about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h
blob: 3b3151ed899bbf58aa70198a1c36bf327cc3d45b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/* Copyright (C) 1998-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#ifndef _SYS_UCONTEXT_H
#define _SYS_UCONTEXT_H	1

#include <features.h>
#include <signal.h>

/* We need the signal context definitions even if they are not used
   included in <signal.h>.  */
#include <bits/sigcontext.h>

#if __WORDSIZE == 32

/* Number of general registers.  */
# define NGREG	48

/* Container for all general registers.  */
typedef unsigned long gregset_t[NGREG];

/* Container for floating-point registers and status */
typedef struct _libc_fpstate
{
	double fpregs[32];
	double fpscr;
	unsigned int _pad[2];
} fpregset_t;

/* Container for Altivec/VMX registers and status.
   Needs to be aligned on a 16-byte boundary. */
typedef struct _libc_vrstate
{
	unsigned int vrregs[32][4];
	unsigned int vrsave;
	unsigned int _pad[2];
	unsigned int vscr;
} vrregset_t;

/* Context to describe whole processor state.  */
typedef struct
{
	gregset_t gregs;
	fpregset_t fpregs;
	vrregset_t vrregs __attribute__((__aligned__(16)));
} mcontext_t;

#else

/* For 64-bit kernels with Altivec support, a machine context is exactly
 * a sigcontext.  For older kernel (without Altivec) the sigcontext matches
 * the mcontext upto but not including the v_regs field.  For kernels that
 * don't AT_HWCAP or return AT_HWCAP without PPC_FEATURE_HAS_ALTIVEC the
 * v_regs field may not exit and should not be referenced.  The v_regd field
 * can be refernced safely only after verifying that PPC_FEATURE_HAS_ALTIVEC
 * is set in AT_HWCAP.  */

/* Number of general registers.  */
# define NGREG	48	/* includes r0-r31, nip, msr, lr, etc.   */
# define NFPREG	33	/* includes fp0-fp31 &fpscr.  */
# define NVRREG	34	/* includes v0-v31, vscr, & vrsave in split vectors */

typedef unsigned long gregset_t[NGREG];
typedef double fpregset_t[NFPREG];

/* Container for Altivec/VMX Vector Status and Control Register.  Only 32-bits
   but can only be copied to/from a 128-bit vector register.  So we allocated
   a whole quadword speedup save/restore.  */
typedef struct _libc_vscr
{
	unsigned int __pad[3];
	unsigned int vscr_word;
} vscr_t;

/* Container for Altivec/VMX registers and status.
   Must to be aligned on a 16-byte boundary. */
typedef struct _libc_vrstate
{
	unsigned int	vrregs[32][4];
	vscr_t		vscr;
	unsigned int	vrsave;
	unsigned int	__pad[3];
} vrregset_t  __attribute__((__aligned__(16)));

typedef struct {
	unsigned long	__glibc_reserved[4];
	int		signal;
	int		__pad0;
	unsigned long	handler;
	unsigned long	oldmask;
	struct pt_regs	*regs;
	gregset_t	gp_regs;
	fpregset_t	fp_regs;
/*
 * To maintain compatibility with current implementations the sigcontext is
 * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
 * followed by an unstructured (vmx_reserve) field of 69 doublewords.  This
 * allows the array of vector registers to be quadword aligned independent of
 * the alignment of the containing sigcontext or ucontext. It is the
 * responsibility of the code setting the sigcontext to set this pointer to
 * either NULL (if this processor does not support the VMX feature) or the
 * address of the first quadword within the allocated (vmx_reserve) area.
 *
 * The pointer (v_regs) of vector type (elf_vrreg_t) is essentually
 * an array of 34 quadword entries.  The entries with
 * indexes 0-31 contain the corresponding vector registers.  The entry with
 * index 32 contains the vscr as the last word (offset 12) within the
 * quadword.  This allows the vscr to be stored as either a quadword (since
 * it must be copied via a vector register to/from storage) or as a word.
 * The entry with index 33 contains the vrsave as the first word (offset 0)
 * within the quadword.
 */
	vrregset_t	*v_regs;
	long		vmx_reserve[NVRREG+NVRREG+1];
} mcontext_t;

#endif

/* Userlevel context.  */
typedef struct ucontext
  {
    unsigned long int uc_flags;
    struct ucontext *uc_link;
    stack_t uc_stack;
#if __WORDSIZE == 32
    /*
     * These fields are set up this way to maximize source and
     * binary compatibility with code written for the old
     * ucontext_t definition, which didn't include space for the
     * registers.
     *
     * Different versions of the kernel have stored the registers on
     * signal delivery at different offsets from the ucontext struct.
     * Programs should thus use the uc_mcontext.uc_regs pointer to
     * find where the registers are actually stored.  The registers
     * will be stored within the ucontext_t struct but not necessarily
     * at a fixed address.  As a side-effect, this lets us achieve
     * 16-byte alignment for the register storage space if the
     * Altivec registers are to be saved, without requiring 16-byte
     * alignment on the whole ucontext_t.
     *
     * The uc_mcontext.regs field is included for source compatibility
     * with programs written against the older ucontext_t definition,
     * and its name should therefore not change.  The uc_pad field
     * is for binary compatibility with programs compiled against the
     * old ucontext_t; it ensures that uc_mcontext.regs and uc_sigmask
     * are at the same offset as previously.
     */
    int uc_pad[7];
    union uc_regs_ptr {
      struct pt_regs *regs;
      mcontext_t *uc_regs;
    } uc_mcontext;
    sigset_t    uc_sigmask;
    char uc_reg_space[sizeof(mcontext_t) + 12];  /* last for extensibility */
#else /* 64-bit */
    sigset_t    uc_sigmask;
    mcontext_t  uc_mcontext;  /* last for extensibility */
#endif
  } ucontext_t;

#endif /* sys/ucontext.h */