1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2 /* nolibc.h
3 * Copyright (C) 2017-2018 Willy Tarreau <w@1wt.eu>
4 */
5
6 /*
7 * This file is designed to be used as a libc alternative for minimal programs
8 * with very limited requirements. It consists of a small number of syscall and
9 * type definitions, and the minimal startup code needed to call main().
10 * All syscalls are declared as static functions so that they can be optimized
11 * away by the compiler when not used.
12 *
13 * Syscalls are split into 3 levels:
14 * - The lower level is the arch-specific syscall() definition, consisting in
15 * assembly code in compound expressions. These are called my_syscall0() to
16 * my_syscall6() depending on the number of arguments. The MIPS
17 * implementation is limited to 5 arguments. All input arguments are cast
18 * to a long stored in a register. These expressions always return the
19 * syscall's return value as a signed long value which is often either a
20 * pointer or the negated errno value.
21 *
22 * - The second level is mostly architecture-independent. It is made of
23 * static functions called sys_<name>() which rely on my_syscallN()
24 * depending on the syscall definition. These functions are responsible
25 * for exposing the appropriate types for the syscall arguments (int,
26 * pointers, etc) and for setting the appropriate return type (often int).
27 * A few of them are architecture-specific because the syscalls are not all
28 * mapped exactly the same among architectures. For example, some archs do
29 * not implement select() and need pselect6() instead, so the sys_select()
30 * function will have to abstract this.
31 *
32 * - The third level is the libc call definition. It exposes the lower raw
33 * sys_<name>() calls in a way that looks like what a libc usually does,
34 * takes care of specific input values, and of setting errno upon error.
35 * There can be minor variations compared to standard libc calls. For
36 * example the open() call always takes 3 args here.
37 *
38 * The errno variable is declared static and unused. This way it can be
39 * optimized away if not used. However this means that a program made of
40 * multiple C files may observe different errno values (one per C file). For
41 * the type of programs this project targets it usually is not a problem. The
42 * resulting program may even be reduced by defining the NOLIBC_IGNORE_ERRNO
43 * macro, in which case the errno value will never be assigned.
44 *
45 * Some stdint-like integer types are defined. These are valid on all currently
46 * supported architectures, because signs are enforced, ints are assumed to be
47 * 32 bits, longs the size of a pointer and long long 64 bits. If more
48 * architectures have to be supported, this may need to be adapted.
49 *
50 * Some macro definitions like the O_* values passed to open(), and some
51 * structures like the sys_stat struct depend on the architecture.
52 *
53 * The definitions start with the architecture-specific parts, which are picked
54 * based on what the compiler knows about the target architecture, and are
55 * completed with the generic code. Since it is the compiler which sets the
56 * target architecture, cross-compiling normally works out of the box without
57 * having to specify anything.
58 *
59 * Finally some very common libc-level functions are provided. It is the case
60 * for a few functions usually found in string.h, ctype.h, or stdlib.h. Nothing
61 * is currently provided regarding stdio emulation.
62 *
63 * The macro NOLIBC is always defined, so that it is possible for a program to
64 * check this macro to know if it is being built against and decide to disable
65 * some features or simply not to include some standard libc files.
66 *
67 * Ideally this file should be split in multiple files for easier long term
68 * maintenance, but provided as a single file as it is now, it's quite
69 * convenient to use. Maybe some variations involving a set of includes at the
70 * top could work.
71 *
72 * A simple static executable may be built this way :
73 * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \
74 * -static -include nolibc.h -lgcc -o hello hello.c
75 *
76 * A very useful calling convention table may be found here :
77 * http://man7.org/linux/man-pages/man2/syscall.2.html
78 *
79 * This doc is quite convenient though not necessarily up to date :
80 * https://w3challs.com/syscalls/
81 *
82 */
83
84 /* Some archs (at least aarch64) don't expose the regular syscalls anymore by
85 * default, either because they have an "_at" replacement, or because there are
86 * more modern alternatives. For now we'd rather still use them.
87 */
88 #define __ARCH_WANT_SYSCALL_NO_AT
89 #define __ARCH_WANT_SYSCALL_NO_FLAGS
90 #define __ARCH_WANT_SYSCALL_DEPRECATED
91
92 #include <asm/unistd.h>
93 #include <asm/ioctls.h>
94 #include <asm/errno.h>
95 #include <linux/fs.h>
96 #include <linux/loop.h>
97
98 #define NOLIBC
99
100 /* this way it will be removed if unused */
101 static int errno;
102
103 #ifndef NOLIBC_IGNORE_ERRNO
104 #define SET_ERRNO(v) do { errno = (v); } while (0)
105 #else
106 #define SET_ERRNO(v) do { } while (0)
107 #endif
108
109 /* errno codes all ensure that they will not conflict with a valid pointer
110 * because they all correspond to the highest addressable memry page.
111 */
112 #define MAX_ERRNO 4095
113
114 /* Declare a few quite common macros and types that usually are in stdlib.h,
115 * stdint.h, ctype.h, unistd.h and a few other common locations.
116 */
117
118 #define NULL ((void *)0)
119
120 /* stdint types */
121 typedef unsigned char uint8_t;
122 typedef signed char int8_t;
123 typedef unsigned short uint16_t;
124 typedef signed short int16_t;
125 typedef unsigned int uint32_t;
126 typedef signed int int32_t;
127 typedef unsigned long long uint64_t;
128 typedef signed long long int64_t;
129 typedef unsigned long size_t;
130 typedef signed long ssize_t;
131 typedef unsigned long uintptr_t;
132 typedef signed long intptr_t;
133 typedef signed long ptrdiff_t;
134
135 /* for stat() */
136 typedef unsigned int dev_t;
137 typedef unsigned long ino_t;
138 typedef unsigned int mode_t;
139 typedef signed int pid_t;
140 typedef unsigned int uid_t;
141 typedef unsigned int gid_t;
142 typedef unsigned long nlink_t;
143 typedef signed long off_t;
144 typedef signed long blksize_t;
145 typedef signed long blkcnt_t;
146 typedef signed long time_t;
147
148 /* for poll() */
149 struct pollfd {
150 int fd;
151 short int events;
152 short int revents;
153 };
154
155 /* for select() */
156 struct timeval {
157 long tv_sec;
158 long tv_usec;
159 };
160
161 /* for pselect() */
162 struct timespec {
163 long tv_sec;
164 long tv_nsec;
165 };
166
167 /* for gettimeofday() */
168 struct timezone {
169 int tz_minuteswest;
170 int tz_dsttime;
171 };
172
173 /* for getdents64() */
174 struct linux_dirent64 {
175 uint64_t d_ino;
176 int64_t d_off;
177 unsigned short d_reclen;
178 unsigned char d_type;
179 char d_name[];
180 };
181
182 /* commonly an fd_set represents 256 FDs */
183 #define FD_SETSIZE 256
184 typedef struct { uint32_t fd32[FD_SETSIZE/32]; } fd_set;
185
186 /* needed by wait4() */
187 struct rusage {
188 struct timeval ru_utime;
189 struct timeval ru_stime;
190 long ru_maxrss;
191 long ru_ixrss;
192 long ru_idrss;
193 long ru_isrss;
194 long ru_minflt;
195 long ru_majflt;
196 long ru_nswap;
197 long ru_inblock;
198 long ru_oublock;
199 long ru_msgsnd;
200 long ru_msgrcv;
201 long ru_nsignals;
202 long ru_nvcsw;
203 long ru_nivcsw;
204 };
205
206 /* stat flags (WARNING, octal here) */
207 #define S_IFDIR 0040000
208 #define S_IFCHR 0020000
209 #define S_IFBLK 0060000
210 #define S_IFREG 0100000
211 #define S_IFIFO 0010000
212 #define S_IFLNK 0120000
213 #define S_IFSOCK 0140000
214 #define S_IFMT 0170000
215
216 #define S_ISDIR(mode) (((mode) & S_IFDIR) == S_IFDIR)
217 #define S_ISCHR(mode) (((mode) & S_IFCHR) == S_IFCHR)
218 #define S_ISBLK(mode) (((mode) & S_IFBLK) == S_IFBLK)
219 #define S_ISREG(mode) (((mode) & S_IFREG) == S_IFREG)
220 #define S_ISFIFO(mode) (((mode) & S_IFIFO) == S_IFIFO)
221 #define S_ISLNK(mode) (((mode) & S_IFLNK) == S_IFLNK)
222 #define S_ISSOCK(mode) (((mode) & S_IFSOCK) == S_IFSOCK)
223
224 #define DT_UNKNOWN 0
225 #define DT_FIFO 1
226 #define DT_CHR 2
227 #define DT_DIR 4
228 #define DT_BLK 6
229 #define DT_REG 8
230 #define DT_LNK 10
231 #define DT_SOCK 12
232
233 /* all the *at functions */
234 #ifndef AT_FDWCD
235 #define AT_FDCWD -100
236 #endif
237
238 /* lseek */
239 #define SEEK_SET 0
240 #define SEEK_CUR 1
241 #define SEEK_END 2
242
243 /* reboot */
244 #define LINUX_REBOOT_MAGIC1 0xfee1dead
245 #define LINUX_REBOOT_MAGIC2 0x28121969
246 #define LINUX_REBOOT_CMD_HALT 0xcdef0123
247 #define LINUX_REBOOT_CMD_POWER_OFF 0x4321fedc
248 #define LINUX_REBOOT_CMD_RESTART 0x01234567
249 #define LINUX_REBOOT_CMD_SW_SUSPEND 0xd000fce2
250
251
252 /* The format of the struct as returned by the libc to the application, which
253 * significantly differs from the format returned by the stat() syscall flavours.
254 */
255 struct stat {
256 dev_t st_dev; /* ID of device containing file */
257 ino_t st_ino; /* inode number */
258 mode_t st_mode; /* protection */
259 nlink_t st_nlink; /* number of hard links */
260 uid_t st_uid; /* user ID of owner */
261 gid_t st_gid; /* group ID of owner */
262 dev_t st_rdev; /* device ID (if special file) */
263 off_t st_size; /* total size, in bytes */
264 blksize_t st_blksize; /* blocksize for file system I/O */
265 blkcnt_t st_blocks; /* number of 512B blocks allocated */
266 time_t st_atime; /* time of last access */
267 time_t st_mtime; /* time of last modification */
268 time_t st_ctime; /* time of last status change */
269 };
270
271 #define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
272 #define WIFEXITED(status) (((status) & 0x7f) == 0)
273
274
275 /* Below comes the architecture-specific code. For each architecture, we have
276 * the syscall declarations and the _start code definition. This is the only
277 * global part. On all architectures the kernel puts everything in the stack
278 * before jumping to _start just above us, without any return address (_start
279 * is not a function but an entry pint). So at the stack pointer we find argc.
280 * Then argv[] begins, and ends at the first NULL. Then we have envp which
281 * starts and ends with a NULL as well. So envp=argv+argc+1.
282 */
283
284 #if defined(__x86_64__)
285 /* Syscalls for x86_64 :
286 * - registers are 64-bit
287 * - syscall number is passed in rax
288 * - arguments are in rdi, rsi, rdx, r10, r8, r9 respectively
289 * - the system call is performed by calling the syscall instruction
290 * - syscall return comes in rax
291 * - rcx and r8..r11 may be clobbered, others are preserved.
292 * - the arguments are cast to long and assigned into the target registers
293 * which are then simply passed as registers to the asm code, so that we
294 * don't have to experience issues with register constraints.
295 * - the syscall number is always specified last in order to allow to force
296 * some registers before (gcc refuses a %-register at the last position).
297 */
298
299 #define my_syscall0(num) \
300 ({ \
301 long _ret; \
302 register long _num asm("rax") = (num); \
303 \
304 asm volatile ( \
305 "syscall\n" \
306 : "=a" (_ret) \
307 : "0"(_num) \
308 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
309 ); \
310 _ret; \
311 })
312
313 #define my_syscall1(num, arg1) \
314 ({ \
315 long _ret; \
316 register long _num asm("rax") = (num); \
317 register long _arg1 asm("rdi") = (long)(arg1); \
318 \
319 asm volatile ( \
320 "syscall\n" \
321 : "=a" (_ret) \
322 : "r"(_arg1), \
323 "0"(_num) \
324 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
325 ); \
326 _ret; \
327 })
328
329 #define my_syscall2(num, arg1, arg2) \
330 ({ \
331 long _ret; \
332 register long _num asm("rax") = (num); \
333 register long _arg1 asm("rdi") = (long)(arg1); \
334 register long _arg2 asm("rsi") = (long)(arg2); \
335 \
336 asm volatile ( \
337 "syscall\n" \
338 : "=a" (_ret) \
339 : "r"(_arg1), "r"(_arg2), \
340 "0"(_num) \
341 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
342 ); \
343 _ret; \
344 })
345
346 #define my_syscall3(num, arg1, arg2, arg3) \
347 ({ \
348 long _ret; \
349 register long _num asm("rax") = (num); \
350 register long _arg1 asm("rdi") = (long)(arg1); \
351 register long _arg2 asm("rsi") = (long)(arg2); \
352 register long _arg3 asm("rdx") = (long)(arg3); \
353 \
354 asm volatile ( \
355 "syscall\n" \
356 : "=a" (_ret) \
357 : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
358 "0"(_num) \
359 : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \
360 ); \
361 _ret; \
362 })
363
364 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
365 ({ \
366 long _ret; \
367 register long _num asm("rax") = (num); \
368 register long _arg1 asm("rdi") = (long)(arg1); \
369 register long _arg2 asm("rsi") = (long)(arg2); \
370 register long _arg3 asm("rdx") = (long)(arg3); \
371 register long _arg4 asm("r10") = (long)(arg4); \
372 \
373 asm volatile ( \
374 "syscall\n" \
375 : "=a" (_ret), "=r"(_arg4) \
376 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
377 "0"(_num) \
378 : "rcx", "r8", "r9", "r11", "memory", "cc" \
379 ); \
380 _ret; \
381 })
382
383 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
384 ({ \
385 long _ret; \
386 register long _num asm("rax") = (num); \
387 register long _arg1 asm("rdi") = (long)(arg1); \
388 register long _arg2 asm("rsi") = (long)(arg2); \
389 register long _arg3 asm("rdx") = (long)(arg3); \
390 register long _arg4 asm("r10") = (long)(arg4); \
391 register long _arg5 asm("r8") = (long)(arg5); \
392 \
393 asm volatile ( \
394 "syscall\n" \
395 : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \
396 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
397 "0"(_num) \
398 : "rcx", "r9", "r11", "memory", "cc" \
399 ); \
400 _ret; \
401 })
402
403 #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
404 ({ \
405 long _ret; \
406 register long _num asm("rax") = (num); \
407 register long _arg1 asm("rdi") = (long)(arg1); \
408 register long _arg2 asm("rsi") = (long)(arg2); \
409 register long _arg3 asm("rdx") = (long)(arg3); \
410 register long _arg4 asm("r10") = (long)(arg4); \
411 register long _arg5 asm("r8") = (long)(arg5); \
412 register long _arg6 asm("r9") = (long)(arg6); \
413 \
414 asm volatile ( \
415 "syscall\n" \
416 : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \
417 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
418 "r"(_arg6), "0"(_num) \
419 : "rcx", "r11", "memory", "cc" \
420 ); \
421 _ret; \
422 })
423
424 /* startup code */
425 asm(".section .text\n"
426 ".global _start\n"
427 "_start:\n"
428 "pop %rdi\n" // argc (first arg, %rdi)
429 "mov %rsp, %rsi\n" // argv[] (second arg, %rsi)
430 "lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx)
431 "and $-16, %rsp\n" // x86 ABI : esp must be 16-byte aligned when
432 "sub $8, %rsp\n" // entering the callee
433 "call main\n" // main() returns the status code, we'll exit with it.
434 "movzb %al, %rdi\n" // retrieve exit code from 8 lower bits
435 "mov $60, %rax\n" // NR_exit == 60
436 "syscall\n" // really exit
437 "hlt\n" // ensure it does not return
438 "");
439
440 /* fcntl / open */
441 #define O_RDONLY 0
442 #define O_WRONLY 1
443 #define O_RDWR 2
444 #define O_CREAT 0x40
445 #define O_EXCL 0x80
446 #define O_NOCTTY 0x100
447 #define O_TRUNC 0x200
448 #define O_APPEND 0x400
449 #define O_NONBLOCK 0x800
450 #define O_DIRECTORY 0x10000
451
452 /* The struct returned by the stat() syscall, equivalent to stat64(). The
453 * syscall returns 116 bytes and stops in the middle of __unused.
454 */
455 struct sys_stat_struct {
456 unsigned long st_dev;
457 unsigned long st_ino;
458 unsigned long st_nlink;
459 unsigned int st_mode;
460 unsigned int st_uid;
461
462 unsigned int st_gid;
463 unsigned int __pad0;
464 unsigned long st_rdev;
465 long st_size;
466 long st_blksize;
467
468 long st_blocks;
469 unsigned long st_atime;
470 unsigned long st_atime_nsec;
471 unsigned long st_mtime;
472
473 unsigned long st_mtime_nsec;
474 unsigned long st_ctime;
475 unsigned long st_ctime_nsec;
476 long __unused[3];
477 };
478
479 #elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
480 /* Syscalls for i386 :
481 * - mostly similar to x86_64
482 * - registers are 32-bit
483 * - syscall number is passed in eax
484 * - arguments are in ebx, ecx, edx, esi, edi, ebp respectively
485 * - all registers are preserved (except eax of course)
486 * - the system call is performed by calling int $0x80
487 * - syscall return comes in eax
488 * - the arguments are cast to long and assigned into the target registers
489 * which are then simply passed as registers to the asm code, so that we
490 * don't have to experience issues with register constraints.
491 * - the syscall number is always specified last in order to allow to force
492 * some registers before (gcc refuses a %-register at the last position).
493 *
494 * Also, i386 supports the old_select syscall if newselect is not available
495 */
496 #define __ARCH_WANT_SYS_OLD_SELECT
497
498 #define my_syscall0(num) \
499 ({ \
500 long _ret; \
501 register long _num asm("eax") = (num); \
502 \
503 asm volatile ( \
504 "int $0x80\n" \
505 : "=a" (_ret) \
506 : "0"(_num) \
507 : "memory", "cc" \
508 ); \
509 _ret; \
510 })
511
512 #define my_syscall1(num, arg1) \
513 ({ \
514 long _ret; \
515 register long _num asm("eax") = (num); \
516 register long _arg1 asm("ebx") = (long)(arg1); \
517 \
518 asm volatile ( \
519 "int $0x80\n" \
520 : "=a" (_ret) \
521 : "r"(_arg1), \
522 "0"(_num) \
523 : "memory", "cc" \
524 ); \
525 _ret; \
526 })
527
528 #define my_syscall2(num, arg1, arg2) \
529 ({ \
530 long _ret; \
531 register long _num asm("eax") = (num); \
532 register long _arg1 asm("ebx") = (long)(arg1); \
533 register long _arg2 asm("ecx") = (long)(arg2); \
534 \
535 asm volatile ( \
536 "int $0x80\n" \
537 : "=a" (_ret) \
538 : "r"(_arg1), "r"(_arg2), \
539 "0"(_num) \
540 : "memory", "cc" \
541 ); \
542 _ret; \
543 })
544
545 #define my_syscall3(num, arg1, arg2, arg3) \
546 ({ \
547 long _ret; \
548 register long _num asm("eax") = (num); \
549 register long _arg1 asm("ebx") = (long)(arg1); \
550 register long _arg2 asm("ecx") = (long)(arg2); \
551 register long _arg3 asm("edx") = (long)(arg3); \
552 \
553 asm volatile ( \
554 "int $0x80\n" \
555 : "=a" (_ret) \
556 : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
557 "0"(_num) \
558 : "memory", "cc" \
559 ); \
560 _ret; \
561 })
562
563 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
564 ({ \
565 long _ret; \
566 register long _num asm("eax") = (num); \
567 register long _arg1 asm("ebx") = (long)(arg1); \
568 register long _arg2 asm("ecx") = (long)(arg2); \
569 register long _arg3 asm("edx") = (long)(arg3); \
570 register long _arg4 asm("esi") = (long)(arg4); \
571 \
572 asm volatile ( \
573 "int $0x80\n" \
574 : "=a" (_ret) \
575 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
576 "0"(_num) \
577 : "memory", "cc" \
578 ); \
579 _ret; \
580 })
581
582 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
583 ({ \
584 long _ret; \
585 register long _num asm("eax") = (num); \
586 register long _arg1 asm("ebx") = (long)(arg1); \
587 register long _arg2 asm("ecx") = (long)(arg2); \
588 register long _arg3 asm("edx") = (long)(arg3); \
589 register long _arg4 asm("esi") = (long)(arg4); \
590 register long _arg5 asm("edi") = (long)(arg5); \
591 \
592 asm volatile ( \
593 "int $0x80\n" \
594 : "=a" (_ret) \
595 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
596 "0"(_num) \
597 : "memory", "cc" \
598 ); \
599 _ret; \
600 })
601
602 /* startup code */
603 asm(".section .text\n"
604 ".global _start\n"
605 "_start:\n"
606 "pop %eax\n" // argc (first arg, %eax)
607 "mov %esp, %ebx\n" // argv[] (second arg, %ebx)
608 "lea 4(%ebx,%eax,4),%ecx\n" // then a NULL then envp (third arg, %ecx)
609 "and $-16, %esp\n" // x86 ABI : esp must be 16-byte aligned when
610 "push %ecx\n" // push all registers on the stack so that we
611 "push %ebx\n" // support both regparm and plain stack modes
612 "push %eax\n"
613 "call main\n" // main() returns the status code in %eax
614 "movzbl %al, %ebx\n" // retrieve exit code from lower 8 bits
615 "movl $1, %eax\n" // NR_exit == 1
616 "int $0x80\n" // exit now
617 "hlt\n" // ensure it does not
618 "");
619
620 /* fcntl / open */
621 #define O_RDONLY 0
622 #define O_WRONLY 1
623 #define O_RDWR 2
624 #define O_CREAT 0x40
625 #define O_EXCL 0x80
626 #define O_NOCTTY 0x100
627 #define O_TRUNC 0x200
628 #define O_APPEND 0x400
629 #define O_NONBLOCK 0x800
630 #define O_DIRECTORY 0x10000
631
632 /* The struct returned by the stat() syscall, 32-bit only, the syscall returns
633 * exactly 56 bytes (stops before the unused array).
634 */
635 struct sys_stat_struct {
636 unsigned long st_dev;
637 unsigned long st_ino;
638 unsigned short st_mode;
639 unsigned short st_nlink;
640 unsigned short st_uid;
641 unsigned short st_gid;
642
643 unsigned long st_rdev;
644 unsigned long st_size;
645 unsigned long st_blksize;
646 unsigned long st_blocks;
647
648 unsigned long st_atime;
649 unsigned long st_atime_nsec;
650 unsigned long st_mtime;
651 unsigned long st_mtime_nsec;
652
653 unsigned long st_ctime;
654 unsigned long st_ctime_nsec;
655 unsigned long __unused[2];
656 };
657
658 #elif defined(__ARM_EABI__)
659 /* Syscalls for ARM in ARM or Thumb modes :
660 * - registers are 32-bit
661 * - stack is 8-byte aligned
662 * ( http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka4127.html)
663 * - syscall number is passed in r7
664 * - arguments are in r0, r1, r2, r3, r4, r5
665 * - the system call is performed by calling svc #0
666 * - syscall return comes in r0.
667 * - only lr is clobbered.
668 * - the arguments are cast to long and assigned into the target registers
669 * which are then simply passed as registers to the asm code, so that we
670 * don't have to experience issues with register constraints.
671 * - the syscall number is always specified last in order to allow to force
672 * some registers before (gcc refuses a %-register at the last position).
673 *
674 * Also, ARM supports the old_select syscall if newselect is not available
675 */
676 #define __ARCH_WANT_SYS_OLD_SELECT
677
678 #define my_syscall0(num) \
679 ({ \
680 register long _num asm("r7") = (num); \
681 register long _arg1 asm("r0"); \
682 \
683 asm volatile ( \
684 "svc #0\n" \
685 : "=r"(_arg1) \
686 : "r"(_num) \
687 : "memory", "cc", "lr" \
688 ); \
689 _arg1; \
690 })
691
692 #define my_syscall1(num, arg1) \
693 ({ \
694 register long _num asm("r7") = (num); \
695 register long _arg1 asm("r0") = (long)(arg1); \
696 \
697 asm volatile ( \
698 "svc #0\n" \
699 : "=r"(_arg1) \
700 : "r"(_arg1), \
701 "r"(_num) \
702 : "memory", "cc", "lr" \
703 ); \
704 _arg1; \
705 })
706
707 #define my_syscall2(num, arg1, arg2) \
708 ({ \
709 register long _num asm("r7") = (num); \
710 register long _arg1 asm("r0") = (long)(arg1); \
711 register long _arg2 asm("r1") = (long)(arg2); \
712 \
713 asm volatile ( \
714 "svc #0\n" \
715 : "=r"(_arg1) \
716 : "r"(_arg1), "r"(_arg2), \
717 "r"(_num) \
718 : "memory", "cc", "lr" \
719 ); \
720 _arg1; \
721 })
722
723 #define my_syscall3(num, arg1, arg2, arg3) \
724 ({ \
725 register long _num asm("r7") = (num); \
726 register long _arg1 asm("r0") = (long)(arg1); \
727 register long _arg2 asm("r1") = (long)(arg2); \
728 register long _arg3 asm("r2") = (long)(arg3); \
729 \
730 asm volatile ( \
731 "svc #0\n" \
732 : "=r"(_arg1) \
733 : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
734 "r"(_num) \
735 : "memory", "cc", "lr" \
736 ); \
737 _arg1; \
738 })
739
740 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
741 ({ \
742 register long _num asm("r7") = (num); \
743 register long _arg1 asm("r0") = (long)(arg1); \
744 register long _arg2 asm("r1") = (long)(arg2); \
745 register long _arg3 asm("r2") = (long)(arg3); \
746 register long _arg4 asm("r3") = (long)(arg4); \
747 \
748 asm volatile ( \
749 "svc #0\n" \
750 : "=r"(_arg1) \
751 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
752 "r"(_num) \
753 : "memory", "cc", "lr" \
754 ); \
755 _arg1; \
756 })
757
758 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
759 ({ \
760 register long _num asm("r7") = (num); \
761 register long _arg1 asm("r0") = (long)(arg1); \
762 register long _arg2 asm("r1") = (long)(arg2); \
763 register long _arg3 asm("r2") = (long)(arg3); \
764 register long _arg4 asm("r3") = (long)(arg4); \
765 register long _arg5 asm("r4") = (long)(arg5); \
766 \
767 asm volatile ( \
768 "svc #0\n" \
769 : "=r" (_arg1) \
770 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
771 "r"(_num) \
772 : "memory", "cc", "lr" \
773 ); \
774 _arg1; \
775 })
776
777 /* startup code */
778 asm(".section .text\n"
779 ".global _start\n"
780 "_start:\n"
781 #if defined(__THUMBEB__) || defined(__THUMBEL__)
782 /* We enter here in 32-bit mode but if some previous functions were in
783 * 16-bit mode, the assembler cannot know, so we need to tell it we're in
784 * 32-bit now, then switch to 16-bit (is there a better way to do it than
785 * adding 1 by hand ?) and tell the asm we're now in 16-bit mode so that
786 * it generates correct instructions. Note that we do not support thumb1.
787 */
788 ".code 32\n"
789 "add r0, pc, #1\n"
790 "bx r0\n"
791 ".code 16\n"
792 #endif
793 "pop {%r0}\n" // argc was in the stack
794 "mov %r1, %sp\n" // argv = sp
795 "add %r2, %r1, %r0, lsl #2\n" // envp = argv + 4*argc ...
796 "add %r2, %r2, $4\n" // ... + 4
797 "and %r3, %r1, $-8\n" // AAPCS : sp must be 8-byte aligned in the
798 "mov %sp, %r3\n" // callee, an bl doesn't push (lr=pc)
799 "bl main\n" // main() returns the status code, we'll exit with it.
800 "and %r0, %r0, $0xff\n" // limit exit code to 8 bits
801 "movs r7, $1\n" // NR_exit == 1
802 "svc $0x00\n"
803 "");
804
805 /* fcntl / open */
806 #define O_RDONLY 0
807 #define O_WRONLY 1
808 #define O_RDWR 2
809 #define O_CREAT 0x40
810 #define O_EXCL 0x80
811 #define O_NOCTTY 0x100
812 #define O_TRUNC 0x200
813 #define O_APPEND 0x400
814 #define O_NONBLOCK 0x800
815 #define O_DIRECTORY 0x4000
816
817 /* The struct returned by the stat() syscall, 32-bit only, the syscall returns
818 * exactly 56 bytes (stops before the unused array). In big endian, the format
819 * differs as devices are returned as short only.
820 */
821 struct sys_stat_struct {
822 #if defined(__ARMEB__)
823 unsigned short st_dev;
824 unsigned short __pad1;
825 #else
826 unsigned long st_dev;
827 #endif
828 unsigned long st_ino;
829 unsigned short st_mode;
830 unsigned short st_nlink;
831 unsigned short st_uid;
832 unsigned short st_gid;
833 #if defined(__ARMEB__)
834 unsigned short st_rdev;
835 unsigned short __pad2;
836 #else
837 unsigned long st_rdev;
838 #endif
839 unsigned long st_size;
840 unsigned long st_blksize;
841 unsigned long st_blocks;
842 unsigned long st_atime;
843 unsigned long st_atime_nsec;
844 unsigned long st_mtime;
845 unsigned long st_mtime_nsec;
846 unsigned long st_ctime;
847 unsigned long st_ctime_nsec;
848 unsigned long __unused[2];
849 };
850
851 #elif defined(__aarch64__)
852 /* Syscalls for AARCH64 :
853 * - registers are 64-bit
854 * - stack is 16-byte aligned
855 * - syscall number is passed in x8
856 * - arguments are in x0, x1, x2, x3, x4, x5
857 * - the system call is performed by calling svc 0
858 * - syscall return comes in x0.
859 * - the arguments are cast to long and assigned into the target registers
860 * which are then simply passed as registers to the asm code, so that we
861 * don't have to experience issues with register constraints.
862 *
863 * On aarch64, select() is not implemented so we have to use pselect6().
864 */
865 #define __ARCH_WANT_SYS_PSELECT6
866
867 #define my_syscall0(num) \
868 ({ \
869 register long _num asm("x8") = (num); \
870 register long _arg1 asm("x0"); \
871 \
872 asm volatile ( \
873 "svc #0\n" \
874 : "=r"(_arg1) \
875 : "r"(_num) \
876 : "memory", "cc" \
877 ); \
878 _arg1; \
879 })
880
881 #define my_syscall1(num, arg1) \
882 ({ \
883 register long _num asm("x8") = (num); \
884 register long _arg1 asm("x0") = (long)(arg1); \
885 \
886 asm volatile ( \
887 "svc #0\n" \
888 : "=r"(_arg1) \
889 : "r"(_arg1), \
890 "r"(_num) \
891 : "memory", "cc" \
892 ); \
893 _arg1; \
894 })
895
896 #define my_syscall2(num, arg1, arg2) \
897 ({ \
898 register long _num asm("x8") = (num); \
899 register long _arg1 asm("x0") = (long)(arg1); \
900 register long _arg2 asm("x1") = (long)(arg2); \
901 \
902 asm volatile ( \
903 "svc #0\n" \
904 : "=r"(_arg1) \
905 : "r"(_arg1), "r"(_arg2), \
906 "r"(_num) \
907 : "memory", "cc" \
908 ); \
909 _arg1; \
910 })
911
912 #define my_syscall3(num, arg1, arg2, arg3) \
913 ({ \
914 register long _num asm("x8") = (num); \
915 register long _arg1 asm("x0") = (long)(arg1); \
916 register long _arg2 asm("x1") = (long)(arg2); \
917 register long _arg3 asm("x2") = (long)(arg3); \
918 \
919 asm volatile ( \
920 "svc #0\n" \
921 : "=r"(_arg1) \
922 : "r"(_arg1), "r"(_arg2), "r"(_arg3), \
923 "r"(_num) \
924 : "memory", "cc" \
925 ); \
926 _arg1; \
927 })
928
929 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
930 ({ \
931 register long _num asm("x8") = (num); \
932 register long _arg1 asm("x0") = (long)(arg1); \
933 register long _arg2 asm("x1") = (long)(arg2); \
934 register long _arg3 asm("x2") = (long)(arg3); \
935 register long _arg4 asm("x3") = (long)(arg4); \
936 \
937 asm volatile ( \
938 "svc #0\n" \
939 : "=r"(_arg1) \
940 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
941 "r"(_num) \
942 : "memory", "cc" \
943 ); \
944 _arg1; \
945 })
946
947 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
948 ({ \
949 register long _num asm("x8") = (num); \
950 register long _arg1 asm("x0") = (long)(arg1); \
951 register long _arg2 asm("x1") = (long)(arg2); \
952 register long _arg3 asm("x2") = (long)(arg3); \
953 register long _arg4 asm("x3") = (long)(arg4); \
954 register long _arg5 asm("x4") = (long)(arg5); \
955 \
956 asm volatile ( \
957 "svc #0\n" \
958 : "=r" (_arg1) \
959 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
960 "r"(_num) \
961 : "memory", "cc" \
962 ); \
963 _arg1; \
964 })
965
966 #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
967 ({ \
968 register long _num asm("x8") = (num); \
969 register long _arg1 asm("x0") = (long)(arg1); \
970 register long _arg2 asm("x1") = (long)(arg2); \
971 register long _arg3 asm("x2") = (long)(arg3); \
972 register long _arg4 asm("x3") = (long)(arg4); \
973 register long _arg5 asm("x4") = (long)(arg5); \
974 register long _arg6 asm("x5") = (long)(arg6); \
975 \
976 asm volatile ( \
977 "svc #0\n" \
978 : "=r" (_arg1) \
979 : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
980 "r"(_arg6), "r"(_num) \
981 : "memory", "cc" \
982 ); \
983 _arg1; \
984 })
985
986 /* startup code */
987 asm(".section .text\n"
988 ".global _start\n"
989 "_start:\n"
990 "ldr x0, [sp]\n" // argc (x0) was in the stack
991 "add x1, sp, 8\n" // argv (x1) = sp
992 "lsl x2, x0, 3\n" // envp (x2) = 8*argc ...
993 "add x2, x2, 8\n" // + 8 (skip null)
994 "add x2, x2, x1\n" // + argv
995 "and sp, x1, -16\n" // sp must be 16-byte aligned in the callee
996 "bl main\n" // main() returns the status code, we'll exit with it.
997 "and x0, x0, 0xff\n" // limit exit code to 8 bits
998 "mov x8, 93\n" // NR_exit == 93
999 "svc #0\n"
1000 "");
1001
1002 /* fcntl / open */
1003 #define O_RDONLY 0
1004 #define O_WRONLY 1
1005 #define O_RDWR 2
1006 #define O_CREAT 0x40
1007 #define O_EXCL 0x80
1008 #define O_NOCTTY 0x100
1009 #define O_TRUNC 0x200
1010 #define O_APPEND 0x400
1011 #define O_NONBLOCK 0x800
1012 #define O_DIRECTORY 0x4000
1013
1014 /* The struct returned by the newfstatat() syscall. Differs slightly from the
1015 * x86_64's stat one by field ordering, so be careful.
1016 */
1017 struct sys_stat_struct {
1018 unsigned long st_dev;
1019 unsigned long st_ino;
1020 unsigned int st_mode;
1021 unsigned int st_nlink;
1022 unsigned int st_uid;
1023 unsigned int st_gid;
1024
1025 unsigned long st_rdev;
1026 unsigned long __pad1;
1027 long st_size;
1028 int st_blksize;
1029 int __pad2;
1030
1031 long st_blocks;
1032 long st_atime;
1033 unsigned long st_atime_nsec;
1034 long st_mtime;
1035
1036 unsigned long st_mtime_nsec;
1037 long st_ctime;
1038 unsigned long st_ctime_nsec;
1039 unsigned int __unused[2];
1040 };
1041
1042 #elif defined(__mips__) && defined(_ABIO32)
1043 /* Syscalls for MIPS ABI O32 :
1044 * - WARNING! there's always a delayed slot!
1045 * - WARNING again, the syntax is different, registers take a '$' and numbers
1046 * do not.
1047 * - registers are 32-bit
1048 * - stack is 8-byte aligned
1049 * - syscall number is passed in v0 (starts at 0xfa0).
1050 * - arguments are in a0, a1, a2, a3, then the stack. The caller needs to
1051 * leave some room in the stack for the callee to save a0..a3 if needed.
1052 * - Many registers are clobbered, in fact only a0..a2 and s0..s8 are
1053 * preserved. See: https://www.linux-mips.org/wiki/Syscall as well as
1054 * scall32-o32.S in the kernel sources.
1055 * - the system call is performed by calling "syscall"
1056 * - syscall return comes in v0, and register a3 needs to be checked to know
1057 * if an error occured, in which case errno is in v0.
1058 * - the arguments are cast to long and assigned into the target registers
1059 * which are then simply passed as registers to the asm code, so that we
1060 * don't have to experience issues with register constraints.
1061 */
1062
1063 #define my_syscall0(num) \
1064 ({ \
1065 register long _num asm("v0") = (num); \
1066 register long _arg4 asm("a3"); \
1067 \
1068 asm volatile ( \
1069 "addiu $sp, $sp, -32\n" \
1070 "syscall\n" \
1071 "addiu $sp, $sp, 32\n" \
1072 : "=r"(_num), "=r"(_arg4) \
1073 : "r"(_num) \
1074 : "memory", "cc", "at", "v1", "hi", "lo", \
1075 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1076 ); \
1077 _arg4 ? -_num : _num; \
1078 })
1079
1080 #define my_syscall1(num, arg1) \
1081 ({ \
1082 register long _num asm("v0") = (num); \
1083 register long _arg1 asm("a0") = (long)(arg1); \
1084 register long _arg4 asm("a3"); \
1085 \
1086 asm volatile ( \
1087 "addiu $sp, $sp, -32\n" \
1088 "syscall\n" \
1089 "addiu $sp, $sp, 32\n" \
1090 : "=r"(_num), "=r"(_arg4) \
1091 : "0"(_num), \
1092 "r"(_arg1) \
1093 : "memory", "cc", "at", "v1", "hi", "lo", \
1094 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1095 ); \
1096 _arg4 ? -_num : _num; \
1097 })
1098
1099 #define my_syscall2(num, arg1, arg2) \
1100 ({ \
1101 register long _num asm("v0") = (num); \
1102 register long _arg1 asm("a0") = (long)(arg1); \
1103 register long _arg2 asm("a1") = (long)(arg2); \
1104 register long _arg4 asm("a3"); \
1105 \
1106 asm volatile ( \
1107 "addiu $sp, $sp, -32\n" \
1108 "syscall\n" \
1109 "addiu $sp, $sp, 32\n" \
1110 : "=r"(_num), "=r"(_arg4) \
1111 : "0"(_num), \
1112 "r"(_arg1), "r"(_arg2) \
1113 : "memory", "cc", "at", "v1", "hi", "lo", \
1114 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1115 ); \
1116 _arg4 ? -_num : _num; \
1117 })
1118
1119 #define my_syscall3(num, arg1, arg2, arg3) \
1120 ({ \
1121 register long _num asm("v0") = (num); \
1122 register long _arg1 asm("a0") = (long)(arg1); \
1123 register long _arg2 asm("a1") = (long)(arg2); \
1124 register long _arg3 asm("a2") = (long)(arg3); \
1125 register long _arg4 asm("a3"); \
1126 \
1127 asm volatile ( \
1128 "addiu $sp, $sp, -32\n" \
1129 "syscall\n" \
1130 "addiu $sp, $sp, 32\n" \
1131 : "=r"(_num), "=r"(_arg4) \
1132 : "0"(_num), \
1133 "r"(_arg1), "r"(_arg2), "r"(_arg3) \
1134 : "memory", "cc", "at", "v1", "hi", "lo", \
1135 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1136 ); \
1137 _arg4 ? -_num : _num; \
1138 })
1139
1140 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
1141 ({ \
1142 register long _num asm("v0") = (num); \
1143 register long _arg1 asm("a0") = (long)(arg1); \
1144 register long _arg2 asm("a1") = (long)(arg2); \
1145 register long _arg3 asm("a2") = (long)(arg3); \
1146 register long _arg4 asm("a3") = (long)(arg4); \
1147 \
1148 asm volatile ( \
1149 "addiu $sp, $sp, -32\n" \
1150 "syscall\n" \
1151 "addiu $sp, $sp, 32\n" \
1152 : "=r" (_num), "=r"(_arg4) \
1153 : "0"(_num), \
1154 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \
1155 : "memory", "cc", "at", "v1", "hi", "lo", \
1156 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1157 ); \
1158 _arg4 ? -_num : _num; \
1159 })
1160
1161 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
1162 ({ \
1163 register long _num asm("v0") = (num); \
1164 register long _arg1 asm("a0") = (long)(arg1); \
1165 register long _arg2 asm("a1") = (long)(arg2); \
1166 register long _arg3 asm("a2") = (long)(arg3); \
1167 register long _arg4 asm("a3") = (long)(arg4); \
1168 register long _arg5 = (long)(arg5); \
1169 \
1170 asm volatile ( \
1171 "addiu $sp, $sp, -32\n" \
1172 "sw %7, 16($sp)\n" \
1173 "syscall\n " \
1174 "addiu $sp, $sp, 32\n" \
1175 : "=r" (_num), "=r"(_arg4) \
1176 : "0"(_num), \
1177 "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \
1178 : "memory", "cc", "at", "v1", "hi", "lo", \
1179 "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \
1180 ); \
1181 _arg4 ? -_num : _num; \
1182 })
1183
1184 /* startup code, note that it's called __start on MIPS */
1185 asm(".section .text\n"
1186 ".set nomips16\n"
1187 ".global __start\n"
1188 ".set noreorder\n"
1189 ".option pic0\n"
1190 ".ent __start\n"
1191 "__start:\n"
1192 "lw $a0,($sp)\n" // argc was in the stack
1193 "addiu $a1, $sp, 4\n" // argv = sp + 4
1194 "sll $a2, $a0, 2\n" // a2 = argc * 4
1195 "add $a2, $a2, $a1\n" // envp = argv + 4*argc ...
1196 "addiu $a2, $a2, 4\n" // ... + 4
1197 "li $t0, -8\n"
1198 "and $sp, $sp, $t0\n" // sp must be 8-byte aligned
1199 "addiu $sp,$sp,-16\n" // the callee expects to save a0..a3 there!
1200 "jal main\n" // main() returns the status code, we'll exit with it.
1201 "nop\n" // delayed slot
1202 "and $a0, $v0, 0xff\n" // limit exit code to 8 bits
1203 "li $v0, 4001\n" // NR_exit == 4001
1204 "syscall\n"
1205 ".end __start\n"
1206 "");
1207
1208 /* fcntl / open */
1209 #define O_RDONLY 0
1210 #define O_WRONLY 1
1211 #define O_RDWR 2
1212 #define O_APPEND 0x0008
1213 #define O_NONBLOCK 0x0080
1214 #define O_CREAT 0x0100
1215 #define O_TRUNC 0x0200
1216 #define O_EXCL 0x0400
1217 #define O_NOCTTY 0x0800
1218 #define O_DIRECTORY 0x10000
1219
1220 /* The struct returned by the stat() syscall. 88 bytes are returned by the
1221 * syscall.
1222 */
1223 struct sys_stat_struct {
1224 unsigned int st_dev;
1225 long st_pad1[3];
1226 unsigned long st_ino;
1227 unsigned int st_mode;
1228 unsigned int st_nlink;
1229 unsigned int st_uid;
1230 unsigned int st_gid;
1231 unsigned int st_rdev;
1232 long st_pad2[2];
1233 long st_size;
1234 long st_pad3;
1235 long st_atime;
1236 long st_atime_nsec;
1237 long st_mtime;
1238 long st_mtime_nsec;
1239 long st_ctime;
1240 long st_ctime_nsec;
1241 long st_blksize;
1242 long st_blocks;
1243 long st_pad4[14];
1244 };
1245
1246 #elif defined(__riscv)
1247
1248 #if __riscv_xlen == 64
1249 #define PTRLOG "3"
1250 #define SZREG "8"
1251 #elif __riscv_xlen == 32
1252 #define PTRLOG "2"
1253 #define SZREG "4"
1254 #endif
1255
1256 /* Syscalls for RISCV :
1257 * - stack is 16-byte aligned
1258 * - syscall number is passed in a7
1259 * - arguments are in a0, a1, a2, a3, a4, a5
1260 * - the system call is performed by calling ecall
1261 * - syscall return comes in a0
1262 * - the arguments are cast to long and assigned into the target
1263 * registers which are then simply passed as registers to the asm code,
1264 * so that we don't have to experience issues with register constraints.
1265 */
1266
1267 #define my_syscall0(num) \
1268 ({ \
1269 register long _num asm("a7") = (num); \
1270 register long _arg1 asm("a0"); \
1271 \
1272 asm volatile ( \
1273 "ecall\n\t" \
1274 : "=r"(_arg1) \
1275 : "r"(_num) \
1276 : "memory", "cc" \
1277 ); \
1278 _arg1; \
1279 })
1280
1281 #define my_syscall1(num, arg1) \
1282 ({ \
1283 register long _num asm("a7") = (num); \
1284 register long _arg1 asm("a0") = (long)(arg1); \
1285 \
1286 asm volatile ( \
1287 "ecall\n" \
1288 : "+r"(_arg1) \
1289 : "r"(_num) \
1290 : "memory", "cc" \
1291 ); \
1292 _arg1; \
1293 })
1294
1295 #define my_syscall2(num, arg1, arg2) \
1296 ({ \
1297 register long _num asm("a7") = (num); \
1298 register long _arg1 asm("a0") = (long)(arg1); \
1299 register long _arg2 asm("a1") = (long)(arg2); \
1300 \
1301 asm volatile ( \
1302 "ecall\n" \
1303 : "+r"(_arg1) \
1304 : "r"(_arg2), \
1305 "r"(_num) \
1306 : "memory", "cc" \
1307 ); \
1308 _arg1; \
1309 })
1310
1311 #define my_syscall3(num, arg1, arg2, arg3) \
1312 ({ \
1313 register long _num asm("a7") = (num); \
1314 register long _arg1 asm("a0") = (long)(arg1); \
1315 register long _arg2 asm("a1") = (long)(arg2); \
1316 register long _arg3 asm("a2") = (long)(arg3); \
1317 \
1318 asm volatile ( \
1319 "ecall\n\t" \
1320 : "+r"(_arg1) \
1321 : "r"(_arg2), "r"(_arg3), \
1322 "r"(_num) \
1323 : "memory", "cc" \
1324 ); \
1325 _arg1; \
1326 })
1327
1328 #define my_syscall4(num, arg1, arg2, arg3, arg4) \
1329 ({ \
1330 register long _num asm("a7") = (num); \
1331 register long _arg1 asm("a0") = (long)(arg1); \
1332 register long _arg2 asm("a1") = (long)(arg2); \
1333 register long _arg3 asm("a2") = (long)(arg3); \
1334 register long _arg4 asm("a3") = (long)(arg4); \
1335 \
1336 asm volatile ( \
1337 "ecall\n" \
1338 : "+r"(_arg1) \
1339 : "r"(_arg2), "r"(_arg3), "r"(_arg4), \
1340 "r"(_num) \
1341 : "memory", "cc" \
1342 ); \
1343 _arg1; \
1344 })
1345
1346 #define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
1347 ({ \
1348 register long _num asm("a7") = (num); \
1349 register long _arg1 asm("a0") = (long)(arg1); \
1350 register long _arg2 asm("a1") = (long)(arg2); \
1351 register long _arg3 asm("a2") = (long)(arg3); \
1352 register long _arg4 asm("a3") = (long)(arg4); \
1353 register long _arg5 asm("a4") = (long)(arg5); \
1354 \
1355 asm volatile ( \
1356 "ecall\n" \
1357 : "+r"(_arg1) \
1358 : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
1359 "r"(_num) \
1360 : "memory", "cc" \
1361 ); \
1362 _arg1; \
1363 })
1364
1365 #define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
1366 ({ \
1367 register long _num asm("a7") = (num); \
1368 register long _arg1 asm("a0") = (long)(arg1); \
1369 register long _arg2 asm("a1") = (long)(arg2); \
1370 register long _arg3 asm("a2") = (long)(arg3); \
1371 register long _arg4 asm("a3") = (long)(arg4); \
1372 register long _arg5 asm("a4") = (long)(arg5); \
1373 register long _arg6 asm("a5") = (long)(arg6); \
1374 \
1375 asm volatile ( \
1376 "ecall\n" \
1377 : "+r"(_arg1) \
1378 : "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), "r"(_arg6), \
1379 "r"(_num) \
1380 : "memory", "cc" \
1381 ); \
1382 _arg1; \
1383 })
1384
1385 /* startup code */
1386 asm(".section .text\n"
1387 ".global _start\n"
1388 "_start:\n"
1389 ".option push\n"
1390 ".option norelax\n"
1391 "lla gp, __global_pointer$\n"
1392 ".option pop\n"
1393 "ld a0, 0(sp)\n" // argc (a0) was in the stack
1394 "add a1, sp, "SZREG"\n" // argv (a1) = sp
1395 "slli a2, a0, "PTRLOG"\n" // envp (a2) = SZREG*argc ...
1396 "add a2, a2, "SZREG"\n" // + SZREG (skip null)
1397 "add a2,a2,a1\n" // + argv
1398 "andi sp,a1,-16\n" // sp must be 16-byte aligned
1399 "call main\n" // main() returns the status code, we'll exit with it.
1400 "andi a0, a0, 0xff\n" // limit exit code to 8 bits
1401 "li a7, 93\n" // NR_exit == 93
1402 "ecall\n"
1403 "");
1404
1405 /* fcntl / open */
1406 #define O_RDONLY 0
1407 #define O_WRONLY 1
1408 #define O_RDWR 2
1409 #define O_CREAT 0x100
1410 #define O_EXCL 0x200
1411 #define O_NOCTTY 0x400
1412 #define O_TRUNC 0x1000
1413 #define O_APPEND 0x2000
1414 #define O_NONBLOCK 0x4000
1415 #define O_DIRECTORY 0x200000
1416
1417 struct sys_stat_struct {
1418 unsigned long st_dev; /* Device. */
1419 unsigned long st_ino; /* File serial number. */
1420 unsigned int st_mode; /* File mode. */
1421 unsigned int st_nlink; /* Link count. */
1422 unsigned int st_uid; /* User ID of the file's owner. */
1423 unsigned int st_gid; /* Group ID of the file's group. */
1424 unsigned long st_rdev; /* Device number, if device. */
1425 unsigned long __pad1;
1426 long st_size; /* Size of file, in bytes. */
1427 int st_blksize; /* Optimal block size for I/O. */
1428 int __pad2;
1429 long st_blocks; /* Number 512-byte blocks allocated. */
1430 long st_atime; /* Time of last access. */
1431 unsigned long st_atime_nsec;
1432 long st_mtime; /* Time of last modification. */
1433 unsigned long st_mtime_nsec;
1434 long st_ctime; /* Time of last status change. */
1435 unsigned long st_ctime_nsec;
1436 unsigned int __unused4;
1437 unsigned int __unused5;
1438 };
1439
1440 #endif
1441
1442
1443 /* Below are the C functions used to declare the raw syscalls. They try to be
1444 * architecture-agnostic, and return either a success or -errno. Declaring them
1445 * static will lead to them being inlined in most cases, but it's still possible
1446 * to reference them by a pointer if needed.
1447 */
1448 static __attribute__((unused))
sys_brk(void * addr)1449 void *sys_brk(void *addr)
1450 {
1451 return (void *)my_syscall1(__NR_brk, addr);
1452 }
1453
1454 static __attribute__((noreturn,unused))
sys_exit(int status)1455 void sys_exit(int status)
1456 {
1457 my_syscall1(__NR_exit, status & 255);
1458 while(1); // shut the "noreturn" warnings.
1459 }
1460
1461 static __attribute__((unused))
sys_chdir(const char * path)1462 int sys_chdir(const char *path)
1463 {
1464 return my_syscall1(__NR_chdir, path);
1465 }
1466
1467 static __attribute__((unused))
sys_chmod(const char * path,mode_t mode)1468 int sys_chmod(const char *path, mode_t mode)
1469 {
1470 #ifdef __NR_fchmodat
1471 return my_syscall4(__NR_fchmodat, AT_FDCWD, path, mode, 0);
1472 #else
1473 return my_syscall2(__NR_chmod, path, mode);
1474 #endif
1475 }
1476
1477 static __attribute__((unused))
sys_chown(const char * path,uid_t owner,gid_t group)1478 int sys_chown(const char *path, uid_t owner, gid_t group)
1479 {
1480 #ifdef __NR_fchownat
1481 return my_syscall5(__NR_fchownat, AT_FDCWD, path, owner, group, 0);
1482 #else
1483 return my_syscall3(__NR_chown, path, owner, group);
1484 #endif
1485 }
1486
1487 static __attribute__((unused))
sys_chroot(const char * path)1488 int sys_chroot(const char *path)
1489 {
1490 return my_syscall1(__NR_chroot, path);
1491 }
1492
1493 static __attribute__((unused))
sys_close(int fd)1494 int sys_close(int fd)
1495 {
1496 return my_syscall1(__NR_close, fd);
1497 }
1498
1499 static __attribute__((unused))
sys_dup(int fd)1500 int sys_dup(int fd)
1501 {
1502 return my_syscall1(__NR_dup, fd);
1503 }
1504
1505 static __attribute__((unused))
sys_dup2(int old,int new)1506 int sys_dup2(int old, int new)
1507 {
1508 return my_syscall2(__NR_dup2, old, new);
1509 }
1510
1511 static __attribute__((unused))
sys_execve(const char * filename,char * const argv[],char * const envp[])1512 int sys_execve(const char *filename, char *const argv[], char *const envp[])
1513 {
1514 return my_syscall3(__NR_execve, filename, argv, envp);
1515 }
1516
1517 static __attribute__((unused))
sys_fork(void)1518 pid_t sys_fork(void)
1519 {
1520 return my_syscall0(__NR_fork);
1521 }
1522
1523 static __attribute__((unused))
sys_fsync(int fd)1524 int sys_fsync(int fd)
1525 {
1526 return my_syscall1(__NR_fsync, fd);
1527 }
1528
1529 static __attribute__((unused))
sys_getdents64(int fd,struct linux_dirent64 * dirp,int count)1530 int sys_getdents64(int fd, struct linux_dirent64 *dirp, int count)
1531 {
1532 return my_syscall3(__NR_getdents64, fd, dirp, count);
1533 }
1534
1535 static __attribute__((unused))
sys_getpgrp(void)1536 pid_t sys_getpgrp(void)
1537 {
1538 return my_syscall0(__NR_getpgrp);
1539 }
1540
1541 static __attribute__((unused))
sys_getpid(void)1542 pid_t sys_getpid(void)
1543 {
1544 return my_syscall0(__NR_getpid);
1545 }
1546
1547 static __attribute__((unused))
sys_gettimeofday(struct timeval * tv,struct timezone * tz)1548 int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
1549 {
1550 return my_syscall2(__NR_gettimeofday, tv, tz);
1551 }
1552
1553 static __attribute__((unused))
sys_ioctl(int fd,unsigned long req,void * value)1554 int sys_ioctl(int fd, unsigned long req, void *value)
1555 {
1556 return my_syscall3(__NR_ioctl, fd, req, value);
1557 }
1558
1559 static __attribute__((unused))
sys_kill(pid_t pid,int signal)1560 int sys_kill(pid_t pid, int signal)
1561 {
1562 return my_syscall2(__NR_kill, pid, signal);
1563 }
1564
1565 static __attribute__((unused))
sys_link(const char * old,const char * new)1566 int sys_link(const char *old, const char *new)
1567 {
1568 #ifdef __NR_linkat
1569 return my_syscall5(__NR_linkat, AT_FDCWD, old, AT_FDCWD, new, 0);
1570 #else
1571 return my_syscall2(__NR_link, old, new);
1572 #endif
1573 }
1574
1575 static __attribute__((unused))
sys_lseek(int fd,off_t offset,int whence)1576 off_t sys_lseek(int fd, off_t offset, int whence)
1577 {
1578 return my_syscall3(__NR_lseek, fd, offset, whence);
1579 }
1580
1581 static __attribute__((unused))
sys_mkdir(const char * path,mode_t mode)1582 int sys_mkdir(const char *path, mode_t mode)
1583 {
1584 #ifdef __NR_mkdirat
1585 return my_syscall3(__NR_mkdirat, AT_FDCWD, path, mode);
1586 #else
1587 return my_syscall2(__NR_mkdir, path, mode);
1588 #endif
1589 }
1590
1591 static __attribute__((unused))
sys_mknod(const char * path,mode_t mode,dev_t dev)1592 long sys_mknod(const char *path, mode_t mode, dev_t dev)
1593 {
1594 #ifdef __NR_mknodat
1595 return my_syscall4(__NR_mknodat, AT_FDCWD, path, mode, dev);
1596 #else
1597 return my_syscall3(__NR_mknod, path, mode, dev);
1598 #endif
1599 }
1600
1601 static __attribute__((unused))
sys_mount(const char * src,const char * tgt,const char * fst,unsigned long flags,const void * data)1602 int sys_mount(const char *src, const char *tgt, const char *fst,
1603 unsigned long flags, const void *data)
1604 {
1605 return my_syscall5(__NR_mount, src, tgt, fst, flags, data);
1606 }
1607
1608 static __attribute__((unused))
sys_open(const char * path,int flags,mode_t mode)1609 int sys_open(const char *path, int flags, mode_t mode)
1610 {
1611 #ifdef __NR_openat
1612 return my_syscall4(__NR_openat, AT_FDCWD, path, flags, mode);
1613 #else
1614 return my_syscall3(__NR_open, path, flags, mode);
1615 #endif
1616 }
1617
1618 static __attribute__((unused))
sys_pivot_root(const char * new,const char * old)1619 int sys_pivot_root(const char *new, const char *old)
1620 {
1621 return my_syscall2(__NR_pivot_root, new, old);
1622 }
1623
1624 static __attribute__((unused))
sys_poll(struct pollfd * fds,int nfds,int timeout)1625 int sys_poll(struct pollfd *fds, int nfds, int timeout)
1626 {
1627 return my_syscall3(__NR_poll, fds, nfds, timeout);
1628 }
1629
1630 static __attribute__((unused))
sys_read(int fd,void * buf,size_t count)1631 ssize_t sys_read(int fd, void *buf, size_t count)
1632 {
1633 return my_syscall3(__NR_read, fd, buf, count);
1634 }
1635
1636 static __attribute__((unused))
sys_reboot(int magic1,int magic2,int cmd,void * arg)1637 ssize_t sys_reboot(int magic1, int magic2, int cmd, void *arg)
1638 {
1639 return my_syscall4(__NR_reboot, magic1, magic2, cmd, arg);
1640 }
1641
1642 static __attribute__((unused))
sys_sched_yield(void)1643 int sys_sched_yield(void)
1644 {
1645 return my_syscall0(__NR_sched_yield);
1646 }
1647
1648 static __attribute__((unused))
sys_select(int nfds,fd_set * rfds,fd_set * wfds,fd_set * efds,struct timeval * timeout)1649 int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
1650 {
1651 #if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect)
1652 struct sel_arg_struct {
1653 unsigned long n;
1654 fd_set *r, *w, *e;
1655 struct timeval *t;
1656 } arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout };
1657 return my_syscall1(__NR_select, &arg);
1658 #elif defined(__ARCH_WANT_SYS_PSELECT6) && defined(__NR_pselect6)
1659 struct timespec t;
1660
1661 if (timeout) {
1662 t.tv_sec = timeout->tv_sec;
1663 t.tv_nsec = timeout->tv_usec * 1000;
1664 }
1665 return my_syscall6(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
1666 #else
1667 #ifndef __NR__newselect
1668 #define __NR__newselect __NR_select
1669 #endif
1670 return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout);
1671 #endif
1672 }
1673
1674 static __attribute__((unused))
sys_setpgid(pid_t pid,pid_t pgid)1675 int sys_setpgid(pid_t pid, pid_t pgid)
1676 {
1677 return my_syscall2(__NR_setpgid, pid, pgid);
1678 }
1679
1680 static __attribute__((unused))
sys_setsid(void)1681 pid_t sys_setsid(void)
1682 {
1683 return my_syscall0(__NR_setsid);
1684 }
1685
1686 static __attribute__((unused))
sys_stat(const char * path,struct stat * buf)1687 int sys_stat(const char *path, struct stat *buf)
1688 {
1689 struct sys_stat_struct stat;
1690 long ret;
1691
1692 #ifdef __NR_newfstatat
1693 /* only solution for arm64 */
1694 ret = my_syscall4(__NR_newfstatat, AT_FDCWD, path, &stat, 0);
1695 #else
1696 ret = my_syscall2(__NR_stat, path, &stat);
1697 #endif
1698 buf->st_dev = stat.st_dev;
1699 buf->st_ino = stat.st_ino;
1700 buf->st_mode = stat.st_mode;
1701 buf->st_nlink = stat.st_nlink;
1702 buf->st_uid = stat.st_uid;
1703 buf->st_gid = stat.st_gid;
1704 buf->st_rdev = stat.st_rdev;
1705 buf->st_size = stat.st_size;
1706 buf->st_blksize = stat.st_blksize;
1707 buf->st_blocks = stat.st_blocks;
1708 buf->st_atime = stat.st_atime;
1709 buf->st_mtime = stat.st_mtime;
1710 buf->st_ctime = stat.st_ctime;
1711 return ret;
1712 }
1713
1714
1715 static __attribute__((unused))
sys_symlink(const char * old,const char * new)1716 int sys_symlink(const char *old, const char *new)
1717 {
1718 #ifdef __NR_symlinkat
1719 return my_syscall3(__NR_symlinkat, old, AT_FDCWD, new);
1720 #else
1721 return my_syscall2(__NR_symlink, old, new);
1722 #endif
1723 }
1724
1725 static __attribute__((unused))
sys_umask(mode_t mode)1726 mode_t sys_umask(mode_t mode)
1727 {
1728 return my_syscall1(__NR_umask, mode);
1729 }
1730
1731 static __attribute__((unused))
sys_umount2(const char * path,int flags)1732 int sys_umount2(const char *path, int flags)
1733 {
1734 return my_syscall2(__NR_umount2, path, flags);
1735 }
1736
1737 static __attribute__((unused))
sys_unlink(const char * path)1738 int sys_unlink(const char *path)
1739 {
1740 #ifdef __NR_unlinkat
1741 return my_syscall3(__NR_unlinkat, AT_FDCWD, path, 0);
1742 #else
1743 return my_syscall1(__NR_unlink, path);
1744 #endif
1745 }
1746
1747 static __attribute__((unused))
sys_wait4(pid_t pid,int * status,int options,struct rusage * rusage)1748 pid_t sys_wait4(pid_t pid, int *status, int options, struct rusage *rusage)
1749 {
1750 return my_syscall4(__NR_wait4, pid, status, options, rusage);
1751 }
1752
1753 static __attribute__((unused))
sys_waitpid(pid_t pid,int * status,int options)1754 pid_t sys_waitpid(pid_t pid, int *status, int options)
1755 {
1756 return sys_wait4(pid, status, options, 0);
1757 }
1758
1759 static __attribute__((unused))
sys_wait(int * status)1760 pid_t sys_wait(int *status)
1761 {
1762 return sys_waitpid(-1, status, 0);
1763 }
1764
1765 static __attribute__((unused))
sys_write(int fd,const void * buf,size_t count)1766 ssize_t sys_write(int fd, const void *buf, size_t count)
1767 {
1768 return my_syscall3(__NR_write, fd, buf, count);
1769 }
1770
1771
1772 /* Below are the libc-compatible syscalls which return x or -1 and set errno.
1773 * They rely on the functions above. Similarly they're marked static so that it
1774 * is possible to assign pointers to them if needed.
1775 */
1776
1777 static __attribute__((unused))
brk(void * addr)1778 int brk(void *addr)
1779 {
1780 void *ret = sys_brk(addr);
1781
1782 if (!ret) {
1783 SET_ERRNO(ENOMEM);
1784 return -1;
1785 }
1786 return 0;
1787 }
1788
1789 static __attribute__((noreturn,unused))
exit(int status)1790 void exit(int status)
1791 {
1792 sys_exit(status);
1793 }
1794
1795 static __attribute__((unused))
chdir(const char * path)1796 int chdir(const char *path)
1797 {
1798 int ret = sys_chdir(path);
1799
1800 if (ret < 0) {
1801 SET_ERRNO(-ret);
1802 ret = -1;
1803 }
1804 return ret;
1805 }
1806
1807 static __attribute__((unused))
chmod(const char * path,mode_t mode)1808 int chmod(const char *path, mode_t mode)
1809 {
1810 int ret = sys_chmod(path, mode);
1811
1812 if (ret < 0) {
1813 SET_ERRNO(-ret);
1814 ret = -1;
1815 }
1816 return ret;
1817 }
1818
1819 static __attribute__((unused))
chown(const char * path,uid_t owner,gid_t group)1820 int chown(const char *path, uid_t owner, gid_t group)
1821 {
1822 int ret = sys_chown(path, owner, group);
1823
1824 if (ret < 0) {
1825 SET_ERRNO(-ret);
1826 ret = -1;
1827 }
1828 return ret;
1829 }
1830
1831 static __attribute__((unused))
chroot(const char * path)1832 int chroot(const char *path)
1833 {
1834 int ret = sys_chroot(path);
1835
1836 if (ret < 0) {
1837 SET_ERRNO(-ret);
1838 ret = -1;
1839 }
1840 return ret;
1841 }
1842
1843 static __attribute__((unused))
close(int fd)1844 int close(int fd)
1845 {
1846 int ret = sys_close(fd);
1847
1848 if (ret < 0) {
1849 SET_ERRNO(-ret);
1850 ret = -1;
1851 }
1852 return ret;
1853 }
1854
1855 static __attribute__((unused))
dup2(int old,int new)1856 int dup2(int old, int new)
1857 {
1858 int ret = sys_dup2(old, new);
1859
1860 if (ret < 0) {
1861 SET_ERRNO(-ret);
1862 ret = -1;
1863 }
1864 return ret;
1865 }
1866
1867 static __attribute__((unused))
execve(const char * filename,char * const argv[],char * const envp[])1868 int execve(const char *filename, char *const argv[], char *const envp[])
1869 {
1870 int ret = sys_execve(filename, argv, envp);
1871
1872 if (ret < 0) {
1873 SET_ERRNO(-ret);
1874 ret = -1;
1875 }
1876 return ret;
1877 }
1878
1879 static __attribute__((unused))
fork(void)1880 pid_t fork(void)
1881 {
1882 pid_t ret = sys_fork();
1883
1884 if (ret < 0) {
1885 SET_ERRNO(-ret);
1886 ret = -1;
1887 }
1888 return ret;
1889 }
1890
1891 static __attribute__((unused))
fsync(int fd)1892 int fsync(int fd)
1893 {
1894 int ret = sys_fsync(fd);
1895
1896 if (ret < 0) {
1897 SET_ERRNO(-ret);
1898 ret = -1;
1899 }
1900 return ret;
1901 }
1902
1903 static __attribute__((unused))
getdents64(int fd,struct linux_dirent64 * dirp,int count)1904 int getdents64(int fd, struct linux_dirent64 *dirp, int count)
1905 {
1906 int ret = sys_getdents64(fd, dirp, count);
1907
1908 if (ret < 0) {
1909 SET_ERRNO(-ret);
1910 ret = -1;
1911 }
1912 return ret;
1913 }
1914
1915 static __attribute__((unused))
getpgrp(void)1916 pid_t getpgrp(void)
1917 {
1918 pid_t ret = sys_getpgrp();
1919
1920 if (ret < 0) {
1921 SET_ERRNO(-ret);
1922 ret = -1;
1923 }
1924 return ret;
1925 }
1926
1927 static __attribute__((unused))
getpid(void)1928 pid_t getpid(void)
1929 {
1930 pid_t ret = sys_getpid();
1931
1932 if (ret < 0) {
1933 SET_ERRNO(-ret);
1934 ret = -1;
1935 }
1936 return ret;
1937 }
1938
1939 static __attribute__((unused))
gettimeofday(struct timeval * tv,struct timezone * tz)1940 int gettimeofday(struct timeval *tv, struct timezone *tz)
1941 {
1942 int ret = sys_gettimeofday(tv, tz);
1943
1944 if (ret < 0) {
1945 SET_ERRNO(-ret);
1946 ret = -1;
1947 }
1948 return ret;
1949 }
1950
1951 static __attribute__((unused))
ioctl(int fd,unsigned long req,void * value)1952 int ioctl(int fd, unsigned long req, void *value)
1953 {
1954 int ret = sys_ioctl(fd, req, value);
1955
1956 if (ret < 0) {
1957 SET_ERRNO(-ret);
1958 ret = -1;
1959 }
1960 return ret;
1961 }
1962
1963 static __attribute__((unused))
kill(pid_t pid,int signal)1964 int kill(pid_t pid, int signal)
1965 {
1966 int ret = sys_kill(pid, signal);
1967
1968 if (ret < 0) {
1969 SET_ERRNO(-ret);
1970 ret = -1;
1971 }
1972 return ret;
1973 }
1974
1975 static __attribute__((unused))
link(const char * old,const char * new)1976 int link(const char *old, const char *new)
1977 {
1978 int ret = sys_link(old, new);
1979
1980 if (ret < 0) {
1981 SET_ERRNO(-ret);
1982 ret = -1;
1983 }
1984 return ret;
1985 }
1986
1987 static __attribute__((unused))
lseek(int fd,off_t offset,int whence)1988 off_t lseek(int fd, off_t offset, int whence)
1989 {
1990 off_t ret = sys_lseek(fd, offset, whence);
1991
1992 if (ret < 0) {
1993 SET_ERRNO(-ret);
1994 ret = -1;
1995 }
1996 return ret;
1997 }
1998
1999 static __attribute__((unused))
mkdir(const char * path,mode_t mode)2000 int mkdir(const char *path, mode_t mode)
2001 {
2002 int ret = sys_mkdir(path, mode);
2003
2004 if (ret < 0) {
2005 SET_ERRNO(-ret);
2006 ret = -1;
2007 }
2008 return ret;
2009 }
2010
2011 static __attribute__((unused))
mknod(const char * path,mode_t mode,dev_t dev)2012 int mknod(const char *path, mode_t mode, dev_t dev)
2013 {
2014 int ret = sys_mknod(path, mode, dev);
2015
2016 if (ret < 0) {
2017 SET_ERRNO(-ret);
2018 ret = -1;
2019 }
2020 return ret;
2021 }
2022
2023 static __attribute__((unused))
mount(const char * src,const char * tgt,const char * fst,unsigned long flags,const void * data)2024 int mount(const char *src, const char *tgt,
2025 const char *fst, unsigned long flags,
2026 const void *data)
2027 {
2028 int ret = sys_mount(src, tgt, fst, flags, data);
2029
2030 if (ret < 0) {
2031 SET_ERRNO(-ret);
2032 ret = -1;
2033 }
2034 return ret;
2035 }
2036
2037 static __attribute__((unused))
open(const char * path,int flags,mode_t mode)2038 int open(const char *path, int flags, mode_t mode)
2039 {
2040 int ret = sys_open(path, flags, mode);
2041
2042 if (ret < 0) {
2043 SET_ERRNO(-ret);
2044 ret = -1;
2045 }
2046 return ret;
2047 }
2048
2049 static __attribute__((unused))
pivot_root(const char * new,const char * old)2050 int pivot_root(const char *new, const char *old)
2051 {
2052 int ret = sys_pivot_root(new, old);
2053
2054 if (ret < 0) {
2055 SET_ERRNO(-ret);
2056 ret = -1;
2057 }
2058 return ret;
2059 }
2060
2061 static __attribute__((unused))
poll(struct pollfd * fds,int nfds,int timeout)2062 int poll(struct pollfd *fds, int nfds, int timeout)
2063 {
2064 int ret = sys_poll(fds, nfds, timeout);
2065
2066 if (ret < 0) {
2067 SET_ERRNO(-ret);
2068 ret = -1;
2069 }
2070 return ret;
2071 }
2072
2073 static __attribute__((unused))
read(int fd,void * buf,size_t count)2074 ssize_t read(int fd, void *buf, size_t count)
2075 {
2076 ssize_t ret = sys_read(fd, buf, count);
2077
2078 if (ret < 0) {
2079 SET_ERRNO(-ret);
2080 ret = -1;
2081 }
2082 return ret;
2083 }
2084
2085 static __attribute__((unused))
reboot(int cmd)2086 int reboot(int cmd)
2087 {
2088 int ret = sys_reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, 0);
2089
2090 if (ret < 0) {
2091 SET_ERRNO(-ret);
2092 ret = -1;
2093 }
2094 return ret;
2095 }
2096
2097 static __attribute__((unused))
sbrk(intptr_t inc)2098 void *sbrk(intptr_t inc)
2099 {
2100 void *ret;
2101
2102 /* first call to find current end */
2103 if ((ret = sys_brk(0)) && (sys_brk(ret + inc) == ret + inc))
2104 return ret + inc;
2105
2106 SET_ERRNO(ENOMEM);
2107 return (void *)-1;
2108 }
2109
2110 static __attribute__((unused))
sched_yield(void)2111 int sched_yield(void)
2112 {
2113 int ret = sys_sched_yield();
2114
2115 if (ret < 0) {
2116 SET_ERRNO(-ret);
2117 ret = -1;
2118 }
2119 return ret;
2120 }
2121
2122 static __attribute__((unused))
select(int nfds,fd_set * rfds,fd_set * wfds,fd_set * efds,struct timeval * timeout)2123 int select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
2124 {
2125 int ret = sys_select(nfds, rfds, wfds, efds, timeout);
2126
2127 if (ret < 0) {
2128 SET_ERRNO(-ret);
2129 ret = -1;
2130 }
2131 return ret;
2132 }
2133
2134 static __attribute__((unused))
setpgid(pid_t pid,pid_t pgid)2135 int setpgid(pid_t pid, pid_t pgid)
2136 {
2137 int ret = sys_setpgid(pid, pgid);
2138
2139 if (ret < 0) {
2140 SET_ERRNO(-ret);
2141 ret = -1;
2142 }
2143 return ret;
2144 }
2145
2146 static __attribute__((unused))
setsid(void)2147 pid_t setsid(void)
2148 {
2149 pid_t ret = sys_setsid();
2150
2151 if (ret < 0) {
2152 SET_ERRNO(-ret);
2153 ret = -1;
2154 }
2155 return ret;
2156 }
2157
2158 static __attribute__((unused))
sleep(unsigned int seconds)2159 unsigned int sleep(unsigned int seconds)
2160 {
2161 struct timeval my_timeval = { seconds, 0 };
2162
2163 if (sys_select(0, 0, 0, 0, &my_timeval) < 0)
2164 return my_timeval.tv_sec + !!my_timeval.tv_usec;
2165 else
2166 return 0;
2167 }
2168
2169 static __attribute__((unused))
stat(const char * path,struct stat * buf)2170 int stat(const char *path, struct stat *buf)
2171 {
2172 int ret = sys_stat(path, buf);
2173
2174 if (ret < 0) {
2175 SET_ERRNO(-ret);
2176 ret = -1;
2177 }
2178 return ret;
2179 }
2180
2181 static __attribute__((unused))
symlink(const char * old,const char * new)2182 int symlink(const char *old, const char *new)
2183 {
2184 int ret = sys_symlink(old, new);
2185
2186 if (ret < 0) {
2187 SET_ERRNO(-ret);
2188 ret = -1;
2189 }
2190 return ret;
2191 }
2192
2193 static __attribute__((unused))
tcsetpgrp(int fd,pid_t pid)2194 int tcsetpgrp(int fd, pid_t pid)
2195 {
2196 return ioctl(fd, TIOCSPGRP, &pid);
2197 }
2198
2199 static __attribute__((unused))
umask(mode_t mode)2200 mode_t umask(mode_t mode)
2201 {
2202 return sys_umask(mode);
2203 }
2204
2205 static __attribute__((unused))
umount2(const char * path,int flags)2206 int umount2(const char *path, int flags)
2207 {
2208 int ret = sys_umount2(path, flags);
2209
2210 if (ret < 0) {
2211 SET_ERRNO(-ret);
2212 ret = -1;
2213 }
2214 return ret;
2215 }
2216
2217 static __attribute__((unused))
unlink(const char * path)2218 int unlink(const char *path)
2219 {
2220 int ret = sys_unlink(path);
2221
2222 if (ret < 0) {
2223 SET_ERRNO(-ret);
2224 ret = -1;
2225 }
2226 return ret;
2227 }
2228
2229 static __attribute__((unused))
wait4(pid_t pid,int * status,int options,struct rusage * rusage)2230 pid_t wait4(pid_t pid, int *status, int options, struct rusage *rusage)
2231 {
2232 pid_t ret = sys_wait4(pid, status, options, rusage);
2233
2234 if (ret < 0) {
2235 SET_ERRNO(-ret);
2236 ret = -1;
2237 }
2238 return ret;
2239 }
2240
2241 static __attribute__((unused))
waitpid(pid_t pid,int * status,int options)2242 pid_t waitpid(pid_t pid, int *status, int options)
2243 {
2244 pid_t ret = sys_waitpid(pid, status, options);
2245
2246 if (ret < 0) {
2247 SET_ERRNO(-ret);
2248 ret = -1;
2249 }
2250 return ret;
2251 }
2252
2253 static __attribute__((unused))
wait(int * status)2254 pid_t wait(int *status)
2255 {
2256 pid_t ret = sys_wait(status);
2257
2258 if (ret < 0) {
2259 SET_ERRNO(-ret);
2260 ret = -1;
2261 }
2262 return ret;
2263 }
2264
2265 static __attribute__((unused))
write(int fd,const void * buf,size_t count)2266 ssize_t write(int fd, const void *buf, size_t count)
2267 {
2268 ssize_t ret = sys_write(fd, buf, count);
2269
2270 if (ret < 0) {
2271 SET_ERRNO(-ret);
2272 ret = -1;
2273 }
2274 return ret;
2275 }
2276
2277 /* some size-optimized reimplementations of a few common str* and mem*
2278 * functions. They're marked static, except memcpy() and raise() which are used
2279 * by libgcc on ARM, so they are marked weak instead in order not to cause an
2280 * error when building a program made of multiple files (not recommended).
2281 */
2282
2283 static __attribute__((unused))
memmove(void * dst,const void * src,size_t len)2284 void *memmove(void *dst, const void *src, size_t len)
2285 {
2286 ssize_t pos = (dst <= src) ? -1 : (long)len;
2287 void *ret = dst;
2288
2289 while (len--) {
2290 pos += (dst <= src) ? 1 : -1;
2291 ((char *)dst)[pos] = ((char *)src)[pos];
2292 }
2293 return ret;
2294 }
2295
2296 static __attribute__((unused))
memset(void * dst,int b,size_t len)2297 void *memset(void *dst, int b, size_t len)
2298 {
2299 char *p = dst;
2300
2301 while (len--)
2302 *(p++) = b;
2303 return dst;
2304 }
2305
2306 static __attribute__((unused))
memcmp(const void * s1,const void * s2,size_t n)2307 int memcmp(const void *s1, const void *s2, size_t n)
2308 {
2309 size_t ofs = 0;
2310 char c1 = 0;
2311
2312 while (ofs < n && !(c1 = ((char *)s1)[ofs] - ((char *)s2)[ofs])) {
2313 ofs++;
2314 }
2315 return c1;
2316 }
2317
2318 static __attribute__((unused))
strcpy(char * dst,const char * src)2319 char *strcpy(char *dst, const char *src)
2320 {
2321 char *ret = dst;
2322
2323 while ((*dst++ = *src++));
2324 return ret;
2325 }
2326
2327 static __attribute__((unused))
strchr(const char * s,int c)2328 char *strchr(const char *s, int c)
2329 {
2330 while (*s) {
2331 if (*s == (char)c)
2332 return (char *)s;
2333 s++;
2334 }
2335 return NULL;
2336 }
2337
2338 static __attribute__((unused))
strrchr(const char * s,int c)2339 char *strrchr(const char *s, int c)
2340 {
2341 const char *ret = NULL;
2342
2343 while (*s) {
2344 if (*s == (char)c)
2345 ret = s;
2346 s++;
2347 }
2348 return (char *)ret;
2349 }
2350
2351 static __attribute__((unused))
nolibc_strlen(const char * str)2352 size_t nolibc_strlen(const char *str)
2353 {
2354 size_t len;
2355
2356 for (len = 0; str[len]; len++);
2357 return len;
2358 }
2359
2360 #define strlen(str) ({ \
2361 __builtin_constant_p((str)) ? \
2362 __builtin_strlen((str)) : \
2363 nolibc_strlen((str)); \
2364 })
2365
2366 static __attribute__((unused))
isdigit(int c)2367 int isdigit(int c)
2368 {
2369 return (unsigned int)(c - '0') <= 9;
2370 }
2371
2372 static __attribute__((unused))
atol(const char * s)2373 long atol(const char *s)
2374 {
2375 unsigned long ret = 0;
2376 unsigned long d;
2377 int neg = 0;
2378
2379 if (*s == '-') {
2380 neg = 1;
2381 s++;
2382 }
2383
2384 while (1) {
2385 d = (*s++) - '0';
2386 if (d > 9)
2387 break;
2388 ret *= 10;
2389 ret += d;
2390 }
2391
2392 return neg ? -ret : ret;
2393 }
2394
2395 static __attribute__((unused))
atoi(const char * s)2396 int atoi(const char *s)
2397 {
2398 return atol(s);
2399 }
2400
2401 static __attribute__((unused))
ltoa(long in)2402 const char *ltoa(long in)
2403 {
2404 /* large enough for -9223372036854775808 */
2405 static char buffer[21];
2406 char *pos = buffer + sizeof(buffer) - 1;
2407 int neg = in < 0;
2408 unsigned long n = neg ? -in : in;
2409
2410 *pos-- = '\0';
2411 do {
2412 *pos-- = '0' + n % 10;
2413 n /= 10;
2414 if (pos < buffer)
2415 return pos + 1;
2416 } while (n);
2417
2418 if (neg)
2419 *pos-- = '-';
2420 return pos + 1;
2421 }
2422
2423 __attribute__((weak,unused))
memcpy(void * dst,const void * src,size_t len)2424 void *memcpy(void *dst, const void *src, size_t len)
2425 {
2426 return memmove(dst, src, len);
2427 }
2428
2429 /* needed by libgcc for divide by zero */
2430 __attribute__((weak,unused))
raise(int signal)2431 int raise(int signal)
2432 {
2433 return kill(getpid(), signal);
2434 }
2435
2436 /* Here come a few helper functions */
2437
2438 static __attribute__((unused))
FD_ZERO(fd_set * set)2439 void FD_ZERO(fd_set *set)
2440 {
2441 memset(set, 0, sizeof(*set));
2442 }
2443
2444 static __attribute__((unused))
FD_SET(int fd,fd_set * set)2445 void FD_SET(int fd, fd_set *set)
2446 {
2447 if (fd < 0 || fd >= FD_SETSIZE)
2448 return;
2449 set->fd32[fd / 32] |= 1 << (fd & 31);
2450 }
2451
2452 /* WARNING, it only deals with the 4096 first majors and 256 first minors */
2453 static __attribute__((unused))
makedev(unsigned int major,unsigned int minor)2454 dev_t makedev(unsigned int major, unsigned int minor)
2455 {
2456 return ((major & 0xfff) << 8) | (minor & 0xff);
2457 }
2458