Merge tag 'nolibc.2022.05.20a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull nolibc library updates from Paul McKenney:
 "This adds a number of library functions and splits this library into
  multiple files"

* tag 'nolibc.2022.05.20a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (61 commits)
  tools/nolibc/string: Implement `strdup()` and `strndup()`
  tools/nolibc/string: Implement `strnlen()`
  tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`
  tools/nolibc/types: Implement `offsetof()` and `container_of()` macro
  tools/nolibc/sys: Implement `mmap()` and `munmap()`
  tools/nolibc: i386: Implement syscall with 6 arguments
  tools/nolibc: Remove .global _start from the entry point code
  tools/nolibc: Replace `asm` with `__asm__`
  tools/nolibc: x86-64: Update System V ABI document link
  tools/nolibc/stdlib: only reference the external environ when inlined
  tools/nolibc/string: do not use __builtin_strlen() at -O0
  tools/nolibc: add the nolibc subdir to the common Makefile
  tools/nolibc: add a makefile to install headers
  tools/nolibc/types: add poll() and waitpid() flag definitions
  tools/nolibc/sys: add syscall definition for getppid()
  tools/nolibc/string: add strcmp() and strncmp()
  tools/nolibc/stdio: add support for '%p' to vfprintf()
  tools/nolibc/stdlib: add a simple getenv() implementation
  tools/nolibc/stdio: make printf(%s) accept NULL
  tools/nolibc/stdlib: implement abort()
  ...

tools/Makefile

@@ -24,6 +24,7 @@ help:
 	@echo '  intel-speed-select     - Intel Speed Select tool'
 	@echo '  kvm_stat               - top-like utility for displaying kvm statistics'
 	@echo '  leds                   - LEDs  tools'
+	@echo '  nolibc                 - nolibc headers testing and installation'
 	@echo '  objtool                - an ELF object analysis tool'
 	@echo '  pci                    - PCI tools'
 	@echo '  perf                   - Linux performance measurement and analysis tool'
@@ -74,6 +75,9 @@ bpf/%: FORCE
 libapi: FORCE
 	$(call descend,lib/api)
 
+nolibc_%: FORCE
+	$(call descend,include/nolibc,$(patsubst nolibc_%,%,$@))
+
 # The perf build does not follow the descend function setup,
 # invoking it via it's own make rule.
 PERF_O   = $(if $(O),$(O)/tools/perf,)

tools/include/nolibc/Makefile

+# SPDX-License-Identifier: GPL-2.0
+# Makefile for nolibc installation and tests
+include ../../scripts/Makefile.include
+
+# we're in ".../tools/include/nolibc"
+ifeq ($(srctree),)
+srctree := $(patsubst %/tools/include/,%,$(dir $(CURDIR)))
+endif
+
+nolibc_arch := $(patsubst arm64,aarch64,$(ARCH))
+arch_file := arch-$(nolibc_arch).h
+all_files := ctype.h errno.h nolibc.h signal.h std.h stdio.h stdlib.h string.h \
+             sys.h time.h types.h unistd.h
+
+# install all headers needed to support a bare-metal compiler
+all:
+
+# Note: when ARCH is "x86" we concatenate both x86_64 and i386
+headers:
+	$(Q)mkdir -p $(OUTPUT)sysroot
+	$(Q)mkdir -p $(OUTPUT)sysroot/include
+	$(Q)cp $(all_files) $(OUTPUT)sysroot/include/
+	$(Q)if [ "$(ARCH)" = "x86" ]; then      \
+		sed -e                          \
+		  's,^#ifndef _NOLIBC_ARCH_X86_64_H,#if !defined(_NOLIBC_ARCH_X86_64_H) \&\& defined(__x86_64__),' \
+		  arch-x86_64.h;                \
+		sed -e                          \
+		  's,^#ifndef _NOLIBC_ARCH_I386_H,#if !defined(_NOLIBC_ARCH_I386_H) \&\& !defined(__x86_64__),' \
+		  arch-i386.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
+
+headers_standalone: headers
+	$(Q)$(MAKE) -C $(srctree) headers
+	$(Q)$(MAKE) -C $(srctree) headers_install INSTALL_HDR_PATH=$(OUTPUT)/sysroot
+
+clean:
+	$(call QUIET_CLEAN, nolibc) rm -rf "$(OUTPUT)sysroot"

tools/include/nolibc/arch-arm.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * ARM specific definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_ARCH_ARM_H
+#define _NOLIBC_ARCH_ARM_H
+
+/* O_* macros for fcntl/open are architecture-specific */
+#define O_RDONLY            0
+#define O_WRONLY            1
+#define O_RDWR              2
+#define O_CREAT          0x40
+#define O_EXCL           0x80
+#define O_NOCTTY        0x100
+#define O_TRUNC         0x200
+#define O_APPEND        0x400
+#define O_NONBLOCK      0x800
+#define O_DIRECTORY    0x4000
+
+/* The struct returned by the stat() syscall, 32-bit only, the syscall returns
+ * exactly 56 bytes (stops before the unused array). In big endian, the format
+ * differs as devices are returned as short only.
+ */
+struct sys_stat_struct {
+#if defined(__ARMEB__)
+	unsigned short st_dev;
+	unsigned short __pad1;
+#else
+	unsigned long  st_dev;
+#endif
+	unsigned long  st_ino;
+	unsigned short st_mode;
+	unsigned short st_nlink;
+	unsigned short st_uid;
+	unsigned short st_gid;
+
+#if defined(__ARMEB__)
+	unsigned short st_rdev;
+	unsigned short __pad2;
+#else
+	unsigned long  st_rdev;
+#endif
+	unsigned long  st_size;
+	unsigned long  st_blksize;
+	unsigned long  st_blocks;
+
+	unsigned long  st_atime;
+	unsigned long  st_atime_nsec;
+	unsigned long  st_mtime;
+	unsigned long  st_mtime_nsec;
+
+	unsigned long  st_ctime;
+	unsigned long  st_ctime_nsec;
+	unsigned long  __unused[2];
+};
+
+/* Syscalls for ARM in ARM or Thumb modes :
+ *   - registers are 32-bit
+ *   - stack is 8-byte aligned
+ *     ( http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka4127.html)
+ *   - syscall number is passed in r7
+ *   - arguments are in r0, r1, r2, r3, r4, r5
+ *   - the system call is performed by calling svc #0
+ *   - syscall return comes in r0.
+ *   - only lr is clobbered.
+ *   - the arguments are cast to long and assigned into the target registers
+ *     which are then simply passed as registers to the asm code, so that we
+ *     don't have to experience issues with register constraints.
+ *   - the syscall number is always specified last in order to allow to force
+ *     some registers before (gcc refuses a %-register at the last position).
+ *
+ * Also, ARM supports the old_select syscall if newselect is not available
+ */
+#define __ARCH_WANT_SYS_OLD_SELECT
+
+#define my_syscall0(num)                                                      \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0");                                   \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r"(_arg1)                                                 \
+		: "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall1(num, arg1)                                                \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0") = (long)(arg1);                    \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r"(_arg1)                                                 \
+		: "r"(_arg1),                                                 \
+		  "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall2(num, arg1, arg2)                                          \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("r1") = (long)(arg2);                    \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r"(_arg1)                                                 \
+		: "r"(_arg1), "r"(_arg2),                                     \
+		  "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3)                                    \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("r1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("r2") = (long)(arg3);                    \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r"(_arg1)                                                 \
+		: "r"(_arg1), "r"(_arg2), "r"(_arg3),                         \
+		  "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4)                              \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("r1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("r2") = (long)(arg3);                    \
+	register long _arg4 __asm__ ("r3") = (long)(arg4);                    \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r"(_arg1)                                                 \
+		: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4),             \
+		  "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5)                        \
+({                                                                            \
+	register long _num __asm__ ("r7") = (num);                            \
+	register long _arg1 __asm__ ("r0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("r1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("r2") = (long)(arg3);                    \
+	register long _arg4 __asm__ ("r3") = (long)(arg4);                    \
+	register long _arg5 __asm__ ("r4") = (long)(arg5);                    \
+	                                                                      \
+	__asm__  volatile (                                                   \
+		"svc #0\n"                                                    \
+		: "=r" (_arg1)                                                \
+		: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
+		  "r"(_num)                                                   \
+		: "memory", "cc", "lr"                                        \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+/* startup code */
+__asm__ (".section .text\n"
+    ".weak _start\n"
+    "_start:\n"
+#if defined(__THUMBEB__) || defined(__THUMBEL__)
+    /* We enter here in 32-bit mode but if some previous functions were in
+     * 16-bit mode, the assembler cannot know, so we need to tell it we're in
+     * 32-bit now, then switch to 16-bit (is there a better way to do it than
+     * adding 1 by hand ?) and tell the asm we're now in 16-bit mode so that
+     * it generates correct instructions. Note that we do not support thumb1.
+     */
+    ".code 32\n"
+    "add     r0, pc, #1\n"
+    "bx      r0\n"
+    ".code 16\n"
+#endif
+    "pop {%r0}\n"                 // argc was in the stack
+    "mov %r1, %sp\n"              // argv = sp
+    "add %r2, %r1, %r0, lsl #2\n" // envp = argv + 4*argc ...
+    "add %r2, %r2, $4\n"          //        ... + 4
+    "and %r3, %r1, $-8\n"         // AAPCS : sp must be 8-byte aligned in the
+    "mov %sp, %r3\n"              //         callee, an bl doesn't push (lr=pc)
+    "bl main\n"                   // main() returns the status code, we'll exit with it.
+    "movs r7, $1\n"               // NR_exit == 1
+    "svc $0x00\n"
+    "");
+
+#endif // _NOLIBC_ARCH_ARM_H

tools/include/nolibc/arch-riscv.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * RISCV (32 and 64) specific definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_ARCH_RISCV_H
+#define _NOLIBC_ARCH_RISCV_H
+
+/* O_* macros for fcntl/open are architecture-specific */
+#define O_RDONLY            0
+#define O_WRONLY            1
+#define O_RDWR              2
+#define O_CREAT         0x100
+#define O_EXCL          0x200
+#define O_NOCTTY        0x400
+#define O_TRUNC        0x1000
+#define O_APPEND       0x2000
+#define O_NONBLOCK     0x4000
+#define O_DIRECTORY  0x200000
+
+struct sys_stat_struct {
+	unsigned long	st_dev;		/* Device.  */
+	unsigned long	st_ino;		/* File serial number.  */
+	unsigned int	st_mode;	/* File mode.  */
+	unsigned int	st_nlink;	/* Link count.  */
+	unsigned int	st_uid;		/* User ID of the file's owner.  */
+	unsigned int	st_gid;		/* Group ID of the file's group. */
+	unsigned long	st_rdev;	/* Device number, if device.  */
+	unsigned long	__pad1;
+	long		st_size;	/* Size of file, in bytes.  */
+	int		st_blksize;	/* Optimal block size for I/O.  */
+	int		__pad2;
+	long		st_blocks;	/* Number 512-byte blocks allocated. */
+	long		st_atime;	/* Time of last access.  */
+	unsigned long	st_atime_nsec;
+	long		st_mtime;	/* Time of last modification.  */
+	unsigned long	st_mtime_nsec;
+	long		st_ctime;	/* Time of last status change.  */
+	unsigned long	st_ctime_nsec;
+	unsigned int	__unused4;
+	unsigned int	__unused5;
+};
+
+#if   __riscv_xlen == 64
+#define PTRLOG "3"
+#define SZREG  "8"
+#elif __riscv_xlen == 32
+#define PTRLOG "2"
+#define SZREG  "4"
+#endif
+
+/* Syscalls for RISCV :
+ *   - stack is 16-byte aligned
+ *   - syscall number is passed in a7
+ *   - arguments are in a0, a1, a2, a3, a4, a5
+ *   - the system call is performed by calling ecall
+ *   - syscall return comes in a0
+ *   - the arguments are cast to long and assigned into the target
+ *     registers which are then simply passed as registers to the asm code,
+ *     so that we don't have to experience issues with register constraints.
+ *
+ * On riscv, select() is not implemented so we have to use pselect6().
+ */
+#define __ARCH_WANT_SYS_PSELECT6
+
+#define my_syscall0(num)                                                      \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0");                                   \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n\t"                                                   \
+		: "=r"(_arg1)                                                 \
+		: "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall1(num, arg1)                                                \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);		      \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n"                                                     \
+		: "+r"(_arg1)                                                 \
+		: "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall2(num, arg1, arg2)                                          \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n"                                                     \
+		: "+r"(_arg1)                                                 \
+		: "r"(_arg2),                                                 \
+		  "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3)                                    \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("a2") = (long)(arg3);                    \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n\t"                                                   \
+		: "+r"(_arg1)                                                 \
+		: "r"(_arg2), "r"(_arg3),                                     \
+		  "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4)                              \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("a2") = (long)(arg3);                    \
+	register long _arg4 __asm__ ("a3") = (long)(arg4);                    \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n"                                                     \
+		: "+r"(_arg1)                                                 \
+		: "r"(_arg2), "r"(_arg3), "r"(_arg4),                         \
+		  "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5)                        \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("a2") = (long)(arg3);                    \
+	register long _arg4 __asm__ ("a3") = (long)(arg4);                    \
+	register long _arg5 __asm__ ("a4") = (long)(arg5);                    \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n"                                                     \
+		: "+r"(_arg1)                                                 \
+		: "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5),             \
+		  "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)                  \
+({                                                                            \
+	register long _num  __asm__ ("a7") = (num);                           \
+	register long _arg1 __asm__ ("a0") = (long)(arg1);                    \
+	register long _arg2 __asm__ ("a1") = (long)(arg2);                    \
+	register long _arg3 __asm__ ("a2") = (long)(arg3);                    \
+	register long _arg4 __asm__ ("a3") = (long)(arg4);                    \
+	register long _arg5 __asm__ ("a4") = (long)(arg5);                    \
+	register long _arg6 __asm__ ("a5") = (long)(arg6);                    \
+									      \
+	__asm__  volatile (                                                   \
+		"ecall\n"                                                     \
+		: "+r"(_arg1)                                                 \
+		: "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \
+		  "r"(_num)                                                   \
+		: "memory", "cc"                                              \
+	);                                                                    \
+	_arg1;                                                                \
+})
+
+/* startup code */
+__asm__ (".section .text\n"
+    ".weak _start\n"
+    "_start:\n"
+    ".option push\n"
+    ".option norelax\n"
+    "lla   gp, __global_pointer$\n"
+    ".option pop\n"
+    "ld    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
+    "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"
+    "");
+
+#endif // _NOLIBC_ARCH_RISCV_H

tools/include/nolibc/arch.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * 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 pint). 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
+
+#if defined(__x86_64__)
+#include "arch-x86_64.h"
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
+#include "arch-i386.h"
+#elif defined(__ARM_EABI__)
+#include "arch-arm.h"
+#elif defined(__aarch64__)
+#include "arch-aarch64.h"
+#elif defined(__mips__) && defined(_ABIO32)
+#include "arch-mips.h"
+#elif defined(__riscv)
+#include "arch-riscv.h"
+#endif
+
+#endif /* _NOLIBC_ARCH_H */

tools/include/nolibc/ctype.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * ctype function definitions for NOLIBC
+ * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_CTYPE_H
+#define _NOLIBC_CTYPE_H
+
+#include "std.h"
+
+/*
+ * As much as possible, please keep functions alphabetically sorted.
+ */
+
+static __attribute__((unused))
+int isascii(int c)
+{
+	/* 0x00..0x7f */
+	return (unsigned int)c <= 0x7f;
+}
+
+static __attribute__((unused))
+int isblank(int c)
+{
+	return c == '\t' || c == ' ';
+}
+
+static __attribute__((unused))
+int iscntrl(int c)
+{
+	/* 0x00..0x1f, 0x7f */
+	return (unsigned int)c < 0x20 || c == 0x7f;
+}
+
+static __attribute__((unused))
+int isdigit(int c)
+{
+	return (unsigned int)(c - '0') < 10;
+}
+
+static __attribute__((unused))
+int isgraph(int c)
+{
+	/* 0x21..0x7e */
+	return (unsigned int)(c - 0x21) < 0x5e;
+}
+
+static __attribute__((unused))
+int islower(int c)
+{
+	return (unsigned int)(c - 'a') < 26;
+}
+
+static __attribute__((unused))
+int isprint(int c)
+{
+	/* 0x20..0x7e */
+	return (unsigned int)(c - 0x20) < 0x5f;
+}
+
+static __attribute__((unused))
+int isspace(int c)
+{
+	/* \t is 0x9, \n is 0xA, \v is 0xB, \f is 0xC, \r is 0xD */
+	return ((unsigned int)c == ' ') || (unsigned int)(c - 0x09) < 5;
+}
+
+static __attribute__((unused))
+int isupper(int c)
+{
+	return (unsigned int)(c - 'A') < 26;
+}
+
+static __attribute__((unused))
+int isxdigit(int c)
+{
+	return isdigit(c) || (unsigned int)(c - 'A') < 6 || (unsigned int)(c - 'a') < 6;
+}
+
+static __attribute__((unused))
+int isalpha(int c)
+{
+	return islower(c) || isupper(c);
+}
+
+static __attribute__((unused))
+int isalnum(int c)
+{
+	return isalpha(c) || isdigit(c);
+}
+
+static __attribute__((unused))
+int ispunct(int c)
+{
+	return isgraph(c) && !isalnum(c);
+}
+
+#endif /* _NOLIBC_CTYPE_H */

tools/include/nolibc/errno.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Minimal errno definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_ERRNO_H
+#define _NOLIBC_ERRNO_H
+
+#include <asm/errno.h>
+
+/* this way it will be removed if unused */
+static int errno;
+
+#ifndef NOLIBC_IGNORE_ERRNO
+#define SET_ERRNO(v) do { errno = (v); } while (0)
+#else
+#define SET_ERRNO(v) do { } while (0)
+#endif
+
+
+/* errno codes all ensure that they will not conflict with a valid pointer
+ * because they all correspond to the highest addressable memory page.
+ */
+#define MAX_ERRNO 4095
+
+#endif /* _NOLIBC_ERRNO_H */

tools/include/nolibc/signal.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * signal function definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_SIGNAL_H
+#define _NOLIBC_SIGNAL_H
+
+#include "std.h"
+#include "arch.h"
+#include "types.h"
+#include "sys.h"
+
+/* This one is not marked static as it's needed by libgcc for divide by zero */
+__attribute__((weak,unused,section(".text.nolibc_raise")))
+int raise(int signal)
+{
+	return sys_kill(sys_getpid(), signal);
+}
+
+#endif /* _NOLIBC_SIGNAL_H */

tools/include/nolibc/std.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * Standard definitions and types for NOLIBC
+ * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_STD_H
+#define _NOLIBC_STD_H
+
+/* Declare a few quite common macros and types that usually are in stdlib.h,
+ * stdint.h, ctype.h, unistd.h and a few other common locations. Please place
+ * integer type definitions and generic macros here, but avoid OS-specific and
+ * syscall-specific stuff, as this file is expected to be included very early.
+ */
+
+/* note: may already be defined */
+#ifndef NULL
+#define NULL ((void *)0)
+#endif
+
+/* stdint types */
+typedef unsigned char       uint8_t;
+typedef   signed char        int8_t;
+typedef unsigned short     uint16_t;
+typedef   signed short      int16_t;
+typedef unsigned int       uint32_t;
+typedef   signed int        int32_t;
+typedef unsigned long long uint64_t;
+typedef   signed long long  int64_t;
+typedef unsigned long        size_t;
+typedef   signed long       ssize_t;
+typedef unsigned long     uintptr_t;
+typedef   signed long      intptr_t;
+typedef   signed long     ptrdiff_t;
+
+/* those are commonly provided by sys/types.h */
+typedef unsigned int          dev_t;
+typedef unsigned long         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   signed long     blksize_t;
+typedef   signed long      blkcnt_t;
+typedef   signed long        time_t;
+
+#endif /* _NOLIBC_STD_H */

tools/include/nolibc/stdio.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * minimal stdio function definitions for NOLIBC
+ * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_STDIO_H
+#define _NOLIBC_STDIO_H
+
+#include <stdarg.h>
+
+#include "std.h"
+#include "arch.h"
+#include "errno.h"
+#include "types.h"
+#include "sys.h"
+#include "stdlib.h"
+#include "string.h"
+
+#ifndef EOF
+#define EOF (-1)
+#endif
+
+/* just define FILE as a non-empty type */
+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;
+
+/* getc(), fgetc(), getchar() */
+
+#define getc(stream) fgetc(stream)
+
+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)
+		return EOF;
+	return ch;
+}
+
+static __attribute__((unused))
+int getchar(void)
+{
+	return fgetc(stdin);
+}
+
+
+/* putc(), fputc(), putchar() */
+
+#define putc(c, stream) fputc(c, stream)
+
+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)
+		return EOF;
+	return ch;
+}
+
+static __attribute__((unused))
+int putchar(int c)
+{
+	return fputc(c, stdout);
+}
+
+
+/* fwrite(), puts(), fputs(). Note that puts() emits '\n' but not fputs(). */
+
+/* internal fwrite()-like function which only takes a size and returns 0 on
+ * success or EOF on error. It automatically retries on short writes.
+ */
+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;
+
+	while (size) {
+		ret = write(fd, buf, size);
+		if (ret <= 0)
+			return EOF;
+		size -= ret;
+		buf += ret;
+	}
+	return 0;
+}
+
+static __attribute__((unused))
+size_t fwrite(const void *s, size_t size, size_t nmemb, FILE *stream)
+{
+	size_t written;
+
+	for (written = 0; written < nmemb; written++) {
+		if (_fwrite(s, size, stream) != 0)
+			break;
+		s += size;
+	}
+	return written;
+}
+
+static __attribute__((unused))
+int fputs(const char *s, FILE *stream)
+{
+	return _fwrite(s, strlen(s), stream);
+}
+
+static __attribute__((unused))
+int puts(const char *s)
+{
+	if (fputs(s, stdout) == EOF)
+		return EOF;
+	return putchar('\n');
+}
+
+
+/* fgets() */
+static __attribute__((unused))
+char *fgets(char *s, int size, FILE *stream)
+{
+	int ofs;
+	int c;
+
+	for (ofs = 0; ofs + 1 < size;) {
+		c = fgetc(stream);
+		if (c == EOF)
+			break;
+		s[ofs++] = c;
+		if (c == '\n')
+			break;
+	}
+	if (ofs < size)
+		s[ofs] = 0;
+	return ofs ? s : NULL;
+}
+
+
+/* minimal vfprintf(). It supports the following formats:
+ *  - %[l*]{d,u,c,x,p}
+ *  - %s
+ *  - unknown modifiers are ignored.
+ */
+static __attribute__((unused))
+int vfprintf(FILE *stream, const char *fmt, va_list args)
+{
+	char escape, lpref, c;
+	unsigned long long v;
+	unsigned int written;
+	size_t len, ofs;
+	char tmpbuf[21];
+	const char *outstr;
+
+	written = ofs = escape = lpref = 0;
+	while (1) {
+		c = fmt[ofs++];
+
+		if (escape) {
+			/* we're in an escape sequence, ofs == 1 */
+			escape = 0;
+			if (c == 'c' || c == 'd' || c == 'u' || c == 'x' || c == 'p') {
+				char *out = tmpbuf;
+
+				if (c == 'p')
+					v = va_arg(args, unsigned long);
+				else if (lpref) {
+					if (lpref > 1)
+						v = va_arg(args, unsigned long long);
+					else
+						v = va_arg(args, unsigned long);
+				} else
+					v = va_arg(args, unsigned int);
+
+				if (c == 'd') {
+					/* sign-extend the value */
+					if (lpref == 0)
+						v = (long long)(int)v;
+					else if (lpref == 1)
+						v = (long long)(long)v;
+				}
+
+				switch (c) {
+				case 'c':
+					out[0] = v;
+					out[1] = 0;
+					break;
+				case 'd':
+					i64toa_r(v, out);
+					break;
+				case 'u':
+					u64toa_r(v, out);
+					break;
+				case 'p':
+					*(out++) = '0';
+					*(out++) = 'x';
+					/* fall through */
+				default: /* 'x' and 'p' above */
+					u64toh_r(v, out);
+					break;
+				}
+				outstr = tmpbuf;
+			}
+			else if (c == 's') {
+				outstr = va_arg(args, char *);
+				if (!outstr)
+					outstr="(null)";
+			}
+			else if (c == '%') {
+				/* queue it verbatim */
+				continue;
+			}
+			else {
+				/* modifiers or final 0 */
+				if (c == 'l') {
+					/* long format prefix, maintain the escape */
+					lpref++;
+				}
+				escape = 1;
+				goto do_escape;
+			}
+			len = strlen(outstr);
+			goto flush_str;
+		}
+
+		/* not an escape sequence */
+		if (c == 0 || c == '%') {
+			/* flush pending data on escape or end */
+			escape = 1;
+			lpref = 0;
+			outstr = fmt;
+			len = ofs - 1;
+		flush_str:
+			if (_fwrite(outstr, len, stream) != 0)
+				break;
+
+			written += len;
+		do_escape:
+			if (c == 0)
+				break;
+			fmt += ofs;
+			ofs = 0;
+			continue;
+		}
+
+		/* literal char, just queue it */
+	}
+	return written;
+}
+
+static __attribute__((unused))
+int fprintf(FILE *stream, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vfprintf(stream, fmt, args);
+	va_end(args);
+	return ret;
+}
+
+static __attribute__((unused))
+int printf(const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = vfprintf(stdout, fmt, args);
+	va_end(args);
+	return ret;
+}
+
+static __attribute__((unused))
+void perror(const char *msg)
+{
+	fprintf(stderr, "%s%serrno=%d\n", (msg && *msg) ? msg : "", (msg && *msg) ? ": " : "", errno);
+}
+
+#endif /* _NOLIBC_STDIO_H */

tools/include/nolibc/time.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * time function definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_TIME_H
+#define _NOLIBC_TIME_H
+
+#include "std.h"
+#include "arch.h"
+#include "types.h"
+#include "sys.h"
+
+static __attribute__((unused))
+time_t time(time_t *tptr)
+{
+	struct timeval tv;
+
+	/* note, cannot fail here */
+	sys_gettimeofday(&tv, NULL);
+
+	if (tptr)
+		*tptr = tv.tv_sec;
+	return tv.tv_sec;
+}
+
+#endif /* _NOLIBC_TIME_H */

tools/include/nolibc/unistd.h

+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * unistd function definitions for NOLIBC
+ * Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
+ */
+
+#ifndef _NOLIBC_UNISTD_H
+#define _NOLIBC_UNISTD_H
+
+#include "std.h"
+#include "arch.h"
+#include "types.h"
+#include "sys.h"
+
+
+static __attribute__((unused))
+int msleep(unsigned int msecs)
+{
+	struct timeval my_timeval = { msecs / 1000, (msecs % 1000) * 1000 };
+
+	if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+		return (my_timeval.tv_sec * 1000) +
+			(my_timeval.tv_usec / 1000) +
+			!!(my_timeval.tv_usec % 1000);
+	else
+		return 0;
+}
+
+static __attribute__((unused))
+unsigned int sleep(unsigned int seconds)
+{
+	struct timeval my_timeval = { seconds, 0 };
+
+	if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
+		return my_timeval.tv_sec + !!my_timeval.tv_usec;
+	else
+		return 0;
+}
+
+static __attribute__((unused))
+int usleep(unsigned int usecs)
+{
+	struct timeval my_timeval = { usecs / 1000000, usecs % 1000000 };
+
+	return sys_select(0, 0, 0, 0, &my_timeval);
+}
+
+static __attribute__((unused))
+int tcsetpgrp(int fd, pid_t pid)
+{
+	return ioctl(fd, TIOCSPGRP, &pid);
+}
+
+#endif /* _NOLIBC_UNISTD_H */