On Mon, 26 Feb 2018, Chris Wilson <ch...@chris-wilson.co.uk> wrote: > As using an unsafe module parameter is, by its very definition, an > expected user action, emitting a warning is overkill. Nothing has yet > gone wrong, and we add a taint flag for any future oops should > something actually go wrong. So instead of having a user controllable > pr_warn, downgrade it to a pr_notice for "a normal, but significant > condition". > > We make use of unsafe kernel parameters in igt (we have not yet > succeeded in removing all such debugging options), which generates a > warning and taints the kernel. The warning is unhelpful as we then need > to filter it out again as we check that every test themselves do not > provoke any kernel warnings.
IGT being https://cgit.freedesktop.org/drm/igt-gpu-tools/ for those not in the DRM/KMS circles. > References: 91f9d330cc14 ("module: make it possible to have unsafe, tainting > module params") > Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> > Cc: Jani Nikula <jani.nik...@intel.com> > Cc: Rusty Russell <ru...@rustcorp.com.au> > Cc: Jean Delvare <kh...@linux-fr.org> > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Li Zhong <zh...@linux.vnet.ibm.com> > Cc: Petri Latvala <petri.latv...@intel.com> > Cc: Daniel Vetter <daniel.vet...@ffwll.ch> Acked-by: Jani Nikula <jani.nik...@intel.com> When I added the unsafe module params, I erred on the side of making more noise about tainting, but there was really no discussion about it. FWIW, I don't mind the change, as long as it's not debug level. BR, Jani. > --- > kernel/params.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/params.c b/kernel/params.c > index cc9108c2a1fd..ce89f757e6da 100644 > --- a/kernel/params.c > +++ b/kernel/params.c > @@ -111,8 +111,8 @@ bool parameq(const char *a, const char *b) > static void param_check_unsafe(const struct kernel_param *kp) > { > if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { > - pr_warn("Setting dangerous option %s - tainting kernel\n", > - kp->name); > + pr_notice("Setting dangerous option %s - tainting kernel\n", > + kp->name); > add_taint(TAINT_USER, LOCKDEP_STILL_OK); > } > } -- Jani Nikula, Intel Open Source Technology Center
