linux-kernel - [PATCH v3 24/25] compiler_attributes.h: Add __disable_sanitizer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211130114433.2580590-25-elver@google.com>
Date:   Tue, 30 Nov 2021 12:44:32 +0100
From:   Marco Elver <elver@...gle.com>
To:     elver@...gle.com, "Paul E. McKenney" <paulmck@...nel.org>
Cc:     Alexander Potapenko <glider@...gle.com>,
        Boqun Feng <boqun.feng@...il.com>,
        Borislav Petkov <bp@...en8.de>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Ingo Molnar <mingo@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Waiman Long <longman@...hat.com>,
        Will Deacon <will@...nel.org>, kasan-dev@...glegroups.com,
        linux-arch@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, llvm@...ts.linux.dev, x86@...nel.org
Subject: [PATCH v3 24/25] compiler_attributes.h: Add __disable_sanitizer_instrumentation

From: Alexander Potapenko <glider@...gle.com>

The new attribute maps to
__attribute__((disable_sanitizer_instrumentation)), which will be
supported by Clang >= 14.0. Future support in GCC is also possible.

This attribute disables compiler instrumentation for kernel sanitizer
tools, making it easier to implement noinstr. It is different from the
existing __no_sanitize* attributes, which may still allow certain types
of instrumentation to prevent false positives.

Signed-off-by: Alexander Potapenko <glider@...gle.com>
Signed-off-by: Marco Elver <elver@...gle.com>
---
v3:
* New patch.
---
 include/linux/compiler_attributes.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index b9121afd8733..37e260020221 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -308,6 +308,24 @@
 # define __compiletime_warning(msg)
 #endif
 
+/*
+ * Optional: only supported since clang >= 14.0
+ *
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#disable-sanitizer-instrumentation
+ *
+ * disable_sanitizer_instrumentation is not always similar to
+ * no_sanitize((<sanitizer-name>)): the latter may still let specific sanitizers
+ * insert code into functions to prevent false positives. Unlike that,
+ * disable_sanitizer_instrumentation prevents all kinds of instrumentation to
+ * functions with the attribute.
+ */
+#if __has_attribute(disable_sanitizer_instrumentation)
+# define __disable_sanitizer_instrumentation \
+	 __attribute__((disable_sanitizer_instrumentation))
+#else
+# define __disable_sanitizer_instrumentation
+#endif
+
 /*
  *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute
  *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute
-- 
2.34.0.rc2.393.gf8c9666880-goog