linux-kernel - [PATCH] kasan: fix clang compilation warning due to stack protector

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-next>] [day] [month] [year] [list]

Message-Id: <ced83584eec86a1a9ce264013cf6c0da5e0add6a.1590686292.git.andreyknvl@google.com>
Date:   Thu, 28 May 2020 19:20:29 +0200
From:   Andrey Konovalov <andreyknvl@...gle.com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>
Cc:     Alexander Potapenko <glider@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>, kasan-dev@...glegroups.com,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Qian Cai <cai@....pw>, Andrey Konovalov <andreyknvl@...gle.com>
Subject: [PATCH] kasan: fix clang compilation warning due to stack protector

KASAN uses a single cc-option invocation to disable both conserve-stack
and stack-protector flags. The former flag is not present in Clang, which
causes cc-option to fail, and results in stack-protector being enabled.

Fix by using separate cc-option calls for each flag. Also collect all
flags in a variable to avoid calling cc-option multiple times for
different files.

Reported-by: Qian Cai <cai@....pw>
Signed-off-by: Andrey Konovalov <andreyknvl@...gle.com>
---
 mm/kasan/Makefile | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index de3121848ddf..bf6f7b1f6b18 100644
--- a/mm/kasan/Makefile
+++ b/mm/kasan/Makefile
@@ -15,14 +15,19 @@ CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS_FTRACE)
 
 # Function splitter causes unnecessary splits in __asan_load1/__asan_store1
 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
-CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_init.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_quarantine.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
-CFLAGS_tags_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CC_FLAGS_KASAN_CONFLICT := $(call cc-option, -fno-conserve-stack)
+CC_FLAGS_KASAN_CONFLICT += $(call cc-option, -fno-stack-protector)
+# Disable branch tracing to avoid recursion.
+CC_FLAGS_KASAN_CONFLICT += -DDISABLE_BRANCH_PROFILING
+
+CFLAGS_common.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_generic.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_generic_report.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_init.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_quarantine.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_report.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_tags.o := $(CC_FLAGS_KASAN_CONFLICT)
+CFLAGS_tags_report.o := $(CC_FLAGS_KASAN_CONFLICT)
 
 obj-$(CONFIG_KASAN) := common.o init.o report.o
 obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o
-- 
2.27.0.rc0.183.gde8f92d652-goog