include/nolibc/arch-x86.h
+++ b/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__) */
diff --git a/tools/include/nolibc/arch.h b/tools/include/nolibc/arch.h
index ef4743aad188..a3adaf433f2c 100644
--- a/tools/include/nolibc/arch.h
+++ b/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
 
diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h
index 369cfb5a0e78..87090bbc53e0 100644
--- a/tools/include/nolibc/compiler.h
+++ b/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) */
diff --git a/tools/include/nolibc/crt.h b/tools/include/nolibc/crt.h
index 961cfe777c35..d9262998dae9 100644
--- a/tools/include/nolibc/crt.h
+++ b/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 */
diff --git a/tools/include/nolibc/dirent.h b/tools/include/nolibc/dirent.h
index 758b95c48e7a..61a122a60327 100644
--- a/tools/include/nolibc/dirent.h
+++ b/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 */
diff --git a/tools/include/nolibc/getopt.h b/tools/include/nolibc/getopt.h
index 217abb95264b..87565e3b6a33 100644
--- a/tools/include/nolibc/getopt.h
+++ b/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)
diff --git a/tools/include/nolibc/inttypes.h b/tools/include/nolibc/inttypes.h
new file mode 100644
index 000000000000..1977bd74bfeb
--- /dev/null
+++ b/tools/include/nolibc/inttypes.h
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+
+#include "nolibc.h"
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index d2f5aa085f8e..272dfc961158 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/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"
diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h
index c71a2c257177..7123aa056cb0 100644
--- a/tools/include/nolibc/stackprotector.h
+++ b/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 */
diff --git a/tools/include/nolibc/std.h b/tools/include/nolibc/std.h
index 2c1ad23b9b5c..392f4dd94158 100644
--- a/tools/include/nolibc/std.h
+++ b/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;
diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 7630234408c5..1f16dab2ac88 100644
--- a/tools/include/nolibc/stdio.h
+++ b/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))
diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index 5fd99a480f82..f184e108ed0a 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/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)
diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index 163a17e7dd38..4000926f44ac 100644
--- a/tools/include/nolibc/string.h
+++ b/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)
 {
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index c5564f57deec..847af1ccbdc9 100644
--- a/tools/include/nolibc/sys.h
+++ b/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
 }
 
@@ -756,51 +767,6 @@ 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);
  */
 
diff --git a/tools/include/nolibc/sys/auxv.h b/tools/include/nolibc/sys/auxv.h
index c52463d6c18d..0e98325e7347 100644
--- a/tools/include/nolibc/sys/auxv.h
+++ b/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 */
diff --git a/tools/include/nolibc/sys/mman.h b/tools/include/nolibc/sys/mman.h
index 5228751b458c..77084ac3405a 100644
--- a/tools/include/nolibc/sys/mman.h
+++ b/tools/include/nolibc/sys/mman.h