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__ |
79 | extern 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 | |