target/arm/arm-semi: Use set_swi_errno() in gdbstub callback functions

When we are routing semihosting operations through the gdbstub, the
work of sorting out the return value and setting errno if necessary
is done by callback functions which are invoked by the gdbstub code.
Clean up some ifdeffery in those functions by having them call
set_swi_errno() to set the semihosting errno.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-7-peter.maydell@linaro.org

target/arm/arm-semi.c

@@ -259,17 +259,11 @@ static void arm_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
 {
     ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = cs->opaque;
-#endif
     target_ulong reg0 = is_a64(env) ? env->xregs[0] : env->regs[0];
 
     if (ret == (target_ulong)-1) {
-#ifdef CONFIG_USER_ONLY
-        ts->swi_errno = err;
-#else
-        syscall_err = err;
-#endif
+        errno = err;
+        set_swi_errno(env, -1);
         reg0 = ret;
     } else {
         /* Fixup syscalls that use nonstardard return conventions.  */
@@ -326,11 +320,8 @@ static void arm_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err)
     } else {
         env->regs[0] = size;
     }
-#ifdef CONFIG_USER_ONLY
-    ((TaskState *)cs->opaque)->swi_errno = err;
-#else
-    syscall_err = err;
-#endif
+    errno = err;
+    set_swi_errno(env, -1);
 }
 
 static int arm_semi_open_guestfd;
@@ -339,15 +330,9 @@ static void arm_semi_open_cb(CPUState *cs, target_ulong ret, target_ulong err)
 {
     ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = cs->opaque;
-#endif
     if (ret == (target_ulong)-1) {
-#ifdef CONFIG_USER_ONLY
-        ts->swi_errno = err;
-#else
-        syscall_err = err;
-#endif
+        errno = err;
+        set_swi_errno(env, -1);
         dealloc_guestfd(arm_semi_open_guestfd);
     } else {
         associate_guestfd(arm_semi_open_guestfd, ret);