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Diffstat (limited to 'tools/include/nolibc')
| -rw-r--r-- | tools/include/nolibc/nolibc.h | 2468 |
1 files changed, 2468 insertions, 0 deletions
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h new file mode 100644 index 000000000..c20d2fe7c --- /dev/null +++ b/tools/include/nolibc/nolibc.h @@ -0,0 +1,2468 @@ +/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ +/* nolibc.h + * Copyright (C) 2017-2018 Willy Tarreau <w@1wt.eu> + */ + +/* + * This file is designed to be used as a libc alternative for minimal programs + * with very limited requirements. It consists of a small number of syscall and + * type definitions, and the minimal startup code needed to call main(). + * All syscalls are declared as static functions so that they can be optimized + * away by the compiler when not used. + * + * Syscalls are split into 3 levels: + * - The lower level is the arch-specific syscall() definition, consisting in + * assembly code in compound expressions. These are called my_syscall0() to + * my_syscall6() depending on the number of arguments. The MIPS + * implementation is limited to 5 arguments. All input arguments are cast + * to a long stored in a register. These expressions always return the + * syscall's return value as a signed long value which is often either a + * pointer or the negated errno value. + * + * - The second level is mostly architecture-independent. It is made of + * static functions called sys_<name>() which rely on my_syscallN() + * depending on the syscall definition. These functions are responsible + * for exposing the appropriate types for the syscall arguments (int, + * pointers, etc) and for setting the appropriate return type (often int). + * A few of them are architecture-specific because the syscalls are not all + * mapped exactly the same among architectures. For example, some archs do + * not implement select() and need pselect6() instead, so the sys_select() + * function will have to abstract this. + * + * - The third level is the libc call definition. It exposes the lower raw + * sys_<name>() calls in a way that looks like what a libc usually does, + * takes care of specific input values, and of setting errno upon error. + * There can be minor variations compared to standard libc calls. For + * example the open() call always takes 3 args here. + * + * The errno variable is declared static and unused. This way it can be + * optimized away if not used. However this means that a program made of + * multiple C files may observe different errno values (one per C file). For + * the type of programs this project targets it usually is not a problem. The + * resulting program may even be reduced by defining the NOLIBC_IGNORE_ERRNO + * macro, in which case the errno value will never be assigned. + * + * Some stdint-like integer types are defined. These are valid on all currently + * supported architectures, because signs are enforced, ints are assumed to be + * 32 bits, longs the size of a pointer and long long 64 bits. If more + * architectures have to be supported, this may need to be adapted. + * + * Some macro definitions like the O_* values passed to open(), and some + * structures like the sys_stat struct depend on the architecture. + * + * The definitions start with the architecture-specific parts, which are picked + * based on what the compiler knows about the target architecture, and are + * completed with the generic code. Since it is the compiler which sets the + * target architecture, cross-compiling normally works out of the box without + * having to specify anything. + * + * Finally some very common libc-level functions are provided. It is the case + * for a few functions usually found in string.h, ctype.h, or stdlib.h. Nothing + * is currently provided regarding stdio emulation. + * + * The macro NOLIBC is always defined, so that it is possible for a program to + * check this macro to know if it is being built against and decide to disable + * some features or simply not to include some standard libc files. + * + * Ideally this file should be split in multiple files for easier long term + * maintenance, but provided as a single file as it is now, it's quite + * convenient to use. Maybe some variations involving a set of includes at the + * top could work. + * + * A simple static executable may be built this way : + * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ + * -static -include nolibc.h -lgcc -o hello hello.c + * + * A very useful calling convention table may be found here : + * http://man7.org/linux/man-pages/man2/syscall.2.html + * + * This doc is quite convenient though not necessarily up to date : + * https://w3challs.com/syscalls/ + * + */ + +/* Some archs (at least aarch64) don't expose the regular syscalls anymore by + * default, either because they have an "_at" replacement, or because there are + * more modern alternatives. For now we'd rather still use them. + */ +#define __ARCH_WANT_SYSCALL_NO_AT +#define __ARCH_WANT_SYSCALL_NO_FLAGS +#define __ARCH_WANT_SYSCALL_DEPRECATED + +#include <asm/unistd.h> +#include <asm/ioctls.h> +#include <asm/errno.h> +#include <linux/fs.h> +#include <linux/loop.h> + +#define NOLIBC + +/* 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 memry page. + */ +#define MAX_ERRNO 4095 + +/* 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. + */ + +#define NULL ((void *)0) + +/* 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; + +/* for stat() */ +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; + +/* for poll() */ +struct pollfd { + int fd; + short int events; + short int revents; +}; + +/* for select() */ +struct timeval { + long tv_sec; + long tv_usec; +}; + +/* for pselect() */ +struct timespec { + long tv_sec; + long tv_nsec; +}; + +/* for gettimeofday() */ +struct timezone { + int tz_minuteswest; + int tz_dsttime; +}; + +/* for getdents64() */ +struct linux_dirent64 { + uint64_t d_ino; + int64_t d_off; + unsigned short d_reclen; + unsigned char d_type; + char d_name[]; +}; + +/* commonly an fd_set represents 256 FDs */ +#define FD_SETSIZE 256 +typedef struct { uint32_t fd32[FD_SETSIZE/32]; } fd_set; + +/* needed by wait4() */ +struct rusage { + struct timeval ru_utime; + struct timeval ru_stime; + long ru_maxrss; + long ru_ixrss; + long ru_idrss; + long ru_isrss; + long ru_minflt; + long ru_majflt; + long ru_nswap; + long ru_inblock; + long ru_oublock; + long ru_msgsnd; + long ru_msgrcv; + long ru_nsignals; + long ru_nvcsw; + long ru_nivcsw; +}; + +/* stat flags (WARNING, octal here) */ +#define S_IFDIR 0040000 +#define S_IFCHR 0020000 +#define S_IFBLK 0060000 +#define S_IFREG 0100000 +#define S_IFIFO 0010000 +#define S_IFLNK 0120000 +#define S_IFSOCK 0140000 +#define S_IFMT 0170000 + +#define S_ISDIR(mode) (((mode) & S_IFDIR) == S_IFDIR) +#define S_ISCHR(mode) (((mode) & S_IFCHR) == S_IFCHR) +#define S_ISBLK(mode) (((mode) & S_IFBLK) == S_IFBLK) +#define S_ISREG(mode) (((mode) & S_IFREG) == S_IFREG) +#define S_ISFIFO(mode) (((mode) & S_IFIFO) == S_IFIFO) +#define S_ISLNK(mode) (((mode) & S_IFLNK) == S_IFLNK) +#define S_ISSOCK(mode) (((mode) & S_IFSOCK) == S_IFSOCK) + +#define DT_UNKNOWN 0 +#define DT_FIFO 1 +#define DT_CHR 2 +#define DT_DIR 4 +#define DT_BLK 6 +#define DT_REG 8 +#define DT_LNK 10 +#define DT_SOCK 12 + +/* all the *at functions */ +#ifndef AT_FDWCD +#define AT_FDCWD -100 +#endif + +/* lseek */ +#define SEEK_SET 0 +#define SEEK_CUR 1 +#define SEEK_END 2 + +/* reboot */ +#define LINUX_REBOOT_MAGIC1 0xfee1dead +#define LINUX_REBOOT_MAGIC2 0x28121969 +#define LINUX_REBOOT_CMD_HALT 0xcdef0123 +#define LINUX_REBOOT_CMD_POWER_OFF 0x4321fedc +#define LINUX_REBOOT_CMD_RESTART 0x01234567 +#define LINUX_REBOOT_CMD_SW_SUSPEND 0xd000fce2 + + +/* The format of the struct as returned by the libc to the application, which + * significantly differs from the format returned by the stat() syscall flavours. + */ +struct stat { + dev_t st_dev; /* ID of device containing file */ + ino_t st_ino; /* inode number */ + mode_t st_mode; /* protection */ + nlink_t st_nlink; /* number of hard links */ + uid_t st_uid; /* user ID of owner */ + gid_t st_gid; /* group ID of owner */ + dev_t st_rdev; /* device ID (if special file) */ + off_t st_size; /* total size, in bytes */ + blksize_t st_blksize; /* blocksize for file system I/O */ + blkcnt_t st_blocks; /* number of 512B blocks allocated */ + time_t st_atime; /* time of last access */ + time_t st_mtime; /* time of last modification */ + time_t st_ctime; /* time of last status change */ +}; + +#define WEXITSTATUS(status) (((status) & 0xff00) >> 8) +#define WIFEXITED(status) (((status) & 0x7f) == 0) + + +/* 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. + */ + +#if defined(__x86_64__) +/* Syscalls for x86_64 : + * - registers are 64-bit + * - syscall number is passed in rax + * - arguments are in rdi, rsi, rdx, r10, r8, r9 respectively + * - the system call is performed by calling the syscall instruction + * - syscall return comes in rax + * - rcx and r8..r11 may be clobbered, others are preserved. + * - 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). + */ + +#define my_syscall0(num) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret) \ + : "0"(_num) \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall1(num, arg1) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret) \ + : "r"(_arg1), \ + "0"(_num) \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), \ + "0"(_num) \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + register long _arg3 asm("rdx") = (long)(arg3); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ + "0"(_num) \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall4(num, arg1, arg2, arg3, arg4) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + register long _arg3 asm("rdx") = (long)(arg3); \ + register long _arg4 asm("r10") = (long)(arg4); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret), "=r"(_arg4) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \ + "0"(_num) \ + : "rcx", "r8", "r9", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + register long _arg3 asm("rdx") = (long)(arg3); \ + register long _arg4 asm("r10") = (long)(arg4); \ + register long _arg5 asm("r8") = (long)(arg5); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ + "0"(_num) \ + : "rcx", "r9", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \ +({ \ + long _ret; \ + register long _num asm("rax") = (num); \ + register long _arg1 asm("rdi") = (long)(arg1); \ + register long _arg2 asm("rsi") = (long)(arg2); \ + register long _arg3 asm("rdx") = (long)(arg3); \ + register long _arg4 asm("r10") = (long)(arg4); \ + register long _arg5 asm("r8") = (long)(arg5); \ + register long _arg6 asm("r9") = (long)(arg6); \ + \ + asm volatile ( \ + "syscall\n" \ + : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ + "r"(_arg6), "0"(_num) \ + : "rcx", "r11", "memory", "cc" \ + ); \ + _ret; \ +}) + +/* startup code */ +/* + * x86-64 System V ABI mandates: + * 1) %rsp must be 16-byte aligned right before the function call. + * 2) The deepest stack frame should be zero (the %rbp). + * + */ +asm(".section .text\n" + ".global _start\n" + "_start:\n" + "pop %rdi\n" // argc (first arg, %rdi) + "mov %rsp, %rsi\n" // argv[] (second arg, %rsi) + "lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx) + "xor %ebp, %ebp\n" // zero the stack frame + "and $-16, %rsp\n" // x86 ABI : esp must be 16-byte aligned before call + "call main\n" // main() returns the status code, we'll exit with it. + "mov %eax, %edi\n" // retrieve exit code (32 bit) + "mov $60, %rax\n" // NR_exit == 60 + "syscall\n" // really exit + "hlt\n" // ensure it does not return + ""); + +/* fcntl / open */ +#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 0x10000 + +/* The struct returned by the stat() syscall, equivalent to stat64(). The + * syscall returns 116 bytes and stops in the middle of __unused. + */ +struct sys_stat_struct { + unsigned long st_dev; + unsigned long st_ino; + unsigned long st_nlink; + unsigned int st_mode; + unsigned int st_uid; + + unsigned int st_gid; + unsigned int __pad0; + unsigned long st_rdev; + long st_size; + long st_blksize; + + 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; + long __unused[3]; +}; + +#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__) +/* Syscalls for i386 : + * - mostly similar to x86_64 + * - registers are 32-bit + * - syscall number is passed in eax + * - arguments are in ebx, ecx, edx, esi, edi, ebp respectively + * - all registers are preserved (except eax of course) + * - the system call is performed by calling int $0x80 + * - syscall return comes in eax + * - 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, i386 supports the old_select syscall if newselect is not available + */ +#define __ARCH_WANT_SYS_OLD_SELECT + +#define my_syscall0(num) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall1(num, arg1) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + register long _arg1 asm("ebx") = (long)(arg1); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "r"(_arg1), \ + "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + register long _arg1 asm("ebx") = (long)(arg1); \ + register long _arg2 asm("ecx") = (long)(arg2); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), \ + "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + register long _arg1 asm("ebx") = (long)(arg1); \ + register long _arg2 asm("ecx") = (long)(arg2); \ + register long _arg3 asm("edx") = (long)(arg3); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ + "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall4(num, arg1, arg2, arg3, arg4) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + register long _arg1 asm("ebx") = (long)(arg1); \ + register long _arg2 asm("ecx") = (long)(arg2); \ + register long _arg3 asm("edx") = (long)(arg3); \ + register long _arg4 asm("esi") = (long)(arg4); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \ + "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ +({ \ + long _ret; \ + register long _num asm("eax") = (num); \ + register long _arg1 asm("ebx") = (long)(arg1); \ + register long _arg2 asm("ecx") = (long)(arg2); \ + register long _arg3 asm("edx") = (long)(arg3); \ + register long _arg4 asm("esi") = (long)(arg4); \ + register long _arg5 asm("edi") = (long)(arg5); \ + \ + asm volatile ( \ + "int $0x80\n" \ + : "=a" (_ret) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ + "0"(_num) \ + : "memory", "cc" \ + ); \ + _ret; \ +}) + +/* startup code */ +/* + * i386 System V ABI mandates: + * 1) last pushed argument must be 16-byte aligned. + * 2) The deepest stack frame should be set to zero + * + */ +asm(".section .text\n" + ".global _start\n" + "_start:\n" + "pop %eax\n" // argc (first arg, %eax) + "mov %esp, %ebx\n" // argv[] (second arg, %ebx) + "lea 4(%ebx,%eax,4),%ecx\n" // then a NULL then envp (third arg, %ecx) + "xor %ebp, %ebp\n" // zero the stack frame + "and $-16, %esp\n" // x86 ABI : esp must be 16-byte aligned before + "sub $4, %esp\n" // the call instruction (args are aligned) + "push %ecx\n" // push all registers on the stack so that we + "push %ebx\n" // support both regparm and plain stack modes + "push %eax\n" + "call main\n" // main() returns the status code in %eax + "mov %eax, %ebx\n" // retrieve exit code (32-bit int) + "movl $1, %eax\n" // NR_exit == 1 + "int $0x80\n" // exit now + "hlt\n" // ensure it does not + ""); + +/* fcntl / open */ +#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 0x10000 + +/* The struct returned by the stat() syscall, 32-bit only, the syscall returns + * exactly 56 bytes (stops before the unused array). + */ +struct sys_stat_struct { + unsigned long st_dev; + unsigned long st_ino; + unsigned short st_mode; + unsigned short st_nlink; + unsigned short st_uid; + unsigned short st_gid; + + unsigned long st_rdev; + 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]; +}; + +#elif defined(__ARM_EABI__) +/* 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" + ".global _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" + ""); + +/* fcntl / open */ +#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]; +}; + +#elif defined(__aarch64__) +/* Syscalls for AARCH64 : + * - registers are 64-bit + * - stack is 16-byte aligned + * - syscall number is passed in x8 + * - arguments are in x0, x1, x2, x3, x4, x5 + * - the system call is performed by calling svc 0 + * - syscall return comes in x0. + * - 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 aarch64, select() is not implemented so we have to use pselect6(). + */ +#define __ARCH_WANT_SYS_PSELECT6 + +#define my_syscall0(num) \ +({ \ + register long _num asm("x8") = (num); \ + register long _arg1 asm("x0"); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define my_syscall1(num, arg1) \ +({ \ + register long _num asm("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_arg1), \ + "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + register long _num asm("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + register long _arg2 asm("x1") = (long)(arg2); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_arg1), "r"(_arg2), \ + "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + register long _num asm("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + register long _arg2 asm("x1") = (long)(arg2); \ + register long _arg3 asm("x2") = (long)(arg3); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ + "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +#define my_syscall4(num, arg1, arg2, arg3, arg4) \ +({ \ + register long _num asm("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + register long _arg2 asm("x1") = (long)(arg2); \ + register long _arg3 asm("x2") = (long)(arg3); \ + register long _arg4 asm("x3") = (long)(arg4); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r"(_arg1) \ + : "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("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + register long _arg2 asm("x1") = (long)(arg2); \ + register long _arg3 asm("x2") = (long)(arg3); \ + register long _arg4 asm("x3") = (long)(arg4); \ + register long _arg5 asm("x4") = (long)(arg5); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r" (_arg1) \ + : "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("x8") = (num); \ + register long _arg1 asm("x0") = (long)(arg1); \ + register long _arg2 asm("x1") = (long)(arg2); \ + register long _arg3 asm("x2") = (long)(arg3); \ + register long _arg4 asm("x3") = (long)(arg4); \ + register long _arg5 asm("x4") = (long)(arg5); \ + register long _arg6 asm("x5") = (long)(arg6); \ + \ + asm volatile ( \ + "svc #0\n" \ + : "=r" (_arg1) \ + : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ + "r"(_arg6), "r"(_num) \ + : "memory", "cc" \ + ); \ + _arg1; \ +}) + +/* startup code */ +asm(".section .text\n" + ".global _start\n" + "_start:\n" + "ldr x0, [sp]\n" // argc (x0) was in the stack + "add x1, sp, 8\n" // argv (x1) = sp + "lsl x2, x0, 3\n" // envp (x2) = 8*argc ... + "add x2, x2, 8\n" // + 8 (skip null) + "add x2, x2, x1\n" // + argv + "and sp, x1, -16\n" // sp must be 16-byte aligned in the callee + "bl main\n" // main() returns the status code, we'll exit with it. + "mov x8, 93\n" // NR_exit == 93 + "svc #0\n" + ""); + +/* fcntl / open */ +#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 newfstatat() syscall. Differs slightly from the + * x86_64's stat one by field ordering, so be careful. + */ +struct sys_stat_struct { + unsigned long st_dev; + unsigned long st_ino; + unsigned int st_mode; + unsigned int st_nlink; + unsigned int st_uid; + unsigned int st_gid; + + unsigned long st_rdev; + unsigned long __pad1; + long st_size; + int st_blksize; + int __pad2; + + long st_blocks; + long st_atime; + unsigned long st_atime_nsec; + long st_mtime; + + unsigned long st_mtime_nsec; + long st_ctime; + unsigned long st_ctime_nsec; + unsigned int __unused[2]; +}; + +#elif defined(__mips__) && defined(_ABIO32) +/* Syscalls for MIPS ABI O32 : + * - WARNING! there's always a delayed slot! + * - WARNING again, the syntax is different, registers take a '$' and numbers + * do not. + * - registers are 32-bit + * - stack is 8-byte aligned + * - syscall number is passed in v0 (starts at 0xfa0). + * - arguments are in a0, a1, a2, a3, then the stack. The caller needs to + * leave some room in the stack for the callee to save a0..a3 if needed. + * - Many registers are clobbered, in fact only a0..a2 and s0..s8 are + * preserved. See: https://www.linux-mips.org/wiki/Syscall as well as + * scall32-o32.S in the kernel sources. + * - the system call is performed by calling "syscall" + * - syscall return comes in v0, and register a3 needs to be checked to know + * if an error occured, in which case errno is in v0. + * - 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. + */ + +#define my_syscall0(num) \ +({ \ + register long _num asm("v0") = (num); \ + register long _arg4 asm("a3"); \ + \ + asm volatile ( \ + "addiu $sp, $sp, -32\n" \ + "syscall\n" \ + "addiu $sp, $sp, 32\n" \ + : "=r"(_num), "=r"(_arg4) \ + : "r"(_num) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +#define my_syscall1(num, arg1) \ +({ \ + register long _num asm("v0") = (num); \ + register long _arg1 asm("a0") = (long)(arg1); \ + register long _arg4 asm("a3"); \ + \ + asm volatile ( \ + "addiu $sp, $sp, -32\n" \ + "syscall\n" \ + "addiu $sp, $sp, 32\n" \ + : "=r"(_num), "=r"(_arg4) \ + : "0"(_num), \ + "r"(_arg1) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +#define my_syscall2(num, arg1, arg2) \ +({ \ + register long _num asm("v0") = (num); \ + register long _arg1 asm("a0") = (long)(arg1); \ + register long _arg2 asm("a1") = (long)(arg2); \ + register long _arg4 asm("a3"); \ + \ + asm volatile ( \ + "addiu $sp, $sp, -32\n" \ + "syscall\n" \ + "addiu $sp, $sp, 32\n" \ + : "=r"(_num), "=r"(_arg4) \ + : "0"(_num), \ + "r"(_arg1), "r"(_arg2) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +#define my_syscall3(num, arg1, arg2, arg3) \ +({ \ + register long _num asm("v0") = (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"); \ + \ + asm volatile ( \ + "addiu $sp, $sp, -32\n" \ + "syscall\n" \ + "addiu $sp, $sp, 32\n" \ + : "=r"(_num), "=r"(_arg4) \ + : "0"(_num), \ + "r"(_arg1), "r"(_arg2), "r"(_arg3) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +#define my_syscall4(num, arg1, arg2, arg3, arg4) \ +({ \ + register long _num asm("v0") = (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 ( \ + "addiu $sp, $sp, -32\n" \ + "syscall\n" \ + "addiu $sp, $sp, 32\n" \ + : "=r" (_num), "=r"(_arg4) \ + : "0"(_num), \ + "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \ +({ \ + register long _num asm("v0") = (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 = (long)(arg5); \ + \ + asm volatile ( \ + "addiu $sp, $sp, -32\n" \ + "sw %7, 16($sp)\n" \ + "syscall\n " \ + "addiu $sp, $sp, 32\n" \ + : "=r" (_num), "=r"(_arg4) \ + : "0"(_num), \ + "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ + : "memory", "cc", "at", "v1", "hi", "lo", \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ + ); \ + _arg4 ? -_num : _num; \ +}) + +/* startup code, note that it's called __start on MIPS */ +asm(".section .text\n" + ".set nomips16\n" + ".global __start\n" + ".set noreorder\n" + ".option pic0\n" + ".ent __start\n" + "__start:\n" + "lw $a0,($sp)\n" // argc was in the stack + "addiu $a1, $sp, 4\n" // argv = sp + 4 + "sll $a2, $a0, 2\n" // a2 = argc * 4 + "add $a2, $a2, $a1\n" // envp = argv + 4*argc ... + "addiu $a2, $a2, 4\n" // ... + 4 + "li $t0, -8\n" + "and $sp, $sp, $t0\n" // sp must be 8-byte aligned + "addiu $sp,$sp,-16\n" // the callee expects to save a0..a3 there! + "jal main\n" // main() returns the status code, we'll exit with it. + "nop\n" // delayed slot + "move $a0, $v0\n" // retrieve 32-bit exit code from v0 + "li $v0, 4001\n" // NR_exit == 4001 + "syscall\n" + ".end __start\n" + ""); + +/* fcntl / open */ +#define O_RDONLY 0 +#define O_WRONLY 1 +#define O_RDWR 2 +#define O_APPEND 0x0008 +#define O_NONBLOCK 0x0080 +#define O_CREAT 0x0100 +#define O_TRUNC 0x0200 +#define O_EXCL 0x0400 +#define O_NOCTTY 0x0800 +#define O_DIRECTORY 0x10000 + +/* The struct returned by the stat() syscall. 88 bytes are returned by the + * syscall. + */ +struct sys_stat_struct { + unsigned int st_dev; + long st_pad1[3]; + unsigned long st_ino; + unsigned int st_mode; + unsigned int st_nlink; + unsigned int st_uid; + unsigned int st_gid; + unsigned int st_rdev; + long st_pad2[2]; + long st_size; + long st_pad3; + long st_atime; + long st_atime_nsec; + long st_mtime; + long st_mtime_nsec; + long st_ctime; + long st_ctime_nsec; + long st_blksize; + long st_blocks; + long st_pad4[14]; +}; + +#elif defined(__riscv) + +#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. + */ + +#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" + ".global _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" + ""); + +/* fcntl / open */ +#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; +}; + +#endif + + +/* Below are the C functions used to declare the raw syscalls. They try to be + * architecture-agnostic, and return either a success or -errno. Declaring them + * static will lead to them being inlined in most cases, but it's still possible + * to reference them by a pointer if needed. + */ +static __attribute__((unused)) +void *sys_brk(void *addr) +{ + return (void *)my_syscall1(__NR_brk, addr); +} + +static __attribute__((noreturn,unused)) +void sys_exit(int status) +{ + my_syscall1(__NR_exit, status & 255); + while(1); // shut the "noreturn" warnings. +} + +static __attribute__((unused)) +int sys_chdir(const char *path) +{ + return my_syscall1(__NR_chdir, path); +} + +static __attribute__((unused)) +int sys_chmod(const char *path, mode_t mode) +{ +#ifdef __NR_fchmodat + return my_syscall4(__NR_fchmodat, AT_FDCWD, path, mode, 0); +#else + return my_syscall2(__NR_chmod, path, mode); +#endif +} + +static __attribute__((unused)) +int sys_chown(const char *path, uid_t owner, gid_t group) +{ +#ifdef __NR_fchownat + return my_syscall5(__NR_fchownat, AT_FDCWD, path, owner, group, 0); +#else + return my_syscall3(__NR_chown, path, owner, group); +#endif +} + +static __attribute__((unused)) +int sys_chroot(const char *path) +{ + return my_syscall1(__NR_chroot, path); +} + +static __attribute__((unused)) +int sys_close(int fd) +{ + return my_syscall1(__NR_close, fd); +} + +static __attribute__((unused)) +int sys_dup(int fd) +{ + return my_syscall1(__NR_dup, fd); +} + +static __attribute__((unused)) +int sys_dup2(int old, int new) +{ + return my_syscall2(__NR_dup2, old, new); +} + +static __attribute__((unused)) +int sys_execve(const char *filename, char *const argv[], char *const envp[]) +{ + return my_syscall3(__NR_execve, filename, argv, envp); +} + +static __attribute__((unused)) +pid_t sys_fork(void) +{ + return my_syscall0(__NR_fork); +} + +static __attribute__((unused)) +int sys_fsync(int fd) +{ + return my_syscall1(__NR_fsync, fd); +} + +static __attribute__((unused)) +int sys_getdents64(int fd, struct linux_dirent64 *dirp, int count) +{ + return my_syscall3(__NR_getdents64, fd, dirp, count); +} + +static __attribute__((unused)) +pid_t sys_getpgrp(void) +{ + return my_syscall0(__NR_getpgrp); +} + +static __attribute__((unused)) +pid_t sys_getpid(void) +{ + return my_syscall0(__NR_getpid); +} + +static __attribute__((unused)) +int sys_gettimeofday(struct timeval *tv, struct timezone *tz) +{ + return my_syscall2(__NR_gettimeofday, tv, tz); +} + +static __attribute__((unused)) +int sys_ioctl(int fd, unsigned long req, void *value) +{ + return my_syscall3(__NR_ioctl, fd, req, value); +} + +static __attribute__((unused)) +int sys_kill(pid_t pid, int signal) +{ + return my_syscall2(__NR_kill, pid, signal); +} + +static __attribute__((unused)) +int sys_link(const char *old, const char *new) +{ +#ifdef __NR_linkat + return my_syscall5(__NR_linkat, AT_FDCWD, old, AT_FDCWD, new, 0); +#else + return my_syscall2(__NR_link, old, new); +#endif +} + +static __attribute__((unused)) +off_t sys_lseek(int fd, off_t offset, int whence) +{ + return my_syscall3(__NR_lseek, fd, offset, whence); +} + +static __attribute__((unused)) +int sys_mkdir(const char *path, mode_t mode) +{ +#ifdef __NR_mkdirat + return my_syscall3(__NR_mkdirat, AT_FDCWD, path, mode); +#else + return my_syscall2(__NR_mkdir, path, mode); +#endif +} + +static __attribute__((unused)) +long sys_mknod(const char *path, mode_t mode, dev_t dev) +{ +#ifdef __NR_mknodat + return my_syscall4(__NR_mknodat, AT_FDCWD, path, mode, dev); +#else + return my_syscall3(__NR_mknod, path, mode, dev); +#endif +} + +static __attribute__((unused)) +int sys_mount(const char *src, const char *tgt, const char *fst, + unsigned long flags, const void *data) +{ + return my_syscall5(__NR_mount, src, tgt, fst, flags, data); +} + +static __attribute__((unused)) +int sys_open(const char *path, int flags, mode_t mode) +{ +#ifdef __NR_openat + return my_syscall4(__NR_openat, AT_FDCWD, path, flags, mode); +#else + return my_syscall3(__NR_open, path, flags, mode); +#endif +} + +static __attribute__((unused)) +int sys_pivot_root(const char *new, const char *old) +{ + return my_syscall2(__NR_pivot_root, new, old); +} + +static __attribute__((unused)) +int sys_poll(struct pollfd *fds, int nfds, int timeout) +{ + return my_syscall3(__NR_poll, fds, nfds, timeout); +} + +static __attribute__((unused)) +ssize_t sys_read(int fd, void *buf, size_t count) +{ + return my_syscall3(__NR_read, fd, buf, count); +} + +static __attribute__((unused)) +ssize_t sys_reboot(int magic1, int magic2, int cmd, void *arg) +{ + return my_syscall4(__NR_reboot, magic1, magic2, cmd, arg); +} + +static __attribute__((unused)) +int sys_sched_yield(void) +{ + return my_syscall0(__NR_sched_yield); +} + +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(__ARCH_WANT_SYS_PSELECT6) && 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 +#ifndef __NR__newselect +#define __NR__newselect __NR_select +#endif + return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout); +#endif +} + +static __attribute__((unused)) +int sys_setpgid(pid_t pid, pid_t pgid) +{ + return my_syscall2(__NR_setpgid, pid, pgid); +} + +static __attribute__((unused)) +pid_t sys_setsid(void) +{ + return my_syscall0(__NR_setsid); +} + +static __attribute__((unused)) +int sys_stat(const char *path, struct stat *buf) +{ + struct sys_stat_struct stat; + long ret; + +#ifdef __NR_newfstatat + /* only solution for arm64 */ + ret = my_syscall4(__NR_newfstatat, AT_FDCWD, path, &stat, 0); +#else + ret = my_syscall2(__NR_stat, path, &stat); +#endif + buf->st_dev = stat.st_dev; + buf->st_ino = stat.st_ino; + buf->st_mode = stat.st_mode; + buf->st_nlink = stat.st_nlink; + buf->st_uid = stat.st_uid; + buf->st_gid = stat.st_gid; + buf->st_rdev = stat.st_rdev; + buf->st_size = stat.st_size; + buf->st_blksize = stat.st_blksize; + buf->st_blocks = stat.st_blocks; + buf->st_atime = stat.st_atime; + buf->st_mtime = stat.st_mtime; + buf->st_ctime = stat.st_ctime; + return ret; +} + + +static __attribute__((unused)) +int sys_symlink(const char *old, const char *new) +{ +#ifdef __NR_symlinkat + return my_syscall3(__NR_symlinkat, old, AT_FDCWD, new); +#else + return my_syscall2(__NR_symlink, old, new); +#endif +} + +static __attribute__((unused)) +mode_t sys_umask(mode_t mode) +{ + return my_syscall1(__NR_umask, mode); +} + +static __attribute__((unused)) +int sys_umount2(const char *path, int flags) +{ + return my_syscall2(__NR_umount2, path, flags); +} + +static __attribute__((unused)) +int sys_unlink(const char *path) +{ +#ifdef __NR_unlinkat + return my_syscall3(__NR_unlinkat, AT_FDCWD, path, 0); +#else + return my_syscall1(__NR_unlink, path); +#endif +} + +static __attribute__((unused)) +pid_t sys_wait4(pid_t pid, int *status, int options, struct rusage *rusage) +{ + return my_syscall4(__NR_wait4, pid, status, options, rusage); +} + +static __attribute__((unused)) +pid_t sys_waitpid(pid_t pid, int *status, int options) +{ + return sys_wait4(pid, status, options, 0); +} + +static __attribute__((unused)) +pid_t sys_wait(int *status) +{ + return sys_waitpid(-1, status, 0); +} + +static __attribute__((unused)) +ssize_t sys_write(int fd, const void *buf, size_t count) +{ + return my_syscall3(__NR_write, fd, buf, count); +} + + +/* Below are the libc-compatible syscalls which return x or -1 and set errno. + * They rely on the functions above. Similarly they're marked static so that it + * is possible to assign pointers to them if needed. + */ + +static __attribute__((unused)) +int brk(void *addr) +{ + void *ret = sys_brk(addr); + + if (!ret) { + SET_ERRNO(ENOMEM); + return -1; + } + return 0; +} + +static __attribute__((noreturn,unused)) +void exit(int status) +{ + sys_exit(status); +} + +static __attribute__((unused)) +int chdir(const char *path) +{ + int ret = sys_chdir(path); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int chmod(const char *path, mode_t mode) +{ + int ret = sys_chmod(path, mode); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int chown(const char *path, uid_t owner, gid_t group) +{ + int ret = sys_chown(path, owner, group); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int chroot(const char *path) +{ + int ret = sys_chroot(path); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int close(int fd) +{ + int ret = sys_close(fd); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int dup2(int old, int new) +{ + int ret = sys_dup2(old, new); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int execve(const char *filename, char *const argv[], char *const envp[]) +{ + int ret = sys_execve(filename, argv, envp); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t fork(void) +{ + pid_t ret = sys_fork(); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int fsync(int fd) +{ + int ret = sys_fsync(fd); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int getdents64(int fd, struct linux_dirent64 *dirp, int count) +{ + int ret = sys_getdents64(fd, dirp, count); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t getpgrp(void) +{ + pid_t ret = sys_getpgrp(); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t getpid(void) +{ + pid_t ret = sys_getpid(); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int gettimeofday(struct timeval *tv, struct timezone *tz) +{ + int ret = sys_gettimeofday(tv, tz); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int ioctl(int fd, unsigned long req, void *value) +{ + int ret = sys_ioctl(fd, req, value); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int kill(pid_t pid, int signal) +{ + int ret = sys_kill(pid, signal); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int link(const char *old, const char *new) +{ + int ret = sys_link(old, new); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +off_t lseek(int fd, off_t offset, int whence) +{ + off_t ret = sys_lseek(fd, offset, whence); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int mkdir(const char *path, mode_t mode) +{ + int ret = sys_mkdir(path, mode); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int mknod(const char *path, mode_t mode, dev_t dev) +{ + int ret = sys_mknod(path, mode, dev); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int mount(const char *src, const char *tgt, + const char *fst, unsigned long flags, + const void *data) +{ + int ret = sys_mount(src, tgt, fst, flags, data); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int open(const char *path, int flags, mode_t mode) +{ + int ret = sys_open(path, flags, mode); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int pivot_root(const char *new, const char *old) +{ + int ret = sys_pivot_root(new, old); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int poll(struct pollfd *fds, int nfds, int timeout) +{ + int ret = sys_poll(fds, nfds, timeout); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +ssize_t read(int fd, void *buf, size_t count) +{ + ssize_t ret = sys_read(fd, buf, count); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int reboot(int cmd) +{ + int ret = sys_reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, 0); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +void *sbrk(intptr_t inc) +{ + void *ret; + + /* first call to find current end */ + if ((ret = sys_brk(0)) && (sys_brk(ret + inc) == ret + inc)) + return ret + inc; + + SET_ERRNO(ENOMEM); + return (void *)-1; +} + +static __attribute__((unused)) +int sched_yield(void) +{ + int ret = sys_sched_yield(); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout) +{ + int ret = sys_select(nfds, rfds, wfds, efds, timeout); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int setpgid(pid_t pid, pid_t pgid) +{ + int ret = sys_setpgid(pid, pgid); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t setsid(void) +{ + pid_t ret = sys_setsid(); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +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 stat(const char *path, struct stat *buf) +{ + int ret = sys_stat(path, buf); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int symlink(const char *old, const char *new) +{ + int ret = sys_symlink(old, new); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int tcsetpgrp(int fd, pid_t pid) +{ + return ioctl(fd, TIOCSPGRP, &pid); +} + +static __attribute__((unused)) +mode_t umask(mode_t mode) +{ + return sys_umask(mode); +} + +static __attribute__((unused)) +int umount2(const char *path, int flags) +{ + int ret = sys_umount2(path, flags); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +int unlink(const char *path) +{ + int ret = sys_unlink(path); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage) +{ + pid_t ret = sys_wait4(pid, status, options, rusage); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t waitpid(pid_t pid, int *status, int options) +{ + pid_t ret = sys_waitpid(pid, status, options); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +pid_t wait(int *status) +{ + pid_t ret = sys_wait(status); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +static __attribute__((unused)) +ssize_t write(int fd, const void *buf, size_t count) +{ + ssize_t ret = sys_write(fd, buf, count); + + if (ret < 0) { + SET_ERRNO(-ret); + ret = -1; + } + return ret; +} + +/* some size-optimized reimplementations of a few common str* and mem* + * functions. They're marked static, except memcpy() and raise() which are used + * by libgcc on ARM, so they are marked weak instead in order not to cause an + * error when building a program made of multiple files (not recommended). + */ + +static __attribute__((unused)) +void *memmove(void *dst, const void *src, size_t len) +{ + ssize_t pos = (dst <= src) ? -1 : (long)len; + void *ret = dst; + + while (len--) { + pos += (dst <= src) ? 1 : -1; + ((char *)dst)[pos] = ((char *)src)[pos]; + } + return ret; +} + +static __attribute__((unused)) +void *memset(void *dst, int b, size_t len) +{ + char *p = dst; + + while (len--) + *(p++) = b; + return dst; +} + +static __attribute__((unused)) +int memcmp(const void *s1, const void *s2, size_t n) +{ + size_t ofs = 0; + int c1 = 0; + + while (ofs < n && !(c1 = ((unsigned char *)s1)[ofs] - ((unsigned char *)s2)[ofs])) { + ofs++; + } + return c1; +} + +static __attribute__((unused)) +char *strcpy(char *dst, const char *src) +{ + char *ret = dst; + + while ((*dst++ = *src++)); + return ret; +} + +static __attribute__((unused)) +char *strchr(const char *s, int c) +{ + while (*s) { + if (*s == (char)c) + return (char *)s; + s++; + } + return NULL; +} + +static __attribute__((unused)) +char *strrchr(const char *s, int c) +{ + const char *ret = NULL; + + while (*s) { + if (*s == (char)c) + ret = s; + s++; + } + return (char *)ret; +} + +static __attribute__((unused)) +size_t nolibc_strlen(const char *str) +{ + size_t len; + + for (len = 0; str[len]; len++); + return len; +} + +#define strlen(str) ({ \ + __builtin_constant_p((str)) ? \ + __builtin_strlen((str)) : \ + nolibc_strlen((str)); \ +}) + +static __attribute__((unused)) +int isdigit(int c) +{ + return (unsigned int)(c - '0') <= 9; +} + +static __attribute__((unused)) +long atol(const char *s) +{ + unsigned long ret = 0; + unsigned long d; + int neg = 0; + + if (*s == '-') { + neg = 1; + s++; + } + + while (1) { + d = (*s++) - '0'; + if (d > 9) + break; + ret *= 10; + ret += d; + } + + return neg ? -ret : ret; +} + +static __attribute__((unused)) +int atoi(const char *s) +{ + return atol(s); +} + +static __attribute__((unused)) +const char *ltoa(long in) +{ + /* large enough for -9223372036854775808 */ + static char buffer[21]; + char *pos = buffer + sizeof(buffer) - 1; + int neg = in < 0; + unsigned long n = neg ? -in : in; + + *pos-- = '\0'; + do { + *pos-- = '0' + n % 10; + n /= 10; + if (pos < buffer) + return pos + 1; + } while (n); + + if (neg) + *pos-- = '-'; + return pos + 1; +} + +__attribute__((weak,unused)) +void *memcpy(void *dst, const void *src, size_t len) +{ + return memmove(dst, src, len); +} + +/* needed by libgcc for divide by zero */ +__attribute__((weak,unused)) +int raise(int signal) +{ + return kill(getpid(), signal); +} + +/* Here come a few helper functions */ + +static __attribute__((unused)) +void FD_ZERO(fd_set *set) +{ + memset(set, 0, sizeof(*set)); +} + +static __attribute__((unused)) +void FD_SET(int fd, fd_set *set) +{ + if (fd < 0 || fd >= FD_SETSIZE) + return; + set->fd32[fd / 32] |= 1 << (fd & 31); +} + +/* WARNING, it only deals with the 4096 first majors and 256 first minors */ +static __attribute__((unused)) +dev_t makedev(unsigned int major, unsigned int minor) +{ + return ((major & 0xfff) << 8) | (minor & 0xff); +} |