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/*

 *  include/asm-s390/user.h

 *

 *  S390 version

 *

 *  Derived from "include/asm-i386/usr.h"

 */

#ifndef _S390_USER_H

#define _S390_USER_H

#include <asm/page.h>

#include <linux/ptrace.h>

/* Core file format: The core file is written in such a way that gdb

   can understand it and provide useful information to the user (under

   linux we use the 'trad-core' bfd).  There are quite a number of

   obstacles to being able to view the contents of the floating point

   registers, and until these are solved you will not be able to view the

   contents of them.  Actually, you can read in the core file and look at

   the contents of the user struct to find out what the floating point

   registers contain.

   The actual file contents are as follows:

   UPAGE: 1 page consisting of a user struct that tells gdb what is present

   in the file.  Directly after this is a copy of the task_struct, which

   is currently not used by gdb, but it may come in useful at some point.

   All of the registers are stored as part of the upage.  The upage should

   always be only one page.

   DATA: The data area is stored.  We use current->end_text to

   current->brk to pick up all of the user variables, plus any memory

   that may have been malloced.  No attempt is made to determine if a page

   is demand-zero or if a page is totally unused, we just cover the entire

   range.  All of the addresses are rounded in such a way that an integral

   number of pages is written.

   STACK: We need the stack information in order to get a meaningful

   backtrace.  We need to write the data from (esp) to

   current->start_stack, so we round each of these off in order to be able

   to write an integer number of pages.

   The minimum core file size is 3 pages, or 12288 bytes.

*/

/*

 * This is the old layout of "struct pt_regs", and

 * is still the layout used by user mode (the new

 * pt_regs doesn't have all registers as the kernel

 * doesn't use the extra segment registers)

 */

/* When the kernel dumps core, it starts by dumping the user struct -

   this will be used by gdb to figure out where the data and stack segments

   are within the file, and what virtual addresses to use. */

struct user {

/* We start with the registers, to mimic the way that "memory" is returned

   from the ptrace(3,...) function.  */

  struct user_regs_struct regs;         /* Where the registers are actually stored */

/* The rest of this junk is to help gdb figure out what goes where */

  size_t   u_tsize;          /* Text segment size (pages). */

  size_t   u_dsize;          /* Data segment size (pages). */

  size_t   u_ssize;          /* Stack segment size (pages). */

  unsigned long start_code;  /* Starting virtual address of text. */

  unsigned long start_stack; /* Starting virtual address of stack area.

                                This is actually the bottom of the stack,

                                the top of the stack is always found in the

                                gprs[15] register.  */

  long int signal;           /* Signal that caused the core dump. */

  struct user_regs_struct *u_ar0;

                                /* Used by gdb to help find the values for */

                                /* the registers. */

  unsigned long magic;          /* To uniquely identify a core file */

  char u_comm[32];              /* User command that was responsible */

};

#define NBPG PAGE_SIZE

#define UPAGES 1

#define HOST_TEXT_START_ADDR (u.start_code)

#define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)

#endif /* _S390_USER_H */