From: ira.weiny@intel.com
To: Dan Williams <dan.j.williams@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Alison Schofield <alison.schofield@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Ben Widawsky <ben.widawsky@intel.com>,
linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: [PATCH V6 08/10] cxl/cdat: Introduce cdat_hdr_valid()
Date: Mon, 31 Jan 2022 23:19:50 -0800 [thread overview]
Message-ID: <20220201071952.900068-9-ira.weiny@intel.com> (raw)
In-Reply-To: <20220201071952.900068-1-ira.weiny@intel.com>
From: Ira Weiny <ira.weiny@intel.com>
The CDAT data is protected by a checksum which should be checked when
the CDAT is read to ensure it is valid. In addition the lengths
specified should be checked.
Introduce cdat_hdr_valid() to check the checksum. While at it check and
store the sequence number.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
Changes from V5
New patch, split out
Update cdat_hdr_valid()
Remove revision and cs field parsing
There is no point in these
Add seq check and debug print.
---
drivers/cxl/cdat.h | 2 ++
drivers/cxl/pci.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h
index 4722b6bbbaf0..a7725d26f2d2 100644
--- a/drivers/cxl/cdat.h
+++ b/drivers/cxl/cdat.h
@@ -88,10 +88,12 @@
*
* @table: cache of CDAT table
* @length: length of cached CDAT table
+ * @seq: Last read Sequence number of the CDAT table
*/
struct cxl_cdat {
void *table;
size_t length;
+ u32 seq;
};
#endif /* !__CXL_CDAT_H__ */
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 28b973a9e29e..c362c75feed2 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -586,6 +586,35 @@ static int cxl_setup_doe_devices(struct cxl_dev_state *cxlds)
return 0;
}
+static bool cxl_cdat_hdr_valid(struct device *dev, struct cxl_cdat *cdat)
+{
+ u32 *table = cdat->table;
+ u8 *data8 = cdat->table;
+ u32 length, seq;
+ u8 check;
+ int i;
+
+ length = FIELD_GET(CDAT_HEADER_DW0_LENGTH, table[0]);
+ if (length < CDAT_HEADER_LENGTH_BYTES)
+ return false;
+
+ if (length > cdat->length)
+ return false;
+
+ seq = FIELD_GET(CDAT_HEADER_DW3_SEQUENCE, table[3]);
+
+ /* Store the sequence for now. */
+ if (cdat->seq != seq) {
+ dev_info(dev, "CDAT seq change %x -> %x\n", cdat->seq, seq);
+ cdat->seq = seq;
+ }
+
+ for (check = 0, i = 0; i < length; i++)
+ check += data8[i];
+
+ return check == 0;
+}
+
#define CDAT_DOE_REQ(entry_handle) \
(FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \
CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \
@@ -658,6 +687,9 @@ static int cxl_cdat_read_table(struct cxl_dev_state *cxlds,
} while (entry_handle != 0xFFFF);
+ if (!cxl_cdat_hdr_valid(cxlds->dev, cdat))
+ return -EIO;
+
return 0;
}
--
2.31.1
next prev parent reply other threads:[~2022-02-01 7:20 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-01 7:19 [PATCH V6 00/10] CXL: Read CDAT and DSMAS data from the device ira.weiny
2022-02-01 7:19 ` [PATCH V6 01/10] PCI: Add vendor ID for the PCI SIG ira.weiny
2022-02-03 17:11 ` Bjorn Helgaas
2022-02-03 20:28 ` Ira Weiny
2022-02-01 7:19 ` [PATCH V6 02/10] PCI: Replace magic constant for PCI Sig Vendor ID ira.weiny
2022-02-04 21:16 ` Dan Williams
2022-02-04 21:49 ` Bjorn Helgaas
2022-03-15 21:48 ` Ira Weiny
2022-02-01 7:19 ` [PATCH V6 03/10] PCI/DOE: Add Data Object Exchange Aux Driver ira.weiny
2022-02-03 22:40 ` Bjorn Helgaas
2022-03-15 21:48 ` Ira Weiny
2022-02-09 0:59 ` Dan Williams
2022-02-09 10:13 ` Jonathan Cameron
2022-02-09 16:26 ` Dan Williams
2022-02-09 16:57 ` Jonathan Cameron
2022-02-09 19:57 ` Dan Williams
2022-02-10 21:51 ` Ira Weiny
2022-03-16 22:50 ` Ira Weiny
2022-03-17 19:37 ` Ira Weiny
2022-02-01 7:19 ` [PATCH V6 04/10] PCI/DOE: Introduce pci_doe_create_doe_devices ira.weiny
2022-02-03 22:44 ` Bjorn Helgaas
2022-02-04 14:51 ` Jonathan Cameron
2022-02-04 16:27 ` Bjorn Helgaas
2022-02-11 2:54 ` Dan Williams
2022-03-24 0:26 ` Ira Weiny
2022-03-24 14:05 ` Jonathan Cameron
2022-03-24 23:44 ` Ira Weiny
2022-03-25 12:02 ` Jonathan Cameron
2022-02-01 7:19 ` [PATCH V6 05/10] cxl/pci: Create DOE auxiliary devices ira.weiny
2022-02-01 7:19 ` [PATCH V6 06/10] cxl/pci: Find the DOE mailbox which supports CDAT ira.weiny
2022-02-01 18:49 ` Ben Widawsky
2022-02-01 22:18 ` Ira Weiny
2022-02-04 14:04 ` Jonathan Cameron
2022-02-01 7:19 ` [PATCH V6 07/10] cxl/mem: Read CDAT table ira.weiny
2022-02-04 13:46 ` Jonathan Cameron
2022-02-01 7:19 ` ira.weiny [this message]
2022-02-01 18:56 ` [PATCH V6 08/10] cxl/cdat: Introduce cdat_hdr_valid() Ben Widawsky
2022-02-01 22:29 ` Ira Weiny
2022-02-04 13:17 ` Jonathan Cameron
2022-02-01 7:19 ` [PATCH V6 09/10] cxl/mem: Retry reading CDAT on failure ira.weiny
2022-02-01 18:59 ` Ben Widawsky
2022-02-01 22:31 ` Ira Weiny
2022-02-04 13:20 ` Jonathan Cameron
2022-02-01 7:19 ` [PATCH V6 10/10] cxl/cdat: Parse out DSMAS data from CDAT table ira.weiny
2022-02-01 19:05 ` Ben Widawsky
2022-02-01 22:37 ` Ira Weiny
2022-02-04 13:33 ` Jonathan Cameron
2022-02-04 13:41 ` Jonathan Cameron
2022-02-04 13:40 ` Jonathan Cameron
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