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authorJason Gunthorpe2018-03-20 21:19:47 +0100
committerJason Gunthorpe2018-03-27 22:25:08 +0200
commit611cb92b082ad16b2fe1258e51d5aca7de540dfb (patch)
tree641fe2e35df9c9441bcf8b324bc179f1b219e86c
parentRDMA: Remove minor pahole differences between 32/64 (diff)
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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: Jason Gunthorpe <jgg@mellanox.com>
-rw-r--r--drivers/infiniband/core/ucma.c9
-rw-r--r--include/uapi/rdma/rdma_user_cm.h5
2 files changed, 12 insertions, 2 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 4bb5bed596c9..db4190b2ed27 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -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;
}
diff --git a/include/uapi/rdma/rdma_user_cm.h b/include/uapi/rdma/rdma_user_cm.h
index c83ef0026079..65399c837762 100644
--- a/include/uapi/rdma/rdma_user_cm.h
+++ b/include/uapi/rdma/rdma_user_cm.h
@@ -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 */