Commit 7701c8be authored by Dan Williams's avatar Dan Williams
Browse files

cxl/hdm: Fail upon detecting 0-sized decoders 



Decoders committed with 0-size lead to later crashes on shutdown as
__cxl_dpa_release() assumes a 'struct resource' has been established in
the in 'cxlds->dpa_res'. Just fail the driver load in this instance
since there are deeper problems with the enumeration or the setup when
this happens.

Fixes: 9c57cde0 ("cxl/hdm: Enumerate allocated DPA")
Cc: <stable@vger.kernel.org>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Reviewed-by: default avatarAlison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/168149843516.792294.11872242648319572632.stgit@dwillia2-xfh.jf.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 09a9639e

drivers/cxl/core/hdm.c

+12 −3
Original line number Diff line number Diff line
@@ -269,8 +269,11 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, 


	lockdep_assert_held_write(&cxl_dpa_rwsem);



	if (!len)

		goto success;

	if (!len) {

		dev_warn(dev, "decoder%d.%d: empty reservation attempted\n",

			 port->id, cxled->cxld.id);

		return -EINVAL;

	}



	if (cxled->dpa_res) {

		dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
@@ -323,7 +326,6 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, 
		cxled->mode = CXL_DECODER_MIXED;

	}



success:

	port->hdm_end++;

	get_device(&cxled->cxld.dev);

	return 0;
@@ -833,6 +835,13 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, 
				 port->id, cxld->id);

			return -ENXIO;

		}



		if (size == 0) {

			dev_warn(&port->dev,

				 "decoder%d.%d: Committed with zero size\n",

				 port->id, cxld->id);

			return -ENXIO;

		}

		port->commit_end = cxld->id;

	} else {

		/* unless / until type-2 drivers arrive, assume type-3 */