ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h

   1 /* Copyright (C) 2003, 2004, 2005, 2009 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19 #include <tls.h>
  20 #ifndef __ASSEMBLER__
  21 # include <nptl/pthreadP.h>
  22 #endif
  23
  24 #if !defined NOT_IN_libc || defined IS_IN_libpthread || defined IS_IN_librt
  25
  26 /* NOTE: We do mark syscalls with unwind annotations, for the benefit of
  27    cancellation; but they're really only accurate at the point of the
  28    syscall.  The ARM unwind directives are not rich enough without adding
  29    a custom personality function.  */
  30
  31 # undef PSEUDO
  32 # define PSEUDO(name, syscall_name, args)                               \
  33   .section ".text";                                                     \
  34     PSEUDO_PROLOGUE;                                                    \
  35   .type __##syscall_name##_nocancel,%function;                          \
  36   .globl __##syscall_name##_nocancel;                                   \
  37   __##syscall_name##_nocancel:                                          \
  38     .cfi_sections .debug_frame;                                         \
  39     cfi_startproc;                                                      \
  40     DO_CALL (syscall_name, args);                                       \
  41     cmn r0, $4096;                                                      \
  42     PSEUDO_RET;                                                         \
  43     cfi_endproc;                                                        \
  44   .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel;      \
  45   ENTRY (name);                                                         \
  46     SINGLE_THREAD_P;                                                    \
  47     DOARGS_##args;                                                      \
  48     bne .Lpseudo_cancel;                                                \
  49     cfi_remember_state;                                                 \
  50     ldr r7, =SYS_ify (syscall_name);                                    \
  51     swi 0x0;                                                            \
  52     UNDOARGS_##args;                                                    \
  53     cmn r0, $4096;                                                      \
  54     PSEUDO_RET;                                                         \
  55     cfi_restore_state;                                                  \
  56   .Lpseudo_cancel:                                                      \
  57     .fnstart;           /* matched by the .fnend in UNDOARGS below.  */ \
  58     DOCARGS_##args;     /* save syscall args etc. around CENABLE.  */   \
  59     CENABLE;                                                            \
  60     mov ip, r0;         /* put mask in safe place.  */                  \
  61     UNDOCARGS_##args;   /* restore syscall args.  */                    \
  62     ldr r7, =SYS_ify (syscall_name);                                    \
  63     swi 0x0;            /* do the call.  */                             \
  64     mov r7, r0;         /* save syscall return value.  */               \
  65     mov r0, ip;         /* get mask back.  */                           \
  66     CDISABLE;                                                           \
  67     mov r0, r7;         /* retrieve return value.  */                   \
  68     RESTORE_LR_##args;                                                  \
  69     UNDOARGS_##args;                                                    \
  70     cmn r0, $4096
  71
  72 /* DOARGS pushes eight bytes on the stack for five arguments, twelve bytes for
  73    six arguments, and four bytes for fewer.  In order to preserve doubleword
  74    alignment, sometimes we must save an extra register.  */
  75
  76 # define RESTART_UNWIND \
  77   .fnend; \
  78   .fnstart; \
  79   .save {r7}; \
  80   .save {lr}
  81
  82 # define DOCARGS_0 \
  83   .save {r7}; \
  84   str lr, [sp, #-4]!; \
  85   cfi_adjust_cfa_offset (4); \
  86   cfi_rel_offset (lr, 0); \
  87   .save {lr}
  88 # define UNDOCARGS_0
  89 # define RESTORE_LR_0 \
  90   ldr lr, [sp], #4; \
  91   cfi_adjust_cfa_offset (-4); \
  92   cfi_restore (lr)
  93
  94 # define DOCARGS_1 \
  95   .save {r7}; \
  96   stmfd sp!, {r0, r1, lr}; \
  97   cfi_adjust_cfa_offset (12); \
  98   cfi_rel_offset (lr, 8); \
  99   .save {lr}; \
 100   .pad #8
 101 # define UNDOCARGS_1 \
 102   ldr r0, [sp], #8; \
 103   cfi_adjust_cfa_offset (-8); \
 104   RESTART_UNWIND
 105 # define RESTORE_LR_1 \
 106   RESTORE_LR_0
 107
 108 # define DOCARGS_2 \
 109   .save {r7}; \
 110   stmfd sp!, {r0, r1, lr}; \
 111   cfi_adjust_cfa_offset (12); \
 112   cfi_rel_offset (lr, 8); \
 113   .save {lr}; \
 114   .pad #8
 115 # define UNDOCARGS_2 \
 116   ldmfd sp!, {r0, r1}; \
 117   cfi_adjust_cfa_offset (-8); \
 118   RESTART_UNWIND
 119 # define RESTORE_LR_2 \
 120   RESTORE_LR_0
 121
 122 # define DOCARGS_3 \
 123   .save {r7}; \
 124   stmfd sp!, {r0, r1, r2, r3, lr}; \
 125   cfi_adjust_cfa_offset (20); \
 126   cfi_rel_offset (lr, 16); \
 127   .save {lr}; \
 128   .pad #16
 129 # define UNDOCARGS_3 \
 130   ldmfd sp!, {r0, r1, r2, r3}; \
 131   cfi_adjust_cfa_offset (-16); \
 132   RESTART_UNWIND
 133 # define RESTORE_LR_3 \
 134   RESTORE_LR_0
 135
 136 # define DOCARGS_4 \
 137   .save {r7}; \
 138   stmfd sp!, {r0, r1, r2, r3, lr}; \
 139   cfi_adjust_cfa_offset (20); \
 140   cfi_rel_offset (lr, 16); \
 141   .save {lr}; \
 142   .pad #16
 143 # define UNDOCARGS_4 \
 144   ldmfd sp!, {r0, r1, r2, r3}; \
 145   cfi_adjust_cfa_offset (-16); \
 146   RESTART_UNWIND
 147 # define RESTORE_LR_4 \
 148   RESTORE_LR_0
 149
 150 /* r4 is only stmfd'ed for correct stack alignment.  */
 151 # define DOCARGS_5 \
 152   .save {r4, r7}; \
 153   stmfd sp!, {r0, r1, r2, r3, r4, lr}; \
 154   cfi_adjust_cfa_offset (24); \
 155   cfi_rel_offset (lr, 20); \
 156   .save {lr}; \
 157   .pad #20
 158 # define UNDOCARGS_5 \
 159   ldmfd sp!, {r0, r1, r2, r3}; \
 160   cfi_adjust_cfa_offset (-16); \
 161   .fnend; \
 162   .fnstart; \
 163   .save {r4, r7}; \
 164   .save {lr}; \
 165   .pad #4
 166 # define RESTORE_LR_5 \
 167   ldmfd sp!, {r4, lr}; \
 168   cfi_adjust_cfa_offset (-8); \
 169   /* r4 will be marked as restored later.  */ \
 170   cfi_restore (lr)
 171
 172 # define DOCARGS_6 \
 173   .save {r4, r5, r7}; \
 174   stmfd sp!, {r0, r1, r2, r3, lr}; \
 175   cfi_adjust_cfa_offset (20); \
 176   cfi_rel_offset (lr, 16); \
 177   .save {lr}; \
 178   .pad #16
 179 # define UNDOCARGS_6 \
 180   ldmfd sp!, {r0, r1, r2, r3}; \
 181   cfi_adjust_cfa_offset (-16); \
 182   .fnend; \
 183   .fnstart; \
 184   .save {r4, r5, r7}; \
 185   .save {lr};
 186 # define RESTORE_LR_6 \
 187   RESTORE_LR_0
 188
 189 # ifdef IS_IN_libpthread
 190 #  define CENABLE       bl PLTJMP(__pthread_enable_asynccancel)
 191 #  define CDISABLE      bl PLTJMP(__pthread_disable_asynccancel)
 192 #  define __local_multiple_threads __pthread_multiple_threads
 193 # elif !defined NOT_IN_libc
 194 #  define CENABLE       bl PLTJMP(__libc_enable_asynccancel)
 195 #  define CDISABLE      bl PLTJMP(__libc_disable_asynccancel)
 196 #  define __local_multiple_threads __libc_multiple_threads
 197 # elif defined IS_IN_librt
 198 #  define CENABLE       bl PLTJMP(__librt_enable_asynccancel)
 199 #  define CDISABLE      bl PLTJMP(__librt_disable_asynccancel)
 200 # else
 201 #  error Unsupported library
 202 # endif
 203
 204 # if defined IS_IN_libpthread || !defined NOT_IN_libc
 205 #  ifndef __ASSEMBLER__
 206 extern int __local_multiple_threads attribute_hidden;
 207 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
 208 #  else
 209 #   define SINGLE_THREAD_P                                              \
 210   ldr ip, 1b;                                                           \
 211 2:                                                                      \
 212   ldr ip, [pc, ip];                                                     \
 213   teq ip, #0;
 214 #   define PSEUDO_PROLOGUE                                              \
 215   1:  .word __local_multiple_threads - 2f - 8;
 216 #  endif
 217 # else
 218 /*  There is no __local_multiple_threads for librt, so use the TCB.  */
 219 #  ifndef __ASSEMBLER__
 220 #   define SINGLE_THREAD_P                                              \
 221   __builtin_expect (THREAD_GETMEM (THREAD_SELF,                         \
 222                                    header.multiple_threads) == 0, 1)
 223 #  else
 224 #   define PSEUDO_PROLOGUE
 225 #   define SINGLE_THREAD_P                                              \
 226   stmfd sp!, {r0, lr};                                                  \
 227   cfi_adjust_cfa_offset (8);                                            \
 228   cfi_rel_offset (lr, 4);                                               \
 229   bl    __aeabi_read_tp;                                                \
 230   ldr   ip, [r0, #MULTIPLE_THREADS_OFFSET];                             \
 231   ldmfd sp!, {r0, lr};                                                  \
 232   cfi_adjust_cfa_offset (-8);                                           \
 233   cfi_restore (lr);                                                     \
 234   teq   ip, #0
 235 #   define SINGLE_THREAD_P_PIC(x) SINGLE_THREAD_P
 236 #  endif
 237 # endif
 238
 239 #elif !defined __ASSEMBLER__
 240
 241 /* For rtld, et cetera.  */
 242 # define SINGLE_THREAD_P 1
 243 # define NO_CANCELLATION 1
 244
 245 #endif
 246
 247 #ifndef __ASSEMBLER__
 248 # define RTLD_SINGLE_THREAD_P \
 249   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
 250                                    header.multiple_threads) == 0, 1)
 251 #endif