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| author | Gary Hook <Gary.Hook@amd.com> | 2019-04-29 22:22:58 +0000 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-04-30 17:59:08 +0200 |
| commit | b51ce3744f115850166f3d6c292b9c8cb849ad4f (patch) | |
| tree | 884ff05efc8c3fb97041f6fcaca61c834c2f9b7c /arch | |
| parent | 0d02113b31b2017dd349ec9df2314e798a90fa6e (diff) | |
| download | linux-b51ce3744f115850166f3d6c292b9c8cb849ad4f.tar.gz linux-b51ce3744f115850166f3d6c292b9c8cb849ad4f.tar.bz2 linux-b51ce3744f115850166f3d6c292b9c8cb849ad4f.zip | |
x86/mm/mem_encrypt: Disable all instrumentation for early SME setup
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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/lib/Makefile | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 140e61843a07..3cb3af51ec89 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -6,6 +6,18 @@ # Produces uninteresting flaky coverage. KCOV_INSTRUMENT_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 + +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_cmdline.o = -pg +endif + +CFLAGS_cmdline.o := $(call cc-option, -fno-stack-protector) +endif + inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt quiet_cmd_inat_tables = GEN $@ |