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

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
......@@ -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;
}
......
......@@ -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 */
......
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