sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h

   1 /* Assembler macros for 64 bit S/390.
   2    Copyright (C) 2001-2019 Free Software Foundation, Inc.
   3    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _LINUX_S390_SYSDEP_H
  21 #define _LINUX_S390_SYSDEP_H
  22
  23 #include <sysdeps/s390/s390-64/sysdep.h>
  24 #include <sysdeps/unix/sysdep.h>
  25 #include <sysdeps/unix/sysv/linux/s390/sysdep.h>
  26 #include <sysdeps/unix/sysv/linux/sysdep.h>
  27 #include <dl-sysdep.h>  /* For RTLD_PRIVATE_ERRNO.  */
  28 #include <tls.h>
  29
  30 /* Define __set_errno() for INLINE_SYSCALL macro below.  */
  31 #ifndef __ASSEMBLER__
  32 #include <errno.h>
  33 #endif
  34
  35 /* For Linux we can use the system call table in the header file
  36         /usr/include/asm/unistd.h
  37    of the kernel.  But these symbols do not follow the SYS_* syntax
  38    so we have to redefine the `SYS_ify' macro here.  */
  39 /* In newer 2.1 kernels __NR_syscall is missing so we define it here.  */
  40 #define __NR_syscall 0
  41
  42 /*
  43  * Newer kernel versions redefined __NR_pread and __NR_pwrite to
  44  * __NR_pread64 and __NR_pwrite64.
  45  */
  46 #ifndef __NR_pread
  47 # define __NR_pread __NR_pread64
  48 #endif
  49 #ifndef __NR_pwrite
  50 # define __NR_pwrite __NR_pwrite64
  51 #endif
  52
  53 #undef SYS_ify
  54 #define SYS_ify(syscall_name)   __NR_##syscall_name
  55
  56 #ifdef __ASSEMBLER__
  57
  58 /* Linux uses a negative return value to indicate syscall errors, unlike
  59    most Unices, which use the condition codes' carry flag.
  60
  61    Since version 2.1 the return value of a system call might be negative
  62    even if the call succeeded.  E.g., the `lseek' system call might return
  63    a large offset.  Therefore we must not anymore test for < 0, but test
  64    for a real error by making sure the value in gpr2 is a real error
  65    number.  Linus said he will make sure that no syscall returns a value
  66    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  67
  68 #undef PSEUDO
  69 #define PSEUDO(name, syscall_name, args)                                      \
  70   .text;                                                                      \
  71   ENTRY (name)                                                                \
  72     DO_CALL (syscall_name, args);                                             \
  73     lghi %r4,-4095 ;                                                          \
  74     clgr %r2,%r4 ;                                                            \
  75     jgnl SYSCALL_ERROR_LABEL
  76
  77 #undef PSEUDO_END
  78 #define PSEUDO_END(name)                                                      \
  79   SYSCALL_ERROR_HANDLER;                                                      \
  80   END (name)
  81
  82 #undef PSEUDO_NOERRNO
  83 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  84   .text;                                                                      \
  85   ENTRY (name)                                                                \
  86     DO_CALL (syscall_name, args)
  87
  88 #undef PSEUDO_END_NOERRNO
  89 #define PSEUDO_END_NOERRNO(name)                                              \
  90   SYSCALL_ERROR_HANDLER;                                                      \
  91   END (name)
  92
  93 #undef PSEUDO_ERRVAL
  94 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  95   .text;                                                                      \
  96   ENTRY (name)                                                                \
  97     DO_CALL (syscall_name, args);                                             \
  98     lcgr %r2,%r2
  99
 100 #undef PSEUDO_END_ERRVAL
 101 #define PSEUDO_END_ERRVAL(name)                                               \
 102   SYSCALL_ERROR_HANDLER;                                                      \
 103   END (name)
 104
 105 #ifndef PIC
 106 # define SYSCALL_ERROR_LABEL syscall_error
 107 # define SYSCALL_ERROR_HANDLER
 108 #else
 109 # if RTLD_PRIVATE_ERRNO
 110 #  define SYSCALL_ERROR_LABEL 0f
 111 #  define SYSCALL_ERROR_HANDLER \
 112 0:  larl  %r1,rtld_errno;                                                     \
 113     lcr   %r2,%r2;                                                            \
 114     st    %r2,0(%r1);                                                         \
 115     lghi  %r2,-1;                                                             \
 116     br    %r14
 117 # elif defined _LIBC_REENTRANT
 118 #  if IS_IN (libc)
 119 #   define SYSCALL_ERROR_ERRNO __libc_errno
 120 #  else
 121 #   define SYSCALL_ERROR_ERRNO errno
 122 #  endif
 123 #  define SYSCALL_ERROR_LABEL 0f
 124 #  define SYSCALL_ERROR_HANDLER \
 125 0:  lcr   %r0,%r2;                                                            \
 126     larl  %r1,SYSCALL_ERROR_ERRNO@indntpoff;                                  \
 127     lg    %r1,0(%r1);                                                         \
 128     ear   %r2,%a0;                                                            \
 129     sllg  %r2,%r2,32;                                                         \
 130     ear   %r2,%a1;                                                            \
 131     st    %r0,0(%r1,%r2);                                                     \
 132     lghi   %r2,-1;                                                            \
 133     br    %r14
 134 # else
 135 #  define SYSCALL_ERROR_LABEL 0f
 136 #  define SYSCALL_ERROR_HANDLER \
 137 0:  larl  %r1,_GLOBAL_OFFSET_TABLE_;                                          \
 138     lg    %r1,errno@GOT(%r1);                                                 \
 139     lcr   %r2,%r2;                                                            \
 140     st    %r2,0(%r1);                                                         \
 141     lghi  %r2,-1;                                                             \
 142     br    %r14
 143 # endif /* _LIBC_REENTRANT */
 144 #endif /* PIC */
 145
 146 /* Linux takes system call arguments in registers:
 147
 148         syscall number  1            call-clobbered
 149         arg 1           2            call-clobbered
 150         arg 2           3            call-clobbered
 151         arg 3           4            call-clobbered
 152         arg 4           5            call-clobbered
 153         arg 5           6            call-saved
 154         arg 6           7            call-saved
 155
 156    (Of course a function with say 3 arguments does not have entries for
 157    arguments 4 and 5.)
 158    For system calls with 6 parameters a stack operation is required
 159    to load the 6th parameter to register 7. Call saved register 7 is
 160    moved to register 0 and back to avoid an additional stack frame.
 161  */
 162
 163 #define DO_CALL(syscall, args)                                                \
 164   .if args > 5;                                                               \
 165     lgr %r0,%r7;                                                              \
 166     lg %r7,160(%r15);                                                         \
 167   .endif;                                                                     \
 168   .if SYS_ify (syscall) < 256;                                                \
 169     svc SYS_ify (syscall);                                                    \
 170   .else;                                                                      \
 171     lghi %r1,SYS_ify (syscall);                                               \
 172     svc 0;                                                                    \
 173   .endif;                                                                     \
 174   .if args > 5;                                                               \
 175     lgr %r7,%r0;                                                              \
 176   .endif
 177
 178 #define ret                                                                   \
 179     br      14
 180
 181 #define ret_NOERRNO                                                           \
 182     br      14
 183
 184 #define ret_ERRVAL                                                            \
 185     br      14
 186
 187 #endif /* __ASSEMBLER__ */
 188
 189 #undef INLINE_SYSCALL
 190 #define INLINE_SYSCALL(name, nr, args...)                                     \
 191   ({                                                                          \
 192     long _ret = INTERNAL_SYSCALL (name, , nr, args);                          \
 193     if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, )))                 \
 194      {                                                                        \
 195        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 196        _ret = -1;                                                             \
 197      }                                                                        \
 198     _ret; })
 199
 200 #undef INTERNAL_SYSCALL_DECL
 201 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 202
 203 #undef INTERNAL_SYSCALL_DIRECT
 204 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 205   ({                                                                          \
 206     DECLARGS_##nr(args)                                                       \
 207     register long _ret __asm__("2");                                          \
 208     __asm__ __volatile__ (                                                    \
 209                           "svc    %b1\n\t"                                    \
 210                           : "=d" (_ret)                                       \
 211                           : "i" (__NR_##name) ASMFMT_##nr                     \
 212                           : "memory" );                                       \
 213     _ret; })
 214
 215 #undef INTERNAL_SYSCALL_SVC0
 216 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 217   ({                                                                          \
 218     DECLARGS_##nr(args)                                                       \
 219     register unsigned long _nr __asm__("1") = (unsigned long)(__NR_##name);   \
 220     register long _ret __asm__("2");                                          \
 221     __asm__ __volatile__ (                                                    \
 222                           "svc    0\n\t"                                      \
 223                           : "=d" (_ret)                                       \
 224                           : "d" (_nr) ASMFMT_##nr                             \
 225                           : "memory" );                                       \
 226     _ret; })
 227
 228 #undef INTERNAL_SYSCALL_NCS
 229 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 230   ({                                                                          \
 231     DECLARGS_##nr(args)                                                       \
 232     register unsigned long _nr __asm__("1") = (unsigned long)(no);            \
 233     register long _ret __asm__("2");                                          \
 234     __asm__ __volatile__ (                                                    \
 235                           "svc    0\n\t"                                      \
 236                           : "=d" (_ret)                                       \
 237                           : "d" (_nr) ASMFMT_##nr                             \
 238                           : "memory" );                                       \
 239     _ret; })
 240
 241 #undef INTERNAL_SYSCALL
 242 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 243   (((__NR_##name) < 256)                                                      \
 244    ? INTERNAL_SYSCALL_DIRECT(name, err, nr, args)                             \
 245    : INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 246
 247 #undef INTERNAL_SYSCALL_ERROR_P
 248 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 249   ((unsigned long) (val) >= -4095UL)
 250
 251 #undef INTERNAL_SYSCALL_ERRNO
 252 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 253
 254 #define DECLARGS_0()
 255 #define DECLARGS_1(arg1) \
 256         register unsigned long gpr2 __asm__ ("2") = (unsigned long)(arg1);
 257 #define DECLARGS_2(arg1, arg2) \
 258         DECLARGS_1(arg1) \
 259         register unsigned long gpr3 __asm__ ("3") = (unsigned long)(arg2);
 260 #define DECLARGS_3(arg1, arg2, arg3) \
 261         DECLARGS_2(arg1, arg2) \
 262         register unsigned long gpr4 __asm__ ("4") = (unsigned long)(arg3);
 263 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 264         DECLARGS_3(arg1, arg2, arg3) \
 265         register unsigned long gpr5 __asm__ ("5") = (unsigned long)(arg4);
 266 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 267         DECLARGS_4(arg1, arg2, arg3, arg4) \
 268         register unsigned long gpr6 __asm__ ("6") = (unsigned long)(arg5);
 269 #define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
 270         DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 271         register unsigned long gpr7 __asm__ ("7") = (unsigned long)(arg6);
 272
 273 #define ASMFMT_0
 274 #define ASMFMT_1 , "0" (gpr2)
 275 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 276 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 277 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 278 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 279 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 280
 281 #define SINGLE_THREAD_BY_GLOBAL         1
 282
 283 /* Pointer mangling support.  */
 284 #if IS_IN (rtld)
 285 /* We cannot use the thread descriptor because in ld.so we use setjmp
 286    earlier than the descriptor is initialized.  */
 287 #else
 288 /* For the time being just use stack_guard rather than a separate
 289    pointer_guard.  */
 290 # ifdef __ASSEMBLER__
 291 #  define PTR_MANGLE(reg, tmpreg) \
 292   ear     tmpreg,%a0;                   \
 293   sllg    tmpreg,tmpreg,32;             \
 294   ear     tmpreg,%a1;                   \
 295   xg      reg,STACK_GUARD(tmpreg)
 296 #  define PTR_MANGLE2(reg, tmpreg) \
 297   xg      reg,STACK_GUARD(tmpreg)
 298 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 299 # else
 300 #  define PTR_MANGLE(var) \
 301   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 302 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 303 # endif
 304 #endif
 305
 306 #endif /* _LINUX_S390_SYSDEP_H */