drm/i915: taint the kernel if unsafe module parameters are set

Taint the kernel if the semaphores, enable_rc6, enable_fbc, or ppgtt
module parameters are modified. These module parameters are for
debugging and testing only, and should never be changed from their
platform specific default values by the users. We do not provide support
for people enabling all the experimental features. Make this clear by
tainting the kernel if the parameters are set.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 7f84dd263ee8966d414341a4d6471d52ca0578c3..9842fd2e742a40d0b83c51f2e9f2dd012e1bc304 100644 (file)
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -66,12 +66,12 @@ module_param_named(powersave, i915.powersave, int, 0600);
 MODULE_PARM_DESC(powersave,
        "Enable powersavings, fbc, downclocking, etc. (default: true)");
 
-module_param_named(semaphores, i915.semaphores, int, 0400);
+module_param_named_unsafe(semaphores, i915.semaphores, int, 0400);
 MODULE_PARM_DESC(semaphores,
        "Use semaphores for inter-ring sync "
        "(default: -1 (use per-chip defaults))");
 
-module_param_named(enable_rc6, i915.enable_rc6, int, 0400);
+module_param_named_unsafe(enable_rc6, i915.enable_rc6, int, 0400);
 MODULE_PARM_DESC(enable_rc6,
        "Enable power-saving render C-state 6. "
        "Different stages can be selected via bitmask values "
@@ -79,7 +79,7 @@ MODULE_PARM_DESC(enable_rc6,
        "For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. "
        "default: -1 (use per-chip default)");
 
-module_param_named(enable_fbc, i915.enable_fbc, int, 0600);
+module_param_named_unsafe(enable_fbc, i915.enable_fbc, int, 0600);
 MODULE_PARM_DESC(enable_fbc,
        "Enable frame buffer compression for power savings "
        "(default: -1 (use per-chip default))");
@@ -113,7 +113,7 @@ MODULE_PARM_DESC(enable_hangcheck,
        "WARNING: Disabling this can cause system wide hangs. "
        "(default: true)");
 
-module_param_named(enable_ppgtt, i915.enable_ppgtt, int, 0400);
+module_param_named_unsafe(enable_ppgtt, i915.enable_ppgtt, int, 0400);
 MODULE_PARM_DESC(enable_ppgtt,
        "Override PPGTT usage. "
        "(-1=auto [default], 0=disabled, 1=aliasing, 2=full)");