[PATCH v4 8/8] cxl/mbox: Block inject and clear poison opcodes in raw mode

From: alison.schofield@intel.com
To: Dan Williams <dan.j.williams@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Ben Widawsky <bwidawsk@kernel.org>,
	Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>, linux-cxl@vger.kernel.org
Subject: [PATCH v4 8/8] cxl/mbox: Block inject and clear poison opcodes in raw mode
Date: Fri, 10 Mar 2023 10:49:09 -0800	[thread overview]
Message-ID: <6952da15b164e18e7f26fb26631839837d9797b3.1678471465.git.alison.schofield@intel.com> (raw)
In-Reply-To: <cover.1678471465.git.alison.schofield@intel.com>

From: Alison Schofield <alison.schofield@intel.com>

Inject and clear poison are commands intended for debug environments,
and can cause data corruption if issued without validation. They are
kernel exclusive commands not available to userspace through ioctls,
but could be submitted via the raw mode ioctl.

Add inject and clear poison to the cxl_disabled_raw_commands[] list.
Attempts by userspace to issue either command via the RAW ioctl fail
with -EPERM.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/core/mbox.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 77fc811bdfed..4b5e65edbc71 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -89,6 +89,10 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
  *
  * CXL_MBOX_OP_[GET_]SCAN_MEDIA: The kernel provides a native error list that
  * is kept up to date with patrol notifications and error management.
+ *
+ * CXL_MBOX_OP_[INJECT|CLEAR]_POISON: The kernel provides a sysfs interface
+ * to these commands that ensures data protection of mapped resources.
+ * See: Documentation/ABI/testing/sysfs-bus-cxl
  */
 static u16 cxl_disabled_raw_commands[] = {
 	CXL_MBOX_OP_ACTIVATE_FW,
@@ -97,6 +101,8 @@ static u16 cxl_disabled_raw_commands[] = {
 	CXL_MBOX_OP_SET_SHUTDOWN_STATE,
 	CXL_MBOX_OP_SCAN_MEDIA,
 	CXL_MBOX_OP_GET_SCAN_MEDIA,
+	CXL_MBOX_OP_INJECT_POISON,
+	CXL_MBOX_OP_CLEAR_POISON,
 };
 
 /*
-- 
2.37.3

