1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef _UAPI__ASM_SIGCONTEXT_H
17 #define _UAPI__ASM_SIGCONTEXT_H
18 
19 #include <linux/types.h>
20 
21 /*
22  * Signal context structure - contains all info to do with the state
23  * before the signal handler was invoked.
24  */
25 struct sigcontext {
26 	__u64 fault_address;
27 	/* AArch64 registers */
28 	__u64 regs[31];
29 	__u64 sp;
30 	__u64 pc;
31 	__u64 pstate;
32 	/* 4K reserved for FP/SIMD state and future expansion */
33 	__u8 __reserved[4096] __attribute__((__aligned__(16)));
34 };
35 
36 /*
37  * Allocation of __reserved[]:
38  * (Note: records do not necessarily occur in the order shown here.)
39  *
40  *	size		description
41  *
42  *	0x210		fpsimd_context
43  *	 0x10		esr_context
44  *	 0x20		extra_context (optional)
45  *	 0x10		terminator (null _aarch64_ctx)
46  *
47  *	0xdb0		(reserved for future allocation)
48  *
49  * New records that can exceed this space need to be opt-in for userspace, so
50  * that an expanded signal frame is not generated unexpectedly.  The mechanism
51  * for opting in will depend on the extension that generates each new record.
52  * The above table documents the maximum set and sizes of records than can be
53  * generated when userspace does not opt in for any such extension.
54  */
55 
56 /*
57  * Header to be used at the beginning of structures extending the user
58  * context. Such structures must be placed after the rt_sigframe on the stack
59  * and be 16-byte aligned. The last structure must be a dummy one with the
60  * magic and size set to 0.
61  */
62 struct _aarch64_ctx {
63 	__u32 magic;
64 	__u32 size;
65 };
66 
67 #define FPSIMD_MAGIC	0x46508001
68 
69 struct fpsimd_context {
70 	struct _aarch64_ctx head;
71 	__u32 fpsr;
72 	__u32 fpcr;
73 	__uint128_t vregs[32];
74 };
75 
76 /* ESR_EL1 context */
77 #define ESR_MAGIC	0x45535201
78 
79 struct esr_context {
80 	struct _aarch64_ctx head;
81 	__u64 esr;
82 };
83 
84 /*
85  * extra_context: describes extra space in the signal frame for
86  * additional structures that don't fit in sigcontext.__reserved[].
87  *
88  * Note:
89  *
90  * 1) fpsimd_context, esr_context and extra_context must be placed in
91  * sigcontext.__reserved[] if present.  They cannot be placed in the
92  * extra space.  Any other record can be placed either in the extra
93  * space or in sigcontext.__reserved[], unless otherwise specified in
94  * this file.
95  *
96  * 2) There must not be more than one extra_context.
97  *
98  * 3) If extra_context is present, it must be followed immediately in
99  * sigcontext.__reserved[] by the terminating null _aarch64_ctx.
100  *
101  * 4) The extra space to which datap points must start at the first
102  * 16-byte aligned address immediately after the terminating null
103  * _aarch64_ctx that follows the extra_context structure in
104  * __reserved[].  The extra space may overrun the end of __reserved[],
105  * as indicated by a sufficiently large value for the size field.
106  *
107  * 5) The extra space must itself be terminated with a null
108  * _aarch64_ctx.
109  */
110 #define EXTRA_MAGIC	0x45585401
111 
112 struct extra_context {
113 	struct _aarch64_ctx head;
114 	__u64 datap; /* 16-byte aligned pointer to extra space cast to __u64 */
115 	__u32 size; /* size in bytes of the extra space */
116 	__u32 __reserved[3];
117 };
118 
119 #endif /* _UAPI__ASM_SIGCONTEXT_H */
120