Make use of the fact that target_elf_gregset_t is a proper structure.
Drop ELF_NREG, target_elf_greg_t, and tswapreg.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/arm/target_elf.h | 11 +++++++----
 linux-user/arm/elfload.c    |  8 +++-----
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/linux-user/arm/target_elf.h b/linux-user/arm/target_elf.h
index 94db3738e8..fa8f8af2f3 100644
--- a/linux-user/arm/target_elf.h
+++ b/linux-user/arm/target_elf.h
@@ -8,16 +8,19 @@
 #ifndef ARM_TARGET_ELF_H
 #define ARM_TARGET_ELF_H
 
+#include "target_ptrace.h"
+
 #define HAVE_ELF_HWCAP          1
 #define HAVE_ELF_HWCAP2         1
 #define HAVE_ELF_PLATFORM       1
 #define HAVE_ELF_CORE_DUMP      1
 
-typedef abi_ulong target_elf_greg_t;
-
-#define ELF_NREG                18
+/*
+ * See linux kernel: arch/arm/include/asm/elf.h, where
+ * elf_gregset_t is mapped to struct pt_regs via sizeof.
+ */
 typedef struct target_elf_gregset_t {
-    target_elf_greg_t regs[ELF_NREG];
+    struct target_pt_regs pt;
 } target_elf_gregset_t;
 
 #endif
diff --git a/linux-user/arm/elfload.c b/linux-user/arm/elfload.c
index 47fe16a1a6..f811c2f07a 100644
--- a/linux-user/arm/elfload.c
+++ b/linux-user/arm/elfload.c
@@ -201,13 +201,11 @@ const char *get_elf_platform(CPUState *cs)
 #undef END
 }
 
-#define tswapreg(ptr)   tswapal(ptr)
-
 void elf_core_copy_regs(target_elf_gregset_t *r, const CPUARMState *env)
 {
     for (int i = 0; i < 16; ++i) {
-        r->regs[i] = tswapreg(env->regs[i]);
+        r->pt.regs[i] = tswapal(env->regs[i]);
     }
-    r->regs[16] = tswapreg(cpsr_read((CPUARMState *)env));
-    r->regs[17] = tswapreg(env->regs[0]); /* XXX */
+    r->pt.cpsr = tswapal(cpsr_read((CPUARMState *)env));
+    r->pt.orig_r0 = tswapal(env->regs[0]); /* FIXME */
 }
-- 
2.43.0