Merge tag 'pull-xenfv-20231121' of git://git.infradead.org/users/dwmw…

…2/qemu into staging Xen fixes for 8.2-rc1 • Disable default serial when xen-console is used • Fix Coverity warning in xen-block # -----BEGIN PGP SIGNATURE----- # # iQJIBAABCAAyFiEEvgfZ/VSAmrLEsP9fY3Ys2mfi81kFAmVcmrAUHGR3bXcyQGlu # ZnJhZGVhZC5vcmcACgkQY3Ys2mfi81njqg/8DFr03kVfwRujIZXDROoq40vjgdOF # MoGgowDNapliXiecVcHzdvFXgRxwr9bhpX5eDEtfgROoH8mbPPd4YZJHdPNM0Yc3 # 0hoSWrIYocsYRAIoozXrtsNw8ep2vSEPNv5+CIVYkkie/mLs02cy43q09cJDzABx # DvmSfC5o5JCs/x3qPLM6ydhnTaUipuPt1wnG9xaJLWgm/U9pK6Ba9w1eNGn8EE7m # ekzpv9lYfCd/KbPogtXAEd7nkCOi/lKQVJmU7auXFi8FKwZNoKOYl3cTVln/EFmT # az3qLSHgOZwElNQEYn0mBa/RgAQ2K9X7n12TgxG30VSUmajxJnl/eKy4ISyaAmwY # vNVhdsXQICqM4OYaD2j8RiXX5YNtIC+MBb7nlUN7invKXE9ZylHbXvOstkUCjQ34 # x9CMVIibPoWk7XGUX+r7KUSwSQnpelVbqBWltkmgNjYuUIShDT6r5cOrYdM2orii # UYOqPJqchbEDNoGwJK45EOSn8Ss5geAWuM7dFL0AuwZAbcKAqGG6vihPnDJyhnWA # EPv2/5h2Vi24fqeWz3W+hckm8LXrc2Ow8A0rY3WAz7CvmBTgYCPx4d4kdTU6Gysn # i8DRoKMhZS9WvHPPxY1v8+ysG1UCCNFe4qH0Wgv+ubSbr5GaK2igWIBQ5bXnuYL8 # R4Ef5pPLpa2jiF4= # =cWon # -----END PGP SIGNATURE----- # gpg: Signature made Tue 21 Nov 2023 06:55:28 EST # gpg: using RSA key BE07D9FD54809AB2C4B0FF5F63762CDA67E2F359 # gpg: issuer "[email protected]" # gpg: Good signature from "David Woodhouse <[email protected]>" [unknown] # gpg: aka "David Woodhouse <[email protected]>" [unknown] # gpg: aka "David Woodhouse <[email protected]>" [unknown] # gpg: aka "David Woodhouse <[email protected]>" [unknown] # gpg: WARNING: The key's User ID is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: BE07 D9FD 5480 9AB2 C4B0 FF5F 6376 2CDA 67E2 F359 * tag 'pull-xenfv-20231121' of git://git.infradead.org/users/dwmw2/qemu: hw/xen: clean up xen_block_find_free_vdev() to avoid Coverity false positive vl: disable default serial when xen-console is enabled Signed-off-by: Stefan Hajnoczi <[email protected]>
OSLL · Nov 21, 2023 · 63ceac2 · 63ceac2
2 parents d50a134 + 6f7997e
commit 63ceac2
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Showing 2 changed files with 22 additions and 3 deletions.
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
@@ -91,9 +91,27 @@ static bool xen_block_find_free_vdev(XenBlockDevice *blockdev, Error **errp)
 
     existing_frontends = qemu_xen_xs_directory(xenbus->xsh, XBT_NULL, fe_path,
                                                &nr_existing);
-    if (!existing_frontends && errno != ENOENT) {
-        error_setg_errno(errp, errno, "cannot read %s", fe_path);
-        return false;
+    if (!existing_frontends) {
+        if (errno == ENOENT) {
+            /*
+             * If the frontend directory doesn't exist because there are
+             * no existing vbd devices, that's fine. Just ensure that we
+             * don't dereference the NULL existing_frontends pointer, by
+             * checking that nr_existing is zero so the loop below is not
+             * entered.
+             *
+             * In fact this is redundant since nr_existing is initialized
+             * to zero, but setting it again here makes it abundantly clear
+             * to Coverity, and to the human reader who doesn't know the
+             * semantics of qemu_xen_xs_directory() off the top of their
+             * head.
+             */
+            nr_existing = 0;
+        } else {
+            /* All other errors accessing the frontend directory are fatal. */
+            error_setg_errno(errp, errno, "cannot read %s", fe_path);
+            return false;
+        }
     }
 
     memset(used_devs, 0, sizeof(used_devs));

diff --git a/system/vl.c b/system/vl.c
@@ -198,6 +198,7 @@ static const struct {
     const char *driver;
     int *flag;
 } default_list[] = {
+    { .driver = "xen-console",          .flag = &default_serial    },
     { .driver = "isa-serial",           .flag = &default_serial    },
     { .driver = "isa-parallel",         .flag = &default_parallel  },
     { .driver = "isa-fdc",              .flag = &default_floppy    },