diff options
| author | Gary Hook <[email protected]> | 2019-04-29 22:22:58 +0000 |
|---|---|---|
| committer | Borislav Petkov <[email protected]> | 2019-04-30 17:59:08 +0200 |
| commit | b51ce3744f115850166f3d6c292b9c8cb849ad4f (patch) | |
| tree | 884ff05efc8c3fb97041f6fcaca61c834c2f9b7c | |
| parent | 0d02113b31b2017dd349ec9df2314e798a90fa6e (diff) | |
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 <[email protected]>
Signed-off-by: Gary R Hook <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Coly Li <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
| -rw-r--r-- | arch/x86/lib/Makefile | 12 | ||||
| -rw-r--r-- | lib/Makefile | 11 |
2 files changed, 23 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 $@ diff --git a/lib/Makefile b/lib/Makefile index 3b08673e8881..18c2be516ab4 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 timerqueue.o xarray.o \ idr.o int_sqrt.o extable.o \ |