sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h

   1 /* Copyright (C) 2000-2018 Free Software Foundation, Inc.
   2    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _LINUX_S390_SYSDEP_H
  20 #define _LINUX_S390_SYSDEP_H
  21
  22 #include <sysdeps/s390/s390-32/sysdep.h>
  23 #include <sysdeps/unix/sysdep.h>
  24 #include <sysdeps/unix/sysv/linux/sysdep.h>
  25 #include <dl-sysdep.h>  /* For RTLD_PRIVATE_ERRNO.  */
  26 #include <tls.h>
  27
  28 /* Define __set_errno() for INLINE_SYSCALL macro below.  */
  29 #ifndef __ASSEMBLER__
  30 #include <errno.h>
  31 #endif
  32
  33 /* For Linux we can use the system call table in the header file
  34         /usr/include/asm/unistd.h
  35    of the kernel.  But these symbols do not follow the SYS_* syntax
  36    so we have to redefine the `SYS_ify' macro here.  */
  37 /* in newer 2.1 kernels __NR_syscall is missing so we define it here */
  38 #define __NR_syscall 0
  39
  40 #undef SYS_ify
  41 #define SYS_ify(syscall_name)   __NR_##syscall_name
  42
  43 #ifdef __ASSEMBLER__
  44
  45 /* Linux uses a negative return value to indicate syscall errors, unlike
  46    most Unices, which use the condition codes' carry flag.
  47
  48    Since version 2.1 the return value of a system call might be negative
  49    even if the call succeeded.  E.g., the `lseek' system call might return
  50    a large offset.  Therefore we must not anymore test for < 0, but test
  51    for a real error by making sure the value in gpr2 is a real error
  52    number.  Linus said he will make sure that no syscall returns a value
  53    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  54
  55 #undef PSEUDO
  56 #define PSEUDO(name, syscall_name, args)                                      \
  57   .text;                                                                      \
  58   ENTRY (name)                                                                \
  59     DO_CALL (syscall_name, args);                                             \
  60     lhi  %r4,-4095 ;                                                          \
  61     clr  %r2,%r4 ;                                                            \
  62     jnl  SYSCALL_ERROR_LABEL
  63
  64 #undef PSEUDO_END
  65 #define PSEUDO_END(name)                                                      \
  66   SYSCALL_ERROR_HANDLER;                                                      \
  67   END (name)
  68
  69 #undef PSEUDO_NOERRNO
  70 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  71   .text;                                                                      \
  72   ENTRY (name)                                                                \
  73     DO_CALL (syscall_name, args)
  74
  75 #undef PSEUDO_END_NOERRNO
  76 #define PSEUDO_END_NOERRNO(name)                                              \
  77   END (name)
  78
  79 #undef PSEUDO_ERRVAL
  80 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  81   .text;                                                                      \
  82   ENTRY (name)                                                                \
  83     DO_CALL (syscall_name, args);                                             \
  84     lcr %r2,%r2
  85
  86 #undef PSEUDO_END_ERRVAL
  87 #define PSEUDO_END_ERRVAL(name)                                               \
  88   END (name)
  89
  90 #ifndef PIC
  91 # define SYSCALL_ERROR_LABEL 0f
  92 # define SYSCALL_ERROR_HANDLER \
  93 0:  basr  %r1,0;                                                              \
  94 1:  l     %r1,2f-1b(%r1);                                                     \
  95     br    %r1;                                                                \
  96 2:  .long syscall_error
  97 #else
  98 # if RTLD_PRIVATE_ERRNO
  99 #  define SYSCALL_ERROR_LABEL 0f
 100 #  define SYSCALL_ERROR_HANDLER \
 101 0:  basr  %r1,0;                                                              \
 102 1:  al    %r1,2f-1b(%r1);                                                     \
 103     lcr   %r2,%r2;                                                            \
 104     st    %r2,0(%r1);                                                         \
 105     lhi   %r2,-1;                                                             \
 106     br    %r14;                                                               \
 107 2:  .long rtld_errno-1b
 108 # elif defined _LIBC_REENTRANT
 109 #  if IS_IN (libc)
 110 #   define SYSCALL_ERROR_ERRNO __libc_errno
 111 #  else
 112 #   define SYSCALL_ERROR_ERRNO errno
 113 #  endif
 114 #  define SYSCALL_ERROR_LABEL 0f
 115 #  define SYSCALL_ERROR_HANDLER \
 116 0:  lcr   %r0,%r2;                                                            \
 117     basr  %r1,0;                                                              \
 118 1:  al    %r1,2f-1b(%r1);                                                     \
 119     l     %r1,SYSCALL_ERROR_ERRNO@gotntpoff(%r1);                             \
 120     ear   %r2,%a0;                                                            \
 121     st    %r0,0(%r1,%r2);                                                     \
 122     lhi   %r2,-1;                                                             \
 123     br    %r14;                                                               \
 124 2:  .long _GLOBAL_OFFSET_TABLE_-1b
 125 # else
 126 #  define SYSCALL_ERROR_LABEL 0f
 127 #  define SYSCALL_ERROR_HANDLER \
 128 0:  basr  %r1,0;                                                              \
 129 1:  al    %r1,2f-1b(%r1);                                                     \
 130     l     %r1,errno@GOT(%r1);                                                 \
 131     lcr   %r2,%r2;                                                            \
 132     st    %r2,0(%r1);                                                         \
 133     lhi   %r2,-1;                                                             \
 134     br    %r14;                                                               \
 135 2:  .long _GLOBAL_OFFSET_TABLE_-1b
 136 # endif /* _LIBC_REENTRANT */
 137 #endif /* PIC */
 138
 139 /* Linux takes system call arguments in registers:
 140
 141         syscall number  1            call-clobbered
 142         arg 1           2            call-clobbered
 143         arg 2           3            call-clobbered
 144         arg 3           4            call-clobbered
 145         arg 4           5            call-clobbered
 146         arg 5           6            call-saved
 147         arg 6           7            call-saved
 148
 149    (Of course a function with say 3 arguments does not have entries for
 150    arguments 4 and 5.)
 151    For system calls with 6 parameters a stack operation is required
 152    to load the 6th parameter to register 7. Call saved register 7 is
 153    moved to register 0 and back to avoid an additional stack frame.
 154  */
 155
 156 #define DO_CALL(syscall, args)                                                \
 157   .if args > 5;                                                               \
 158     lr %r0,%r7;                                                               \
 159     l %r7,96(%r15);                                                           \
 160   .endif;                                                                     \
 161   .if SYS_ify (syscall) < 256;                                                \
 162     svc SYS_ify (syscall);                                                    \
 163   .else;                                                                      \
 164     lhi %r1,SYS_ify (syscall);                                                \
 165     svc 0;                                                                    \
 166   .endif;                                                                     \
 167   .if args > 5;                                                               \
 168     lr %r7,%r0;                                                               \
 169   .endif
 170
 171 #define ret                                                                   \
 172     br      14
 173
 174 #define ret_NOERRNO                                                           \
 175     br      14
 176
 177 #define ret_ERRVAL                                                            \
 178     br      14
 179
 180 #endif /* __ASSEMBLER__ */
 181
 182 #undef INLINE_SYSCALL
 183 #define INLINE_SYSCALL(name, nr, args...)                                     \
 184   ({                                                                          \
 185     unsigned int _ret = INTERNAL_SYSCALL (name, , nr, args);                  \
 186     if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, )))                 \
 187      {                                                                        \
 188        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 189        _ret = 0xffffffff;                                                     \
 190      }                                                                        \
 191     (int) _ret; })
 192
 193 #undef INTERNAL_SYSCALL_DECL
 194 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 195
 196 #undef INTERNAL_SYSCALL_DIRECT
 197 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 198   ({                                                                          \
 199     DECLARGS_##nr(args)                                                       \
 200     register int _ret __asm__("2");                                           \
 201     __asm__ __volatile__ (                                                    \
 202                           "svc    %b1\n\t"                                    \
 203                           : "=d" (_ret)                                       \
 204                           : "i" (__NR_##name) ASMFMT_##nr                     \
 205                           : "memory" );                                       \
 206     _ret; })
 207
 208 #undef INTERNAL_SYSCALL_SVC0
 209 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 210   ({                                                                          \
 211     DECLARGS_##nr(args)                                                       \
 212     register unsigned long _nr __asm__("1") = (unsigned long)(__NR_##name);   \
 213     register int _ret __asm__("2");                                           \
 214     __asm__ __volatile__ (                                                    \
 215                           "svc    0\n\t"                                      \
 216                           : "=d" (_ret)                                       \
 217                           : "d" (_nr) ASMFMT_##nr                             \
 218                           : "memory" );                                       \
 219     _ret; })
 220
 221 #undef INTERNAL_SYSCALL_NCS
 222 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 223   ({                                                                          \
 224     DECLARGS_##nr(args)                                                       \
 225     register unsigned long _nr __asm__("1") = (unsigned long)(no);            \
 226     register int _ret __asm__("2");                                           \
 227     __asm__ __volatile__ (                                                    \
 228                           "svc    0\n\t"                                      \
 229                           : "=d" (_ret)                                       \
 230                           : "d" (_nr) ASMFMT_##nr                             \
 231                           : "memory" );                                       \
 232     _ret; })
 233
 234 #undef INTERNAL_SYSCALL
 235 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 236   (((__NR_##name) < 256) ?                                                    \
 237     INTERNAL_SYSCALL_DIRECT(name, err, nr, args) :                            \
 238     INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 239
 240 #undef INTERNAL_SYSCALL_ERROR_P
 241 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 242   ((unsigned int) (val) >= 0xfffff001u)
 243
 244 #undef INTERNAL_SYSCALL_ERRNO
 245 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 246
 247 #define DECLARGS_0()
 248 #define DECLARGS_1(arg1) \
 249         register unsigned long gpr2 __asm__ ("2") = (unsigned long)(arg1);
 250 #define DECLARGS_2(arg1, arg2) \
 251         DECLARGS_1(arg1) \
 252         register unsigned long gpr3 __asm__ ("3") = (unsigned long)(arg2);
 253 #define DECLARGS_3(arg1, arg2, arg3) \
 254         DECLARGS_2(arg1, arg2) \
 255         register unsigned long gpr4 __asm__ ("4") = (unsigned long)(arg3);
 256 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 257         DECLARGS_3(arg1, arg2, arg3) \
 258         register unsigned long gpr5 __asm__ ("5") = (unsigned long)(arg4);
 259 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 260         DECLARGS_4(arg1, arg2, arg3, arg4) \
 261         register unsigned long gpr6 __asm__ ("6") = (unsigned long)(arg5);
 262 #define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
 263         DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 264         register unsigned long gpr7 __asm__ ("7") = (unsigned long)(arg6);
 265
 266 #define ASMFMT_0
 267 #define ASMFMT_1 , "0" (gpr2)
 268 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 269 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 270 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 271 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 272 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 273
 274 /* List of system calls which are supported as vsyscalls.  */
 275 #define HAVE_CLOCK_GETRES_VSYSCALL      1
 276 #define HAVE_CLOCK_GETTIME_VSYSCALL     1
 277 #define HAVE_GETTIMEOFDAY_VSYSCALL      1
 278 #define HAVE_GETCPU_VSYSCALL            1
 279
 280 /* Pointer mangling support.  */
 281 #if IS_IN (rtld)
 282 /* We cannot use the thread descriptor because in ld.so we use setjmp
 283    earlier than the descriptor is initialized.  */
 284 #else
 285 /* For the time being just use stack_guard rather than a separate
 286    pointer_guard.  */
 287 # ifdef __ASSEMBLER__
 288 #  define PTR_MANGLE(reg, tmpreg) \
 289   ear     tmpreg,%a0;                   \
 290   x       reg,STACK_GUARD(tmpreg)
 291 #  define PTR_MANGLE2(reg, tmpreg) \
 292   x       reg,STACK_GUARD(tmpreg)
 293 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 294 # else
 295 #  define PTR_MANGLE(var) \
 296   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 297 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 298 # endif
 299 #endif
 300
 301 #endif /* _LINUX_S390_SYSDEP_H */