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    <http://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/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 /*
  42  * Newer kernel versions redefined __NR_pread and __NR_pwrite to
  43  * __NR_pread64 and __NR_pwrite64.
  44  */
  45 #ifndef __NR_pread
  46 # define __NR_pread __NR_pread64
  47 #endif
  48 #ifndef __NR_pwrite
  49 # define __NR_pwrite __NR_pwrite64
  50 #endif
  51
  52 #undef SYS_ify
  53 #define SYS_ify(syscall_name)   __NR_##syscall_name
  54
  55 #ifdef __ASSEMBLER__
  56
  57 /* Linux uses a negative return value to indicate syscall errors, unlike
  58    most Unices, which use the condition codes' carry flag.
  59
  60    Since version 2.1 the return value of a system call might be negative
  61    even if the call succeeded.  E.g., the `lseek' system call might return
  62    a large offset.  Therefore we must not anymore test for < 0, but test
  63    for a real error by making sure the value in gpr2 is a real error
  64    number.  Linus said he will make sure that no syscall returns a value
  65    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  66
  67 #undef PSEUDO
  68 #define PSEUDO(name, syscall_name, args)                                      \
  69   .text;                                                                      \
  70   ENTRY (name)                                                                \
  71     DO_CALL (syscall_name, args);                                             \
  72     lghi %r4,-4095 ;                                                          \
  73     clgr %r2,%r4 ;                                                            \
  74     jgnl SYSCALL_ERROR_LABEL
  75
  76 #undef PSEUDO_END
  77 #define PSEUDO_END(name)                                                      \
  78   SYSCALL_ERROR_HANDLER;                                                      \
  79   END (name)
  80
  81 #undef PSEUDO_NOERRNO
  82 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  83   .text;                                                                      \
  84   ENTRY (name)                                                                \
  85     DO_CALL (syscall_name, args)
  86
  87 #undef PSEUDO_END_NOERRNO
  88 #define PSEUDO_END_NOERRNO(name)                                              \
  89   SYSCALL_ERROR_HANDLER;                                                      \
  90   END (name)
  91
  92 #undef PSEUDO_ERRVAL
  93 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  94   .text;                                                                      \
  95   ENTRY (name)                                                                \
  96     DO_CALL (syscall_name, args);                                             \
  97     lcgr %r2,%r2
  98
  99 #undef PSEUDO_END_ERRVAL
 100 #define PSEUDO_END_ERRVAL(name)                                               \
 101   SYSCALL_ERROR_HANDLER;                                                      \
 102   END (name)
 103
 104 #ifndef PIC
 105 # define SYSCALL_ERROR_LABEL syscall_error
 106 # define SYSCALL_ERROR_HANDLER
 107 #else
 108 # if RTLD_PRIVATE_ERRNO
 109 #  define SYSCALL_ERROR_LABEL 0f
 110 #  define SYSCALL_ERROR_HANDLER \
 111 0:  larl  %r1,rtld_errno;                                                     \
 112     lcr   %r2,%r2;                                                            \
 113     st    %r2,0(%r1);                                                         \
 114     lghi  %r2,-1;                                                             \
 115     br    %r14
 116 # elif defined _LIBC_REENTRANT
 117 #  if IS_IN (libc)
 118 #   define SYSCALL_ERROR_ERRNO __libc_errno
 119 #  else
 120 #   define SYSCALL_ERROR_ERRNO errno
 121 #  endif
 122 #  define SYSCALL_ERROR_LABEL 0f
 123 #  define SYSCALL_ERROR_HANDLER \
 124 0:  lcr   %r0,%r2;                                                            \
 125     larl  %r1,SYSCALL_ERROR_ERRNO@indntpoff;                                  \
 126     lg    %r1,0(%r1);                                                         \
 127     ear   %r2,%a0;                                                            \
 128     sllg  %r2,%r2,32;                                                         \
 129     ear   %r2,%a1;                                                            \
 130     st    %r0,0(%r1,%r2);                                                     \
 131     lghi   %r2,-1;                                                            \
 132     br    %r14
 133 # else
 134 #  define SYSCALL_ERROR_LABEL 0f
 135 #  define SYSCALL_ERROR_HANDLER \
 136 0:  larl  %r1,_GLOBAL_OFFSET_TABLE_;                                          \
 137     lg    %r1,errno@GOT(%r1);                                                 \
 138     lcr   %r2,%r2;                                                            \
 139     st    %r2,0(%r1);                                                         \
 140     lghi  %r2,-1;                                                             \
 141     br    %r14
 142 # endif /* _LIBC_REENTRANT */
 143 #endif /* PIC */
 144
 145 /* Linux takes system call arguments in registers:
 146
 147         syscall number  1            call-clobbered
 148         arg 1           2            call-clobbered
 149         arg 2           3            call-clobbered
 150         arg 3           4            call-clobbered
 151         arg 4           5            call-clobbered
 152         arg 5           6            call-saved
 153         arg 6           7            call-saved
 154
 155    (Of course a function with say 3 arguments does not have entries for
 156    arguments 4 and 5.)
 157    For system calls with 6 parameters a stack operation is required
 158    to load the 6th parameter to register 7. Call saved register 7 is
 159    moved to register 0 and back to avoid an additional stack frame.
 160  */
 161
 162 #define DO_CALL(syscall, args)                                                \
 163   .if args > 5;                                                               \
 164     lgr %r0,%r7;                                                              \
 165     lg %r7,160(%r15);                                                         \
 166   .endif;                                                                     \
 167   .if SYS_ify (syscall) < 256;                                                \
 168     svc SYS_ify (syscall);                                                    \
 169   .else;                                                                      \
 170     lghi %r1,SYS_ify (syscall);                                               \
 171     svc 0;                                                                    \
 172   .endif;                                                                     \
 173   .if args > 5;                                                               \
 174     lgr %r7,%r0;                                                              \
 175   .endif
 176
 177 #define ret                                                                   \
 178     br      14
 179
 180 #define ret_NOERRNO                                                           \
 181     br      14
 182
 183 #define ret_ERRVAL                                                            \
 184     br      14
 185
 186 #endif /* __ASSEMBLER__ */
 187
 188 #undef INLINE_SYSCALL
 189 #define INLINE_SYSCALL(name, nr, args...)                                     \
 190   ({                                                                          \
 191     long _ret = INTERNAL_SYSCALL (name, , nr, args);                          \
 192     if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, )))                 \
 193      {                                                                        \
 194        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 195        _ret = -1;                                                             \
 196      }                                                                        \
 197     _ret; })
 198
 199 #undef INTERNAL_SYSCALL_DECL
 200 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 201
 202 #undef INTERNAL_SYSCALL_DIRECT
 203 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 204   ({                                                                          \
 205     DECLARGS_##nr(args)                                                       \
 206     register long _ret __asm__("2");                                          \
 207     __asm__ __volatile__ (                                                    \
 208                           "svc    %b1\n\t"                                    \
 209                           : "=d" (_ret)                                       \
 210                           : "i" (__NR_##name) ASMFMT_##nr                     \
 211                           : "memory" );                                       \
 212     _ret; })
 213
 214 #undef INTERNAL_SYSCALL_SVC0
 215 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 216   ({                                                                          \
 217     DECLARGS_##nr(args)                                                       \
 218     register unsigned long _nr __asm__("1") = (unsigned long)(__NR_##name);   \
 219     register long _ret __asm__("2");                                          \
 220     __asm__ __volatile__ (                                                    \
 221                           "svc    0\n\t"                                      \
 222                           : "=d" (_ret)                                       \
 223                           : "d" (_nr) ASMFMT_##nr                             \
 224                           : "memory" );                                       \
 225     _ret; })
 226
 227 #undef INTERNAL_SYSCALL_NCS
 228 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 229   ({                                                                          \
 230     DECLARGS_##nr(args)                                                       \
 231     register unsigned long _nr __asm__("1") = (unsigned long)(no);            \
 232     register long _ret __asm__("2");                                          \
 233     __asm__ __volatile__ (                                                    \
 234                           "svc    0\n\t"                                      \
 235                           : "=d" (_ret)                                       \
 236                           : "d" (_nr) ASMFMT_##nr                             \
 237                           : "memory" );                                       \
 238     _ret; })
 239
 240 #undef INTERNAL_SYSCALL
 241 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 242   (((__NR_##name) < 256)                                                      \
 243    ? INTERNAL_SYSCALL_DIRECT(name, err, nr, args)                             \
 244    : INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 245
 246 #undef INTERNAL_SYSCALL_ERROR_P
 247 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 248   ((unsigned long) (val) >= -4095UL)
 249
 250 #undef INTERNAL_SYSCALL_ERRNO
 251 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 252
 253 #define DECLARGS_0()
 254 #define DECLARGS_1(arg1) \
 255         register unsigned long gpr2 __asm__ ("2") = (unsigned long)(arg1);
 256 #define DECLARGS_2(arg1, arg2) \
 257         DECLARGS_1(arg1) \
 258         register unsigned long gpr3 __asm__ ("3") = (unsigned long)(arg2);
 259 #define DECLARGS_3(arg1, arg2, arg3) \
 260         DECLARGS_2(arg1, arg2) \
 261         register unsigned long gpr4 __asm__ ("4") = (unsigned long)(arg3);
 262 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 263         DECLARGS_3(arg1, arg2, arg3) \
 264         register unsigned long gpr5 __asm__ ("5") = (unsigned long)(arg4);
 265 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 266         DECLARGS_4(arg1, arg2, arg3, arg4) \
 267         register unsigned long gpr6 __asm__ ("6") = (unsigned long)(arg5);
 268 #define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
 269         DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 270         register unsigned long gpr7 __asm__ ("7") = (unsigned long)(arg6);
 271
 272 #define ASMFMT_0
 273 #define ASMFMT_1 , "0" (gpr2)
 274 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 275 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 276 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 277 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 278 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 279
 280 /* List of system calls which are supported as vsyscalls.  */
 281 #define HAVE_CLOCK_GETRES_VSYSCALL      1
 282 #define HAVE_CLOCK_GETTIME_VSYSCALL     1
 283 #define HAVE_GETTIMEOFDAY_VSYSCALL      1
 284 #define HAVE_GETCPU_VSYSCALL            1
 285
 286 #define SINGLE_THREAD_BY_GLOBAL         1
 287
 288 /* Pointer mangling support.  */
 289 #if IS_IN (rtld)
 290 /* We cannot use the thread descriptor because in ld.so we use setjmp
 291    earlier than the descriptor is initialized.  */
 292 #else
 293 /* For the time being just use stack_guard rather than a separate
 294    pointer_guard.  */
 295 # ifdef __ASSEMBLER__
 296 #  define PTR_MANGLE(reg, tmpreg) \
 297   ear     tmpreg,%a0;                   \
 298   sllg    tmpreg,tmpreg,32;             \
 299   ear     tmpreg,%a1;                   \
 300   xg      reg,STACK_GUARD(tmpreg)
 301 #  define PTR_MANGLE2(reg, tmpreg) \
 302   xg      reg,STACK_GUARD(tmpreg)
 303 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 304 # else
 305 #  define PTR_MANGLE(var) \
 306   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 307 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 308 # endif
 309 #endif
 310
 311 #endif /* _LINUX_S390_SYSDEP_H */