From 164793379ad3b7ef5fc5a28260c111358892dff3 Mon Sep 17 00:00:00 2001 From: Andrew Donnellan Date: Thu, 28 Jul 2016 15:39:41 +1000 Subject: cxl: Fix NULL dereference in cxl_context_init() on PowerVM guests Commit f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") added a "min_pe" field to struct cxl_service_layer_ops, to allow us to work around a Mellanox CX-4 hardware limitation. When allocating the PE number in cxl_context_init(), we read from ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number. Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL, and guests don't have a cxl_service_layer_ops struct anywhere. Move min_pe from struct cxl_service_layer_ops to struct cxl so it's accessible in both native and PowerVM environments. For the Mellanox CX-4, set the min_pe value in set_sl_ops(). Fixes: f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4") Reported-by: Frederic Barrat Signed-off-by: Andrew Donnellan Acked-by: Ian Munsie Reviewed-by: Frederic Barrat Signed-off-by: Michael Ellerman --- drivers/misc/cxl/context.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/misc/cxl/context.c') diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index bdee9a01ef35..c466ee2b0c97 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -90,8 +90,7 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, */ mutex_lock(&afu->contexts_lock); idr_preload(GFP_KERNEL); - i = idr_alloc(&ctx->afu->contexts_idr, ctx, - ctx->afu->adapter->native->sl_ops->min_pe, + i = idr_alloc(&ctx->afu->contexts_idr, ctx, ctx->afu->adapter->min_pe, ctx->afu->num_procs, GFP_NOWAIT); idr_preload_end(); mutex_unlock(&afu->contexts_lock); -- cgit v1.2.3