semihosting: Split out semihost_sys_flen

The ARM-specific SYS_FLEN isn't really something that can be
reused by other semihosting apis, but there are parts that can
reused for the implementation of semihost_sys_fstat.

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

1 files changed, 13 insertions, 61 deletions

diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index 3cdc2b6efc..68e13d9077 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -285,44 +285,25 @@ static target_ulong common_semi_flen_buf(CPUState *cs)
 }
 
 static void
-common_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err)
+common_semi_flen_fstat_cb(CPUState *cs, target_ulong ret, target_ulong err)
 {
     if (!err) {
         /* The size is always stored in big-endian order, extract the value. */
         uint64_t size;
-        cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) +
-                            offsetof(struct gdb_stat, gdb_st_size),
-                            &size, 8, 0);
-        ret = be64_to_cpu(size);
+        if (cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) +
+                                offsetof(struct gdb_stat, gdb_st_size),
+                                &size, 8, 0)) {
+            ret = -1, err = EFAULT;
+        } else {
+            size = be64_to_cpu(size);
+            if (ret != size) {
+                ret = -1, err = EOVERFLOW;
+            }
+        }
     }
     common_semi_cb(cs, ret, err);
 }
 
-/*
- * 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 to the guest
- * via common_semi_cb.
- */
-typedef void sys_flenfn(CPUState *cs, GuestFD *gf);
-
-static void host_flenfn(CPUState *cs, GuestFD *gf)
-{
-    struct stat buf;
-
-    if (fstat(gf->hostfd, &buf)) {
-        common_semi_cb(cs, -1, errno);
-    } else {
-        common_semi_cb(cs, buf.st_size, 0);
-    }
-}
-
-static void gdb_flenfn(CPUState *cs, GuestFD *gf)
-{
-    gdb_do_syscall(common_semi_flen_cb, "fstat,%x,%x",
-                   gf->hostfd, common_semi_flen_buf(cs));
-}
-
 #define SHFB_MAGIC_0 0x53
 #define SHFB_MAGIC_1 0x48
 #define SHFB_MAGIC_2 0x46
@@ -340,27 +321,6 @@ static const uint8_t featurefile_data[] = {
     SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */
 };
 
-static void staticfile_flenfn(CPUState *cs, GuestFD *gf)
-{
-    common_semi_cb(cs, gf->staticfile.len, 0);
-}
-
-typedef struct GuestFDFunctions {
-    sys_flenfn *flenfn;
-} GuestFDFunctions;
-
-static const GuestFDFunctions guestfd_fns[] = {
-    [GuestFDHost] = {
-        .flenfn = host_flenfn,
-    },
-    [GuestFDGDB] = {
-        .flenfn = gdb_flenfn,
-    },
-    [GuestFDStatic] = {
-        .flenfn = staticfile_flenfn,
-    },
-};
-
 /*
  * Do a semihosting call.
  *
@@ -379,7 +339,6 @@ void do_common_semihosting(CPUState *cs)
     char * s;
     int nr;
     uint32_t ret;
-    GuestFD *gf;
     int64_t elapsed;
 
     nr = common_semi_arg(cs, 0) & 0xffffffffU;
@@ -493,12 +452,8 @@ void do_common_semihosting(CPUState *cs)
 
     case TARGET_SYS_FLEN:
         GET_ARG(0);
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            goto do_badf;
-        }
-        guestfd_fns[gf->type].flenfn(cs, gf);
+        semihost_sys_flen(cs, common_semi_flen_fstat_cb, common_semi_cb,
+                          arg0, common_semi_flen_buf(cs));
         break;
 
     case TARGET_SYS_TMPNAM:
@@ -820,9 +775,6 @@ void do_common_semihosting(CPUState *cs)
         cpu_dump_state(cs, stderr, 0);
         abort();
 
-    do_badf:
-        common_semi_cb(cs, -1, EBADF);
-        break;
     do_fault:
         common_semi_cb(cs, -1, EFAULT);
         break;