sysdeps/unix/sysv/linux/aarch64/sysdep-cancel.h

   1 /* Copyright (C) 2003-2015 Free Software Foundation, Inc.
   2
   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 #include <sysdep.h>
  20 #include <tls.h>
  21 #ifndef __ASSEMBLER__
  22 # include <nptl/pthreadP.h>
  23 #endif
  24
  25 #if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt)
  26
  27 # undef PSEUDO
  28 # define PSEUDO(name, syscall_name, args)                               \
  29         .section ".text";                                               \
  30 ENTRY (__##syscall_name##_nocancel);                                    \
  31 .Lpseudo_nocancel:                                                      \
  32         DO_CALL (syscall_name, args);                                   \
  33 .Lpseudo_finish:                                                        \
  34         cmn     x0, 4095;                                               \
  35         b.cs    .Lsyscall_error;                                        \
  36         .subsection 2;                                                  \
  37         .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel; \
  38 ENTRY (name);                                                           \
  39         SINGLE_THREAD_P(16);                                            \
  40         cbz     w16, .Lpseudo_nocancel;                                 \
  41         /* Setup common stack frame no matter the number of args.       \
  42            Also save the first arg, since it's basically free.  */      \
  43         stp     x30, x0, [sp, -64]!;                                    \
  44         cfi_adjust_cfa_offset (64);                                     \
  45         cfi_rel_offset (x30, 0);                                        \
  46         DOCARGS_##args;         /* save syscall args around CENABLE.  */ \
  47         CENABLE;                                                        \
  48         mov     x16, x0;        /* save mask around syscall.  */        \
  49         UNDOCARGS_##args;       /* restore syscall args.  */            \
  50         DO_CALL (syscall_name, args);                                   \
  51         str     x0, [sp, 8];    /* save result around CDISABLE.  */     \
  52         mov     x0, x16;        /* restore mask for CDISABLE.  */       \
  53         CDISABLE;                                                       \
  54         /* Break down the stack frame, restoring result at once.  */    \
  55         ldp     x30, x0, [sp], 64;                                      \
  56         cfi_adjust_cfa_offset (-64);                                    \
  57         cfi_restore (x30);                                              \
  58         b       .Lpseudo_finish;                                        \
  59         cfi_endproc;                                                    \
  60         .size   name, .-name;                                           \
  61         .previous
  62
  63 # undef PSEUDO_END
  64 # define PSEUDO_END(name)                                               \
  65         SYSCALL_ERROR_HANDLER;                                          \
  66         cfi_endproc
  67
  68 # define DOCARGS_0
  69 # define DOCARGS_1
  70 # define DOCARGS_2      str x1, [sp, 16]
  71 # define DOCARGS_3      stp x1, x2, [sp, 16]
  72 # define DOCARGS_4      DOCARGS_3; str x3, [sp, 32]
  73 # define DOCARGS_5      DOCARGS_3; stp x3, x4, [sp, 32]
  74 # define DOCARGS_6      DOCARGS_5; str x5, [sp, 48]
  75
  76 # define UNDOCARGS_0
  77 # define UNDOCARGS_1    ldr x0, [sp, 8]
  78 # define UNDOCARGS_2    ldp x0, x1, [sp, 8]
  79 # define UNDOCARGS_3    UNDOCARGS_1; ldp x1, x2, [sp, 16]
  80 # define UNDOCARGS_4    UNDOCARGS_2; ldp x2, x3, [sp, 24]
  81 # define UNDOCARGS_5    UNDOCARGS_3; ldp x3, x4, [sp, 32]
  82 # define UNDOCARGS_6    UNDOCARGS_4; ldp x4, x5, [sp, 40]
  83
  84 # if IS_IN (libpthread)
  85 #  define CENABLE       bl __pthread_enable_asynccancel
  86 #  define CDISABLE      bl __pthread_disable_asynccancel
  87 #  define __local_multiple_threads __pthread_multiple_threads
  88 # elif IS_IN (libc)
  89 #  define CENABLE       bl __libc_enable_asynccancel
  90 #  define CDISABLE      bl __libc_disable_asynccancel
  91 #  define __local_multiple_threads __libc_multiple_threads
  92 # elif IS_IN (librt)
  93 #  define CENABLE       bl __librt_enable_asynccancel
  94 #  define CDISABLE      bl __librt_disable_asynccancel
  95 # else
  96 #  error Unsupported library
  97 # endif
  98
  99 # if IS_IN (libpthread) || IS_IN (libc)
 100 #  ifndef __ASSEMBLER__
 101 extern int __local_multiple_threads attribute_hidden;
 102 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
 103 #  else
 104 #   define SINGLE_THREAD_P(R)                                           \
 105         adrp    x##R, __local_multiple_threads;                         \
 106         ldr     w##R, [x##R, :lo12:__local_multiple_threads]
 107 #  endif
 108 # else
 109 /*  There is no __local_multiple_threads for librt, so use the TCB.  */
 110 #  ifndef __ASSEMBLER__
 111 #   define SINGLE_THREAD_P                                              \
 112   __builtin_expect (THREAD_GETMEM (THREAD_SELF,                         \
 113                                    header.multiple_threads) == 0, 1)
 114 #  else
 115 #   define SINGLE_THREAD_P(R)                                           \
 116         mrs     x##R, tpidr_el0;                                        \
 117         sub     x##R, x##R, PTHREAD_SIZEOF;                             \
 118         ldr     w##R, [x##R, PTHREAD_MULTIPLE_THREADS_OFFSET]
 119 #  endif
 120 # endif
 121
 122 #elif !defined __ASSEMBLER__
 123
 124 /* For rtld, et cetera.  */
 125 # define SINGLE_THREAD_P 1
 126 # define NO_CANCELLATION 1
 127
 128 #endif
 129
 130 #ifndef __ASSEMBLER__
 131 # define RTLD_SINGLE_THREAD_P \
 132   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
 133                                    header.multiple_threads) == 0, 1)
 134 #endif