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/m68k/target_elf.h | 24 ++++++++++++++++-----
 linux-user/m68k/elfload.c    | 42 +++++++++++++++++-------------------
 2 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/linux-user/m68k/target_elf.h b/linux-user/m68k/target_elf.h
index cd6908ab57..0737412cee 100644
--- a/linux-user/m68k/target_elf.h
+++ b/linux-user/m68k/target_elf.h
@@ -10,12 +10,26 @@
 
 #define HAVE_ELF_CORE_DUMP      1
 
-typedef abi_ulong target_elf_greg_t;
-
-/* See linux kernel: arch/m68k/include/asm/elf.h.  */
-#define ELF_NREG                20
+/*
+ * See linux kernel: arch/m68k/include/asm/elf.h, where
+ * elf_gregset_t is mapped to struct user_regs_struct via sizeof.
+ *
+ * Note that user_regs_struct has
+ *    short stkadj, sr;
+ *    ...
+ *    short fmtvec, __fill;
+ * but ELF_CORE_COPY_REGS writes to unsigned longs.
+ * Therefore adjust the sr and fmtvec fields to match.
+ */
 typedef struct target_elf_gregset_t {
-    target_elf_greg_t regs[ELF_NREG];
+    abi_ulong d1, d2, d3, d4, d5, d6, d7;
+    abi_ulong a0, a1, a2, a3, a4, a5, a6;
+    abi_ulong d0;
+    abi_ulong usp;
+    abi_ulong orig_d0;
+    abi_ulong sr;
+    abi_ulong pc;
+    abi_ulong fmtvec;
 } target_elf_gregset_t;
 
 #endif
diff --git a/linux-user/m68k/elfload.c b/linux-user/m68k/elfload.c
index 2970ff7dec..423d1f680a 100644
--- a/linux-user/m68k/elfload.c
+++ b/linux-user/m68k/elfload.c
@@ -18,28 +18,26 @@ const char *get_elf_cpu_model(uint32_t eflags)
     return "any";
 }
 
-#define tswapreg(ptr)   tswapal(ptr)
-
 void elf_core_copy_regs(target_elf_gregset_t *r, const CPUM68KState *env)
 {
-    r->regs[0] = tswapreg(env->dregs[1]);
-    r->regs[1] = tswapreg(env->dregs[2]);
-    r->regs[2] = tswapreg(env->dregs[3]);
-    r->regs[3] = tswapreg(env->dregs[4]);
-    r->regs[4] = tswapreg(env->dregs[5]);
-    r->regs[5] = tswapreg(env->dregs[6]);
-    r->regs[6] = tswapreg(env->dregs[7]);
-    r->regs[7] = tswapreg(env->aregs[0]);
-    r->regs[8] = tswapreg(env->aregs[1]);
-    r->regs[9] = tswapreg(env->aregs[2]);
-    r->regs[10] = tswapreg(env->aregs[3]);
-    r->regs[11] = tswapreg(env->aregs[4]);
-    r->regs[12] = tswapreg(env->aregs[5]);
-    r->regs[13] = tswapreg(env->aregs[6]);
-    r->regs[14] = tswapreg(env->dregs[0]);
-    r->regs[15] = tswapreg(env->aregs[7]);
-    r->regs[16] = tswapreg(env->dregs[0]); /* FIXME: orig_d0 */
-    r->regs[17] = tswapreg(env->sr);
-    r->regs[18] = tswapreg(env->pc);
-    r->regs[19] = 0;  /* FIXME: regs->format | regs->vector */
+    r->d1 = tswapal(env->dregs[1]);
+    r->d2 = tswapal(env->dregs[2]);
+    r->d3 = tswapal(env->dregs[3]);
+    r->d4 = tswapal(env->dregs[4]);
+    r->d5 = tswapal(env->dregs[5]);
+    r->d6 = tswapal(env->dregs[6]);
+    r->d7 = tswapal(env->dregs[7]);
+    r->a0 = tswapal(env->aregs[0]);
+    r->a1 = tswapal(env->aregs[1]);
+    r->a2 = tswapal(env->aregs[2]);
+    r->a3 = tswapal(env->aregs[3]);
+    r->a4 = tswapal(env->aregs[4]);
+    r->a5 = tswapal(env->aregs[5]);
+    r->a6 = tswapal(env->aregs[6]);
+    r->d0 = tswapal(env->dregs[0]);
+    r->usp = tswapal(env->aregs[7]);
+    r->orig_d0 = tswapal(env->dregs[0]); /* FIXME */
+    r->sr = tswapal(env->sr);
+    r->pc = tswapal(env->pc);
+    /* FIXME: regs->format | regs->vector */
 }
-- 
2.43.0