[ 19/46] arm64: elf: fix core dumping to match what glibc expects

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@arm.com>

commit 9cf2b72b25f3f6a5a1a46a4f36037e66de52465c upstream.

The kernel's internal definition of ELF_NGREG uses struct pt_regs, which
means that we disagree with userspace on the size of coredumps since
glibc correctly uses the user-visible struct user_pt_regs.

This patch fixes our ELF_NGREG definition to use struct user_pt_regs
and introduces our own ELF_CORE_COPY_REGS to convert between the user
and kernel structure definitions.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm64/include/asm/elf.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -26,7 +26,10 @@
 
 typedef unsigned long elf_greg_t;
 
-#define ELF_NGREG (sizeof (struct pt_regs) / sizeof(elf_greg_t))
+#define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
+#define ELF_CORE_COPY_REGS(dest, regs)	\
+	*(struct user_pt_regs *)&(dest) = (regs)->user_regs;
+
 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 typedef struct user_fpsimd_state elf_fpregset_t;