diff options
| author | Gary Hook <Gary.Hook@amd.com> | 2019-04-29 22:22:58 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-25 18:25:36 +0200 |
| commit | 489e5d8c7652b9ba230481a3782d25a8e7d08467 (patch) | |
| tree | e64a4d5d8f93257dde33439c462ba764bf7fc0b3 /lib | |
| parent | abda2930ae57681328c6c066ee4db6814a4aee83 (diff) | |
| download | linux-stable-489e5d8c7652b9ba230481a3782d25a8e7d08467.tar.gz linux-stable-489e5d8c7652b9ba230481a3782d25a8e7d08467.tar.bz2 linux-stable-489e5d8c7652b9ba230481a3782d25a8e7d08467.zip | |
x86/mm/mem_encrypt: Disable all instrumentation for early SME setup
[ Upstream commit b51ce3744f115850166f3d6c292b9c8cb849ad4f ]
Enablement of AMD's Secure Memory Encryption feature is determined very
early after start_kernel() is entered. Part of this procedure involves
scanning the command line for the parameter 'mem_encrypt'.
To determine intended state, the function sme_enable() uses library
functions cmdline_find_option() and strncmp(). Their use occurs early
enough such that it cannot be assumed that any instrumentation subsystem
is initialized.
For example, making calls to a KASAN-instrumented function before KASAN
is set up will result in the use of uninitialized memory and a boot
failure.
When AMD's SME support is enabled, conditionally disable instrumentation
of these dependent functions in lib/string.c and arch/x86/lib/cmdline.c.
[ bp: Get rid of intermediary nostackp var and cleanup whitespace. ]
Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption")
Reported-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: "luto@kernel.org" <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "mingo@redhat.com" <mingo@redhat.com>
Cc: "peterz@infradead.org" <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/155657657552.7116.18363762932464011367.stgit@sosrh3.amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile index b1ac45032903..4ea31c2d982d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -17,6 +17,17 @@ KCOV_INSTRUMENT_list_debug.o := n KCOV_INSTRUMENT_debugobjects.o := n KCOV_INSTRUMENT_dynamic_debug.o := n +# Early boot use of cmdline, don't instrument it +ifdef CONFIG_AMD_MEM_ENCRYPT +KASAN_SANITIZE_string.o := n + +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_string.o = -pg +endif + +CFLAGS_string.o := $(call cc-option, -fno-stack-protector) +endif + lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o timerqueue.o\ idr.o int_sqrt.o extable.o \ |