IB/core: Add ib_is_udata_cleared
Extending core and vendor verb commands require us to check that the
unknown part of the user's given command is all zeros.
Adding ib_is_udata_cleared in order to do so.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 36acb30..bbb1c34 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -53,6 +53,8 @@
#include <uapi/linux/if_ether.h>
#include <net/ipv6.h>
#include <net/ip.h>
+#include <linux/string.h>
+#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/mmu_notifier.h>
@@ -1922,6 +1924,31 @@
return copy_to_user(udata->outbuf, src, len) ? -EFAULT : 0;
}
+static inline bool ib_is_udata_cleared(struct ib_udata *udata,
+ size_t offset,
+ size_t len)
+{
+ const void __user *p = udata->inbuf + offset;
+ bool ret = false;
+ u8 *buf;
+
+ if (len > USHRT_MAX)
+ return false;
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return false;
+
+ if (copy_from_user(buf, p, len))
+ goto free;
+
+ ret = !memchr_inv(buf, 0, len);
+
+free:
+ kfree(buf);
+ return ret;
+}
+
/**
* ib_modify_qp_is_ok - Check that the supplied attribute mask
* contains all required attributes and no attributes not allowed for