[PATCH 16/22] gpu: host1x: Forbid unrelated SETCLASS opcode in the firewall

[Dmitry Osipenko]

On 23.05.2017 03:39, Erik Faye-Lund wrote:
> On Tue, May 23, 2017 at 2:14 AM, Dmitry Osipenko <digetx at gmail.com> wrote:
>> Several channels could be made to write the same unit concurrently via the
>> SETCLASS opcode, trusting userspace is a bad idea. It should be possible to
>> drop the per-client channel reservation and add a per-unit locking by
>> inserting MLOCK's to the command stream to re-allow the SETCLASS opcode, but
>> it will be much more work. Let's forbid the unit-unrelated class changes for
>> now.
>>
>> Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
>> ---
>>  drivers/gpu/drm/tegra/drm.c  |  1 +
>>  drivers/gpu/drm/tegra/drm.h  |  1 +
>>  drivers/gpu/drm/tegra/gr2d.c | 12 ++++++++++++
>>  drivers/gpu/host1x/job.c     | 24 ++++++++++++++++++++----
>>  include/linux/host1x.h       |  5 ++++-
>>  5 files changed, 38 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
>> index cdb05d6efde4..17416e1c219a 100644
>> --- a/drivers/gpu/drm/tegra/drm.c
>> +++ b/drivers/gpu/drm/tegra/drm.c
>> @@ -531,6 +531,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
>>         }
>>
>>         job->is_addr_reg = context->client->ops->is_addr_reg;
>> +       job->is_valid_class = context->client->ops->is_valid_class;
>>         job->syncpt_incrs = syncpt.incrs;
>>         job->syncpt_id = syncpt.id;
>>         job->timeout = 10000;
>> diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
>> index 85aa2e3d9d4e..6d6da01282f3 100644
>> --- a/drivers/gpu/drm/tegra/drm.h
>> +++ b/drivers/gpu/drm/tegra/drm.h
>> @@ -83,6 +83,7 @@ struct tegra_drm_client_ops {
>>                             struct tegra_drm_context *context);
>>         void (*close_channel)(struct tegra_drm_context *context);
>>         int (*is_addr_reg)(struct device *dev, u32 class, u32 offset);
>> +       int (*is_valid_class)(u32 class);
>>         int (*submit)(struct tegra_drm_context *context,
>>                       struct drm_tegra_submit *args, struct drm_device *drm,
>>                       struct drm_file *file);
>> diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
>> index 02cd3e37a6ec..782231c41a1a 100644
>> --- a/drivers/gpu/drm/tegra/gr2d.c
>> +++ b/drivers/gpu/drm/tegra/gr2d.c
>> @@ -109,10 +109,22 @@ static int gr2d_is_addr_reg(struct device *dev, u32 class, u32 offset)
>>         return 0;
>>  }
>>
>> +static int gr2d_is_valid_class(u32 class)
>> +{
>> +       switch (class) {
>> +       case HOST1X_CLASS_GR2D:
>> +       case HOST1X_CLASS_GR2D_SB:
>> +               return 1;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>>  static const struct tegra_drm_client_ops gr2d_ops = {
>>         .open_channel = gr2d_open_channel,
>>         .close_channel = gr2d_close_channel,
>>         .is_addr_reg = gr2d_is_addr_reg,
>> +       .is_valid_class = gr2d_is_valid_class,
>>         .submit = tegra_drm_submit,
>>  };
>>
>> diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
>> index cf335c5979e2..65e12219405a 100644
>> --- a/drivers/gpu/host1x/job.c
>> +++ b/drivers/gpu/host1x/job.c
>> @@ -358,6 +358,9 @@ struct host1x_firewall {
>>
>>  static int check_register(struct host1x_firewall *fw, unsigned long offset)
>>  {
>> +       if (!fw->job->is_addr_reg)
>> +               return 0;
>> +
>>         if (fw->job->is_addr_reg(fw->dev, fw->class, offset)) {
>>                 if (!fw->num_relocs)
>>                         return -EINVAL;
>> @@ -372,6 +375,19 @@ static int check_register(struct host1x_firewall *fw, unsigned long offset)
>>         return 0;
>>  }
>>
>> +static int check_class(struct host1x_firewall *fw, u32 class)
>> +{
>> +       if (!fw->job->is_valid_class) {
>> +               if (fw->class != class)
>> +                       return -EINVAL;
>> +       } else {
>> +               if (!fw->job->is_valid_class(fw->class))
>> +                       return -EINVAL;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>>  static int check_mask(struct host1x_firewall *fw)
>>  {
>>         u32 mask = fw->mask;
>> @@ -445,11 +461,9 @@ static int validate(struct host1x_firewall *fw, struct host1x_job_gather *g)
>>  {
>>         u32 *cmdbuf_base = (u32 *)fw->job->gather_copy_mapped +
>>                 (g->offset / sizeof(u32));
>> +       u32 job_class = fw->class;
>>         int err = 0;
>>
>> -       if (!fw->job->is_addr_reg)
>> -               return 0;
>> -
>>         fw->words = g->words;
>>         fw->cmdbuf = g->bo;
>>         fw->offset = 0;
>> @@ -469,7 +483,9 @@ static int validate(struct host1x_firewall *fw, struct host1x_job_gather *g)
>>                         fw->class = word >> 6 & 0x3ff;
>>                         fw->mask = word & 0x3f;
>>                         fw->reg = word >> 16 & 0xfff;
>> -                       err = check_mask(fw);
>> +                       err = check_class(fw, job_class);
>> +                       if (!err)
>> +                               err = check_mask(fw);
>>                         if (err)
>>                                 goto out;
>>                         break;
>> diff --git a/include/linux/host1x.h b/include/linux/host1x.h
>> index aa323e43ae4e..561d6bb6580d 100644
>> --- a/include/linux/host1x.h
>> +++ b/include/linux/host1x.h
>> @@ -233,7 +233,10 @@ struct host1x_job {
>>         u8 *gather_copy_mapped;
>>
>>         /* Check if register is marked as an address reg */
>> -       int (*is_addr_reg)(struct device *dev, u32 reg, u32 class);
>> +       int (*is_addr_reg)(struct device *dev, u32 class, u32 reg);
> 
> This seems like an unrelated fix, you might want to mention it in the
> commit message at least.
> 
Yeah, I slipped in this typo fix here as I got confused by the swapped class-reg
in the function proto while was writing this patch.

-- 
Dmitry