1 files changed, 37 insertions, 7 deletions

diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
index 02cd673d47..e5f1e2aaaf 100644
--- a/target/arm/arm-semi.c
+++ b/target/arm/arm-semi.c
@@ -109,6 +109,7 @@ static int open_modeflags[12] = {
 typedef enum GuestFDType {
     GuestFDUnused = 0,
     GuestFDHost = 1,
+    GuestFDGDB = 2,
 } GuestFDType;
 
 /*
@@ -172,14 +173,14 @@ static GuestFD *do_get_guestfd(int guestfd)
 /*
  * Associate the specified guest fd (which must have been
  * allocated via alloc_fd() and not previously used) with
- * the specified host fd.
+ * the specified host/gdb fd.
  */
 static void associate_guestfd(int guestfd, int hostfd)
 {
     GuestFD *gf = do_get_guestfd(guestfd);
 
     assert(gf);
-    gf->type = GuestFDHost;
+    gf->type = use_gdb_syscalls() ? GuestFDGDB : GuestFDHost;
     gf->hostfd = hostfd;
 }
 
@@ -376,6 +377,39 @@ static target_ulong arm_gdb_syscall(ARMCPU *cpu, gdb_syscall_complete_cb cb,
     return is_a64(env) ? env->xregs[0] : env->regs[0];
 }
 
+/*
+ * Types for functions implementing various semihosting calls
+ * for specific types of guest file descriptor. These must all
+ * do the work and return the required return value for the guest,
+ * setting the guest errno if appropriate.
+ */
+typedef uint32_t sys_closefn(ARMCPU *cpu, GuestFD *gf);
+
+static uint32_t host_closefn(ARMCPU *cpu, GuestFD *gf)
+{
+    CPUARMState *env = &cpu->env;
+
+    return set_swi_errno(env, close(gf->hostfd));
+}
+
+static uint32_t gdb_closefn(ARMCPU *cpu, GuestFD *gf)
+{
+    return arm_gdb_syscall(cpu, arm_semi_cb, "close,%x", gf->hostfd);
+}
+
+typedef struct GuestFDFunctions {
+    sys_closefn *closefn;
+} GuestFDFunctions;
+
+static const GuestFDFunctions guestfd_fns[] = {
+    [GuestFDHost] = {
+        .closefn = host_closefn,
+    },
+    [GuestFDGDB] = {
+        .closefn = gdb_closefn,
+    },
+};
+
 /* Read the input value from the argument block; fail the semihosting
  * call if the memory read fails.
  */
@@ -485,11 +519,7 @@ target_ulong do_arm_semihosting(CPUARMState *env)
             return set_swi_errno(env, -1);
         }
 
-        if (use_gdb_syscalls()) {
-            ret = arm_gdb_syscall(cpu, arm_semi_cb, "close,%x", gf->hostfd);
-        } else {
-            ret = set_swi_errno(env, close(gf->hostfd));
-        }
+        ret = guestfd_fns[gf->type].closefn(cpu, gf);
         dealloc_guestfd(arg0);
         return ret;
     case TARGET_SYS_WRITEC: