ldso/include/dl-syscall.h

   1 /*
   2  * Copyright (C) 2000-2005 by Erik Andersen <andersen@codepoet.org>
   3  *
   4  * GNU Lesser General Public License version 2.1 or later.
   5  */
   6
   7 #ifndef _DL_SYSCALL_H
   8 #define _DL_SYSCALL_H
   9
  10 /* We can't use the real errno in ldso, since it has not yet
  11  * been dynamicly linked in yet. */
  12 #include "sys/syscall.h"
  13 extern int _dl_errno;
  14 #undef __set_errno
  15 #define __set_errno(X) {(_dl_errno) = (X);}
  16
  17 /* Pull in the arch specific syscall implementation */
  18 #include <dl-syscalls.h>
  19 /*  For MAP_ANONYMOUS -- differs between platforms */
  20 #define _SYS_MMAN_H 1
  21 #include <bits/mman.h>
  22
  23 #ifdef __ARCH_HAS_DEPRECATED_SYSCALLS__
  24 /* Pull in whatever this particular arch's kernel thinks the kernel version of
  25  * struct stat should look like.  It turns out that each arch has a different
  26  * opinion on the subject, and different kernel revs use different names... */
  27 #define kernel_stat stat
  28 #include <bits/kernel_stat.h>
  29 #include <bits/kernel_types.h>
  30
  31 /* Protection bits.  */
  32 #define S_ISUID         04000   /* Set user ID on execution.  */
  33 #define S_ISGID         02000   /* Set group ID on execution.  */
  34
  35 #else
  36 /* 1. common-generic ABI doesn't need kernel_stat translation
  37  * 3. S_IS?ID already provided by stat.h
  38  */
  39 #include <sys/stat.h>
  40 #endif
  41
  42
  43 /* Here are the definitions for some syscalls that are used
  44    by the dynamic linker.  The idea is that we want to be able
  45    to call these before the errno symbol is dynamicly linked, so
  46    we use our own version here.  Note that we cannot assume any
  47    dynamic linking at all, so we cannot return any error codes.
  48    We just punt if there is an error. */
  49 #define __NR__dl_exit __NR_exit
  50 static __always_inline attribute_noreturn __cold void _dl_exit(int status)
  51 {
  52         INLINE_SYSCALL(_dl_exit, 1, status);
  53 #if __GNUC_PREREQ(4, 5)
  54         __builtin_unreachable(); /* shut up warning: 'noreturn' function does return*/
  55 #else
  56         while (1);
  57 #endif
  58 }
  59
  60 #define __NR__dl_close __NR_close
  61 static __always_inline _syscall1(int, _dl_close, int, fd)
  62
  63 #if defined __NR_openat && !defined __NR_open
  64 static __always_inline int _dl_open(const char *fn,
  65                                                 int flags, __kernel_mode_t mode)
  66 {
  67         return INLINE_SYSCALL(openat, 4, AT_FDCWD, fn, flags, mode);
  68 }
  69
  70 #elif defined __NR_open
  71 # define __NR__dl_open __NR_open
  72 static __always_inline _syscall3(int, _dl_open, const char *, fn, int, flags,
  73                         __kernel_mode_t, mode)
  74 #endif
  75
  76 #define __NR__dl_write __NR_write
  77 static __always_inline _syscall3(unsigned long, _dl_write, int, fd,
  78                         const void *, buf, unsigned long, count)
  79
  80 #define __NR__dl_read __NR_read
  81 static __always_inline _syscall3(unsigned long, _dl_read, int, fd,
  82                         const void *, buf, unsigned long, count)
  83
  84 #define __NR__dl_mprotect __NR_mprotect
  85 static __always_inline _syscall3(int, _dl_mprotect, const void *, addr,
  86                         unsigned long, len, int, prot)
  87
  88 #if defined __NR_fstatat64 && !defined __NR_stat
  89 # define __NR__dl_fstatat64 __NR_fstatat64
  90 static __always_inline _syscall4(int, _dl_fstatat64, int, fd, const char *,
  91                                  fn, struct stat *, stat, int, flags)
  92
  93 static __always_inline int _dl_stat(const char *file_name,
  94                         struct stat *buf)
  95 {
  96         return _dl_fstatat64(AT_FDCWD, file_name, buf, 0);
  97 }
  98 #elif defined __NR_newfstatat && !defined __NR_stat
  99 # define __NR__dl_newfstatat __NR_newfstatat
 100 static __always_inline _syscall4(int, _dl_newfstatat, int, fd, const char *,
 101                                  fn, struct stat *, stat, int, flags)
 102
 103 static __always_inline int _dl_stat(const char *file_name,
 104                         struct stat *buf)
 105 {
 106         return _dl_newfstatat(AT_FDCWD, file_name, buf, 0);
 107 }
 108 #elif defined __NR_stat
 109 # define __NR__dl_stat __NR_stat
 110 static __always_inline _syscall2(int, _dl_stat, const char *, file_name,
 111                         struct stat *, buf)
 112 #endif
 113
 114 #if defined __NR_fstat64 && !defined __NR_fstat
 115 # define __NR__dl_fstat __NR_fstat64
 116 #elif defined __NR_fstat
 117 # define __NR__dl_fstat __NR_fstat
 118 #endif
 119 static __always_inline _syscall2(int, _dl_fstat, int, fd, struct stat *, buf)
 120
 121 #define __NR__dl_munmap __NR_munmap
 122 static __always_inline _syscall2(int, _dl_munmap, void *, start, unsigned long, length)
 123
 124 #ifdef __NR_getxuid
 125 # define __NR_getuid __NR_getxuid
 126 #endif
 127 #define __NR__dl_getuid __NR_getuid
 128 static __always_inline _syscall0(uid_t, _dl_getuid)
 129
 130 #ifndef __NR_geteuid
 131 # define __NR_geteuid __NR_getuid
 132 #endif
 133 #define __NR__dl_geteuid __NR_geteuid
 134 static __always_inline _syscall0(uid_t, _dl_geteuid)
 135
 136 #ifdef __NR_getxgid
 137 # define __NR_getgid __NR_getxgid
 138 #endif
 139 #define __NR__dl_getgid __NR_getgid
 140 static __always_inline _syscall0(gid_t, _dl_getgid)
 141
 142 #ifndef __NR_getegid
 143 # define __NR_getegid __NR_getgid
 144 #endif
 145 #define __NR__dl_getegid __NR_getegid
 146 static __always_inline _syscall0(gid_t, _dl_getegid)
 147
 148 #ifdef __NR_getxpid
 149 # define __NR_getpid __NR_getxpid
 150 #endif
 151 #define __NR__dl_getpid __NR_getpid
 152 static __always_inline _syscall0(gid_t, _dl_getpid)
 153
 154 #if defined __NR_readlinkat
 155 # define __NR__dl_readlink __NR_readlinkat
 156 static __always_inline _syscall4(int, _dl_readlink, int, id, const char *, path,
 157                                                 char *, buf, size_t, bufsiz)
 158 #endif
 159
 160 #ifdef __NR_pread64
 161 #define __NR___syscall_pread __NR_pread64
 162 #ifdef __UCLIBC_SYSCALL_ALIGN_64BIT__
 163 static __always_inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf, size_t, dummy,
 164                         size_t, count, off_t, offset_hi, off_t, offset_lo)
 165
 166 static __always_inline ssize_t
 167 _dl_pread(int fd, void *buf, size_t count, off_t offset)
 168 {
 169         return __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR((offset >> 32), (offset & 0xffffffff)));
 170 }
 171 #else
 172 static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
 173                         size_t, count, off_t, offset_hi, off_t, offset_lo)
 174
 175 static __always_inline ssize_t
 176 _dl_pread(int fd, void *buf, size_t count, off_t offset)
 177 {
 178         return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset));
 179 }
 180 #endif
 181 #elif defined __NR_pread
 182 #define __NR___syscall_pread __NR_pread
 183 static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
 184                         size_t, count, off_t, offset_hi, off_t, offset_lo)
 185
 186 static __always_inline ssize_t
 187 _dl_pread(int fd, void *buf, size_t count, off_t offset)
 188 {
 189         return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset));
 190 }
 191 #endif
 192
 193 #ifdef __UCLIBC_HAS_SSP__
 194 # include <sys/time.h>
 195 # define __NR__dl_gettimeofday __NR_gettimeofday
 196 static __always_inline _syscall2(int, _dl_gettimeofday, struct timeval *, tv,
 197 # ifdef __USE_BSD
 198                         struct timezone *
 199 # else
 200                         void *
 201 # endif
 202                                                 , tz)
 203 #endif
 204
 205 /* Some architectures always use 12 as page shift for mmap2() eventhough the
 206  * real PAGE_SHIFT != 12.  Other architectures use the same value as
 207  * PAGE_SHIFT...
 208  */
 209 #ifndef MMAP2_PAGE_SHIFT
 210 # define MMAP2_PAGE_SHIFT 12
 211 #endif
 212
 213 #define MAP_FAILED ((void *) -1)
 214 #define _dl_mmap_check_error(X) (((void *)X) == MAP_FAILED)
 215
 216 static __always_inline
 217 void *_dl_mmap(void *addr, unsigned long size, int prot,
 218                int flags, int fd, unsigned long offset)
 219 {
 220 #if defined(__UCLIBC_MMAP_HAS_6_ARGS__) && defined(__NR_mmap)
 221         /* first try mmap(), syscall6() style */
 222         return (void *)INLINE_SYSCALL(mmap, 6, addr, size, prot, flags, fd, offset);
 223
 224 #elif defined(__NR_mmap2) && !defined (__mcoldfire__)
 225         /* then try mmap2() */
 226         unsigned long shifted;
 227
 228         if (offset & ((1 << MMAP2_PAGE_SHIFT) - 1))
 229                 return MAP_FAILED;
 230
 231         /* gcc needs help with putting things onto the stack */
 232         shifted = offset >> MMAP2_PAGE_SHIFT;
 233         return (void *)INLINE_SYSCALL(mmap2, 6, addr, size, prot, flags, fd, shifted);
 234
 235 #elif defined(__NR_mmap)
 236         /* finally, fall back to mmap(), syscall1() style */
 237         unsigned long buffer[6];
 238         buffer[0] = (unsigned long) addr;
 239         buffer[1] = (unsigned long) size;
 240         buffer[2] = (unsigned long) prot;
 241         buffer[3] = (unsigned long) flags;
 242         buffer[4] = (unsigned long) fd;
 243         buffer[5] = (unsigned long) offset;
 244         return (void *)INLINE_SYSCALL(mmap, 1, buffer);
 245 #else
 246 # error "Your architecture doesn't seem to provide mmap() !?"
 247 #endif
 248 }
 249
 250 #endif /* _DL_SYSCALL_H */