[PATCH v4 10/17] tools/xenstore: make domain_is_unprivileged() an inline function

From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>, Wei Liu <wl@xen.org>,
	Julien Grall <julien@xen.org>,
	Anthony PERARD <anthony.perard@citrix.com>,
	Julien Grall <jgrall@amazon.com>
Subject: [PATCH v4 10/17] tools/xenstore: make domain_is_unprivileged() an inline function
Date: Wed, 18 Jan 2023 10:50:09 +0100	[thread overview]
Message-ID: <20230118095016.13091-11-jgross@suse.com> (raw)
In-Reply-To: <20230118095016.13091-1-jgross@suse.com>

clang 14 is complaining about a NULL dereference for constructs like:

  domain_is_unprivileged(conn) ? conn->in : NULL

as it can't know that domain_is_unprivileged(conn) will return false
if conn is NULL.

Fix that by making domain_is_unprivileged() an inline function (and
related to that domid_is_unprivileged(), too).

In order not having to make struct domain public, use conn->id instead
of conn->domain->domid for the test.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
---
 tools/xenstore/xenstored_core.h   | 10 ++++++++++
 tools/xenstore/xenstored_domain.c | 11 -----------
 tools/xenstore/xenstored_domain.h |  2 --
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 62d8ee96bd..6548200d8e 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -318,6 +318,16 @@ void unmap_xenbus(void *interface);
 
 static inline int xenbus_master_domid(void) { return dom0_domid; }
 
+static inline bool domid_is_unprivileged(unsigned int domid)
+{
+	return domid != dom0_domid && domid != priv_domid;
+}
+
+static inline bool domain_is_unprivileged(const struct connection *conn)
+{
+	return conn && domid_is_unprivileged(conn->id);
+}
+
 /* Return the event channel used by xenbus. */
 evtchn_port_t xenbus_evtchn(void);
 
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index a703c0ef47..10880a32d9 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -408,17 +408,6 @@ void handle_event(void)
 		barf_perror("Failed to write to event fd");
 }
 
-static bool domid_is_unprivileged(unsigned int domid)
-{
-	return domid != dom0_domid && domid != priv_domid;
-}
-
-bool domain_is_unprivileged(struct connection *conn)
-{
-	return conn && conn->domain &&
-	       domid_is_unprivileged(conn->domain->domid);
-}
-
 static char *talloc_domain_path(const void *context, unsigned int domid)
 {
 	return talloc_asprintf(context, "/local/domain/%u", domid);
diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index 1e402f2609..22996e2576 100644
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -59,8 +59,6 @@ void ignore_connection(struct connection *conn, unsigned int err);
 /* Returns the implicit path of a connection (only domains have this) */
 const char *get_implicit_path(const struct connection *conn);
 
-bool domain_is_unprivileged(struct connection *conn);
-
 /* Remove node permissions for no longer existing domains. */
 int domain_adjust_node_perms(struct node *node);
 int domain_alloc_permrefs(struct node_perms *perms);
-- 
2.35.3


