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arch
s390
include
asm
user.h
Go to the documentation of this file.
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/*
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* S390 version
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*
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* Derived from "include/asm-i386/usr.h"
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*/
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#ifndef _S390_USER_H
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#define _S390_USER_H
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#include <asm/page.h>
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#include <asm/ptrace.h>
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/* Core file format: The core file is written in such a way that gdb
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can understand it and provide useful information to the user (under
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linux we use the 'trad-core' bfd). There are quite a number of
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obstacles to being able to view the contents of the floating point
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registers, and until these are solved you will not be able to view the
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contents of them. Actually, you can read in the core file and look at
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the contents of the user struct to find out what the floating point
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registers contain.
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The actual file contents are as follows:
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UPAGE: 1 page consisting of a user struct that tells gdb what is present
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in the file. Directly after this is a copy of the task_struct, which
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is currently not used by gdb, but it may come in useful at some point.
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All of the registers are stored as part of the upage. The upage should
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always be only one page.
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DATA: The data area is stored. We use current->end_text to
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current->brk to pick up all of the user variables, plus any memory
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that may have been malloced. No attempt is made to determine if a page
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is demand-zero or if a page is totally unused, we just cover the entire
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range. All of the addresses are rounded in such a way that an integral
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number of pages is written.
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STACK: We need the stack information in order to get a meaningful
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backtrace. We need to write the data from (esp) to
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current->start_stack, so we round each of these off in order to be able
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to write an integer number of pages.
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The minimum core file size is 3 pages, or 12288 bytes.
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*/
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/*
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* This is the old layout of "struct pt_regs", and
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* is still the layout used by user mode (the new
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* pt_regs doesn't have all registers as the kernel
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* doesn't use the extra segment registers)
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*/
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/* When the kernel dumps core, it starts by dumping the user struct -
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this will be used by gdb to figure out where the data and stack segments
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are within the file, and what virtual addresses to use. */
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struct
user
{
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/* We start with the registers, to mimic the way that "memory" is returned
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from the ptrace(3,...) function. */
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struct
user_regs_struct
regs
;
/* Where the registers are actually stored */
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/* The rest of this junk is to help gdb figure out what goes where */
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unsigned
long
int
u_tsize
;
/* Text segment size (pages). */
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unsigned
long
int
u_dsize
;
/* Data segment size (pages). */
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unsigned
long
int
u_ssize
;
/* Stack segment size (pages). */
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unsigned
long
start_code
;
/* Starting virtual address of text. */
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unsigned
long
start_stack
;
/* Starting virtual address of stack area.
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This is actually the bottom of the stack,
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the top of the stack is always found in the
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esp register. */
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long
int
signal
;
/* Signal that caused the core dump. */
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unsigned
long
u_ar0
;
/* Used by gdb to help find the values for */
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/* the registers. */
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unsigned
long
magic
;
/* To uniquely identify a core file */
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char
u_comm
[32];
/* User command that was responsible */
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};
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#define NBPG PAGE_SIZE
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#define UPAGES 1
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#define HOST_TEXT_START_ADDR (u.start_code)
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#define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG)
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#endif
/* _S390_USER_H */
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