/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ /* * Syscall definitions for NOLIBC (those in man(2)) * Copyright (C) 2017-2021 Willy Tarreau */ #ifndef _NOLIBC_SYS_H #define _NOLIBC_SYS_H #include #include "std.h" /* system includes */ #include #include // for SIGCHLD #include #include #include #include #include #include "arch.h" #include "errno.h" #include "types.h" /* Functions in this file only describe syscalls. They're declared static so * that the compiler usually decides to inline them while still being allowed * to pass a pointer to one of their instances. Each syscall exists in two * versions: * - the "internal" ones, which matches the raw syscall interface at the * kernel level, which may sometimes slightly differ from the documented * libc-level ones. For example most of them return either a valid value * or -errno. All of these are prefixed with "sys_". They may be called * by non-portable applications if desired. * * - the "exported" ones, whose interface must closely match the one * documented in man(2), that applications are supposed to expect. These * ones rely on the internal ones, and set errno. * * Each syscall will be defined with the two functions, sorted in alphabetical * order applied to the exported names. * * In case of doubt about the relevance of a function here, only those which * set errno should be defined here. Wrappers like those appearing in man(3) * should not be placed here. */ /* * int brk(void *addr); * void *sbrk(intptr_t inc) */ static __attribute__((unused)) void *sys_brk(void *addr) { return (void *)my_syscall1(__NR_brk, addr); } static __attribute__((unused)) int brk(void *addr) { void *ret = sys_brk(addr); if (!ret) { SET_ERRNO(ENOMEM); return -1; } return 0; } 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; } /* * int chdir(const char *path); */ static __attribute__((unused)) int sys_chdir(const char *path) { return my_syscall1(__NR_chdir, path); } static __attribute__((unused)) int chdir(const char *path) { int ret = sys_chdir(path); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int chmod(const char *path, mode_t mode); */ 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); #elif defined(__NR_chmod) return my_syscall2(__NR_chmod, path, mode); #else #error Neither __NR_fchmodat nor __NR_chmod defined, cannot implement sys_chmod() #endif } 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; } /* * int chown(const char *path, uid_t owner, gid_t group); */ 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); #elif defined(__NR_chown) return my_syscall3(__NR_chown, path, owner, group); #else #error Neither __NR_fchownat nor __NR_chown defined, cannot implement sys_chown() #endif } 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; } /* * int chroot(const char *path); */ static __attribute__((unused)) int sys_chroot(const char *path) { return my_syscall1(__NR_chroot, path); } static __attribute__((unused)) int chroot(const char *path) { int ret = sys_chroot(path); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int close(int fd); */ static __attribute__((unused)) int sys_close(int fd) { return my_syscall1(__NR_close, fd); } static __attribute__((unused)) int close(int fd) { int ret = sys_close(fd); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int dup(int fd); */ static __attribute__((unused)) int sys_dup(int fd) { return my_syscall1(__NR_dup, fd); } static __attribute__((unused)) int dup(int fd) { int ret = sys_dup(fd); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int dup2(int old, int new); */ static __attribute__((unused)) int sys_dup2(int old, int new) { #ifdef __NR_dup3 return my_syscall3(__NR_dup3, old, new, 0); #elif defined(__NR_dup2) return my_syscall2(__NR_dup2, old, new); #else #error Neither __NR_dup3 nor __NR_dup2 defined, cannot implement sys_dup2() #endif } 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; } /* * int dup3(int old, int new, int flags); */ #ifdef __NR_dup3 static __attribute__((unused)) int sys_dup3(int old, int new, int flags) { return my_syscall3(__NR_dup3, old, new, flags); } static __attribute__((unused)) int dup3(int old, int new, int flags) { int ret = sys_dup3(old, new, flags); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } #endif /* * int execve(const char *filename, char *const argv[], char *const envp[]); */ 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)) 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; } /* * void exit(int status); */ static __attribute__((noreturn,unused)) void sys_exit(int status) { my_syscall1(__NR_exit, status & 255); while(1); // shut the "noreturn" warnings. } static __attribute__((noreturn,unused)) void exit(int status) { sys_exit(status); } /* * pid_t fork(void); */ static __attribute__((unused)) pid_t sys_fork(void) { #ifdef __NR_clone /* note: some archs only have clone() and not fork(). Different archs * have a different API, but most archs have the flags on first arg and * will not use the rest with no other flag. */ return my_syscall5(__NR_clone, SIGCHLD, 0, 0, 0, 0); #elif defined(__NR_fork) return my_syscall0(__NR_fork); #else #error Neither __NR_clone nor __NR_fork defined, cannot implement sys_fork() #endif } static __attribute__((unused)) pid_t fork(void) { pid_t ret = sys_fork(); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int fsync(int fd); */ static __attribute__((unused)) int sys_fsync(int fd) { return my_syscall1(__NR_fsync, fd); } static __attribute__((unused)) int fsync(int fd) { int ret = sys_fsync(fd); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int getdents64(int fd, struct linux_dirent64 *dirp, int count); */ 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)) 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; } /* * pid_t getpgid(pid_t pid); */ static __attribute__((unused)) pid_t sys_getpgid(pid_t pid) { return my_syscall1(__NR_getpgid, pid); } static __attribute__((unused)) pid_t getpgid(pid_t pid) { pid_t ret = sys_getpgid(pid); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * pid_t getpgrp(void); */ static __attribute__((unused)) pid_t sys_getpgrp(void) { return sys_getpgid(0); } static __attribute__((unused)) pid_t getpgrp(void) { return sys_getpgrp(); } /* * pid_t getpid(void); */ static __attribute__((unused)) pid_t sys_getpid(void) { return my_syscall0(__NR_getpid); } static __attribute__((unused)) pid_t getpid(void) { return sys_getpid(); } /* * pid_t getppid(void); */ static __attribute__((unused)) pid_t sys_getppid(void) { return my_syscall0(__NR_getppid); } static __attribute__((unused)) pid_t getppid(void) { return sys_getppid(); } /* * pid_t gettid(void); */ static __attribute__((unused)) pid_t sys_gettid(void) { return my_syscall0(__NR_gettid); } static __attribute__((unused)) pid_t gettid(void) { return sys_gettid(); } /* * int gettimeofday(struct timeval *tv, struct timezone *tz); */ static __attribute__((unused)) int sys_gettimeofday(struct timeval *tv, struct timezone *tz) { return my_syscall2(__NR_gettimeofday, tv, tz); } 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; } /* * int ioctl(int fd, unsigned long req, void *value); */ 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 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; } /* * int kill(pid_t pid, int signal); */ static __attribute__((unused)) int sys_kill(pid_t pid, int signal) { return my_syscall2(__NR_kill, pid, signal); } 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; } /* * int link(const char *old, const char *new); */ 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); #elif defined(__NR_link) return my_syscall2(__NR_link, old, new); #else #error Neither __NR_linkat nor __NR_link defined, cannot implement sys_link() #endif } 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; } /* * off_t lseek(int fd, off_t offset, int whence); */ 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)) 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; } /* * int mkdir(const char *path, mode_t mode); */ static __attribute__((unused)) int sys_mkdir(const char *path, mode_t mode) { #ifdef __NR_mkdirat return my_syscall3(__NR_mkdirat, AT_FDCWD, path, mode); #elif defined(__NR_mkdir) return my_syscall2(__NR_mkdir, path, mode); #else #error Neither __NR_mkdirat nor __NR_mkdir defined, cannot implement sys_mkdir() #endif } 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; } /* * int mknod(const char *path, mode_t mode, dev_t dev); */ 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); #elif defined(__NR_mknod) return my_syscall3(__NR_mknod, path, mode, dev); #else #error Neither __NR_mknodat nor __NR_mknod defined, cannot implement sys_mknod() #endif } 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; } #ifndef MAP_SHARED #define MAP_SHARED 0x01 /* Share changes */ #define MAP_PRIVATE 0x02 /* Changes are private */ #define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */ #endif #ifndef MAP_FAILED #define MAP_FAILED ((void *)-1) #endif static __attribute__((unused)) void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { #ifndef my_syscall6 /* Function not implemented. */ return (void *)-ENOSYS; #else int n; #if defined(__NR_mmap2) n = __NR_mmap2; offset >>= 12; #else n = __NR_mmap; #endif return (void *)my_syscall6(n, addr, length, prot, flags, fd, offset); #endif } static __attribute__((unused)) void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { void *ret = sys_mmap(addr, length, prot, flags, fd, offset); if ((unsigned long)ret >= -4095UL) { SET_ERRNO(-(long)ret); ret = MAP_FAILED; } return ret; } static __attribute__((unused)) int sys_munmap(void *addr, size_t length) { return my_syscall2(__NR_munmap, addr, length); } static __attribute__((unused)) int munmap(void *addr, size_t length) { int ret = sys_munmap(addr, length); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int mount(const char *source, const char *target, * const char *fstype, unsigned long flags, * const void *data); */ 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 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; } /* * int open(const char *path, int flags[, mode_t mode]); */ 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); #elif defined(__NR_open) return my_syscall3(__NR_open, path, flags, mode); #else #error Neither __NR_openat nor __NR_open defined, cannot implement sys_open() #endif } static __attribute__((unused)) int open(const char *path, int flags, ...) { mode_t mode = 0; int ret; if (flags & O_CREAT) { va_list args; va_start(args, flags); mode = va_arg(args, mode_t); va_end(args); } ret = sys_open(path, flags, mode); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int pivot_root(const char *new, const char *old); */ 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 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; } /* * int poll(struct pollfd *fds, int nfds, int timeout); */ static __attribute__((unused)) int sys_poll(struct pollfd *fds, int nfds, int timeout) { #if defined(__NR_ppoll) struct timespec t; if (timeout >= 0) { t.tv_sec = timeout / 1000; t.tv_nsec = (timeout % 1000) * 1000000; } return my_syscall4(__NR_ppoll, fds, nfds, (timeout >= 0) ? &t : NULL, NULL); #elif defined(__NR_poll) return my_syscall3(__NR_poll, fds, nfds, timeout); #else #error Neither __NR_ppoll nor __NR_poll defined, cannot implement sys_poll() #endif } 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; } /* * ssize_t read(int fd, void *buf, size_t count); */ 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 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; } /* * int reboot(int cmd); * is among LINUX_REBOOT_CMD_* */ 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 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; } /* * int sched_yield(void); */ static __attribute__((unused)) int sys_sched_yield(void) { return my_syscall0(__NR_sched_yield); } static __attribute__((unused)) int sched_yield(void) { int ret = sys_sched_yield(); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int select(int nfds, fd_set *read_fds, fd_set *write_fds, * fd_set *except_fds, struct timeval *timeout); */ static __attribute__((unused)) int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout) { #if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect) struct sel_arg_struct { unsigned long n; fd_set *r, *w, *e; struct timeval *t; } arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout }; return my_syscall1(__NR_select, &arg); #elif defined(__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); #elif defined(__NR__newselect) || defined(__NR_select) #ifndef __NR__newselect #define __NR__newselect __NR_select #endif return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout); #else #error None of __NR_select, __NR_pselect6, nor __NR__newselect defined, cannot implement sys_select() #endif } 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; } /* * int setpgid(pid_t pid, pid_t pgid); */ static __attribute__((unused)) int sys_setpgid(pid_t pid, pid_t pgid) { return my_syscall2(__NR_setpgid, pid, pgid); } 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; } /* * pid_t setsid(void); */ static __attribute__((unused)) pid_t sys_setsid(void) { return my_syscall0(__NR_setsid); } static __attribute__((unused)) pid_t setsid(void) { pid_t ret = sys_setsid(); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int stat(const char *path, struct stat *buf); * Warning: the struct stat's layout is arch-dependent. */ 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); #elif defined(__NR_stat) ret = my_syscall2(__NR_stat, path, &stat); #else #error Neither __NR_newfstatat nor __NR_stat defined, cannot implement sys_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 stat(const char *path, struct stat *buf) { int ret = sys_stat(path, buf); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * int symlink(const char *old, const char *new); */ static __attribute__((unused)) int sys_symlink(const char *old, const char *new) { #ifdef __NR_symlinkat return my_syscall3(__NR_symlinkat, old, AT_FDCWD, new); #elif defined(__NR_symlink) return my_syscall2(__NR_symlink, old, new); #else #error Neither __NR_symlinkat nor __NR_symlink defined, cannot implement sys_symlink() #endif } 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; } /* * mode_t umask(mode_t mode); */ static __attribute__((unused)) mode_t sys_umask(mode_t mode) { return my_syscall1(__NR_umask, mode); } static __attribute__((unused)) mode_t umask(mode_t mode) { return sys_umask(mode); } /* * int umount2(const char *path, int flags); */ static __attribute__((unused)) int sys_umount2(const char *path, int flags) { return my_syscall2(__NR_umount2, path, flags); } 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; } /* * int unlink(const char *path); */ static __attribute__((unused)) int sys_unlink(const char *path) { #ifdef __NR_unlinkat return my_syscall3(__NR_unlinkat, AT_FDCWD, path, 0); #elif defined(__NR_unlink) return my_syscall1(__NR_unlink, path); #else #error Neither __NR_unlinkat nor __NR_unlink defined, cannot implement sys_unlink() #endif } static __attribute__((unused)) int unlink(const char *path) { int ret = sys_unlink(path); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * pid_t wait(int *status); * pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage); * pid_t waitpid(pid_t pid, int *status, int options); */ 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 wait(int *status) { pid_t ret = sys_wait4(-1, status, 0, NULL); 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_wait4(pid, status, options, NULL); if (ret < 0) { SET_ERRNO(-ret); ret = -1; } return ret; } /* * ssize_t write(int fd, const void *buf, size_t count); */ static __attribute__((unused)) ssize_t sys_write(int fd, const void *buf, size_t count) { return my_syscall3(__NR_write, fd, buf, count); } 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; } /* make sure to include all global symbols */ #include "nolibc.h" #endif /* _NOLIBC_SYS_H */