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

   1 /* Copyright (C) 2000-2019 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    <https://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/s390/sysdep.h>
  25 #include <sysdeps/unix/sysv/linux/sysdep.h>
  26 #include <dl-sysdep.h>  /* For RTLD_PRIVATE_ERRNO.  */
  27 #include <tls.h>
  28
  29 /* Define __set_errno() for INLINE_SYSCALL macro below.  */
  30 #ifndef __ASSEMBLER__
  31 #include <errno.h>
  32 #endif
  33
  34 /* For Linux we can use the system call table in the header file
  35         /usr/include/asm/unistd.h
  36    of the kernel.  But these symbols do not follow the SYS_* syntax
  37    so we have to redefine the `SYS_ify' macro here.  */
  38 /* in newer 2.1 kernels __NR_syscall is missing so we define it here */
  39 #define __NR_syscall 0
  40
  41 #undef SYS_ify
  42 #define SYS_ify(syscall_name)   __NR_##syscall_name
  43
  44 #ifdef __ASSEMBLER__
  45
  46 /* Linux uses a negative return value to indicate syscall errors, unlike
  47    most Unices, which use the condition codes' carry flag.
  48
  49    Since version 2.1 the return value of a system call might be negative
  50    even if the call succeeded.  E.g., the `lseek' system call might return
  51    a large offset.  Therefore we must not anymore test for < 0, but test
  52    for a real error by making sure the value in gpr2 is a real error
  53    number.  Linus said he will make sure that no syscall returns a value
  54    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  55
  56 #undef PSEUDO
  57 #define PSEUDO(name, syscall_name, args)                                      \
  58   .text;                                                                      \
  59   ENTRY (name)                                                                \
  60     DO_CALL (syscall_name, args);                                             \
  61     lhi  %r4,-4095 ;                                                          \
  62     clr  %r2,%r4 ;                                                            \
  63     jnl  SYSCALL_ERROR_LABEL
  64
  65 #undef PSEUDO_END
  66 #define PSEUDO_END(name)                                                      \
  67   SYSCALL_ERROR_HANDLER;                                                      \
  68   END (name)
  69
  70 #undef PSEUDO_NOERRNO
  71 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  72   .text;                                                                      \
  73   ENTRY (name)                                                                \
  74     DO_CALL (syscall_name, args)
  75
  76 #undef PSEUDO_END_NOERRNO
  77 #define PSEUDO_END_NOERRNO(name)                                              \
  78   END (name)
  79
  80 #undef PSEUDO_ERRVAL
  81 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  82   .text;                                                                      \
  83   ENTRY (name)                                                                \
  84     DO_CALL (syscall_name, args);                                             \
  85     lcr %r2,%r2
  86
  87 #undef PSEUDO_END_ERRVAL
  88 #define PSEUDO_END_ERRVAL(name)                                               \
  89   END (name)
  90
  91 #ifndef PIC
  92 # define SYSCALL_ERROR_LABEL 0f
  93 # define SYSCALL_ERROR_HANDLER \
  94 0:  basr  %r1,0;                                                              \
  95 1:  l     %r1,2f-1b(%r1);                                                     \
  96     br    %r1;                                                                \
  97 2:  .long syscall_error
  98 #else
  99 # if RTLD_PRIVATE_ERRNO
 100 #  define SYSCALL_ERROR_LABEL 0f
 101 #  define SYSCALL_ERROR_HANDLER \
 102 0:  basr  %r1,0;                                                              \
 103 1:  al    %r1,2f-1b(%r1);                                                     \
 104     lcr   %r2,%r2;                                                            \
 105     st    %r2,0(%r1);                                                         \
 106     lhi   %r2,-1;                                                             \
 107     br    %r14;                                                               \
 108 2:  .long rtld_errno-1b
 109 # elif defined _LIBC_REENTRANT
 110 #  if IS_IN (libc)
 111 #   define SYSCALL_ERROR_ERRNO __libc_errno
 112 #  else
 113 #   define SYSCALL_ERROR_ERRNO errno
 114 #  endif
 115 #  define SYSCALL_ERROR_LABEL 0f
 116 #  define SYSCALL_ERROR_HANDLER \
 117 0:  lcr   %r0,%r2;                                                            \
 118     basr  %r1,0;                                                              \
 119 1:  al    %r1,2f-1b(%r1);                                                     \
 120     l     %r1,SYSCALL_ERROR_ERRNO@gotntpoff(%r1);                             \
 121     ear   %r2,%a0;                                                            \
 122     st    %r0,0(%r1,%r2);                                                     \
 123     lhi   %r2,-1;                                                             \
 124     br    %r14;                                                               \
 125 2:  .long _GLOBAL_OFFSET_TABLE_-1b
 126 # else
 127 #  define SYSCALL_ERROR_LABEL 0f
 128 #  define SYSCALL_ERROR_HANDLER \
 129 0:  basr  %r1,0;                                                              \
 130 1:  al    %r1,2f-1b(%r1);                                                     \
 131     l     %r1,errno@GOT(%r1);                                                 \
 132     lcr   %r2,%r2;                                                            \
 133     st    %r2,0(%r1);                                                         \
 134     lhi   %r2,-1;                                                             \
 135     br    %r14;                                                               \
 136 2:  .long _GLOBAL_OFFSET_TABLE_-1b
 137 # endif /* _LIBC_REENTRANT */
 138 #endif /* PIC */
 139
 140 /* Linux takes system call arguments in registers:
 141
 142         syscall number  1            call-clobbered
 143         arg 1           2            call-clobbered
 144         arg 2           3            call-clobbered
 145         arg 3           4            call-clobbered
 146         arg 4           5            call-clobbered
 147         arg 5           6            call-saved
 148         arg 6           7            call-saved
 149
 150    (Of course a function with say 3 arguments does not have entries for
 151    arguments 4 and 5.)
 152    For system calls with 6 parameters a stack operation is required
 153    to load the 6th parameter to register 7. Call saved register 7 is
 154    moved to register 0 and back to avoid an additional stack frame.
 155  */
 156
 157 #define DO_CALL(syscall, args)                                                \
 158   .if args > 5;                                                               \
 159     lr %r0,%r7;                                                               \
 160     l %r7,96(%r15);                                                           \
 161   .endif;                                                                     \
 162   .if SYS_ify (syscall) < 256;                                                \
 163     svc SYS_ify (syscall);                                                    \
 164   .else;                                                                      \
 165     lhi %r1,SYS_ify (syscall);                                                \
 166     svc 0;                                                                    \
 167   .endif;                                                                     \
 168   .if args > 5;                                                               \
 169     lr %r7,%r0;                                                               \
 170   .endif
 171
 172 #define ret                                                                   \
 173     br      14
 174
 175 #define ret_NOERRNO                                                           \
 176     br      14
 177
 178 #define ret_ERRVAL                                                            \
 179     br      14
 180
 181 #endif /* __ASSEMBLER__ */
 182
 183 #undef INLINE_SYSCALL
 184 #define INLINE_SYSCALL(name, nr, args...)                                     \
 185   ({                                                                          \
 186     unsigned int _ret = INTERNAL_SYSCALL (name, , nr, args);                  \
 187     if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, )))                 \
 188      {                                                                        \
 189        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 190        _ret = 0xffffffff;                                                     \
 191      }                                                                        \
 192     (int) _ret; })
 193
 194 #undef INTERNAL_SYSCALL_DECL
 195 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 196
 197 #undef INTERNAL_SYSCALL_DIRECT
 198 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 199   ({                                                                          \
 200     DECLARGS_##nr(args)                                                       \
 201     register int _ret __asm__("2");                                           \
 202     __asm__ __volatile__ (                                                    \
 203                           "svc    %b1\n\t"                                    \
 204                           : "=d" (_ret)                                       \
 205                           : "i" (__NR_##name) ASMFMT_##nr                     \
 206                           : "memory" );                                       \
 207     _ret; })
 208
 209 #undef INTERNAL_SYSCALL_SVC0
 210 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 211   ({                                                                          \
 212     DECLARGS_##nr(args)                                                       \
 213     register unsigned long _nr __asm__("1") = (unsigned long)(__NR_##name);   \
 214     register int _ret __asm__("2");                                           \
 215     __asm__ __volatile__ (                                                    \
 216                           "svc    0\n\t"                                      \
 217                           : "=d" (_ret)                                       \
 218                           : "d" (_nr) ASMFMT_##nr                             \
 219                           : "memory" );                                       \
 220     _ret; })
 221
 222 #undef INTERNAL_SYSCALL_NCS
 223 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 224   ({                                                                          \
 225     DECLARGS_##nr(args)                                                       \
 226     register unsigned long _nr __asm__("1") = (unsigned long)(no);            \
 227     register int _ret __asm__("2");                                           \
 228     __asm__ __volatile__ (                                                    \
 229                           "svc    0\n\t"                                      \
 230                           : "=d" (_ret)                                       \
 231                           : "d" (_nr) ASMFMT_##nr                             \
 232                           : "memory" );                                       \
 233     _ret; })
 234
 235 #undef INTERNAL_SYSCALL
 236 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 237   (((__NR_##name) < 256)                                                      \
 238    ? INTERNAL_SYSCALL_DIRECT(name, err, nr, args)                             \
 239    : INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 240
 241 #undef INTERNAL_SYSCALL_ERROR_P
 242 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 243   ((unsigned int) (val) >= 0xfffff001u)
 244
 245 #undef INTERNAL_SYSCALL_ERRNO
 246 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 247
 248 #define DECLARGS_0()
 249 #define DECLARGS_1(arg1) \
 250         register unsigned long gpr2 __asm__ ("2") = (unsigned long)(arg1);
 251 #define DECLARGS_2(arg1, arg2) \
 252         DECLARGS_1(arg1) \
 253         register unsigned long gpr3 __asm__ ("3") = (unsigned long)(arg2);
 254 #define DECLARGS_3(arg1, arg2, arg3) \
 255         DECLARGS_2(arg1, arg2) \
 256         register unsigned long gpr4 __asm__ ("4") = (unsigned long)(arg3);
 257 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 258         DECLARGS_3(arg1, arg2, arg3) \
 259         register unsigned long gpr5 __asm__ ("5") = (unsigned long)(arg4);
 260 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 261         DECLARGS_4(arg1, arg2, arg3, arg4) \
 262         register unsigned long gpr6 __asm__ ("6") = (unsigned long)(arg5);
 263 #define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
 264         DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 265         register unsigned long gpr7 __asm__ ("7") = (unsigned long)(arg6);
 266
 267 #define ASMFMT_0
 268 #define ASMFMT_1 , "0" (gpr2)
 269 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 270 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 271 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 272 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 273 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 274
 275 /* Pointer mangling support.  */
 276 #if IS_IN (rtld)
 277 /* We cannot use the thread descriptor because in ld.so we use setjmp
 278    earlier than the descriptor is initialized.  */
 279 #else
 280 /* For the time being just use stack_guard rather than a separate
 281    pointer_guard.  */
 282 # ifdef __ASSEMBLER__
 283 #  define PTR_MANGLE(reg, tmpreg) \
 284   ear     tmpreg,%a0;                   \
 285   x       reg,STACK_GUARD(tmpreg)
 286 #  define PTR_MANGLE2(reg, tmpreg) \
 287   x       reg,STACK_GUARD(tmpreg)
 288 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 289 # else
 290 #  define PTR_MANGLE(var) \
 291   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 292 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 293 # endif
 294 #endif
 295
 296 #endif /* _LINUX_S390_SYSDEP_H */