From 4eee4920f05e39e22571deb57f1c314ce7a46e7f Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Mon, 17 Aug 2015 17:30:52 +0100 Subject: [PATCH] drm/i915: fix driver's versions of WARN_ON & WARN_ON_ONCE The current versions of these two macros don't work correctly if the argument expression happens to contain a modulo operator (%) -- when stringified, it gets interpreted as a printf formatting character! With a specifically crafted parameter, this could probably cause a kernel OOPS; consider WARN_ON(p%s) or WARN_ON(f %*pEp). Instead, we should use an explicit "%s" format, with the stringified expression as the coresponding literal-string argument. Signed-off-by: Dave Gordon Reviewed-by: Paulo Zanoni Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 61244455347f..ce41d24c6888 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -68,11 +68,11 @@ BUILD_BUG_ON(__i915_warn_cond); \ WARN(__i915_warn_cond, "WARN_ON(" #x ")"); }) #else -#define WARN_ON(x) WARN((x), "WARN_ON(" #x ")") +#define WARN_ON(x) WARN((x), "WARN_ON(%s)", #x ) #endif #undef WARN_ON_ONCE -#define WARN_ON_ONCE(x) WARN_ONCE((x), "WARN_ON_ONCE(" #x ")") +#define WARN_ON_ONCE(x) WARN_ONCE((x), "WARN_ON_ONCE(%s)", #x ) #define MISSING_CASE(x) WARN(1, "Missing switch case (%lu) in %s\n", \ (long) (x), __func__); -- 2.39.2