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From: Kees Cook <keescook@chromium.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Olof Johansson <olof@lixom.net>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	George Spelvin <linux@sciencehorizons.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	David Windsor <dwindsor@gmail.com>,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com
Subject: [PATCH v2 2/7] bug: Improve unlikely() in data corruption check
Date: Tue,  4 Apr 2017 15:12:13 -0700	[thread overview]
Message-ID: <1491343938-75336-3-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1491343938-75336-1-git-send-email-keescook@chromium.org>

This improves the compiler branch-hinting used in CHECK_DATA_CORRUPTION(),
similar to how it is done in WARN_ON() and friends.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/bug.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index db1e41c69bac..b6cfcb7f778f 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -130,15 +130,15 @@ static inline enum bug_trap_type report_bug(unsigned long bug_addr,
 static inline __must_check bool check_data_corruption(bool v) { return v; }
 #define CHECK_DATA_CORRUPTION(condition, fmt, ...)			 \
 	check_data_corruption(({					 \
-		bool corruption = unlikely(condition);			 \
-		if (corruption) {					 \
+		bool corruption = !!(condition);			 \
+		if (unlikely(corruption)) {				 \
 			if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \
 				pr_err(fmt, ##__VA_ARGS__);		 \
 				BUG();					 \
 			} else						 \
 				WARN(1, fmt, ##__VA_ARGS__);		 \
 		}							 \
-		corruption;						 \
+		unlikely(corruption);					 \
 	}))
 
 #endif	/* _LINUX_BUG_H */
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Olof Johansson <olof@lixom.net>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	George Spelvin <linux@sciencehorizons.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	David Windsor <dwindsor@gmail.com>,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com
Subject: [kernel-hardening] [PATCH v2 2/7] bug: Improve unlikely() in data corruption check
Date: Tue,  4 Apr 2017 15:12:13 -0700	[thread overview]
Message-ID: <1491343938-75336-3-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1491343938-75336-1-git-send-email-keescook@chromium.org>

This improves the compiler branch-hinting used in CHECK_DATA_CORRUPTION(),
similar to how it is done in WARN_ON() and friends.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/bug.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index db1e41c69bac..b6cfcb7f778f 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -130,15 +130,15 @@ static inline enum bug_trap_type report_bug(unsigned long bug_addr,
 static inline __must_check bool check_data_corruption(bool v) { return v; }
 #define CHECK_DATA_CORRUPTION(condition, fmt, ...)			 \
 	check_data_corruption(({					 \
-		bool corruption = unlikely(condition);			 \
-		if (corruption) {					 \
+		bool corruption = !!(condition);			 \
+		if (unlikely(corruption)) {				 \
 			if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \
 				pr_err(fmt, ##__VA_ARGS__);		 \
 				BUG();					 \
 			} else						 \
 				WARN(1, fmt, ##__VA_ARGS__);		 \
 		}							 \
-		corruption;						 \
+		unlikely(corruption);					 \
 	}))
 
 #endif	/* _LINUX_BUG_H */
-- 
2.7.4

  parent reply	other threads:[~2017-04-04 22:12 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-04 22:12 [PATCH v2] bug: further enhance use of CHECK_DATA_CORRUPTION Kees Cook
2017-04-04 22:12 ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` [PATCH v2 1/7] bug: Clarify help text for BUG_ON_DATA_CORRUPTION Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-05  5:47   ` Ian Campbell
2017-04-05 19:32     ` Kees Cook
2017-04-05 19:32       ` Kees Cook
2017-04-04 22:12 ` Kees Cook [this message]
2017-04-04 22:12   ` [kernel-hardening] [PATCH v2 2/7] bug: Improve unlikely() in data corruption check Kees Cook
2017-04-04 22:12 ` [PATCH v2 3/7] bug: Use WARN_ONCE() for CHECK_DATA_CORRUPTION() Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` [PATCH v2 4/7] bug: Enable DEBUG_CREDENTIALS under BUG_ON_DATA_CORRUPTION Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` [PATCH v2 5/7] bug: Enable DEBUG_SG " Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` [PATCH v2 6/7] notifiers: Use CHECK_DATA_CORRUPTION() on checks Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` [PATCH v2 7/7] refcount: Check bad states with CHECK_DATA_CORRUPTION() Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2021-01-04 23:07 ` [PATCH v2] bug: further enhance use of CHECK_DATA_CORRUPTION Josh Poimboeuf

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