[PATCH v4 38/53] semihosting: Create semihost_sys_{stat,fstat}

[Richard Henderson <richard.henderson@linaro.org>]

These syscalls will be used by m68k and nios2 semihosting.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/semihosting/syscalls.h |   7 ++
 semihosting/syscalls.c         | 137 +++++++++++++++++++++++++++++++++
 2 files changed, 144 insertions(+)

diff --git a/include/semihosting/syscalls.h b/include/semihosting/syscalls.h
index c9f9e66be1..ecc97751a9 100644
--- a/include/semihosting/syscalls.h
+++ b/include/semihosting/syscalls.h
@@ -49,6 +49,13 @@ void semihost_sys_flen(CPUState *cs, gdb_syscall_complete_cb fstat_cb,
                        gdb_syscall_complete_cb flen_cb,
                        int fd, target_ulong fstat_addr);
 
+void semihost_sys_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+                        int fd, target_ulong addr);
+
+void semihost_sys_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+                       target_ulong fname, target_ulong fname_len,
+                       target_ulong addr);
+
 void semihost_sys_remove(CPUState *cs, gdb_syscall_complete_cb complete,
                          target_ulong fname, target_ulong fname_len);
 
diff --git a/semihosting/syscalls.c b/semihosting/syscalls.c
index de846ced32..d21064716d 100644
--- a/semihosting/syscalls.c
+++ b/semihosting/syscalls.c
@@ -63,6 +63,52 @@ static int validate_lock_user_string(char **pstr, CPUState *cs,
     return ret;
 }
 
+/*
+ * TODO: Note that gdb always stores the stat structure big-endian.
+ * So far, that's ok, as the only two targets using this are also
+ * big-endian.  Until we do something with gdb, also produce the
+ * same big-endian result from the host.
+ */
+static int copy_stat_to_user(CPUState *cs, target_ulong addr,
+                             const struct stat *s)
+{
+    CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+    struct gdb_stat *p;
+
+    if (s->st_dev != (uint32_t)s->st_dev ||
+        s->st_ino != (uint32_t)s->st_ino) {
+        return -EOVERFLOW;
+    }
+
+    p = lock_user(VERIFY_WRITE, addr, sizeof(struct gdb_stat), 0);
+    if (!p) {
+        return -EFAULT;
+    }
+
+    p->gdb_st_dev = cpu_to_be32(s->st_dev);
+    p->gdb_st_ino = cpu_to_be32(s->st_ino);
+    p->gdb_st_mode = cpu_to_be32(s->st_mode);
+    p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
+    p->gdb_st_uid = cpu_to_be32(s->st_uid);
+    p->gdb_st_gid = cpu_to_be32(s->st_gid);
+    p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
+    p->gdb_st_size = cpu_to_be64(s->st_size);
+#ifdef _WIN32
+    /* Windows stat is missing some fields.  */
+    p->gdb_st_blksize = 0;
+    p->gdb_st_blocks = 0;
+#else
+    p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
+    p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
+#endif
+    p->gdb_st_atime = cpu_to_be32(s->st_atime);
+    p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
+    p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
+
+    unlock_user(p, addr, sizeof(struct gdb_stat));
+    return 0;
+}
+
 /*
  * GDB semihosting syscall implementations.
  */
@@ -133,6 +179,19 @@ static void gdb_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
     gdb_do_syscall(complete, "fstat,%x,%x", (target_ulong)gf->hostfd, addr);
 }
 
+static void gdb_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+                     target_ulong fname, target_ulong fname_len,
+                     target_ulong addr)
+{
+    int len = validate_strlen(cs, fname, fname_len);
+    if (len < 0) {
+        complete(cs, -1, -len);
+        return;
+    }
+
+    gdb_do_syscall(complete, "stat,%s,%x", fname, len, addr);
+}
+
 static void gdb_remove(CPUState *cs, gdb_syscall_complete_cb complete,
                        target_ulong fname, target_ulong fname_len)
 {
@@ -321,6 +380,51 @@ static void host_flen(CPUState *cs, gdb_syscall_complete_cb complete,
     }
 }
 
+static void host_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+                       GuestFD *gf, target_ulong addr)
+{
+    struct stat buf;
+    int ret;
+
+    ret = fstat(gf->hostfd, &buf);
+    if (ret) {
+        complete(cs, -1, errno);
+        return;
+    }
+    ret = copy_stat_to_user(cs, addr, &buf);
+    complete(cs, ret ? -1 : 0, ret ? -ret : 0);
+}
+
+static void host_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+                      target_ulong fname, target_ulong fname_len,
+                      target_ulong addr)
+{
+    CPUArchState *env G_GNUC_UNUSED = cs->env_ptr;
+    struct stat buf;
+    char *name;
+    int ret, err;
+
+    ret = validate_lock_user_string(&name, cs, fname, fname_len);
+    if (ret < 0) {
+        complete(cs, -1, -ret);
+        return;
+    }
+
+    ret = stat(name, &buf);
+    if (ret) {
+        err = errno;
+    } else {
+        ret = copy_stat_to_user(cs, addr, &buf);
+        err = 0;
+        if (ret < 0) {
+            err = -ret;
+            ret = -1;
+        }
+    }
+    complete(cs, ret, err);
+    unlock_user(name, fname, 0);
+}
+
 static void host_remove(CPUState *cs, gdb_syscall_complete_cb complete,
                         target_ulong fname, target_ulong fname_len)
 {
@@ -629,6 +733,39 @@ void semihost_sys_flen(CPUState *cs, gdb_syscall_complete_cb fstat_cb,
     }
 }
 
+void semihost_sys_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
+                        int fd, target_ulong addr)
+{
+    GuestFD *gf = get_guestfd(fd);
+
+    if (!gf) {
+        complete(cs, -1, EBADF);
+        return;
+    }
+    switch (gf->type) {
+    case GuestFDGDB:
+        gdb_fstat(cs, complete, gf, addr);
+        break;
+    case GuestFDHost:
+        host_fstat(cs, complete, gf, addr);
+        break;
+    case GuestFDStatic:
+    default:
+        g_assert_not_reached();
+    }
+}
+
+void semihost_sys_stat(CPUState *cs, gdb_syscall_complete_cb complete,
+                       target_ulong fname, target_ulong fname_len,
+                       target_ulong addr)
+{
+    if (use_gdb_syscalls()) {
+        gdb_stat(cs, complete, fname, fname_len, addr);
+    } else {
+        host_stat(cs, complete, fname, fname_len, addr);
+    }
+}
+
 void semihost_sys_remove(CPUState *cs, gdb_syscall_complete_cb complete,
                          target_ulong fname, target_ulong fname_len)
 {
-- 
2.34.1