Robert Richter 623c075133 cxl/mbox: Fix Payload Length check for Get Log command ... Commit 2aeaf663b8 introduced strict checking for variable length payload size validation. The payload length of received data must match the size of the requested data by the caller except for the case where the min_out value is set. The Get Log command does not have a header with a length field set. The Log size is determined by the Get Supported Logs command (CXL 3.0, 8.2.9.5.1). However, the actual size can be smaller and the number of valid bytes in the payload output must be determined reading the Payload Length field (CXL 3.0, Table 8-36, Note 2). Two issues arise: The command can successfully complete with a payload length of zero. And, the valid payload length must then also be consumed by the caller. Change cxl_xfer_log() to pass the number of payload bytes back to the caller to determine the number of log entries. Implement the payload handling as a special case where mbox_cmd->size_out is consulted when cxl_internal_send_cmd() returns -EIO. A WARN_ONCE() is added to check that -EIO is only returned in case of an unexpected output size. Logs can be bigger than the maximum payload length and multiple Get Log commands can be issued. If the received payload size is smaller than the maximum payload size we can assume all valid bytes have been fetched. Stop sending further Get Log commands then. On that occasion, change debug messages to also report the opcodes of supported commands. The variable payload commands GET_LSA and SET_LSA are not affected by this strict check: SET_LSA cannot be broken because SET_LSA does not return an output payload, and GET_LSA never expects short reads. Fixes: 2aeaf663b8 ("cxl/mbox: Add variable output size validation for internal commands") Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20230119094934.86067-1-rrichter@amd.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>		2023-01-27 13:58:11 -08:00
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core	cxl/mbox: Fix Payload Length check for Get Log command	2023-01-27 13:58:11 -08:00
acpi.c	cxl: fix spelling mistakes	2023-01-26 15:57:42 -08:00
cxl.h	cxl/pci: Move tracepoint definitions to drivers/cxl/core/	2023-01-04 17:11:11 -08:00
cxlmem.h	cxl/mbox: Add variable output size validation for internal commands	2022-12-06 14:36:02 -08:00
cxlpci.h	cxl/pci: Move tracepoint definitions to drivers/cxl/core/	2023-01-04 17:11:11 -08:00
Kconfig	cxl: fix spelling mistakes	2023-01-26 15:57:42 -08:00
Makefile	cxl/pmem: Introduce nvdimm_security_ops with ->get_flags() operation	2022-11-30 16:30:47 -08:00
mem.c	cxl/port: Add RCD endpoint port enumeration	2022-12-05 10:32:26 -08:00
pci.c	cxl/pci: Show opcode in debug messages when sending a command	2023-01-24 17:52:54 -08:00
pmem.c	cxl/mbox: Enable cxl_mbox_send_cmd() users to validate output size	2022-12-06 14:36:02 -08:00
port.c	cxl/port: Read CDAT table	2022-07-19 15:38:05 -07:00
security.c	cxl/mbox: Enable cxl_mbox_send_cmd() users to validate output size	2022-12-06 14:36:02 -08:00