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 <[email protected]> Reviewed-by: Moshe Lazer <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
