All of lore.kernel.org
 help / color / mirror / Atom feed
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 3/7] bug: Use WARN_ONCE() for CHECK_DATA_CORRUPTION()
Date: Tue,  4 Apr 2017 15:12:14 -0700	[thread overview]
Message-ID: <1491343938-75336-4-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1491343938-75336-1-git-send-email-keescook@chromium.org>

Since users of CHECK_DATA_CORRUPTION() should be failing safe, the
condition that triggers a WARN() may recur. This would mean a logging
DoS of the system, so switch to WARN_ONCE() instead. (Those wanting
per-instance notifications should already be building with
CONFIG_BUG_ON_DATA_CORRUPTION so there is no change in that case.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/bug.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index b6cfcb7f778f..c011438a7c6c 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -136,7 +136,7 @@ static inline __must_check bool check_data_corruption(bool v) { return v; }
 				pr_err(fmt, ##__VA_ARGS__);		 \
 				BUG();					 \
 			} else						 \
-				WARN(1, fmt, ##__VA_ARGS__);		 \
+				WARN_ONCE(1, fmt, ##__VA_ARGS__);	 \
 		}							 \
 		unlikely(corruption);					 \
 	}))
-- 
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 3/7] bug: Use WARN_ONCE() for CHECK_DATA_CORRUPTION()
Date: Tue,  4 Apr 2017 15:12:14 -0700	[thread overview]
Message-ID: <1491343938-75336-4-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1491343938-75336-1-git-send-email-keescook@chromium.org>

Since users of CHECK_DATA_CORRUPTION() should be failing safe, the
condition that triggers a WARN() may recur. This would mean a logging
DoS of the system, so switch to WARN_ONCE() instead. (Those wanting
per-instance notifications should already be building with
CONFIG_BUG_ON_DATA_CORRUPTION so there is no change in that case.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/bug.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/bug.h b/include/linux/bug.h
index b6cfcb7f778f..c011438a7c6c 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -136,7 +136,7 @@ static inline __must_check bool check_data_corruption(bool v) { return v; }
 				pr_err(fmt, ##__VA_ARGS__);		 \
 				BUG();					 \
 			} else						 \
-				WARN(1, fmt, ##__VA_ARGS__);		 \
+				WARN_ONCE(1, fmt, ##__VA_ARGS__);	 \
 		}							 \
 		unlikely(corruption);					 \
 	}))
-- 
2.7.4

  parent reply	other threads:[~2017-04-04 22:13 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 ` [PATCH v2 2/7] bug: Improve unlikely() in data corruption check Kees Cook
2017-04-04 22:12   ` [kernel-hardening] " Kees Cook
2017-04-04 22:12 ` Kees Cook [this message]
2017-04-04 22:12   ` [kernel-hardening] [PATCH v2 3/7] bug: Use WARN_ONCE() for CHECK_DATA_CORRUPTION() 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1491343938-75336-4-git-send-email-keescook@chromium.org \
    --to=keescook@chromium.org \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=chris@chris-wilson.co.uk \
    --cc=dwindsor@gmail.com \
    --cc=geert@linux-m68k.org \
    --cc=jakub.kicinski@netronome.com \
    --cc=jpoimboe@redhat.com \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=kvalo@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@sciencehorizons.net \
    --cc=mingo@kernel.org \
    --cc=olof@lixom.net \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=viresh.kumar@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.