From: Arnd Bergmann <arnd@arndb.de>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>, akpm@linux-foundation.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Arnd Bergmann <arnd@arndb.de>,
stable@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
Dmitry Vyukov <dvyukov@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, Kees Cook <keescook@chromium.org>,
Matthew Wilcox <willy@infradead.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH] [v2] ubsan: build ubsan.c more conservatively
Date: Mon, 22 Jul 2019 14:50:44 +0200 [thread overview]
Message-ID: <20190722125139.1335385-1-arnd@arndb.de> (raw)
objtool points out several conditions that it does not like, depending
on the combination with other configuration options and compiler
variants:
stack protector:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0xbf: call to __stack_chk_fail() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0xbe: call to __stack_chk_fail() with UACCESS enabled
stackleak plugin:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x4a: call to stackleak_track_stack() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x4a: call to stackleak_track_stack() with UACCESS enabled
kasan:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x25: call to memcpy() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x25: call to memcpy() with UACCESS enabled
The stackleak and kasan options just need to be disabled for this file
as we do for other files already. For the stack protector, we already
attempt to disable it, but this fails on clang because the check is
mixed with the gcc specific -fno-conserve-stack option. According
to Andrey Ryabinin, that option is not even needed, dropping it here
fixes the stackprotector issue.
Fixes: d08965a27e84 ("x86/uaccess, ubsan: Fix UBSAN vs. SMAP")
Link: https://lore.kernel.org/lkml/20190617123109.667090-1-arnd@arndb.de/t/
Link: https://lore.kernel.org/lkml/20190722091050.2188664-1-arnd@arndb.de/t/
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2:
- drop -fno-conserve-stack
- fix the Fixes: line
---
lib/Makefile | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/Makefile b/lib/Makefile
index 095601ce371d..29c02a924973 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -279,7 +279,8 @@ obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
obj-$(CONFIG_UBSAN) += ubsan.o
UBSAN_SANITIZE_ubsan.o := n
-CFLAGS_ubsan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+KASAN_SANITIZE_ubsan.o := n
+CFLAGS_ubsan.o := $(call cc-option, -fno-stack-protector) $(DISABLE_STACKLEAK_PLUGIN)
obj-$(CONFIG_SBITMAP) += sbitmap.o
--
2.20.0
next reply other threads:[~2019-07-22 12:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 12:50 Arnd Bergmann [this message]
2019-07-22 12:56 ` [PATCH] [v2] ubsan: build ubsan.c more conservatively Andrey Ryabinin
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