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 1/7] bug: Clarify help text for BUG_ON_DATA_CORRUPTION
Date: Tue, 4 Apr 2017 15:12:12 -0700 [thread overview]
Message-ID: <1491343938-75336-2-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1491343938-75336-1-git-send-email-keescook@chromium.org>
This expands on the Kconfig help text for CONFIG_BUG_ON_DATA_CORRUPTION to
more clearly explain the rationale of BUG vs WARN. Additionally fixes a
grammar glitch in the macro comment.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/bug.h | 3 ++-
lib/Kconfig.debug | 9 ++++++---
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/include/linux/bug.h b/include/linux/bug.h
index 687b557fc5eb..db1e41c69bac 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -124,7 +124,8 @@ static inline enum bug_trap_type report_bug(unsigned long bug_addr,
/*
* Since detected data corruption should stop operation on the affected
- * structures. Return value must be checked and sanely acted on by caller.
+ * structures, require that the condition is checked and sanely acted on
+ * by the caller.
*/
static inline __must_check bool check_data_corruption(bool v) { return v; }
#define CHECK_DATA_CORRUPTION(condition, fmt, ...) \
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 77fadface4f9..5ac4d1148385 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1998,9 +1998,12 @@ config BUG_ON_DATA_CORRUPTION
bool "Trigger a BUG when data corruption is detected"
select DEBUG_LIST
help
- Select this option if the kernel should BUG when it encounters
- data corruption in kernel memory structures when they get checked
- for validity.
+ This option enables several inexpensive data corruption checks.
+ Most of these checks normally just WARN and try to further avoid
+ the corruption. Selecting this option upgrades these to BUGs so
+ that the offending process is killed. Additionally, the system
+ owner can furhter configure the system for immediate reboots
+ (via panic_on_oops sysctl) or crash dumps.
If unsure, say N.
--
2.7.4
next prev parent reply other threads:[~2017-04-04 22:13 UTC|newest]
Thread overview: 11+ 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 ` Kees Cook [this message]
2017-04-05 5:47 ` [kernel-hardening] [PATCH v2 1/7] bug: Clarify help text for BUG_ON_DATA_CORRUPTION Ian Campbell
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 ` [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 ` [PATCH v2 5/7] bug: Enable DEBUG_SG " 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 ` [PATCH v2 7/7] refcount: Check bad states with CHECK_DATA_CORRUPTION() Kees Cook
2021-01-04 23:07 ` [PATCH v2] bug: further enhance use of CHECK_DATA_CORRUPTION Josh Poimboeuf
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