semihosting: Split out semihost_sys_system

Split out the non-ARM specific portions of SYS_SYSTEM to a
reusable function.

Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/semihosting/syscalls.h

@@ -56,4 +56,7 @@ void semihost_sys_rename(CPUState *cs, gdb_syscall_complete_cb complete,
                          target_ulong oname, target_ulong oname_len,
                          target_ulong nname, target_ulong nname_len);
 
+void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete,
+                         target_ulong cmd, target_ulong cmd_len);
+
 #endif /* SEMIHOSTING_SYSCALLS_H */

semihosting/arm-compat-semi.c

@@ -507,17 +507,7 @@ void do_common_semihosting(CPUState *cs)
     case TARGET_SYS_SYSTEM:
         GET_ARG(0);
         GET_ARG(1);
-        if (use_gdb_syscalls()) {
+        semihost_sys_system(cs, common_semi_cb, arg0, arg1 + 1);
-            gdb_do_syscall(common_semi_cb, "system,%s", arg0, (int)arg1 + 1);
-            break;
-        }
-        s = lock_user_string(arg0);
-        if (!s) {
-            goto do_fault;
-        }
-        ret = system(s);
-        unlock_user(s, arg0, 0);
-        common_semi_cb(cs, ret, ret == -1 ? errno : 0);
         break;
 
     case TARGET_SYS_ERRNO:

semihosting/syscalls.c

@@ -165,6 +165,18 @@ static void gdb_rename(CPUState *cs, gdb_syscall_complete_cb complete,
     gdb_do_syscall(complete, "rename,%s,%s", oname, olen, nname, nlen);
 }
 
+static void gdb_system(CPUState *cs, gdb_syscall_complete_cb complete,
+                       target_ulong cmd, target_ulong cmd_len)
+{
+    int len = validate_strlen(cs, cmd, cmd_len);
+    if (len < 0) {
+        complete(cs, -1, -len);
+        return;
+    }
+
+    gdb_do_syscall(complete, "system,%s", cmd, len);
+}
+
 /*
  * Host semihosting syscall implementations.
  */
@@ -353,6 +365,24 @@ static void host_rename(CPUState *cs, gdb_syscall_complete_cb complete,
     unlock_user(nstr, nname, 0);
 }
 
+static void host_system(CPUState *cs, gdb_syscall_complete_cb complete,
+                        target_ulong cmd, target_ulong cmd_len)
+{
+    CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+    char *p;
+    int ret;
+
+    ret = validate_lock_user_string(&p, cs, cmd, cmd_len);
+    if (ret < 0) {
+        complete(cs, -1, -ret);
+        return;
+    }
+
+    ret = system(p);
+    complete(cs, ret, ret == -1 ? errno : 0);
+    unlock_user(p, cmd, 0);
+}
+
 /*
  * Static file semihosting syscall implementations.
  */
@@ -619,3 +649,13 @@ void semihost_sys_rename(CPUState *cs, gdb_syscall_complete_cb complete,
         host_rename(cs, complete, oname, oname_len, nname, nname_len);
     }
 }
+
+void semihost_sys_system(CPUState *cs, gdb_syscall_complete_cb complete,
+                         target_ulong cmd, target_ulong cmd_len)
+{
+    if (use_gdb_syscalls()) {
+        gdb_system(cs, complete, cmd, cmd_len);
+    } else {
+        host_system(cs, complete, cmd, cmd_len);
+    }
+}