sysdeps/unix/sysv/linux/arm/eabi/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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <sysdep.h>
  20 #include <tls.h>
  21 #ifndef __ASSEMBLER__
  22 # include <nptl/pthreadP.h>
  23 #endif
  24
  25 #if !defined NOT_IN_libc || defined IS_IN_libpthread || defined IS_IN_librt
  26
  27 /* NOTE: We do mark syscalls with unwind annotations, for the benefit of
  28    cancellation; but they're really only accurate at the point of the
  29    syscall.  The ARM unwind directives are not rich enough without adding
  30    a custom personality function.  */
  31
  32 # undef PSEUDO
  33 # define PSEUDO(name, syscall_name, args)                               \
  34   .section ".text";                                                     \
  35     PSEUDO_PROLOGUE;                                                    \
  36   .type __##syscall_name##_nocancel,%function;                          \
  37   .globl __##syscall_name##_nocancel;                                   \
  38   __##syscall_name##_nocancel:                                          \
  39     .cfi_sections .debug_frame;                                         \
  40     cfi_startproc;                                                      \
  41     DO_CALL (syscall_name, args);                                       \
  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     DO_CALL (syscall_name, 0);                                          \
  51     UNDOARGS_##args;                                                    \
  52     cmn r0, $4096;                                                      \
  53     PSEUDO_RET;                                                         \
  54     cfi_restore_state;                                                  \
  55   .Lpseudo_cancel:                                                      \
  56     .fnstart;                                                           \
  57     DOCARGS_##args;     /* save syscall args etc. around CENABLE.  */   \
  58     CENABLE;                                                            \
  59     mov ip, r0;         /* put mask in safe place.  */                  \
  60     UNDOCARGS_##args;   /* restore syscall args.  */                    \
  61     ldr r7, =SYS_ify (syscall_name);                                    \
  62     swi 0x0;            /* do the call.  */                             \
  63     .fnend;             /* Past here we can't easily unwind.  */        \
  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 four bytes on the stack for five arguments, eight bytes for
  73    six arguments, and nothing 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, lr}
  80
  81 # define DOCARGS_0 \
  82   stmfd sp!, {r7, lr}; \
  83   cfi_adjust_cfa_offset (8); \
  84   cfi_rel_offset (r7, 0); \
  85   cfi_rel_offset (lr, 4); \
  86   .save {r7, lr}
  87 # define UNDOCARGS_0
  88 # define RESTORE_LR_0 \
  89   ldmfd sp!, {r7, lr}; \
  90   cfi_adjust_cfa_offset (-8); \
  91   cfi_restore (r7); \
  92   cfi_restore (lr)
  93
  94 # define DOCARGS_1 \
  95   stmfd sp!, {r0, r1, r7, lr}; \
  96   cfi_adjust_cfa_offset (16); \
  97   cfi_rel_offset (r7, 8); \
  98   cfi_rel_offset (lr, 12); \
  99   .save {r7, 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   stmfd sp!, {r0, r1, r7, lr}; \
 110   cfi_adjust_cfa_offset (16); \
 111   cfi_rel_offset (r7, 8); \
 112   cfi_rel_offset (lr, 12); \
 113   .save {r7, 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   stmfd sp!, {r0, r1, r2, r3, r7, lr}; \
 124   cfi_adjust_cfa_offset (24); \
 125   cfi_rel_offset (r7, 16); \
 126   cfi_rel_offset (lr, 20); \
 127   .save {r7, 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   stmfd sp!, {r0, r1, r2, r3, r7, lr}; \
 138   cfi_adjust_cfa_offset (24); \
 139   cfi_rel_offset (r7, 16); \
 140   cfi_rel_offset (lr, 20); \
 141   .save {r7, 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}; \
 153   stmfd sp!, {r0, r1, r2, r3, r4, r7, lr}; \
 154   cfi_adjust_cfa_offset (28); \
 155   cfi_rel_offset (r7, 20); \
 156   cfi_rel_offset (lr, 24); \
 157   .save {r7, lr}; \
 158   .pad #20
 159 # define UNDOCARGS_5 \
 160   ldmfd sp!, {r0, r1, r2, r3}; \
 161   cfi_adjust_cfa_offset (-16); \
 162   .fnend; \
 163   .fnstart; \
 164   .save {r4}; \
 165   .save {r7, lr}; \
 166   .pad #4
 167 # define RESTORE_LR_5 \
 168   ldmfd sp!, {r4, r7, lr}; \
 169   cfi_adjust_cfa_offset (-12); \
 170   /* r4 will be marked as restored later.  */ \
 171   cfi_restore (r7); \
 172   cfi_restore (lr)
 173
 174 # define DOCARGS_6 \
 175   .save {r4, r5}; \
 176   stmfd sp!, {r0, r1, r2, r3, r7, lr}; \
 177   cfi_adjust_cfa_offset (24); \
 178   cfi_rel_offset (r7, 16); \
 179   cfi_rel_offset (lr, 20); \
 180   .save {r7, lr}; \
 181   .pad #16
 182 # define UNDOCARGS_6 \
 183   ldmfd sp!, {r0, r1, r2, r3}; \
 184   cfi_adjust_cfa_offset (-16); \
 185   .fnend; \
 186   .fnstart; \
 187   .save {r4, r5}; \
 188   .save {r7, lr}
 189 # define RESTORE_LR_6 \
 190   RESTORE_LR_0
 191
 192 # ifdef IS_IN_libpthread
 193 #  define CENABLE       bl PLTJMP(__pthread_enable_asynccancel)
 194 #  define CDISABLE      bl PLTJMP(__pthread_disable_asynccancel)
 195 #  define __local_multiple_threads __pthread_multiple_threads
 196 # elif !defined NOT_IN_libc
 197 #  define CENABLE       bl PLTJMP(__libc_enable_asynccancel)
 198 #  define CDISABLE      bl PLTJMP(__libc_disable_asynccancel)
 199 #  define __local_multiple_threads __libc_multiple_threads
 200 # elif defined IS_IN_librt
 201 #  define CENABLE       bl PLTJMP(__librt_enable_asynccancel)
 202 #  define CDISABLE      bl PLTJMP(__librt_disable_asynccancel)
 203 # else
 204 #  error Unsupported library
 205 # endif
 206
 207 # if defined IS_IN_libpthread || !defined NOT_IN_libc
 208 #  ifndef __ASSEMBLER__
 209 extern int __local_multiple_threads attribute_hidden;
 210 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
 211 #  else
 212 #   define SINGLE_THREAD_P                                              \
 213   ldr ip, 1b;                                                           \
 214 2:                                                                      \
 215   ldr ip, [pc, ip];                                                     \
 216   teq ip, #0;
 217 #   define PSEUDO_PROLOGUE                                              \
 218   1:  .word __local_multiple_threads - 2f - 8;
 219 #  endif
 220 # else
 221 /*  There is no __local_multiple_threads for librt, so use the TCB.  */
 222 #  ifndef __ASSEMBLER__
 223 #   define SINGLE_THREAD_P                                              \
 224   __builtin_expect (THREAD_GETMEM (THREAD_SELF,                         \
 225                                    header.multiple_threads) == 0, 1)
 226 #  else
 227 #   define PSEUDO_PROLOGUE
 228 #   define SINGLE_THREAD_P                                              \
 229   stmfd sp!, {r0, lr};                                                  \
 230   cfi_adjust_cfa_offset (8);                                            \
 231   cfi_rel_offset (lr, 4);                                               \
 232   bl    __aeabi_read_tp;                                                \
 233   ldr   ip, [r0, #MULTIPLE_THREADS_OFFSET];                             \
 234   ldmfd sp!, {r0, lr};                                                  \
 235   cfi_adjust_cfa_offset (-8);                                           \
 236   cfi_restore (lr);                                                     \
 237   teq   ip, #0
 238 #   define SINGLE_THREAD_P_PIC(x) SINGLE_THREAD_P
 239 #  endif
 240 # endif
 241
 242 #elif !defined __ASSEMBLER__
 243
 244 /* For rtld, et cetera.  */
 245 # define SINGLE_THREAD_P 1
 246 # define NO_CANCELLATION 1
 247
 248 #endif
 249
 250 #ifndef __ASSEMBLER__
 251 # define RTLD_SINGLE_THREAD_P \
 252   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
 253                                    header.multiple_threads) == 0, 1)
 254 #endif