From 3fbf78b2526831342973ba21654d0b9c79360e94 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Sun, 16 Dec 2018 22:28:50 +0100 Subject: [PATCH] ocxl: Fix endiannes bug in ocxl_link_update_pe() commit e1e71e201703500f708bdeaf64660a2a178cb6a0 upstream. All fields in the PE are big-endian. Use cpu_to_be32() like everywhere else something is written to the PE. Otherwise a wrong TID will be used by the NPU. If this TID happens to point to an existing thread sharing the same mm, it could be woken up by error. This is highly improbable though. The likely outcome of this is the NPU not finding the target thread and forcing the AFU into sending an interrupt, which userspace is supposed to handle anyway. Fixes: e948e06fc63a ("ocxl: Expose the thread_id needed for wait on POWER9") Cc: stable@vger.kernel.org # v4.18 Signed-off-by: Greg Kurz Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- drivers/misc/ocxl/link.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index 31695a0..646d164 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -566,7 +566,7 @@ int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid) mutex_lock(&spa->spa_lock); - pe->tid = tid; + pe->tid = cpu_to_be32(tid); /* * The barrier makes sure the PE is updated -- 2.7.4