1 files changed, 71 insertions, 0 deletions
diff --git a/arch/s390/include/asm/user.h b/arch/s390/include/asm/user.h
new file mode 100644
index 000000000..8e8aaf485
--- /dev/null
+++ b/arch/s390/include/asm/user.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  S390 version
+ *
+ *  Derived from "include/asm-i386/usr.h"
+ */
+
+#ifndef _S390_USER_H
+#define _S390_USER_H
+
+#include <asm/page.h>
+#include <asm/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 */
+  unsigned long int u_tsize;	/* Text segment size (pages). */
+  unsigned long int u_dsize;	/* Data segment size (pages). */
+  unsigned long int 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
+				   esp register.  */
+  long int signal;     		/* Signal that caused the core dump. */
+  unsigned long 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 */
+};
+
+#endif /* _S390_USER_H */