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

   1 /* Assembler macros for 64 bit S/390.
   2    Copyright (C) 2001-2014 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 <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 /*
  41  * Newer kernel versions redefined __NR_pread and __NR_pwrite to
  42  * __NR_pread64 and __NR_pwrite64.
  43  */
  44 #ifndef __NR_pread
  45 # define __NR_pread __NR_pread64
  46 #endif
  47 #ifndef __NR_pwrite
  48 # define __NR_pwrite __NR_pwrite64
  49 #endif
  50
  51 #undef SYS_ify
  52 #define SYS_ify(syscall_name)   __NR_##syscall_name
  53
  54 #ifdef __ASSEMBLER__
  55
  56 /* Linux uses a negative return value to indicate syscall errors, unlike
  57    most Unices, which use the condition codes' carry flag.
  58
  59    Since version 2.1 the return value of a system call might be negative
  60    even if the call succeeded.  E.g., the `lseek' system call might return
  61    a large offset.  Therefore we must not anymore test for < 0, but test
  62    for a real error by making sure the value in gpr2 is a real error
  63    number.  Linus said he will make sure that no syscall returns a value
  64    in -1 .. -4095 as a valid result so we can savely test with -4095.  */
  65
  66 #undef PSEUDO
  67 #define PSEUDO(name, syscall_name, args)                                      \
  68   .text;                                                                      \
  69   ENTRY (name)                                                                \
  70     DO_CALL (syscall_name, args);                                             \
  71     lghi %r4,-4095 ;                                                          \
  72     clgr %r2,%r4 ;                                                            \
  73     jgnl SYSCALL_ERROR_LABEL
  74
  75 #undef PSEUDO_END
  76 #define PSEUDO_END(name)                                                      \
  77   SYSCALL_ERROR_HANDLER;                                                      \
  78   END (name)
  79
  80 #undef PSEUDO_NOERRNO
  81 #define PSEUDO_NOERRNO(name, syscall_name, args)                              \
  82   .text;                                                                      \
  83   ENTRY (name)                                                                \
  84     DO_CALL (syscall_name, args)
  85
  86 #undef PSEUDO_END_NOERRNO
  87 #define PSEUDO_END_NOERRNO(name)                                              \
  88   SYSCALL_ERROR_HANDLER;                                                      \
  89   END (name)
  90
  91 #undef PSEUDO_ERRVAL
  92 #define PSEUDO_ERRVAL(name, syscall_name, args)                               \
  93   .text;                                                                      \
  94   ENTRY (name)                                                                \
  95     DO_CALL (syscall_name, args);                                             \
  96     lcgr %r2,%r2
  97
  98 #undef PSEUDO_END_ERRVAL
  99 #define PSEUDO_END_ERRVAL(name)                                               \
 100   SYSCALL_ERROR_HANDLER;                                                      \
 101   END (name)
 102
 103 #ifndef PIC
 104 # define SYSCALL_ERROR_LABEL syscall_error
 105 # define SYSCALL_ERROR_HANDLER
 106 #else
 107 # if RTLD_PRIVATE_ERRNO
 108 #  define SYSCALL_ERROR_LABEL 0f
 109 #  define SYSCALL_ERROR_HANDLER \
 110 0:  larl  %r1,rtld_errno;                                                     \
 111     lcr   %r2,%r2;                                                            \
 112     st    %r2,0(%r1);                                                         \
 113     lghi  %r2,-1;                                                             \
 114     br    %r14
 115 # elif defined _LIBC_REENTRANT
 116 #  ifndef NOT_IN_libc
 117 #   define SYSCALL_ERROR_ERRNO __libc_errno
 118 #  else
 119 #   define SYSCALL_ERROR_ERRNO errno
 120 #  endif
 121 #  define SYSCALL_ERROR_LABEL 0f
 122 #  define SYSCALL_ERROR_HANDLER \
 123 0:  lcr   %r0,%r2;                                                            \
 124     larl  %r1,SYSCALL_ERROR_ERRNO@indntpoff;                                  \
 125     lg    %r1,0(%r1);                                                         \
 126     ear   %r2,%a0;                                                            \
 127     sllg  %r2,%r2,32;                                                         \
 128     ear   %r2,%a1;                                                            \
 129     st    %r0,0(%r1,%r2);                                                     \
 130     lghi   %r2,-1;                                                            \
 131     br    %r14
 132 # else
 133 #  define SYSCALL_ERROR_LABEL 0f
 134 #  define SYSCALL_ERROR_HANDLER \
 135 0:  larl  %r1,_GLOBAL_OFFSET_TABLE_;                                          \
 136     lg    %r1,errno@GOT(%r1);                                                 \
 137     lcr   %r2,%r2;                                                            \
 138     st    %r2,0(%r1);                                                         \
 139     lghi  %r2,-1;                                                             \
 140     br    %r14
 141 # endif /* _LIBC_REENTRANT */
 142 #endif /* PIC */
 143
 144 /* Linux takes system call arguments in registers:
 145
 146         syscall number  1            call-clobbered
 147         arg 1           2            call-clobbered
 148         arg 2           3            call-clobbered
 149         arg 3           4            call-clobbered
 150         arg 4           5            call-clobbered
 151         arg 5           6            call-saved
 152         arg 6           7            call-saved
 153
 154    (Of course a function with say 3 arguments does not have entries for
 155    arguments 4 and 5.)
 156    For system calls with 6 parameters a stack operation is required
 157    to load the 6th parameter to register 7. Call saved register 7 is
 158    moved to register 0 and back to avoid an additional stack frame.
 159  */
 160
 161 #define DO_CALL(syscall, args)                                                \
 162   .if args > 5;                                                               \
 163     lgr %r0,%r7;                                                              \
 164     lg %r7,160(%r15);                                                         \
 165   .endif;                                                                     \
 166   .if SYS_ify (syscall) < 256;                                                \
 167     svc SYS_ify (syscall);                                                    \
 168   .else;                                                                      \
 169     lghi %r1,SYS_ify (syscall);                                               \
 170     svc 0;                                                                    \
 171   .endif;                                                                     \
 172   .if args > 5;                                                               \
 173     lgr %r7,%r0;                                                              \
 174   .endif
 175
 176 #define ret                                                                   \
 177     br      14
 178
 179 #define ret_NOERRNO                                                           \
 180     br      14
 181
 182 #define ret_ERRVAL                                                            \
 183     br      14
 184
 185 #endif /* __ASSEMBLER__ */
 186
 187 #undef INLINE_SYSCALL
 188 #define INLINE_SYSCALL(name, nr, args...)                                     \
 189   ({                                                                          \
 190     long _ret = INTERNAL_SYSCALL (name, , nr, args);                          \
 191     if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (_ret, )))                 \
 192      {                                                                        \
 193        __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                         \
 194        _ret = -1;                                                             \
 195      }                                                                        \
 196     _ret; })
 197
 198 #undef INTERNAL_SYSCALL_DECL
 199 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
 200
 201 #undef INTERNAL_SYSCALL_DIRECT
 202 #define INTERNAL_SYSCALL_DIRECT(name, err, nr, args...)                       \
 203   ({                                                                          \
 204     DECLARGS_##nr(args)                                                       \
 205     register long _ret asm("2");                                              \
 206     asm volatile (                                                            \
 207     "svc    %b1\n\t"                                                          \
 208     : "=d" (_ret)                                                             \
 209     : "i" (__NR_##name) ASMFMT_##nr                                           \
 210     : "memory" );                                                             \
 211     _ret; })
 212
 213 #undef INTERNAL_SYSCALL_SVC0
 214 #define INTERNAL_SYSCALL_SVC0(name, err, nr, args...)                         \
 215   ({                                                                          \
 216     DECLARGS_##nr(args)                                                       \
 217     register unsigned long _nr asm("1") = (unsigned long)(__NR_##name);       \
 218     register long _ret asm("2");                                              \
 219     asm volatile (                                                            \
 220     "svc    0\n\t"                                                            \
 221     : "=d" (_ret)                                                             \
 222     : "d" (_nr) ASMFMT_##nr                                                   \
 223     : "memory" );                                                             \
 224     _ret; })
 225
 226 #undef INTERNAL_SYSCALL_NCS
 227 #define INTERNAL_SYSCALL_NCS(no, err, nr, args...)                            \
 228   ({                                                                          \
 229     DECLARGS_##nr(args)                                                       \
 230     register unsigned long _nr asm("1") = (unsigned long)(no);                \
 231     register long _ret asm("2");                                              \
 232     asm volatile (                                                            \
 233     "svc    0\n\t"                                                            \
 234     : "=d" (_ret)                                                             \
 235     : "d" (_nr) ASMFMT_##nr                                                   \
 236     : "memory" );                                                             \
 237     _ret; })
 238
 239 #undef INTERNAL_SYSCALL
 240 #define INTERNAL_SYSCALL(name, err, nr, args...)                              \
 241   (((__NR_##name) < 256) ?                                                    \
 242     INTERNAL_SYSCALL_DIRECT(name, err, nr, args) :                            \
 243     INTERNAL_SYSCALL_SVC0(name, err,nr, args))
 244
 245 #undef INTERNAL_SYSCALL_ERROR_P
 246 #define INTERNAL_SYSCALL_ERROR_P(val, err)                                    \
 247   ((unsigned long) (val) >= -4095UL)
 248
 249 #undef INTERNAL_SYSCALL_ERRNO
 250 #define INTERNAL_SYSCALL_ERRNO(val, err)        (-(val))
 251
 252 #define DECLARGS_0()
 253 #define DECLARGS_1(arg1) \
 254         register unsigned long gpr2 asm ("2") = (unsigned long)(arg1);
 255 #define DECLARGS_2(arg1, arg2) \
 256         DECLARGS_1(arg1) \
 257         register unsigned long gpr3 asm ("3") = (unsigned long)(arg2);
 258 #define DECLARGS_3(arg1, arg2, arg3) \
 259         DECLARGS_2(arg1, arg2) \
 260         register unsigned long gpr4 asm ("4") = (unsigned long)(arg3);
 261 #define DECLARGS_4(arg1, arg2, arg3, arg4) \
 262         DECLARGS_3(arg1, arg2, arg3) \
 263         register unsigned long gpr5 asm ("5") = (unsigned long)(arg4);
 264 #define DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 265         DECLARGS_4(arg1, arg2, arg3, arg4) \
 266         register unsigned long gpr6 asm ("6") = (unsigned long)(arg5);
 267 #define DECLARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
 268         DECLARGS_5(arg1, arg2, arg3, arg4, arg5) \
 269         register unsigned long gpr7 asm ("7") = (unsigned long)(arg6);
 270
 271 #define ASMFMT_0
 272 #define ASMFMT_1 , "0" (gpr2)
 273 #define ASMFMT_2 , "0" (gpr2), "d" (gpr3)
 274 #define ASMFMT_3 , "0" (gpr2), "d" (gpr3), "d" (gpr4)
 275 #define ASMFMT_4 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5)
 276 #define ASMFMT_5 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6)
 277 #define ASMFMT_6 , "0" (gpr2), "d" (gpr3), "d" (gpr4), "d" (gpr5), "d" (gpr6), "d" (gpr7)
 278
 279 #define CLOBBER_0 , "3", "4", "5"
 280 #define CLOBBER_1 , "3", "4", "5"
 281 #define CLOBBER_2 , "4", "5"
 282 #define CLOBBER_3 , "5"
 283 #define CLOBBER_4
 284 #define CLOBBER_5
 285 #define CLOBBER_6
 286
 287 /* List of system calls which are supported as vsyscalls.  */
 288 #define HAVE_CLOCK_GETRES_VSYSCALL      1
 289 #define HAVE_CLOCK_GETTIME_VSYSCALL     1
 290
 291 /* This version is for kernels that implement system calls that
 292    behave like function calls as far as register saving.
 293    It falls back to the syscall in the case that the vDSO doesn't
 294    exist or fails for ENOSYS */
 295 #ifdef SHARED
 296 # define INLINE_VSYSCALL(name, nr, args...) \
 297   ({                                                                          \
 298     __label__ out;                                                            \
 299     __label__ iserr;                                                          \
 300     long int _ret;                                                            \
 301                                                                               \
 302     if (__vdso_##name != NULL)                                                \
 303       {                                                                       \
 304         _ret = INTERNAL_VSYSCALL_NCS (__vdso_##name, , nr, ##args);           \
 305         if (!INTERNAL_SYSCALL_ERROR_P (_ret, ))                               \
 306           goto out;                                                           \
 307         if (INTERNAL_SYSCALL_ERRNO (_ret, ) != ENOSYS)                        \
 308           goto iserr;                                                         \
 309       }                                                                       \
 310                                                                               \
 311     _ret = INTERNAL_SYSCALL (name, , nr, ##args);                             \
 312     if (INTERNAL_SYSCALL_ERROR_P (_ret, ))                                    \
 313       {                                                                       \
 314       iserr:                                                                  \
 315         __set_errno (INTERNAL_SYSCALL_ERRNO (_ret, ));                        \
 316         _ret = -1L;                                                           \
 317       }                                                                       \
 318   out:                                                                        \
 319     (int) _ret;                                                               \
 320   })
 321 #else
 322 # define INLINE_VSYSCALL(name, nr, args...) \
 323   INLINE_SYSCALL (name, nr, ##args)
 324 #endif
 325
 326 #ifdef SHARED
 327 # define INTERNAL_VSYSCALL(name, err, nr, args...) \
 328   ({                                                                          \
 329     __label__ out;                                                            \
 330     long int _ret;                                                            \
 331                                                                               \
 332     if (__vdso_##name != NULL)                                                \
 333       {                                                                       \
 334         _ret = INTERNAL_VSYSCALL_NCS (__vdso_##name, err, nr, ##args);        \
 335         if (!INTERNAL_SYSCALL_ERROR_P (_ret, err)                             \
 336             || INTERNAL_SYSCALL_ERRNO (_ret, err) != ENOSYS)                  \
 337           goto out;                                                           \
 338       }                                                                       \
 339     _ret = INTERNAL_SYSCALL (name, err, nr, ##args);                          \
 340   out:                                                                        \
 341     _ret;                                                                     \
 342   })
 343 #else
 344 # define INTERNAL_VSYSCALL(name, err, nr, args...) \
 345   INTERNAL_SYSCALL (name, err, nr, ##args)
 346 #endif
 347
 348 /* This version is for internal uses when there is no desire
 349    to set errno */
 350 #define INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK(name, err, nr, args...)         \
 351   ({                                                                          \
 352     long int _ret = ENOSYS;                                                   \
 353                                                                               \
 354     if (__vdso_##name != NULL)                                                \
 355       _ret = INTERNAL_VSYSCALL_NCS (__vdso_##name, err, nr, ##args);          \
 356     else                                                                      \
 357       err = 1 << 28;                                                          \
 358     _ret;                                                                     \
 359   })
 360
 361 #define INTERNAL_VSYSCALL_NCS(fn, err, nr, args...)                           \
 362   ({                                                                          \
 363     DECLARGS_##nr(args)                                                       \
 364     register long _ret asm("2");                                              \
 365     asm volatile (                                                            \
 366     "lgr 10,14\n\t"                                                          \
 367     "basr 14,%1\n\t"                                                          \
 368     "lgr 14,10\n\t"                                                          \
 369     : "=d" (_ret)                                                             \
 370     : "a" (fn) ASMFMT_##nr                                                    \
 371     : "cc", "memory", "0", "1", "10" CLOBBER_##nr);                          \
 372     _ret; })
 373
 374 /* Pointer mangling support.  */
 375 #if IS_IN (rtld)
 376 /* We cannot use the thread descriptor because in ld.so we use setjmp
 377    earlier than the descriptor is initialized.  */
 378 #else
 379 /* For the time being just use stack_guard rather than a separate
 380    pointer_guard.  */
 381 # ifdef __ASSEMBLER__
 382 #  define PTR_MANGLE(reg, tmpreg) \
 383   ear     tmpreg,%a0;                   \
 384   sllg    tmpreg,tmpreg,32;             \
 385   ear     tmpreg,%a1;                   \
 386   xg      reg,STACK_GUARD(tmpreg)
 387 #  define PTR_MANGLE2(reg, tmpreg) \
 388   xg      reg,STACK_GUARD(tmpreg)
 389 #  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
 390 # else
 391 #  define PTR_MANGLE(var) \
 392   (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
 393 #  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
 394 # endif
 395 #endif
 396
 397 #endif /* _LINUX_S390_SYSDEP_H */