[PATCH v6 06/13] x86/bugs: Rename SLS to CONFIG_MITIGATION_SLS

From: Breno Leitao
Date: Tue Nov 21 2023 - 12:12:11 EST


CPU mitigations config entries are inconsistent, and names are hard to
related. There are concrete benefits for both users and developers of
having all the mitigation config options living in the same config
namespace.

The mitigation options should have consistency and start with
MITIGATION.

Rename the Kconfig entry from SLS to MITIGATION_SLS.

Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
arch/x86/Kconfig | 2 +-
arch/x86/Makefile | 2 +-
arch/x86/include/asm/linkage.h | 4 ++--
arch/x86/kernel/alternative.c | 4 ++--
arch/x86/kernel/ftrace.c | 3 ++-
arch/x86/net/bpf_jit_comp.c | 4 ++--
scripts/Makefile.lib | 2 +-
7 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 862be9b3b216..fa246de60cdb 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2580,7 +2580,7 @@ config CPU_SRSO
help
Enable the SRSO mitigation needed on AMD Zen1-4 machines.

-config SLS
+config MITIGATION_SLS
bool "Mitigate Straight-Line-Speculation"
depends on CC_HAS_SLS && X86_64
select OBJTOOL if HAVE_OBJTOOL
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index b8d23ed059fb..5ce8c30e7701 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -205,7 +205,7 @@ ifdef CONFIG_MITIGATION_RETPOLINE
endif
endif

-ifdef CONFIG_SLS
+ifdef CONFIG_MITIGATION_SLS
KBUILD_CFLAGS += -mharden-sls=all
endif

diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index c5165204c66f..09e2d026df33 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -43,7 +43,7 @@
#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define RET jmp __x86_return_thunk
#else /* CONFIG_MITIGATION_RETPOLINE */
-#ifdef CONFIG_SLS
+#ifdef CONFIG_MITIGATION_SLS
#define RET ret; int3
#else
#define RET ret
@@ -55,7 +55,7 @@
#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define ASM_RET "jmp __x86_return_thunk\n\t"
#else /* CONFIG_MITIGATION_RETPOLINE */
-#ifdef CONFIG_SLS
+#ifdef CONFIG_MITIGATION_SLS
#define ASM_RET "ret; int3\n\t"
#else
#define ASM_RET "ret\n\t"
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5ec887d065ce..b01d49862497 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -637,8 +637,8 @@ static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
/*
* The compiler is supposed to EMIT an INT3 after every unconditional
* JMP instruction due to AMD BTC. However, if the compiler is too old
- * or SLS isn't enabled, we still need an INT3 after indirect JMPs
- * even on Intel.
+ * or MITIGATION_SLS isn't enabled, we still need an INT3 after
+ * indirect JMPs even on Intel.
*/
if (op == JMP32_INSN_OPCODE && i < insn->length)
bytes[i++] = INT3_INSN_OPCODE;
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 93bc52d4a472..70139d9d2e01 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -307,7 +307,8 @@ union ftrace_op_code_union {
} __attribute__((packed));
};

-#define RET_SIZE (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
+#define RET_SIZE \
+ (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_MITIGATION_SLS))

static unsigned long
create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index ef732f323926..96a63c4386a9 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -469,7 +469,7 @@ static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip)
emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
} else {
EMIT2(0xFF, 0xE0 + reg); /* jmp *%\reg */
- if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) || IS_ENABLED(CONFIG_SLS))
+ if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) || IS_ENABLED(CONFIG_MITIGATION_SLS))
EMIT1(0xCC); /* int3 */
}

@@ -484,7 +484,7 @@ static void emit_return(u8 **pprog, u8 *ip)
emit_jump(&prog, x86_return_thunk, ip);
} else {
EMIT1(0xC3); /* ret */
- if (IS_ENABLED(CONFIG_SLS))
+ if (IS_ENABLED(CONFIG_MITIGATION_SLS))
EMIT1(0xCC); /* int3 */
}

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index d6e157938b5f..0d5461276179 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -264,7 +264,7 @@ endif
objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
objtool-args-$(CONFIG_MITIGATION_RETPOLINE) += --retpoline
objtool-args-$(CONFIG_RETHUNK) += --rethunk
-objtool-args-$(CONFIG_SLS) += --sls
+objtool-args-$(CONFIG_MITIGATION_SLS) += --sls
objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval
objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call
objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess
--
2.34.1