x86: kmsan: disable instrumentation of unsupported code

Instrumenting some files with KMSAN will result in kernel being unable to
link, boot or crashing at runtime for various reasons (e.g.  infinite
recursion caused by instrumentation hooks calling instrumented code
again).

Completely omit KMSAN instrumentation in the following places:
 - arch/x86/boot and arch/x86/realmode/rm, as KMSAN doesn't work for i386;
 - arch/x86/entry/vdso, which isn't linked with KMSAN runtime;
 - three files in arch/x86/kernel - boot problems;
 - arch/x86/mm/cpu_entry_area.c - recursion.

Link: https://lkml.kernel.org/r/20220915150417.722975-33-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index ffec8bb..9860ca5 100644 (file)
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -12,6 +12,7 @@
 # Sanitizer runtimes are unavailable and cannot be linked for early boot code.
 KASAN_SANITIZE                 := n
 KCSAN_SANITIZE                 := n
+KMSAN_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 35ce1a6..3a261ab 100644 (file)
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -20,6 +20,7 @@
 # Sanitizer runtimes are unavailable and cannot be linked for early boot code.
 KASAN_SANITIZE                 := n
 KCSAN_SANITIZE                 := n
+KMSAN_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 12f6c4d..ce4eb7e 100644 (file)
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -11,6 +11,9 @@ include $(srctree)/lib/vdso/Makefile
 
 # Sanitizer runtimes are unavailable and cannot be linked here.
 KASAN_SANITIZE                 := n
+KMSAN_SANITIZE_vclock_gettime.o := n
+KMSAN_SANITIZE_vgetcpu.o       := n
+
 UBSAN_SANITIZE                 := n
 KCSAN_SANITIZE                 := n
 OBJECT_FILES_NON_STANDARD      := y

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index a20a5eb..ac564c5 100644 (file)
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -33,6 +33,8 @@ KASAN_SANITIZE_sev.o                                  := n
 # With some compiler versions the generated code results in boot hangs, caused
 # by several compilation units. To be safe, disable all instrumentation.
 KCSAN_SANITIZE := n
+KMSAN_SANITIZE_head$(BITS).o                           := n
+KMSAN_SANITIZE_nmi.o                                   := n
 
 # If instrumentation of this dir is enabled, boot hangs during first second.
 # Probably could be more selective here, but note that files related to irqs,

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 9661e3e..f10a921 100644 (file)
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -12,6 +12,7 @@ endif
 # If these files are instrumented, boot hangs during the first second.
 KCOV_INSTRUMENT_common.o := n
 KCOV_INSTRUMENT_perf_event.o := n
+KMSAN_SANITIZE_common.o := n
 
 # As above, instrumenting secondary CPU boot code causes boot hangs.
 KCSAN_SANITIZE_common.o := n

diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 829c140..afb6f71 100644 (file)
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -14,6 +14,8 @@ KASAN_SANITIZE_pgprot.o               := n
 # Disable KCSAN entirely, because otherwise we get warnings that some functions
 # reference __initdata sections.
 KCSAN_SANITIZE := n
+# Avoid recursion by not calling KMSAN hooks for CEA code.
+KMSAN_SANITIZE_cpu_entry_area.o := n
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_mem_encrypt.o            = -pg

diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 83f1b6a..f614009 100644 (file)
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -10,6 +10,7 @@
 # Sanitizer runtimes are unavailable and cannot be linked here.
 KASAN_SANITIZE                 := n
 KCSAN_SANITIZE                 := n
+KMSAN_SANITIZE                 := n
 OBJECT_FILES_NON_STANDARD      := y
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.