1/* Copyright (C) 2002-2016 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, 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/* The code to disable cancellation depends on the fact that the called
28 functions are special. They don't modify registers other than %rax
29 and %r11 if they return. Therefore we don't have to preserve other
30 registers around these calls. */
31# undef PSEUDO
32# define PSEUDO(name, syscall_name, args) \
33 .text; \
34 ENTRY (name) \
35 SINGLE_THREAD_P; \
36 jne L(pseudo_cancel); \
37 .type __##syscall_name##_nocancel,@function; \
38 .globl __##syscall_name##_nocancel; \
39 __##syscall_name##_nocancel: \
40 DO_CALL (syscall_name, args); \
41 cmpq $-4095, %rax; \
42 jae SYSCALL_ERROR_LABEL; \
43 ret; \
44 .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel; \
45 L(pseudo_cancel): \
46 /* We always have to align the stack before calling a function. */ \
47 subq $8, %rsp; cfi_adjust_cfa_offset (8); \
48 CENABLE \
49 /* The return value from CENABLE is argument for CDISABLE. */ \
50 movq %rax, (%rsp); \
51 DO_CALL (syscall_name, args); \
52 movq (%rsp), %rdi; \
53 /* Save %rax since it's the error code from the syscall. */ \
54 movq %rax, %rdx; \
55 CDISABLE \
56 movq %rdx, %rax; \
57 addq $8,%rsp; cfi_adjust_cfa_offset (-8); \
58 cmpq $-4095, %rax; \
59 jae SYSCALL_ERROR_LABEL
60
61
62# if IS_IN (libpthread)
63# define CENABLE call __pthread_enable_asynccancel;
64# define CDISABLE call __pthread_disable_asynccancel;
65# define __local_multiple_threads __pthread_multiple_threads
66# elif IS_IN (libc)
67# define CENABLE call __libc_enable_asynccancel;
68# define CDISABLE call __libc_disable_asynccancel;
69# define __local_multiple_threads __libc_multiple_threads
70# elif IS_IN (librt)
71# define CENABLE call __librt_enable_asynccancel;
72# define CDISABLE call __librt_disable_asynccancel;
73# else
74# error Unsupported library
75# endif
76
77# if IS_IN (libpthread) || IS_IN (libc)
78# ifndef __ASSEMBLER__
79extern int __local_multiple_threads attribute_hidden;
80# define SINGLE_THREAD_P \
81 __builtin_expect (__local_multiple_threads == 0, 1)
82# else
83# define SINGLE_THREAD_P cmpl $0, __local_multiple_threads(%rip)
84# endif
85
86# else
87
88# ifndef __ASSEMBLER__
89# define SINGLE_THREAD_P \
90 __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
91 header.multiple_threads) == 0, 1)
92# else
93# define SINGLE_THREAD_P cmpl $0, %fs:MULTIPLE_THREADS_OFFSET
94# endif
95
96# endif
97
98#elif !defined __ASSEMBLER__
99
100# define SINGLE_THREAD_P (1)
101# define NO_CANCELLATION 1
102
103#endif
104
105#ifndef __ASSEMBLER__
106# define RTLD_SINGLE_THREAD_P \
107 __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
108 header.multiple_threads) == 0, 1)
109#endif
110