File: /usr/src/linux/include/asm-i386/user.h
1 #ifndef _I386_USER_H
2 #define _I386_USER_H
3
4 #include <asm/page.h>
5 #include <linux/ptrace.h>
6 /* Core file format: The core file is written in such a way that gdb
7 can understand it and provide useful information to the user (under
8 linux we use the 'trad-core' bfd). There are quite a number of
9 obstacles to being able to view the contents of the floating point
10 registers, and until these are solved you will not be able to view the
11 contents of them. Actually, you can read in the core file and look at
12 the contents of the user struct to find out what the floating point
13 registers contain.
14 The actual file contents are as follows:
15 UPAGE: 1 page consisting of a user struct that tells gdb what is present
16 in the file. Directly after this is a copy of the task_struct, which
17 is currently not used by gdb, but it may come in useful at some point.
18 All of the registers are stored as part of the upage. The upage should
19 always be only one page.
20 DATA: The data area is stored. We use current->end_text to
21 current->brk to pick up all of the user variables, plus any memory
22 that may have been malloced. No attempt is made to determine if a page
23 is demand-zero or if a page is totally unused, we just cover the entire
24 range. All of the addresses are rounded in such a way that an integral
25 number of pages is written.
26 STACK: We need the stack information in order to get a meaningful
27 backtrace. We need to write the data from (esp) to
28 current->start_stack, so we round each of these off in order to be able
29 to write an integer number of pages.
30 The minimum core file size is 3 pages, or 12288 bytes.
31 */
32
33 /*
34 * Pentium III FXSR, SSE support
35 * Gareth Hughes <gareth@valinux.com>, May 2000
36 *
37 * Provide support for the GDB 5.0+ PTRACE_{GET|SET}FPXREGS requests for
38 * interacting with the FXSR-format floating point environment. Floating
39 * point data can be accessed in the regular format in the usual manner,
40 * and both the standard and SIMD floating point data can be accessed via
41 * the new ptrace requests. In either case, changes to the FPU environment
42 * will be reflected in the task's state as expected.
43 */
44
45 struct user_i387_struct {
46 long cwd;
47 long swd;
48 long twd;
49 long fip;
50 long fcs;
51 long foo;
52 long fos;
53 long st_space[20]; /* 8*10 bytes for each FP-reg = 80 bytes */
54 };
55
56 struct user_fxsr_struct {
57 unsigned short cwd;
58 unsigned short swd;
59 unsigned short twd;
60 unsigned short fop;
61 long fip;
62 long fcs;
63 long foo;
64 long fos;
65 long mxcsr;
66 long reserved;
67 long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */
68 long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */
69 long padding[56];
70 };
71
72 /*
73 * This is the old layout of "struct pt_regs", and
74 * is still the layout used by user mode (the new
75 * pt_regs doesn't have all registers as the kernel
76 * doesn't use the extra segment registers)
77 */
78 struct user_regs_struct {
79 long ebx, ecx, edx, esi, edi, ebp, eax;
80 unsigned short ds, __ds, es, __es;
81 unsigned short fs, __fs, gs, __gs;
82 long orig_eax, eip;
83 unsigned short cs, __cs;
84 long eflags, esp;
85 unsigned short ss, __ss;
86 };
87
88 /* When the kernel dumps core, it starts by dumping the user struct -
89 this will be used by gdb to figure out where the data and stack segments
90 are within the file, and what virtual addresses to use. */
91 struct user{
92 /* We start with the registers, to mimic the way that "memory" is returned
93 from the ptrace(3,...) function. */
94 struct user_regs_struct regs; /* Where the registers are actually stored */
95 /* ptrace does not yet supply these. Someday.... */
96 int u_fpvalid; /* True if math co-processor being used. */
97 /* for this mess. Not yet used. */
98 struct user_i387_struct i387; /* Math Co-processor registers. */
99 /* The rest of this junk is to help gdb figure out what goes where */
100 unsigned long int u_tsize; /* Text segment size (pages). */
101 unsigned long int u_dsize; /* Data segment size (pages). */
102 unsigned long int u_ssize; /* Stack segment size (pages). */
103 unsigned long start_code; /* Starting virtual address of text. */
104 unsigned long start_stack; /* Starting virtual address of stack area.
105 This is actually the bottom of the stack,
106 the top of the stack is always found in the
107 esp register. */
108 long int signal; /* Signal that caused the core dump. */
109 int reserved; /* No longer used */
110 struct user_pt_regs * u_ar0; /* Used by gdb to help find the values for */
111 /* the registers. */
112 struct user_i387_struct* u_fpstate; /* Math Co-processor pointer. */
113 unsigned long magic; /* To uniquely identify a core file */
114 char u_comm[32]; /* User command that was responsible */
115 int u_debugreg[8];
116 };
117 #define NBPG PAGE_SIZE
118 #define UPAGES 1
119 #define HOST_TEXT_START_ADDR (u.start_code)
120 #define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
121
122 #endif /* _I386_USER_H */
123