[PATCH] drm/amdgpu/pm: Remove VLA usage

Christian König ckoenig.leichtzumerken at gmail.com
Tue Jul 17 06:58:21 UTC 2018


> Who's tree should this go through?
To answer the question: When Rex is ok with that he pushes it to our 
internal amd-staging-drm-next tree.

Alex then pushes that tree to a public server and at some point sends a 
pull request for inclusion in drm-next.

Regards,
Christian.

Am 17.07.2018 um 08:23 schrieb Zhu, Rex:
> Patch is:
> Reviewed-by: Rex Zhu<rezhu at amd.com <mailto:rezhu at amd.com>>
>
>
>
> Best Regards
> Rex
>
>
> ------------------------------------------------------------------------
> *From:* keescook at google.com <keescook at google.com> on behalf of Kees 
> Cook <keescook at chromium.org>
> *Sent:* Tuesday, July 17, 2018 11:59 AM
> *To:* Deucher, Alexander
> *Cc:* LKML; Koenig, Christian; Zhou, David(ChunMing); David Airlie; 
> Zhu, Rex; Huang, Ray; Kuehling, Felix; amd-gfx list; Maling list - DRI 
> developers
> *Subject:* Re: [PATCH] drm/amdgpu/pm: Remove VLA usage
> On Wed, Jun 20, 2018 at 11:26 AM, Kees Cook <keescook at chromium.org> wrote:
> > In the quest to remove all stack VLA usage from the kernel[1], this
> > uses the maximum sane buffer size and removes copy/paste code.
> >
> > [1] 
> https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
> >
> > Signed-off-by: Kees Cook <keescook at chromium.org>
>
> Friendly ping! Who's tree should this go through?
>
> Thanks!
>
> -Kees
>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 100 +++++++++++--------------
> >  1 file changed, 42 insertions(+), 58 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> > index b455da487782..5eb98cde22ed 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> > @@ -593,40 +593,59 @@ static ssize_t amdgpu_get_pp_dpm_sclk(struct 
> device *dev,
> >                 return snprintf(buf, PAGE_SIZE, "\n");
> >  }
> >
> > -static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
> > -               struct device_attribute *attr,
> > -               const char *buf,
> > -               size_t count)
> > +/*
> > + * Worst case: 32 bits individually specified, in octal at 12 
> characters
> > + * per line (+1 for \n).
> > + */
> > +#define AMDGPU_MASK_BUF_MAX    (32 * 13)
> > +
> > +static ssize_t amdgpu_read_mask(const char *buf, size_t count, 
> uint32_t *mask)
> >  {
> > -       struct drm_device *ddev = dev_get_drvdata(dev);
> > -       struct amdgpu_device *adev = ddev->dev_private;
> >         int ret;
> >         long level;
> > -       uint32_t mask = 0;
> >         char *sub_str = NULL;
> >         char *tmp;
> > -       char buf_cpy[count];
> > +       char buf_cpy[AMDGPU_MASK_BUF_MAX + 1];
> >         const char delimiter[3] = {' ', '\n', '\0'};
> > +       size_t bytes;
> >
> > -       memcpy(buf_cpy, buf, count+1);
> > +       *mask = 0;
> > +
> > +       bytes = min(count, sizeof(buf_cpy) - 1);
> > +       memcpy(buf_cpy, buf, bytes);
> > +       buf_cpy[bytes] = '\0';
> >         tmp = buf_cpy;
> >         while (tmp[0]) {
> > -               sub_str =  strsep(&tmp, delimiter);
> > +               sub_str = strsep(&tmp, delimiter);
> >                 if (strlen(sub_str)) {
> >                         ret = kstrtol(sub_str, 0, &level);
> > -
> > -                       if (ret) {
> > -                               count = -EINVAL;
> > -                               goto fail;
> > -                       }
> > -                       mask |= 1 << level;
> > +                       if (ret)
> > +                               return -EINVAL;
> > +                       *mask |= 1 << level;
> >                 } else
> >                         break;
> >         }
> > +
> > +       return 0;
> > +}
> > +
> > +static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
> > +               struct device_attribute *attr,
> > +               const char *buf,
> > +               size_t count)
> > +{
> > +       struct drm_device *ddev = dev_get_drvdata(dev);
> > +       struct amdgpu_device *adev = ddev->dev_private;
> > +       int ret;
> > +       uint32_t mask = 0;
> > +
> > +       ret = amdgpu_read_mask(buf, count, &mask);
> > +       if (ret)
> > +               return ret;
> > +
> >         if (adev->powerplay.pp_funcs->force_clock_level)
> > amdgpu_dpm_force_clock_level(adev, PP_SCLK, mask);
> >
> > -fail:
> >         return count;
> >  }
> >
> > @@ -651,32 +670,15 @@ static ssize_t amdgpu_set_pp_dpm_mclk(struct 
> device *dev,
> >         struct drm_device *ddev = dev_get_drvdata(dev);
> >         struct amdgpu_device *adev = ddev->dev_private;
> >         int ret;
> > -       long level;
> >         uint32_t mask = 0;
> > -       char *sub_str = NULL;
> > -       char *tmp;
> > -       char buf_cpy[count];
> > -       const char delimiter[3] = {' ', '\n', '\0'};
> >
> > -       memcpy(buf_cpy, buf, count+1);
> > -       tmp = buf_cpy;
> > -       while (tmp[0]) {
> > -               sub_str =  strsep(&tmp, delimiter);
> > -               if (strlen(sub_str)) {
> > -                       ret = kstrtol(sub_str, 0, &level);
> > +       ret = amdgpu_read_mask(buf, count, &mask);
> > +       if (ret)
> > +               return ret;
> >
> > -                       if (ret) {
> > -                               count = -EINVAL;
> > -                               goto fail;
> > -                       }
> > -                       mask |= 1 << level;
> > -               } else
> > -                       break;
> > -       }
> >         if (adev->powerplay.pp_funcs->force_clock_level)
> > amdgpu_dpm_force_clock_level(adev, PP_MCLK, mask);
> >
> > -fail:
> >         return count;
> >  }
> >
> > @@ -701,33 +703,15 @@ static ssize_t amdgpu_set_pp_dpm_pcie(struct 
> device *dev,
> >         struct drm_device *ddev = dev_get_drvdata(dev);
> >         struct amdgpu_device *adev = ddev->dev_private;
> >         int ret;
> > -       long level;
> >         uint32_t mask = 0;
> > -       char *sub_str = NULL;
> > -       char *tmp;
> > -       char buf_cpy[count];
> > -       const char delimiter[3] = {' ', '\n', '\0'};
> > -
> > -       memcpy(buf_cpy, buf, count+1);
> > -       tmp = buf_cpy;
> >
> > -       while (tmp[0]) {
> > -               sub_str =  strsep(&tmp, delimiter);
> > -               if (strlen(sub_str)) {
> > -                       ret = kstrtol(sub_str, 0, &level);
> > +       ret = amdgpu_read_mask(buf, count, &mask);
> > +       if (ret)
> > +               return ret;
> >
> > -                       if (ret) {
> > -                               count = -EINVAL;
> > -                               goto fail;
> > -                       }
> > -                       mask |= 1 << level;
> > -               } else
> > -                       break;
> > -       }
> >         if (adev->powerplay.pp_funcs->force_clock_level)
> > amdgpu_dpm_force_clock_level(adev, PP_PCIE, mask);
> >
> > -fail:
> >         return count;
> >  }
> >
> > --
> > 2.17.1
> >
> >
> > --
> > Kees Cook
> > Pixel Security
>
>
>
> -- 
> Kees Cook
> Pixel Security
>
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

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