[PATCH 4.20 070/117] acpi/nfit: Fix command-supported detection

From: Greg Kroah-Hartman
Date: Tue Jan 29 2019 - 06:41:27 EST


4.20-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dan Williams <dan.j.williams@xxxxxxxxx>

commit 11189c1089da413aa4b5fd6be4c4d47c78968819 upstream.

The _DSM function number validation only happens to succeed when the
generic Linux command number translation corresponds with a
DSM-family-specific function number. This breaks NVDIMM-N
implementations that correctly implement _LSR, _LSW, and _LSI, but do
not happen to publish support for DSM function numbers 4, 5, and 6.

Recall that the support for _LS{I,R,W} family of methods results in the
DIMM being marked as supporting those command numbers at
acpi_nfit_register_dimms() time. The DSM function mask is only used for
ND_CMD_CALL support of non-NVDIMM_FAMILY_INTEL devices.

Fixes: 31eca76ba2fc ("nfit, libnvdimm: limited/whitelisted dimm command...")
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://github.com/pmem/ndctl/issues/78
Reported-by: Sujith Pandel <sujith_pandel@xxxxxxxx>
Tested-by: Sujith Pandel <sujith_pandel@xxxxxxxx>
Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/acpi/nfit/core.c | 54 ++++++++++++++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 14 deletions(-)

--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -394,6 +394,32 @@ static u8 nfit_dsm_revid(unsigned family
return id;
}

+static int cmd_to_func(struct nfit_mem *nfit_mem, unsigned int cmd,
+ struct nd_cmd_pkg *call_pkg)
+{
+ if (call_pkg) {
+ int i;
+
+ if (nfit_mem->family != call_pkg->nd_family)
+ return -ENOTTY;
+
+ for (i = 0; i < ARRAY_SIZE(call_pkg->nd_reserved2); i++)
+ if (call_pkg->nd_reserved2[i])
+ return -EINVAL;
+ return call_pkg->nd_command;
+ }
+
+ /* Linux ND commands == NVDIMM_FAMILY_INTEL function numbers */
+ if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
+ return cmd;
+
+ /*
+ * Force function number validation to fail since 0 is never
+ * published as a valid function in dsm_mask.
+ */
+ return 0;
+}
+
int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
{
@@ -407,30 +433,23 @@ int acpi_nfit_ctl(struct nvdimm_bus_desc
unsigned long cmd_mask, dsm_mask;
u32 offset, fw_status = 0;
acpi_handle handle;
- unsigned int func;
const guid_t *guid;
- int rc, i;
+ int func, rc, i;

if (cmd_rc)
*cmd_rc = -EINVAL;
- func = cmd;
- if (cmd == ND_CMD_CALL) {
- call_pkg = buf;
- func = call_pkg->nd_command;
-
- for (i = 0; i < ARRAY_SIZE(call_pkg->nd_reserved2); i++)
- if (call_pkg->nd_reserved2[i])
- return -EINVAL;
- }

if (nvdimm) {
struct acpi_device *adev = nfit_mem->adev;

if (!adev)
return -ENOTTY;
- if (call_pkg && nfit_mem->family != call_pkg->nd_family)
- return -ENOTTY;

+ if (cmd == ND_CMD_CALL)
+ call_pkg = buf;
+ func = cmd_to_func(nfit_mem, cmd, call_pkg);
+ if (func < 0)
+ return func;
dimm_name = nvdimm_name(nvdimm);
cmd_name = nvdimm_cmd_name(cmd);
cmd_mask = nvdimm_cmd_mask(nvdimm);
@@ -441,6 +460,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_desc
} else {
struct acpi_device *adev = to_acpi_dev(acpi_desc);

+ func = cmd;
cmd_name = nvdimm_bus_cmd_name(cmd);
cmd_mask = nd_desc->cmd_mask;
dsm_mask = cmd_mask;
@@ -455,7 +475,13 @@ int acpi_nfit_ctl(struct nvdimm_bus_desc
if (!desc || (cmd && (desc->out_num + desc->in_num == 0)))
return -ENOTTY;

- if (!test_bit(cmd, &cmd_mask) || !test_bit(func, &dsm_mask))
+ /*
+ * Check for a valid command. For ND_CMD_CALL, we also have to
+ * make sure that the DSM function is supported.
+ */
+ if (cmd == ND_CMD_CALL && !test_bit(func, &dsm_mask))
+ return -ENOTTY;
+ else if (!test_bit(cmd, &cmd_mask))
return -ENOTTY;

in_obj.type = ACPI_TYPE_PACKAGE;