arch/x86/include/asm/user_64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_USER_64_H
   3 #define _ASM_X86_USER_64_H
   4
   5 #include <asm/types.h>
   6 #include <asm/page.h>
   7 /* Core file format: The core file is written in such a way that gdb
   8    can understand it and provide useful information to the user.
   9    There are quite a number of obstacles to being able to view the
  10    contents of the floating point registers, and until these are
  11    solved you will not be able to view the contents of them.
  12    Actually, you can read in the core file and look at the contents of
  13    the user struct to find out what the floating point registers
  14    contain.
  15
  16    The actual file contents are as follows:
  17    UPAGE: 1 page consisting of a user struct that tells gdb what is present
  18    in the file.  Directly after this is a copy of the task_struct, which
  19    is currently not used by gdb, but it may come in useful at some point.
  20    All of the registers are stored as part of the upage.  The upage should
  21    always be only one page.
  22    DATA: The data area is stored.  We use current->end_text to
  23    current->brk to pick up all of the user variables, plus any memory
  24    that may have been malloced.  No attempt is made to determine if a page
  25    is demand-zero or if a page is totally unused, we just cover the entire
  26    range.  All of the addresses are rounded in such a way that an integral
  27    number of pages is written.
  28    STACK: We need the stack information in order to get a meaningful
  29    backtrace.  We need to write the data from (esp) to
  30    current->start_stack, so we round each of these off in order to be able
  31    to write an integer number of pages.
  32    The minimum core file size is 3 pages, or 12288 bytes.  */
  33
  34 /*
  35  * Pentium III FXSR, SSE support
  36  *      Gareth Hughes <gareth@valinux.com>, May 2000
  37  *
  38  * Provide support for the GDB 5.0+ PTRACE_{GET|SET}FPXREGS requests for
  39  * interacting with the FXSR-format floating point environment.  Floating
  40  * point data can be accessed in the regular format in the usual manner,
  41  * and both the standard and SIMD floating point data can be accessed via
  42  * the new ptrace requests.  In either case, changes to the FPU environment
  43  * will be reflected in the task's state as expected.
  44  *
  45  * x86-64 support by Andi Kleen.
  46  */
  47
  48 /* This matches the 64bit FXSAVE format as defined by AMD. It is the same
  49    as the 32bit format defined by Intel, except that the selector:offset pairs
  50    for data and eip are replaced with flat 64bit pointers. */
  51 struct user_i387_struct {
  52         unsigned short  cwd;
  53         unsigned short  swd;
  54         unsigned short  twd;    /* Note this is not the same as
  55                                    the 32bit/x87/FSAVE twd */
  56         unsigned short  fop;
  57         __u64   rip;
  58         __u64   rdp;
  59         __u32   mxcsr;
  60         __u32   mxcsr_mask;
  61         __u32   st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
  62         __u32   xmm_space[64];  /* 16*16 bytes for each XMM-reg = 256 bytes */
  63         __u32   padding[24];
  64 };
  65
  66 /*
  67  * Segment register layout in coredumps.
  68  */
  69 struct user_regs_struct {
  70         unsigned long   r15;
  71         unsigned long   r14;
  72         unsigned long   r13;
  73         unsigned long   r12;
  74         unsigned long   bp;
  75         unsigned long   bx;
  76         unsigned long   r11;
  77         unsigned long   r10;
  78         unsigned long   r9;
  79         unsigned long   r8;
  80         unsigned long   ax;
  81         unsigned long   cx;
  82         unsigned long   dx;
  83         unsigned long   si;
  84         unsigned long   di;
  85         unsigned long   orig_ax;
  86         unsigned long   ip;
  87         unsigned long   cs;
  88         unsigned long   flags;
  89         unsigned long   sp;
  90         unsigned long   ss;
  91         unsigned long   fs_base;
  92         unsigned long   gs_base;
  93         unsigned long   ds;
  94         unsigned long   es;
  95         unsigned long   fs;
  96         unsigned long   gs;
  97 };
  98
  99 /* When the kernel dumps core, it starts by dumping the user struct -
 100    this will be used by gdb to figure out where the data and stack segments
 101    are within the file, and what virtual addresses to use. */
 102
 103 struct user {
 104 /* We start with the registers, to mimic the way that "memory" is returned
 105    from the ptrace(3,...) function.  */
 106   struct user_regs_struct regs; /* Where the registers are actually stored */
 107 /* ptrace does not yet supply these.  Someday.... */
 108   int u_fpvalid;                /* True if math co-processor being used. */
 109                                 /* for this mess. Not yet used. */
 110   int pad0;
 111   struct user_i387_struct i387; /* Math Co-processor registers. */
 112 /* The rest of this junk is to help gdb figure out what goes where */
 113   unsigned long int u_tsize;    /* Text segment size (pages). */
 114   unsigned long int u_dsize;    /* Data segment size (pages). */
 115   unsigned long int u_ssize;    /* Stack segment size (pages). */
 116   unsigned long start_code;     /* Starting virtual address of text. */
 117   unsigned long start_stack;    /* Starting virtual address of stack area.
 118                                    This is actually the bottom of the stack,
 119                                    the top of the stack is always found in the
 120                                    esp register.  */
 121   long int signal;              /* Signal that caused the core dump. */
 122   int reserved;                 /* No longer used */
 123   int pad1;
 124   unsigned long u_ar0;          /* Used by gdb to help find the values for */
 125                                 /* the registers. */
 126   struct user_i387_struct *u_fpstate;   /* Math Co-processor pointer. */
 127   unsigned long magic;          /* To uniquely identify a core file */
 128   char u_comm[32];              /* User command that was responsible */
 129   unsigned long u_debugreg[8];
 130   unsigned long error_code; /* CPU error code or 0 */
 131   unsigned long fault_address; /* CR3 or 0 */
 132 };
 133 #define NBPG PAGE_SIZE
 134 #define UPAGES 1
 135 #define HOST_TEXT_START_ADDR (u.start_code)
 136 #define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
 137
 138 #endif /* _ASM_X86_USER_64_H */