xref: /openbmc/linux/arch/arm/include/asm/ucontext.h (revision 12c3dca2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASMARM_UCONTEXT_H
3 #define _ASMARM_UCONTEXT_H
4 
5 #include <asm/fpstate.h>
6 #include <asm/user.h>
7 
8 /*
9  * struct sigcontext only has room for the basic registers, but struct
10  * ucontext now has room for all registers which need to be saved and
11  * restored.  Coprocessor registers are stored in uc_regspace.  Each
12  * coprocessor's saved state should start with a documented 32-bit magic
13  * number, followed by a 32-bit word giving the coproccesor's saved size.
14  * uc_regspace may be expanded if necessary, although this takes some
15  * coordination with glibc.
16  */
17 
18 struct ucontext {
19 	unsigned long	  uc_flags;
20 	struct ucontext  *uc_link;
21 	stack_t		  uc_stack;
22 	struct sigcontext uc_mcontext;
23 	sigset_t	  uc_sigmask;
24 	/* Allow for uc_sigmask growth.  Glibc uses a 1024-bit sigset_t.  */
25 	int		  __unused[32 - (sizeof (sigset_t) / sizeof (int))];
26 	/* Last for extensibility.  Eight byte aligned because some
27 	   coprocessors require eight byte alignment.  */
28  	unsigned long	  uc_regspace[128] __attribute__((__aligned__(8)));
29 };
30 
31 #ifdef __KERNEL__
32 
33 /*
34  * Coprocessor save state.  The magic values and specific
35  * coprocessor's layouts are part of the userspace ABI.  Each one of
36  * these should be a multiple of eight bytes and aligned to eight
37  * bytes, to prevent unpredictable padding in the signal frame.
38  */
39 
40 /*
41  * Dummy padding block: if this magic is encountered, the block should
42  * be skipped using the corresponding size field.
43  */
44 #define DUMMY_MAGIC		0xb0d9ed01
45 
46 #ifdef CONFIG_IWMMXT
47 /* iwmmxt_area is 0x98 bytes long, preceded by 8 bytes of signature */
48 #define IWMMXT_MAGIC		0x12ef842a
49 #define IWMMXT_STORAGE_SIZE	(IWMMXT_SIZE + 8)
50 
51 struct iwmmxt_sigframe {
52 	unsigned long	magic;
53 	unsigned long	size;
54 	struct iwmmxt_struct storage;
55 } __attribute__((__aligned__(8)));
56 #endif /* CONFIG_IWMMXT */
57 
58 #ifdef CONFIG_VFP
59 #define VFP_MAGIC		0x56465001
60 
61 struct vfp_sigframe
62 {
63 	unsigned long		magic;
64 	unsigned long		size;
65 	struct user_vfp		ufp;
66 	struct user_vfp_exc	ufp_exc;
67 } __attribute__((__aligned__(8)));
68 
69 /*
70  *  8 byte for magic and size, 264 byte for ufp, 12 bytes for ufp_exc,
71  *  4 bytes padding.
72  */
73 #define VFP_STORAGE_SIZE	sizeof(struct vfp_sigframe)
74 
75 #endif /* CONFIG_VFP */
76 
77 /*
78  * Auxiliary signal frame.  This saves stuff like FP state.
79  * The layout of this structure is not part of the user ABI,
80  * because the config options aren't.  uc_regspace is really
81  * one of these.
82  */
83 struct aux_sigframe {
84 #ifdef CONFIG_IWMMXT
85 	struct iwmmxt_sigframe	iwmmxt;
86 #endif
87 #ifdef CONFIG_VFP
88 	struct vfp_sigframe	vfp;
89 #endif
90 	/* Something that isn't a valid magic number for any coprocessor.  */
91 	unsigned long		end_magic;
92 } __attribute__((__aligned__(8)));
93 
94 #endif
95 
96 #endif /* !_ASMARM_UCONTEXT_H */
97