On 04/21/2015 09:51 PM, Fenghua Yu wrote:
> +     /*
> +      * Copy rest of xstates in compact format to user.
> +      */
> +     for (i = 2; i < xstate_features; i++) {
> +             if (test_bit(i, (unsigned long *)&pcntxt_mask)) {
> +                     int user_offset, kernel_offset;
> +                     int size;
> +
> +                     user_offset = xstate_offsets[i];
> +                     kernel_offset = xstate_comp_offsets[i];
> +                     size = xstate_sizes[i];
> +
> +                     if (__copy_to_user(buf_fx + user_offset,
> +                                  xsave + kernel_offset, size))
> +                             return -1;
> +             }
> +     }

Is this checking the right bitmap?

The 'xsaves' documentation says: "If RFBM[i] = 1, XSTATE_BV[i] is set to
the value of XINUSE[i]".  Where "XINUSE denotes the state-component
bitmap corresponding to the init optimization".

So shouldn't this be checking xsave->xsave_hdr.xstate_bv instead of
pcntxt_mask?  The will be equal unless the "init optimization" is in play.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to