include/asm-i386/user.h

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