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Commit 611cb92b authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

RDMA/ucma: Fix uABI structure layouts for 32/64 compat 



The rdma_ucm_event_resp is a different length on 32 and 64 bit compiles.

The kernel requires it to be the expected length or longer so 32 bit
builds running on a 64 bit kernel will not work.

Retain full compat by having all kernels accept a struct with or without
the trailing reserved field.

Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 38b48808

drivers/infiniband/core/ucma.c

+7 −2
Original line number Diff line number Diff line
@@ -382,7 +382,11 @@ static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf, 
	struct ucma_event *uevent;

	int ret = 0;



	if (out_len < sizeof uevent->resp)

	/*

	 * Old 32 bit user space does not send the 4 byte padding in the

	 * reserved field. We don't care, allow it to keep working.

	 */

	if (out_len < sizeof(uevent->resp) - sizeof(uevent->resp.reserved))

		return -ENOSPC;



	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
@@ -417,7 +421,8 @@ static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf, 
	}



	if (copy_to_user((void __user *)(unsigned long)cmd.response,

			 &uevent->resp, sizeof uevent->resp)) {

			 &uevent->resp,

			 min_t(size_t, out_len, sizeof(uevent->resp)))) {

		ret = -EFAULT;

		goto done;

	}

include/uapi/rdma/rdma_user_cm.h

+5 −0
Original line number Diff line number Diff line
@@ -270,10 +270,15 @@ struct rdma_ucm_event_resp { 
	__u32 id;

	__u32 event;

	__u32 status;

	/*

	 * NOTE: This union is not aligned to 8 bytes so none of the union

	 * members may contain a u64 or anything with higher alignment than 4.

	 */

	union {

		struct rdma_ucm_conn_param conn;

		struct rdma_ucm_ud_param   ud;

	} param;

	__u32 reserved;

};



/* Option levels */