drm/i915: Warn against variable length arrays

VLA are strongly discouraged in the kernel due to ambiguity they impose
on the limited stack space and security concerns over manipulating the
stack frame. Add -Wvla to our compiler flags so that CI rejects them.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180313004055.25411-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 4eee91a3a236df6e2c8d3f9e42c3d7dbd0fe02f4..fcb8a7b27ae2ffa75464e2327cc3c10a398bb361 100644 (file)
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -12,7 +12,7 @@
 # Note the danger in using -Wall -Wextra is that when CI updates gcc we
 # will most likely get a sudden build breakage... Hopefully we will fix
 # new warnings before CI updates!
-subdir-ccflags-y := -Wall -Wextra
+subdir-ccflags-y := -Wall -Wextra -Wvla
 subdir-ccflags-y += $(call cc-disable-warning, unused-parameter)
 subdir-ccflags-y += $(call cc-disable-warning, type-limits)
 subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers)