4.19-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kurz groug@kaod.org
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 groug@kaod.org Acked-by: Andrew Donnellan andrew.donnellan@au1.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/misc/ocxl/link.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -566,7 +566,7 @@ int ocxl_link_update_pe(void *link_handl
mutex_lock(&spa->spa_lock);
- pe->tid = tid; + pe->tid = cpu_to_be32(tid);
/* * The barrier makes sure the PE is updated