From edc41b3c5489996e4c1ec820bf102660bf745c45 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 10 Apr 2018 16:35:18 -0700
Subject: [PATCH] kernel/params.c: downgrade warning for unsafe parameters
Git-commit: edc41b3c5489996e4c1ec820bf102660bf745c45
Patch-mainline: v4.17-rc1
References: bsc#1051510

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
(https://cgit.freedesktop.org/drm/igt-gpu-tools/) (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.

Link: http://lkml.kernel.org/r/20180226151919.9674-1-chris@chris-wilson.co.uk
Fixes: 91f9d330cc14 ("module: make it possible to have unsafe, tainting module params")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Petri Latvala <petri.latvala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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);
 	}
 }
-- 
2.18.0