[mini-os master] reset file type in close() in one place only

[patchbot@xxxxxxx]

commit 83558bc823b3b0e14d9321f587d6d7bfb990380b
Author:     Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Sun Jan 16 07:45:24 2022 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Jan 17 10:55:46 2022 +0000

    reset file type in close() in one place only
    
    Today the file type in struct file is set to FTYPE_NONE for each
    file type individually. Do that at the end of close() handling for
    all types.
    
    While at it wipe the complete struct file, too, in order to avoid
    old data creeping into a new allocated struct file.
    
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
    Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
---
 lib/sys.c | 54 ++++++++++++++++++++++++++++--------------------------
 lib/xs.c  |  1 -
 2 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/lib/sys.c b/lib/sys.c
index 9a03875..333e47c 100644
--- a/lib/sys.c
+++ b/lib/sys.c
@@ -424,84 +424,86 @@ int fsync(int fd) {
 
 int close(int fd)
 {
+    int res = 0;
+
+    if ( fd < 0 || fd >= ARRAY_SIZE(files) )
+        goto error;
+
     printk("close(%d)\n", fd);
     switch (files[fd].type) {
         default:
-           files[fd].type = FTYPE_NONE;
-           return 0;
+            break;
 #ifdef CONFIG_XENBUS
        case FTYPE_XENBUS:
             xs_daemon_close((void*)(intptr_t) fd);
-            return 0;
+            break;
 #endif
 #ifdef HAVE_LWIP
-       case FTYPE_SOCKET: {
-           int res = lwip_close(files[fd].fd);
-           files[fd].type = FTYPE_NONE;
-           return res;
-       }
+       case FTYPE_SOCKET:
+            res = lwip_close(files[fd].fd);
+            break;
 #endif
 #ifdef CONFIG_LIBXENCTRL
        case FTYPE_XC:
            minios_interface_close_fd(fd);
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_LIBXENEVTCHN
        case FTYPE_EVTCHN:
            minios_evtchn_close_fd(fd);
-            return 0;
+            break;
 #endif
 #ifdef CONFIG_LIBXENGNTTAB
        case FTYPE_GNTMAP:
            minios_gnttab_close_fd(fd);
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_NETFRONT
        case FTYPE_TAP:
            shutdown_netfront(files[fd].dev);
-           files[fd].type = FTYPE_NONE;
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_BLKFRONT
        case FTYPE_BLK:
             shutdown_blkfront(files[fd].dev);
-           files[fd].type = FTYPE_NONE;
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_TPMFRONT
        case FTYPE_TPMFRONT:
             shutdown_tpmfront(files[fd].dev);
-           files[fd].type = FTYPE_NONE;
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_TPM_TIS
        case FTYPE_TPM_TIS:
             shutdown_tpm_tis(files[fd].dev);
-           files[fd].type = FTYPE_NONE;
-           return 0;
+            break;
 #endif
 #ifdef CONFIG_KBDFRONT
        case FTYPE_KBD:
             shutdown_kbdfront(files[fd].dev);
-            files[fd].type = FTYPE_NONE;
-            return 0;
+            break;
 #endif
 #ifdef CONFIG_FBFRONT
        case FTYPE_FB:
             shutdown_fbfront(files[fd].dev);
-            files[fd].type = FTYPE_NONE;
-            return 0;
+            break;
 #endif
 #ifdef CONFIG_CONSFRONT
         case FTYPE_SAVEFILE:
         case FTYPE_CONSOLE:
             fini_consfront(files[fd].dev);
-            files[fd].type = FTYPE_NONE;
-            return 0;
+            break;
 #endif
        case FTYPE_NONE:
-           break;
+            goto error;
     }
+
+    memset(files + fd, 0, sizeof(struct file));
+    BUILD_BUG_ON(FTYPE_NONE != 0);
+
+    return res;
+
+ error:
     printk("close(%d): Bad descriptor\n", fd);
     errno = EBADF;
     return -1;
diff --git a/lib/xs.c b/lib/xs.c
index 0459f52..4af0f96 100644
--- a/lib/xs.c
+++ b/lib/xs.c
@@ -35,7 +35,6 @@ void xs_daemon_close(struct xs_handle *h)
         next = event->next;
         free(event);
     }
-    files[fd].type = FTYPE_NONE;
 }
 
 int xs_fileno(struct xs_handle *h)
--
generated by git-patchbot for /home/xen/git/mini-os.git#master