nptl/sysdeps/unix/sysv/linux/x86_64/sysdep-cancel.h

   1 /* Copyright (C) 2002-2006, 2009 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2002.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <sysdep.h>
  21 #include <tls.h>
  22 #ifndef __ASSEMBLER__
  23 # include <nptl/pthreadP.h>
  24 #endif
  25
  26 #if !defined NOT_IN_libc || defined IS_IN_libpthread || defined IS_IN_librt
  27
  28 /* The code to disable cancellation depends on the fact that the called
  29    functions are special.  They don't modify registers other than %rax
  30    and %r11 if they return.  Therefore we don't have to preserve other
  31    registers around these calls.  */
  32 # undef PSEUDO
  33 # define PSEUDO(name, syscall_name, args)                                     \
  34   .text;                                                                      \
  35   ENTRY (name)                                                                \
  36     SINGLE_THREAD_P;                                                          \
  37     jne L(pseudo_cancel);                                                     \
  38   .type __##syscall_name##_nocancel,@function;                                \
  39   .globl __##syscall_name##_nocancel;                                         \
  40   __##syscall_name##_nocancel:                                                \
  41     DO_CALL (syscall_name, args);                                             \
  42     cmpq $-4095, %rax;                                                        \
  43     jae SYSCALL_ERROR_LABEL;                                                  \
  44     ret;                                                                      \
  45   .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel;            \
  46   L(pseudo_cancel):                                                           \
  47     /* We always have to align the stack before calling a function.  */       \
  48     subq $8, %rsp; cfi_adjust_cfa_offset (8);                                 \
  49     CENABLE                                                                   \
  50     /* The return value from CENABLE is argument for CDISABLE.  */            \
  51     movq %rax, (%rsp);                                                        \
  52     DO_CALL (syscall_name, args);                                             \
  53     movq (%rsp), %rdi;                                                        \
  54     /* Save %rax since it's the error code from the syscall.  */              \
  55     movq %rax, %rdx;                                                          \
  56     CDISABLE                                                                  \
  57     movq %rdx, %rax;                                                          \
  58     addq $8,%rsp; cfi_adjust_cfa_offset (-8);                                 \
  59     cmpq $-4095, %rax;                                                        \
  60     jae SYSCALL_ERROR_LABEL;                                                  \
  61   L(pseudo_end):
  62
  63
  64 # ifdef IS_IN_libpthread
  65 #  define CENABLE       call __pthread_enable_asynccancel;
  66 #  define CDISABLE      call __pthread_disable_asynccancel;
  67 #  define __local_multiple_threads __pthread_multiple_threads
  68 # elif !defined NOT_IN_libc
  69 #  define CENABLE       call __libc_enable_asynccancel;
  70 #  define CDISABLE      call __libc_disable_asynccancel;
  71 #  define __local_multiple_threads __libc_multiple_threads
  72 # elif defined IS_IN_librt
  73 #  define CENABLE       call __librt_enable_asynccancel;
  74 #  define CDISABLE      call __librt_disable_asynccancel;
  75 # else
  76 #  error Unsupported library
  77 # endif
  78
  79 # if defined IS_IN_libpthread || !defined NOT_IN_libc
  80 #  ifndef __ASSEMBLER__
  81 extern int __local_multiple_threads attribute_hidden;
  82 #   define SINGLE_THREAD_P \
  83   __builtin_expect (__local_multiple_threads == 0, 1)
  84 #  else
  85 #   define SINGLE_THREAD_P cmpl $0, __local_multiple_threads(%rip)
  86 #  endif
  87
  88 # else
  89
  90 #  ifndef __ASSEMBLER__
  91 #   define SINGLE_THREAD_P \
  92   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
  93                                    header.multiple_threads) == 0, 1)
  94 #  else
  95 #   define SINGLE_THREAD_P cmpl $0, %fs:MULTIPLE_THREADS_OFFSET
  96 #  endif
  97
  98 # endif
  99
 100 #elif !defined __ASSEMBLER__
 101
 102 # define SINGLE_THREAD_P (1)
 103 # define NO_CANCELLATION 1
 104
 105 #endif
 106
 107 #ifndef __ASSEMBLER__
 108 # define RTLD_SINGLE_THREAD_P \
 109   __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
 110                                    header.multiple_threads) == 0, 1)
 111 #endif