From: Keno Fischer <k...@juliacomputing.com>
Signed-off-by: Keno Fischer <k...@juliacomputing.com>
Signed-off-by: Michael Roitzsch <reactorcont...@icloud.com>
Because XATTR_SIZE_MAX is not defined on Darwin,
create a cross-platform P9_XATTR_SIZE_MAX instead.
[Will Cohen: - Adjust coding style
- Lower XATTR_SIZE_MAX to 64k
- Add explanatory context related to XATTR_SIZE_MAX]
[Fabian Franz: - Move XATTR_SIZE_MAX reference from 9p.c to
P9_XATTR_SIZE_MAX in 9p.h]
Signed-off-by: Will Cohen <wwco...@gmail.com>
Signed-off-by: Fabian Franz <fabianfranz....@gmail.com>
[Will Cohen: - For P9_XATTR_MAX, ensure that Linux uses
XATTR_SIZE_MAX, Darwin uses 64k, and error
out for undefined hosts]
Signed-off-by: Will Cohen <wwco...@gmail.com>
Message-Id: <20220227223522.91937-7-wwco...@gmail.com>
Signed-off-by: Christian Schoenebeck <qemu_...@crudebyte.com>
Reviewed-by: Christian Schoenebeck <qemu_...@crudebyte.com>
---
hw/9pfs/9p.c | 2 +-
hw/9pfs/9p.h | 18 ++++++++++++++++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 14e84c3bcf..7405352c37 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3949,7 +3949,7 @@ static void coroutine_fn v9fs_xattrcreate(void *opaque)
rflags |= XATTR_REPLACE;
}
- if (size > XATTR_SIZE_MAX) {
+ if (size > P9_XATTR_SIZE_MAX) {
err = -E2BIG;
goto out_nofid;
}
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index 1567b67841..94b273b3d0 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -479,4 +479,22 @@ struct V9fsTransport {
void (*push_and_notify)(V9fsPDU *pdu);
};
+#if defined(XATTR_SIZE_MAX)
+/* Linux */
+#define P9_XATTR_SIZE_MAX XATTR_SIZE_MAX
+#elif defined(CONFIG_DARWIN)
+/*
+ * Darwin doesn't seem to define a maximum xattr size in its user
+ * space header, so manually configure it across platforms as 64k.
+ *
+ * Having no limit at all can lead to QEMU crashing during large g_malloc()
+ * calls. Because QEMU does not currently support macOS guests, the below
+ * preliminary solution only works due to its being a reflection of the limit
of
+ * Linux guests.
+ */
+#define P9_XATTR_SIZE_MAX 65536
+#else
+#error Missing definition for P9_XATTR_SIZE_MAX for this host system
+#endif
+
#endif
--
2.20.1
