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authorAlison Schofield <alison.schofield@intel.com>2022-03-31 04:27:11 +0300
committerDan Williams <dan.j.williams@intel.com>2022-04-13 02:07:00 +0300
commit6dd0e5cc87b33aee9cfe4d485c4d8b8382701558 (patch)
tree52748b66f2c77de4d011decb96951e2cfe469dc1 /drivers/cxl
parentce522ba9ef7e2d9fb22a39eb3371c0c64e2a433e (diff)
downloadlinux-6dd0e5cc87b33aee9cfe4d485c4d8b8382701558.tar.xz
cxl/mbox: Move cxl_mem_command construction to helper funcs
Sanitizing and constructing a cxl_mem_command from a userspace command is part of the validation process prior to submitting the command to a CXL device. Move this work to helper functions: cxl_to_mem_cmd(), cxl_to_mem_cmd_raw(). This declutters cxl_validate_cmd_from_user() in preparation for adding new validation steps. Signed-off-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/7d9b826f29262e3a484cb4bb7b63872134d60bd7.1648687552.git.alison.schofield@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
-rw-r--r--drivers/cxl/core/mbox.c147
1 files changed, 76 insertions, 71 deletions
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index be61a0d8016b..1f2175f0f687 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -207,76 +207,42 @@ static bool cxl_mem_raw_command_allowed(u16 opcode)
return true;
}
-/**
- * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
- * @cxlds: The device data for the operation
- * @send_cmd: &struct cxl_send_command copied in from userspace.
- * @out_cmd: Sanitized and populated &struct cxl_mem_command.
- *
- * Return:
- * * %0 - @out_cmd is ready to send.
- * * %-ENOTTY - Invalid command specified.
- * * %-EINVAL - Reserved fields or invalid values were used.
- * * %-ENOMEM - Input or output buffer wasn't sized properly.
- * * %-EPERM - Attempted to use a protected command.
- * * %-EBUSY - Kernel has claimed exclusive access to this opcode
- *
- * The result of this command is a fully validated command in @out_cmd that is
- * safe to send to the hardware.
- *
- * See handle_mailbox_cmd_from_user()
- */
-static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
- const struct cxl_send_command *send_cmd,
- struct cxl_mem_command *out_cmd)
+static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
+ const struct cxl_send_command *send_cmd,
+ struct cxl_dev_state *cxlds)
{
- const struct cxl_command_info *info;
- struct cxl_mem_command *c;
-
- if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
- return -ENOTTY;
-
- /*
- * The user can never specify an input payload larger than what hardware
- * supports, but output can be arbitrarily large (simply write out as
- * much data as the hardware provides).
- */
- if (send_cmd->in.size > cxlds->payload_size)
+ if (send_cmd->raw.rsvd)
return -EINVAL;
/*
- * Checks are bypassed for raw commands but a WARN/taint will occur
- * later in the callchain
+ * Unlike supported commands, the output size of RAW commands
+ * gets passed along without further checking, so it must be
+ * validated here.
*/
- if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW) {
- const struct cxl_mem_command temp = {
- .info = {
- .id = CXL_MEM_COMMAND_ID_RAW,
- .flags = 0,
- .size_in = send_cmd->in.size,
- .size_out = send_cmd->out.size,
- },
- .opcode = send_cmd->raw.opcode
- };
-
- if (send_cmd->raw.rsvd)
- return -EINVAL;
+ if (send_cmd->out.size > cxlds->payload_size)
+ return -EINVAL;
- /*
- * Unlike supported commands, the output size of RAW commands
- * gets passed along without further checking, so it must be
- * validated here.
- */
- if (send_cmd->out.size > cxlds->payload_size)
- return -EINVAL;
+ if (!cxl_mem_raw_command_allowed(send_cmd->raw.opcode))
+ return -EPERM;
- if (!cxl_mem_raw_command_allowed(send_cmd->raw.opcode))
- return -EPERM;
+ *mem_cmd = (struct cxl_mem_command) {
+ .info = {
+ .id = CXL_MEM_COMMAND_ID_RAW,
+ .size_in = send_cmd->in.size,
+ .size_out = send_cmd->out.size,
+ },
+ .opcode = send_cmd->raw.opcode
+ };
- memcpy(out_cmd, &temp, sizeof(temp));
+ return 0;
+}
- return 0;
- }
+static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
+ const struct cxl_send_command *send_cmd,
+ struct cxl_dev_state *cxlds)
+{
+ struct cxl_mem_command *c = &cxl_mem_commands[send_cmd->id];
+ const struct cxl_command_info *info = &c->info;
if (send_cmd->flags & ~CXL_MEM_COMMAND_FLAG_MASK)
return -EINVAL;
@@ -287,10 +253,6 @@ static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
if (send_cmd->in.rsvd || send_cmd->out.rsvd)
return -EINVAL;
- /* Convert user's command into the internal representation */
- c = &cxl_mem_commands[send_cmd->id];
- info = &c->info;
-
/* Check that the command is enabled for hardware */
if (!test_bit(info->id, cxlds->enabled_cmds))
return -ENOTTY;
@@ -307,15 +269,58 @@ static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
if (info->size_out >= 0 && send_cmd->out.size < info->size_out)
return -ENOMEM;
- memcpy(out_cmd, c, sizeof(*c));
- out_cmd->info.size_in = send_cmd->in.size;
+ *mem_cmd = (struct cxl_mem_command) {
+ .info = {
+ .id = info->id,
+ .flags = info->flags,
+ .size_in = send_cmd->in.size,
+ .size_out = send_cmd->out.size,
+ },
+ .opcode = c->opcode
+ };
+
+ return 0;
+}
+
+/**
+ * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
+ * @cxlds: The device data for the operation
+ * @send_cmd: &struct cxl_send_command copied in from userspace.
+ * @out_cmd: Sanitized and populated &struct cxl_mem_command.
+ *
+ * Return:
+ * * %0 - @out_cmd is ready to send.
+ * * %-ENOTTY - Invalid command specified.
+ * * %-EINVAL - Reserved fields or invalid values were used.
+ * * %-ENOMEM - Input or output buffer wasn't sized properly.
+ * * %-EPERM - Attempted to use a protected command.
+ * * %-EBUSY - Kernel has claimed exclusive access to this opcode
+ *
+ * The result of this command is a fully validated command in @out_cmd that is
+ * safe to send to the hardware.
+ *
+ * See handle_mailbox_cmd_from_user()
+ */
+static int cxl_validate_cmd_from_user(struct cxl_dev_state *cxlds,
+ const struct cxl_send_command *send_cmd,
+ struct cxl_mem_command *out_cmd)
+{
+ if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
+ return -ENOTTY;
+
/*
- * XXX: out_cmd->info.size_out will be controlled by the driver, and the
- * specified number of bytes @send_cmd->out.size will be copied back out
- * to userspace.
+ * The user can never specify an input payload larger than what hardware
+ * supports, but output can be arbitrarily large (simply write out as
+ * much data as the hardware provides).
*/
+ if (send_cmd->in.size > cxlds->payload_size)
+ return -EINVAL;
- return 0;
+ /* Sanitize and construct a cxl_mem_command */
+ if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW)
+ return cxl_to_mem_cmd_raw(out_cmd, send_cmd, cxlds);
+ else
+ return cxl_to_mem_cmd(out_cmd, send_cmd, cxlds);
}
int cxl_query_cmd(struct cxl_memdev *cxlmd,