diff mbox series

[8/8] x86, kcsan: Enable KCSAN for x86

Message ID 20191016083959.186860-9-elver@google.com (mailing list archive)
State New, archived
Headers show
Series Add Kernel Concurrency Sanitizer (KCSAN) | expand

Commit Message

Marco Elver Oct. 16, 2019, 8:39 a.m. UTC 
This patch enables KCSAN for x86, with updates to build rules to not use
KCSAN for several incompatible compilation units.

Signed-off-by: Marco Elver <elver@google.com>
---
 arch/x86/Kconfig                      | 1 +
 arch/x86/boot/Makefile                | 1 +
 arch/x86/boot/compressed/Makefile     | 1 +
 arch/x86/entry/vdso/Makefile          | 1 +
 arch/x86/include/asm/bitops.h         | 2 +-
 arch/x86/kernel/Makefile              | 6 ++++++
 arch/x86/kernel/cpu/Makefile          | 3 +++
 arch/x86/lib/Makefile                 | 2 ++
 arch/x86/mm/Makefile                  | 3 +++
 arch/x86/purgatory/Makefile           | 1 +
 arch/x86/realmode/Makefile            | 1 +
 arch/x86/realmode/rm/Makefile         | 1 +
 drivers/firmware/efi/libstub/Makefile | 1 +
 13 files changed, 23 insertions(+), 1 deletion(-)

Comments

Dave Hansen Oct. 16, 2019, 4:14 p.m. UTC | #1 
On 10/16/19 1:39 AM, Marco Elver wrote:
> This patch enables KCSAN for x86, with updates to build rules to not use
> KCSAN for several incompatible compilation units.

First of all KCSAN looks really interesting!

For the x86 code, though, I'd really appreciate some specific notes on
why individual compilation units are incompatible.  There might be some
that were missed, and we have to figure out what we do for any future
work.  Knowing the logic used on these would be really helpful in the
future.
Marco Elver Oct. 16, 2019, 5:04 p.m. UTC | #2 
On Wed, 16 Oct 2019 at 18:14, Dave Hansen <dave.hansen@intel.com> wrote:
>
> On 10/16/19 1:39 AM, Marco Elver wrote:
> > This patch enables KCSAN for x86, with updates to build rules to not use
> > KCSAN for several incompatible compilation units.
>
> First of all KCSAN looks really interesting!
>
> For the x86 code, though, I'd really appreciate some specific notes on
> why individual compilation units are incompatible.  There might be some
> that were missed, and we have to figure out what we do for any future
> work.  Knowing the logic used on these would be really helpful in the
> future.

Thanks!  I will add comments where I can for v2. For most of them, I
followed the examples of KASAN and co, and will try to reevaluate each
one.

-- Marco
diff mbox series

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d6e1faa28c58..81859be4a005 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -226,6 +226,7 @@  config X86
 	select VIRT_TO_BUS
 	select X86_FEATURE_NAMES		if PROC_FS
 	select PROC_PID_ARCH_STATUS		if PROC_FS
+	select HAVE_ARCH_KCSAN if X86_64
 
 config INSTRUCTION_DECODER
 	def_bool y
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index e2839b5c246c..2f9e928acae6 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -10,6 +10,7 @@ 
 #
 
 KASAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
 # Kernel does not boot with kcov instrumentation here.
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 6b84afdd7538..0921689f7c70 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -18,6 +18,7 @@ 
 #	compressed vmlinux.bin.all + u32 size of vmlinux.bin.all
 
 KASAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 0f2154106d01..d2cd34d2ac4e 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -12,6 +12,7 @@  include $(srctree)/lib/vdso/Makefile
 KBUILD_CFLAGS += $(DISABLE_LTO)
 KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 7d1f6a49bfae..a36d900960e4 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -201,7 +201,7 @@  arch_test_and_change_bit(long nr, volatile unsigned long *addr)
 	return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr);
 }
 
-static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr)
+static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr)
 {
 	return ((1UL << (nr & (BITS_PER_LONG-1))) &
 		(addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 3578ad248bc9..adccbbfa47e4 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -28,6 +28,12 @@  KASAN_SANITIZE_dumpstack_$(BITS).o			:= n
 KASAN_SANITIZE_stacktrace.o				:= n
 KASAN_SANITIZE_paravirt.o				:= n
 
+KCSAN_SANITIZE_head$(BITS).o				:= n
+KCSAN_SANITIZE_dumpstack.o				:= n
+KCSAN_SANITIZE_dumpstack_$(BITS).o			:= n
+KCSAN_SANITIZE_stacktrace.o				:= n
+KCSAN_SANITIZE_paravirt.o				:= n
+
 OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o	:= y
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
 OBJECT_FILES_NON_STANDARD_paravirt_patch.o		:= y
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index d7a1e5a9331c..7651c4f37e5e 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -3,6 +3,9 @@ 
 # Makefile for x86-compatible CPU details, features and quirks
 #
 
+KCSAN_SANITIZE_common.o = n
+KCSAN_SANITIZE_perf_event.o = n
+
 # Don't trace early stages of a secondary CPU boot
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_common.o = -pg
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 5246db42de45..4e4b74f525f2 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -5,11 +5,13 @@ 
 
 # Produces uninteresting flaky coverage.
 KCOV_INSTRUMENT_delay.o	:= n
+KCSAN_SANITIZE_delay.o := n
 
 # Early boot use of cmdline; don't instrument it
 ifdef CONFIG_AMD_MEM_ENCRYPT
 KCOV_INSTRUMENT_cmdline.o := n
 KASAN_SANITIZE_cmdline.o  := n
+KCSAN_SANITIZE_cmdline.o  := n
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_cmdline.o = -pg
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 84373dc9b341..ee871602f96a 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -7,6 +7,9 @@  KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
 KASAN_SANITIZE_mem_encrypt.o		:= n
 KASAN_SANITIZE_mem_encrypt_identity.o	:= n
 
+KCSAN_SANITIZE_mem_encrypt.o		:= n
+KCSAN_SANITIZE_mem_encrypt_identity.o	:= n
+
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_mem_encrypt.o		= -pg
 CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index fb4ee5444379..72060744f34f 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -18,6 +18,7 @@  LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefa
 targets += purgatory.ro
 
 KASAN_SANITIZE	:= n
+KCSAN_SANITIZE	:= n
 KCOV_INSTRUMENT := n
 
 # These are adjustments to the compiler flags used for objects that
diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile
index 682c895753d9..4fc7ce2534dd 100644
--- a/arch/x86/realmode/Makefile
+++ b/arch/x86/realmode/Makefile
@@ -7,6 +7,7 @@ 
 #
 #
 KASAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
 subdir- := rm
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index f60501a384f9..6f7fbe9dfda6 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -7,6 +7,7 @@ 
 #
 #
 KASAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 0460c7581220..a56981286623 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -32,6 +32,7 @@  KBUILD_CFLAGS			:= $(cflags-y) -DDISABLE_BRANCH_PROFILING \
 
 GCOV_PROFILE			:= n
 KASAN_SANITIZE			:= n
+KCSAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y