| Message ID | 154751742416.1617064.8252289468130584022.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | acpi/nfit: Fix command-supported detection | expand |
Dan Williams <dan.j.williams@intel.com> writes: > Changes since v1 [1]: > * Include another patch make sure that function-number zero can be > safely used as an invalid function number (Jeff) > * Add a comment clarifying why zero is an invalid function number (Jeff) > * Pass nfit_mem to cmd_to_func() (Jeff) > * Collect a Tested-by from Sujith > [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html For the series: Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Thanks, Dan! > > --- > > Quote patch2 changelog: > > 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. > > --- > > Dan Williams (2): > acpi/nfit: Block function zero DSMs > acpi/nfit: Fix command-supported detection > > > drivers/acpi/nfit/core.c | 53 ++++++++++++++++++++++++++++++++++------------ > 1 file changed, 39 insertions(+), 14 deletions(-)
On Tue, Jan 15, 2019 at 6:16 AM Jeff Moyer <jmoyer@redhat.com> wrote: > > Dan Williams <dan.j.williams@intel.com> writes: > > > Changes since v1 [1]: > > * Include another patch make sure that function-number zero can be > > safely used as an invalid function number (Jeff) > > * Add a comment clarifying why zero is an invalid function number (Jeff) > > * Pass nfit_mem to cmd_to_func() (Jeff) > > * Collect a Tested-by from Sujith > > [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html > > For the series: > > Reviewed-by: Jeff Moyer <jmoyer@redhat.com> > > Thanks, Dan! Thanks, although I just realized one more change. The ND_CMD_CALL case should zero out command after the function translation, otherwise userspace can call functions that the kernel is blocking in the dsm_mask. Holler if this invalidates your "Reviewed-by". diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 87e02f281e51..d7747aceb7ab 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -463,6 +463,12 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, func = cmd_to_func(nfit_mem, cmd, buf); if (func < 0) return func; + /* + * In the ND_CMD_CALL case we're now dependent on 'func' + * being validated by the dimm's dsm_mask + */ + if (cmd == ND_CMD_CALL) + cmd = 0; dimm_name = nvdimm_name(nvdimm); cmd_name = nvdimm_cmd_name(cmd); cmd_mask = nvdimm_cmd_mask(nvdimm); @@ -477,8 +483,10 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, cmd_name = nvdimm_bus_cmd_name(cmd); cmd_mask = nd_desc->cmd_mask; dsm_mask = cmd_mask; - if (cmd == ND_CMD_CALL) + if (cmd == ND_CMD_CALL) { dsm_mask = nd_desc->bus_dsm_mask; + cmd = 0; + } desc = nd_cmd_bus_desc(cmd); guid = to_nfit_uuid(NFIT_DEV_BUS); handle = adev->handle;
Dan Williams <dan.j.williams@intel.com> writes: > On Tue, Jan 15, 2019 at 6:16 AM Jeff Moyer <jmoyer@redhat.com> wrote: >> >> Dan Williams <dan.j.williams@intel.com> writes: >> >> > Changes since v1 [1]: >> > * Include another patch make sure that function-number zero can be >> > safely used as an invalid function number (Jeff) >> > * Add a comment clarifying why zero is an invalid function number (Jeff) >> > * Pass nfit_mem to cmd_to_func() (Jeff) >> > * Collect a Tested-by from Sujith >> > [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html >> >> For the series: >> >> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> >> >> Thanks, Dan! > > Thanks, although I just realized one more change. The ND_CMD_CALL case > should zero out command after the function translation, otherwise > userspace can call functions that the kernel is blocking in the > dsm_mask. > > Holler if this invalidates your "Reviewed-by". AAAAAAAHHHHHHHHHH!!!! :) > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > index 87e02f281e51..d7747aceb7ab 100644 > --- a/drivers/acpi/nfit/core.c > +++ b/drivers/acpi/nfit/core.c > @@ -463,6 +463,12 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor > *nd_desc, struct nvdimm *nvdimm, > func = cmd_to_func(nfit_mem, cmd, buf); > if (func < 0) > return func; > + /* > + * In the ND_CMD_CALL case we're now dependent on 'func' > + * being validated by the dimm's dsm_mask > + */ > + if (cmd == ND_CMD_CALL) > + cmd = 0; > dimm_name = nvdimm_name(nvdimm); > cmd_name = nvdimm_cmd_name(cmd); > cmd_mask = nvdimm_cmd_mask(nvdimm); dsm_mask = nfit_mem->dsm_mask; desc = nd_cmd_dimm_desc(cmd); That sure doesn't look right. Now cmd_name and desc will be wrong. > @@ -477,8 +483,10 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor > *nd_desc, struct nvdimm *nvdimm, > cmd_name = nvdimm_bus_cmd_name(cmd); > cmd_mask = nd_desc->cmd_mask; > dsm_mask = cmd_mask; > - if (cmd == ND_CMD_CALL) > + if (cmd == ND_CMD_CALL) { > dsm_mask = nd_desc->bus_dsm_mask; > + cmd = 0; > + } > desc = nd_cmd_bus_desc(cmd); And again here. We could reorder the zeroing, or you could modify the check for a valid comand/function. Something like this? /* * 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; Which way do you think is cleaner? Cheers, Jeff
On Tue, Jan 15, 2019 at 12:39 PM Jeff Moyer <jmoyer@redhat.com> wrote: > > Dan Williams <dan.j.williams@intel.com> writes: > > > On Tue, Jan 15, 2019 at 6:16 AM Jeff Moyer <jmoyer@redhat.com> wrote: > >> > >> Dan Williams <dan.j.williams@intel.com> writes: > >> > >> > Changes since v1 [1]: > >> > * Include another patch make sure that function-number zero can be > >> > safely used as an invalid function number (Jeff) > >> > * Add a comment clarifying why zero is an invalid function number (Jeff) > >> > * Pass nfit_mem to cmd_to_func() (Jeff) > >> > * Collect a Tested-by from Sujith > >> > [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html > >> > >> For the series: > >> > >> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> > >> > >> Thanks, Dan! > > > > Thanks, although I just realized one more change. The ND_CMD_CALL case > > should zero out command after the function translation, otherwise > > userspace can call functions that the kernel is blocking in the > > dsm_mask. > > > > Holler if this invalidates your "Reviewed-by". > > AAAAAAAHHHHHHHHHH!!!! > > :) > > > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > > index 87e02f281e51..d7747aceb7ab 100644 > > --- a/drivers/acpi/nfit/core.c > > +++ b/drivers/acpi/nfit/core.c > > @@ -463,6 +463,12 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor > > *nd_desc, struct nvdimm *nvdimm, > > func = cmd_to_func(nfit_mem, cmd, buf); > > if (func < 0) > > return func; > > + /* > > + * In the ND_CMD_CALL case we're now dependent on 'func' > > + * being validated by the dimm's dsm_mask > > + */ > > + if (cmd == ND_CMD_CALL) > > + cmd = 0; > > dimm_name = nvdimm_name(nvdimm); > > cmd_name = nvdimm_cmd_name(cmd); > > cmd_mask = nvdimm_cmd_mask(nvdimm); > dsm_mask = nfit_mem->dsm_mask; > desc = nd_cmd_dimm_desc(cmd); > > That sure doesn't look right. Now cmd_name and desc will be wrong. Ah, whoops, yes good catch. Guess this shows there is not good ND_CMD_CALL coverage in the unit tests... > > > @@ -477,8 +483,10 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor > > *nd_desc, struct nvdimm *nvdimm, > > cmd_name = nvdimm_bus_cmd_name(cmd); > > cmd_mask = nd_desc->cmd_mask; > > dsm_mask = cmd_mask; > > - if (cmd == ND_CMD_CALL) > > + if (cmd == ND_CMD_CALL) { > > dsm_mask = nd_desc->bus_dsm_mask; > > + cmd = 0; > > + } > > desc = nd_cmd_bus_desc(cmd); > > And again here. > > We could reorder the zeroing, or you could modify the check for a valid > comand/function. Something like this? > > /* > * 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; > > Which way do you think is cleaner? Modifying the check looks cleaner. Thanks for hollering!
Changes since v1 [1]: * Include another patch make sure that function-number zero can be safely used as an invalid function number (Jeff) * Add a comment clarifying why zero is an invalid function number (Jeff) * Pass nfit_mem to cmd_to_func() (Jeff) * Collect a Tested-by from Sujith [1]: https://lists.01.org/pipermail/linux-nvdimm/2019-January/019435.html --- Quote patch2 changelog: 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. --- Dan Williams (2): acpi/nfit: Block function zero DSMs acpi/nfit: Fix command-supported detection drivers/acpi/nfit/core.c | 53 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 39 insertions(+), 14 deletions(-)