1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 #include <sys/cdefs.h>
32 
33 #include <limits.h>
34 #include <linux/signal.h>
35 #include <sys/types.h>
36 
37 /* The arm and x86 kernel header files don't define _NSIG. */
38 #ifndef _KERNEL__NSIG
39 #define _KERNEL__NSIG 64
40 #endif
41 
42 /* Userspace's NSIG is the kernel's _NSIG + 1. */
43 #define _NSIG (_KERNEL__NSIG + 1)
44 #define NSIG _NSIG
45 
46 typedef int sig_atomic_t;
47 
48 typedef __sighandler_t sig_t; /* BSD compatibility. */
49 typedef __sighandler_t sighandler_t; /* glibc compatibility. */
50 
51 /* sigset_t is already large enough on LP64, but LP32's sigset_t
52  * is just `unsigned long`.
53  */
54 #if defined(__LP64__)
55 typedef sigset_t sigset64_t;
56 #else
57 typedef struct { unsigned long __bits[_KERNEL__NSIG/(8*sizeof(long))]; } sigset64_t;
58 #endif
59 
60 /* The kernel's struct sigaction doesn't match the POSIX one. */
61 
62 #if defined(__LP64__)
63 
64 /* For 64-bit, that's the only problem, and we only need two structs
65  * for source compatibility with 32-bit. */
66 
67 #define __SIGACTION_BODY \
68   int sa_flags; \
69   union { \
70     sighandler_t sa_handler; \
71     void (*sa_sigaction)(int, struct siginfo*, void*); \
72   }; \
73   sigset_t sa_mask; \
74   void (*sa_restorer)(void); \
75 
76 struct sigaction { __SIGACTION_BODY };
77 struct sigaction64 { __SIGACTION_BODY };
78 
79 #undef __SIGACTION_BODY
80 
81 #else
82 
83 /* For 32-bit, Android's ABIs used a too-small sigset_t that doesn't
84  * support RT signals, so we need two different structs.
85  */
86 
87 /* The arm32 kernel headers also pollute the namespace with these,
88  * but our header scrubber doesn't know how to remove #defines. */
89 #undef sa_handler
90 #undef sa_sigaction
91 
92 struct sigaction {
93   union {
94     sighandler_t sa_handler;
95     void (*sa_sigaction)(int, struct siginfo*, void*);
96   };
97   sigset_t sa_mask;
98   int sa_flags;
99   void (*sa_restorer)(void);
100 };
101 
102 struct sigaction64 {
103   union {
104     sighandler_t sa_handler;
105     void (*sa_sigaction)(int, struct siginfo*, void*);
106   };
107   int sa_flags;
108   void (*sa_restorer)(void);
109   sigset64_t sa_mask;
110 };
111 
112 #endif
113