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@xxxxxxxxxxxx>
Reviewed-by: Moshe Lazer <moshel@xxxxxxxxxxxx>
---
include/rdma/ib_verbs.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 31fb409..0ad89e3 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1947,6 +1947,73 @@ static inline int ib_copy_to_udata(struct ib_udata *udata, void *src, size_t len
return copy_to_user(udata->outbuf, src, len) ? -EFAULT : 0;
}
+#define IB_UDATA_ELEMENT_CLEARED(type, ptr, len, expected) \
+ ({type v; \
+ typeof(ptr) __ptr = ptr; \
+ \
+ ptr = (void *)ptr + sizeof(type); \
+ len -= sizeof(type); \
+ !copy_from_user(&v, __ptr, sizeof(v)) && (v == expected); })
+
+static inline bool ib_is_udata_cleared(struct ib_udata *udata,
+ u8 cleared_char,
+ size_t offset,
+ size_t len)
+{
+ const void __user *p = udata->inbuf + offset;
+#ifdef CONFIG_64BIT
+ u64 expected = cleared_char;
+#else
+ u32 expected = cleared_char;
+#endif
+
+ if (len > USHRT_MAX)
+ return false;
+
+ if (len && (uintptr_t)p & 1)
+ if (!IB_UDATA_ELEMENT_CLEARED(u8, p, len, expected))
+ return false;
+
+ expected = expected << 8 | expected;
+ if (len >= 2 && (uintptr_t)p & 2)
+ if (!IB_UDATA_ELEMENT_CLEARED(u16, p, len, expected))
+ return false;
+
+ expected = expected << 16 | expected;
+#ifdef CONFIG_64BIT
+ if (len >= 4 && (uintptr_t)p & 4)
+ if (!IB_UDATA_ELEMENT_CLEARED(u32, p, len, expected))
+ return false;
+
+ expected = expected << 32 | expected;
+#define IB_UDATA_CLEAR_LOOP_TYPE u64
+#else
+#define IB_UDATA_CLEAR_LOOP_TYPE u32
+#endif
+ while (len >= sizeof(IB_UDATA_CLEAR_LOOP_TYPE))
+ if (!IB_UDATA_ELEMENT_CLEARED(IB_UDATA_CLEAR_LOOP_TYPE, p, len,
+ expected))
+ return false;
+
+#ifdef CONFIG_64BIT
+ expected = expected >> 32;
+ if (len >= 4 && (uintptr_t)p & 4)
+ if (!IB_UDATA_ELEMENT_CLEARED(u32, p, len, expected))
+ return false;
+#endif
+ expected = expected >> 16;
+ if (len >= 2 && (uintptr_t)p & 2)
+ if (!IB_UDATA_ELEMENT_CLEARED(u16, p, len, expected))
+ return false;
+
+ expected = expected >> 8;
+ if (len)
+ if (!IB_UDATA_ELEMENT_CLEARED(u8, p, len, expected))
+ return false;
+
+ return true;
+}
+
/**
* ib_modify_qp_is_ok - Check that the supplied attribute mask
* contains all required attributes and no attributes not allowed for
--
2.1.0
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