Quoting Ram Moon, AnandX (2021-02-16 12:05:23) > Hi Chris, > > -----Original Message----- > From: dri-devel <dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Chris Wilson > Sent: Monday, February 15, 2021 6:10 PM > To: Auld, Matthew <matthew.auld@xxxxxxxxx>; Ram Moon, AnandX <anandx.ram.moon@xxxxxxxxx>; Surendrakumar Upadhyay, TejaskumarX <tejaskumarx.surendrakumar.upadhyay@xxxxxxxxx>; Ursulin, Tvrtko <tvrtko.ursulin@xxxxxxxxx>; Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: [Intel-gfx] [PATCH] drm/i915/gem: Add a check for object size for corner cases > > Quoting Ram Moon, AnandX (2021-02-15 12:29:17) > > Hi Chris, > > > > -----Original Message----- > > From: dri-devel <dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of > > Chris Wilson > > Sent: Wednesday, February 10, 2021 4:15 PM > > To: Ram Moon, AnandX <anandx.ram.moon@xxxxxxxxx>; Jani Nikula > > <jani.nikula@xxxxxxxxxxxxxxx>; Auld, Matthew <matthew.auld@xxxxxxxxx>; > > Surendrakumar Upadhyay, TejaskumarX > > <tejaskumarx.surendrakumar.upadhyay@xxxxxxxxx>; Ursulin, Tvrtko > > <tvrtko.ursulin@xxxxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; > > intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > Cc: Ram Moon, AnandX <anandx.ram.moon@xxxxxxxxx> > > Subject: Re: [Intel-gfx] [PATCH] drm/i915/gem: Add a check for object > > size for corner cases > > > > Quoting Anand Moon (2021-02-10 07:59:29) > > > Add check for object size to return appropriate error -E2BIG or > > > -EINVAL to avoid WARM_ON and successful return for some testcase. > > > > No. You miss the point of having those warnings. We need to inspect the code to remove the last remaining "int pagenum", and then we can remove the GEM_WARN_ON((sz) >> PAGE_SHIFT > INT_MAX). These are not emitted for users, only for us to motivate us into finally fixing the code. > > -Chris > > > > Yes, I got your point these check are meant to catch up integer overflow. > > > > I have check with the IGT testcase case _gem_create_ and > > _gem_userptr_blits_ which fails pass size *-1ull << 32* left shift > > and *0~* which leads to integer overflow ie _negative_ size passed to create i915_gem_create via ioctl this leads to GM_WARN_ON. > > > > Can we drop these testcase so that we don't break the kernel ? > > The kernel rejects the ioctl with the expected errno. We leave a warning purely for the benefit of CI, only when compiled for debugging and not by default, so that we have a persistent reminder to do the code review. > What's broken? > -Chris > > All though the testcase return with appropriate error we observe kernel taint see below. Which is an intentional taint added for CI so that we get a warning and a visible bug so that we can allocate resources to _fix_ the underlying problems in the code. -Chris _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
