Add linux/elfcore-compat.h

This adds the linux/elfcore-compat.h header file, which is the CONFIG_COMPAT
analog of the linux/elfcore.h header.  Each arch that needs to fake out
fs/binfmt_elf.c for its compat code can use this header to replace the
hand-copied definitions of the compat variants of struct elf_prstatus et al.
Only the pr_reg field varies by arch, so asm/{compat,elf}.h must define
compat_elf_gregset_t before linux/elfcore-compat.h can be used.

It's a clean-up that every arch with compat core dumping code can benefit
from.  I only touched the ones I have handy to test at home.  Doing the same
for each other arch should be straightforward, and I'm happy to offer tips.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/elfcore-compat.h

+#ifndef _LINUX_ELFCORE_COMPAT_H
+#define _LINUX_ELFCORE_COMPAT_H
+
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/compat.h>
+
+/*
+ * Make sure these layouts match the linux/elfcore.h native definitions.
+ */
+
+struct compat_elf_siginfo
+{
+	compat_int_t			si_signo;
+	compat_int_t			si_code;
+	compat_int_t			si_errno;
+};
+
+struct compat_elf_prstatus
+{
+	struct compat_elf_siginfo	pr_info;
+	short				pr_cursig;
+	compat_ulong_t			pr_sigpend;
+	compat_ulong_t			pr_sighold;
+	compat_pid_t			pr_pid;
+	compat_pid_t			pr_ppid;
+	compat_pid_t			pr_pgrp;
+	compat_pid_t			pr_sid;
+	struct compat_timeval		pr_utime;
+	struct compat_timeval		pr_stime;
+	struct compat_timeval		pr_cutime;
+	struct compat_timeval		pr_cstime;
+	compat_elf_gregset_t		pr_reg;
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+	compat_ulong_t			pr_exec_fdpic_loadmap;
+	compat_ulong_t			pr_interp_fdpic_loadmap;
+#endif
+	compat_int_t			pr_fpvalid;
+};
+
+struct compat_elf_prpsinfo
+{
+	char				pr_state;
+	char				pr_sname;
+	char				pr_zomb;
+	char				pr_nice;
+	compat_ulong_t			pr_flag;
+	compat_uid_t			pr_uid;
+	compat_gid_t			pr_gid;
+	compat_pid_t			pr_pid, pr_ppid, pr_pgrp, pr_sid;
+	char				pr_fname[16];
+	char				pr_psargs[ELF_PRARGSZ];
+};
+
+#endif /* _LINUX_ELFCORE_COMPAT_H */