linux-user: Create do_init_main_thread

Provide a unified function to initialize the main thread.
Keep target_pt_regs isolated to this function.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/elfload.c

@@ -3619,7 +3619,10 @@ static int elf_core_dump(int signr, const CPUArchState *env)
 }
 #endif /* USE_ELF_CORE_DUMP */
 
-void do_init_thread(struct target_pt_regs *regs, struct image_info *infop)
+void do_init_main_thread(CPUState *cs, struct image_info *infop)
 {
-    init_thread(regs, infop);
+    target_pt_regs regs = { };
+
+    init_thread(&regs, infop);
+    target_cpu_copy_regs(cpu_env(cs), &regs);
 }

linux-user/linuxload.c

@@ -139,8 +139,7 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
 }
 
 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
-                struct target_pt_regs *regs, struct image_info *infop,
-                struct linux_binprm *bprm)
+                struct image_info *infop, struct linux_binprm *bprm)
 {
     int retval;
 
@@ -175,8 +174,7 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
         return retval;
     }
 
-    /* Success.  Initialize important registers. */
-    do_init_thread(regs, infop);
+    /* Success. */
     return 0;
 }
 

linux-user/loader.h

@@ -82,12 +82,11 @@ struct linux_binprm {
     int (*core_dump)(int, const CPUArchState *); /* coredump routine */
 };
 
-void do_init_thread(struct target_pt_regs *regs, struct image_info *infop);
+void do_init_main_thread(CPUState *cs, struct image_info *infop);
 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
                               abi_ulong stringp, int push_ptr);
 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
-             struct target_pt_regs *regs, struct image_info *infop,
-             struct linux_binprm *);
+                struct image_info *infop, struct linux_binprm *);
 
 uint32_t get_elf_eflags(int fd);
 int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);

linux-user/main.c

@@ -696,7 +696,6 @@ static int parse_args(int argc, char **argv)
 
 int main(int argc, char **argv, char **envp)
 {
-    struct target_pt_regs regs1, *regs = &regs1;
     struct image_info info1, *info = &info1;
     struct linux_binprm bprm;
     TaskState *ts;
@@ -762,9 +761,6 @@ int main(int argc, char **argv, char **envp)
     trace_init_file();
     qemu_plugin_load_list(&plugins, &error_fatal);
 
-    /* Zero out regs */
-    memset(regs, 0, sizeof(struct target_pt_regs));
-
     /* Zero out image_info */
     memset(info, 0, sizeof(struct image_info));
 
@@ -988,8 +984,8 @@ int main(int argc, char **argv, char **envp)
 
     fd_trans_init();
 
-    ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
-        info, &bprm);
+    ret = loader_exec(execfd, exec_path, target_argv, target_environ,
+                      info, &bprm);
     if (ret != 0) {
         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
         _exit(EXIT_FAILURE);
@@ -1041,7 +1037,7 @@ int main(int argc, char **argv, char **envp)
        the real value of GUEST_BASE into account.  */
     tcg_prologue_init();
 
-    target_cpu_copy_regs(env, regs);
+    do_init_main_thread(cpu, info);
 
     if (gdbstub) {
         gdbserver_start(gdbstub, &error_fatal);