x86/bugs: Rename CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE

Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.

[ mingo: Converted a few more uses in comments/messages as well. ]

Suggested-by: Josh Poimboeuf <[e-mail]>
Signed-off-by: Breno Leitao <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>
Reviewed-by: Ariel Miculas <[e-mail]>
Acked-by: Josh Poimboeuf <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/admin-guide/hw-vuln/spectre.rst

···
    -mindirect-branch=thunk-extern -mindirect-branch-register options.
    If the kernel is compiled with a Clang compiler, the compiler needs
    to support -mretpoline-external-thunk option.  The kernel config
-   CONFIG_RETPOLINE needs to be turned on, and the CPU needs to run with
-   the latest updated microcode.
+   CONFIG_MITIGATION_RETPOLINE needs to be turned on, and the CPU needs
+   to run with the latest updated microcode.
 
    On Intel Skylake-era systems the mitigation covers most, but not all,
    cases. See :ref:`[3] <spec_ref3>` for more details.
···
 		Selecting 'on' will, and 'auto' may, choose a
 		mitigation method at run time according to the
 		CPU, the available microcode, the setting of the
-		CONFIG_RETPOLINE configuration option, and the
-		compiler with which the kernel was built.
+		CONFIG_MITIGATION_RETPOLINE configuration option,
+		and the compiler with which the kernel was built.
 
 		Selecting 'on' will also enable the mitigation
 		against user space to user space task attacks.

Documentation/admin-guide/kernel-parameters.txt

···
 			Selecting 'on' will, and 'auto' may, choose a
 			mitigation method at run time according to the
 			CPU, the available microcode, the setting of the
-			CONFIG_RETPOLINE configuration option, and the
-			compiler with which the kernel was built.
+			CONFIG_MITIGATION_RETPOLINE configuration option,
+			and the compiler with which the kernel was built.
 
 			Selecting 'on' will also enable the mitigation
 			against user space to user space task attacks.

arch/x86/Kconfig

···
 
 config FINEIBT
 	def_bool y
-	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
+	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
 	select CALL_PADDING
 
 config HAVE_CALL_THUNKS
···
 
 	  See Documentation/arch/x86/pti.rst for more details.
 
-config RETPOLINE
+config MITIGATION_RETPOLINE
 	bool "Avoid speculative indirect branches in kernel"
 	select OBJTOOL if HAVE_OBJTOOL
 	default y
···
 
 config RETHUNK
 	bool "Enable return-thunks"
-	depends on RETPOLINE && CC_HAS_RETURN_THUNK
+	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
 	select OBJTOOL if HAVE_OBJTOOL
 	default y if X86_64
 	help

arch/x86/Makefile

···
 KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
 
 # Avoid indirect branches in kernel to deal with Spectre
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
   KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
   # Additionally, avoid generating expensive indirect jumps which
   # are subject to retpolines for small number of switch cases.
···
 
 archprepare: checkbin
 checkbin:
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
 ifeq ($(RETPOLINE_CFLAGS),)
 	@echo "You are building kernel with non-retpoline compiler." >&2
 	@echo "Please update your compiler." >&2

arch/x86/entry/vdso/Makefile

···
        -fno-omit-frame-pointer -foptimize-sibling-calls \
        -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
 
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
   CFL += $(RETPOLINE_VDSO_CFLAGS)
 endif
···
 KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
 KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
 
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
 ifneq ($(RETPOLINE_VDSO_CFLAGS),)
   KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
 endif

arch/x86/include/asm/disabled-features.h

···
 # define DISABLE_PTI		(1 << (X86_FEATURE_PTI & 31))
 #endif
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 # define DISABLE_RETPOLINE	0
 #else
 # define DISABLE_RETPOLINE	((1 << (X86_FEATURE_RETPOLINE & 31)) | \

arch/x86/include/asm/linkage.h

···
 
 #if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
 #define RET	jmp __x86_return_thunk
-#else /* CONFIG_RETPOLINE */
+#else /* CONFIG_MITIGATION_RETPOLINE */
 #ifdef CONFIG_SLS
 #define RET	ret; int3
 #else
 #define RET	ret
 #endif
-#endif /* CONFIG_RETPOLINE */
+#endif /* CONFIG_MITIGATION_RETPOLINE */
 
 #else /* __ASSEMBLY__ */
 
 #if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
 #define ASM_RET	"jmp __x86_return_thunk\n\t"
-#else /* CONFIG_RETPOLINE */
+#else /* CONFIG_MITIGATION_RETPOLINE */
 #ifdef CONFIG_SLS
 #define ASM_RET	"ret; int3\n\t"
 #else
 #define ASM_RET	"ret\n\t"
 #endif
-#endif /* CONFIG_RETPOLINE */
+#endif /* CONFIG_MITIGATION_RETPOLINE */
 
 #endif /* __ASSEMBLY__ */
 

arch/x86/include/asm/nospec-branch.h

···
  * instruction irrespective of kCFI.
  */
 .macro JMP_NOSPEC reg:req
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	__CS_PREFIX \reg
 	jmp	__x86_indirect_thunk_\reg
 #else
···
 .endm
 
 .macro CALL_NOSPEC reg:req
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	__CS_PREFIX \reg
 	call	__x86_indirect_thunk_\reg
 #else
···
 
 #endif /* CONFIG_MITIGATION_CALL_DEPTH_TRACKING */
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 
 #define GEN(reg) \
 	extern retpoline_thunk_t __x86_indirect_thunk_ ## reg;
···
 
 /*
  * Inline asm uses the %V modifier which is only in newer GCC
- * which is ensured when CONFIG_RETPOLINE is defined.
+ * which is ensured when CONFIG_MITIGATION_RETPOLINE is defined.
  */
 # define CALL_NOSPEC						\
 	ALTERNATIVE_2(						\

arch/x86/kernel/alternative.c

···
 	return insn->opcode.bytes[0] == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80;
 }
 
-#if defined(CONFIG_RETPOLINE) && defined(CONFIG_OBJTOOL)
+#if defined(CONFIG_MITIGATION_RETPOLINE) && defined(CONFIG_OBJTOOL)
 
 /*
  * CALL/JMP *%\reg
···
 void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
 #endif /* CONFIG_RETHUNK */
 
-#else /* !CONFIG_RETPOLINE || !CONFIG_OBJTOOL */
+#else /* !CONFIG_MITIGATION_RETPOLINE || !CONFIG_OBJTOOL */
 
 void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { }
 void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
 
-#endif /* CONFIG_RETPOLINE && CONFIG_OBJTOOL */
+#endif /* CONFIG_MITIGATION_RETPOLINE && CONFIG_OBJTOOL */
 
 #ifdef CONFIG_X86_KERNEL_IBT
 

arch/x86/kernel/cpu/bugs.c

···
 static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init =
 	SPECTRE_V2_USER_NONE;
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 static bool spectre_v2_bad_module;
 
 bool retpoline_module_ok(bool has_retpoline)
···
 	     cmd == SPECTRE_V2_CMD_RETPOLINE_GENERIC ||
 	     cmd == SPECTRE_V2_CMD_EIBRS_LFENCE ||
 	     cmd == SPECTRE_V2_CMD_EIBRS_RETPOLINE) &&
-	    !IS_ENABLED(CONFIG_RETPOLINE)) {
+	    !IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)) {
 		pr_err("%s selected but not compiled in. Switching to AUTO select\n",
 		       mitigation_options[i].option);
 		return SPECTRE_V2_CMD_AUTO;
···
 
 static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void)
 {
-	if (!IS_ENABLED(CONFIG_RETPOLINE)) {
+	if (!IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)) {
 		pr_err("Kernel not compiled with retpoline; no mitigation available!");
 		return SPECTRE_V2_NONE;
 	}

arch/x86/kernel/ftrace.c

···
 	} __attribute__((packed));
 };
 
-#define RET_SIZE		(IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
+#define RET_SIZE	(IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
 
 static unsigned long
 create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)

arch/x86/kernel/kprobes/opt.c

···
 		 * However, the kernel built with retpolines or IBT has jump
 		 * tables disabled so the check can be skipped altogether.
 		 */
-		if (!IS_ENABLED(CONFIG_RETPOLINE) &&
+		if (!IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) &&
 		    !IS_ENABLED(CONFIG_X86_KERNEL_IBT) &&
 		    insn_is_indirect_jump(&insn))
 			return 0;

arch/x86/kernel/vmlinux.lds.S

···
 		LOCK_TEXT
 		KPROBES_TEXT
 		SOFTIRQENTRY_TEXT
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 		*(.text..__x86.indirect_thunk)
 		*(.text..__x86.return_thunk)
 #endif
···
 	}
 #endif
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	/*
 	 * List of instructions that call/jmp/jcc to retpoline thunks
 	 * __x86_indirect_thunk_*(). These instructions can be patched along

arch/x86/kvm/mmu/mmu.c

···
 static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu,
 						  struct kvm_mmu *mmu)
 {
-	if (IS_ENABLED(CONFIG_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3)
+	if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && mmu->get_guest_pgd == get_guest_cr3)
 		return kvm_read_cr3(vcpu);
 
 	return mmu->get_guest_pgd(vcpu);

arch/x86/kvm/mmu/mmu_internal.h

···
 	if (!prefetch)
 		vcpu->stat.pf_taken++;
 
-	if (IS_ENABLED(CONFIG_RETPOLINE) && fault.is_tdp)
+	if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && fault.is_tdp)
 		r = kvm_tdp_page_fault(vcpu, &fault);
 	else
 		r = vcpu->arch.mmu->page_fault(vcpu, &fault);

arch/x86/kvm/svm/svm.c

···
 	if (!svm_check_exit_valid(exit_code))
 		return svm_handle_invalid_exit(vcpu, exit_code);
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	if (exit_code == SVM_EXIT_MSR)
 		return msr_interception(vcpu);
 	else if (exit_code == SVM_EXIT_VINTR)

arch/x86/kvm/svm/vmenter.S

···
 7:	vmload %_ASM_AX
 8:
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
 	FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE
 #endif
···
 	/* Pop @svm to RDI, guest registers have been saved already. */
 	pop %_ASM_DI
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
 	FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE
 #endif

arch/x86/kvm/vmx/vmx.c

···
 
 	if (exit_reason.basic >= kvm_vmx_max_exit_handlers)
 		goto unexpected_vmexit;
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	if (exit_reason.basic == EXIT_REASON_MSR_WRITE)
 		return kvm_emulate_wrmsr(vcpu);
 	else if (exit_reason.basic == EXIT_REASON_PREEMPTION_TIMER)

arch/x86/lib/Makefile

···
 lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
 lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
 lib-$(CONFIG_FUNCTION_ERROR_INJECTION)	+= error-inject.o
-lib-$(CONFIG_RETPOLINE) += retpoline.o
+lib-$(CONFIG_MITIGATION_RETPOLINE) += retpoline.o
 
 obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
 obj-y += iomem.o

arch/x86/net/bpf_jit_comp.c

···
 			emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
 	} else {
 		EMIT2(0xFF, 0xE0 + reg);	/* jmp *%\reg */
-		if (IS_ENABLED(CONFIG_RETPOLINE) || IS_ENABLED(CONFIG_SLS))
+		if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) || IS_ENABLED(CONFIG_SLS))
 			EMIT1(0xCC);		/* int3 */
 	}
 

arch/x86/net/bpf_jit_comp32.c

···
 	u8 *prog = *pprog;
 	int cnt = 0;
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	EMIT1_off32(0xE9, (u8 *)__x86_indirect_thunk_edx - (ip + 5));
 #else
 	EMIT2(0xFF, 0xE2);

arch/x86/purgatory/Makefile

···
 PURGATORY_CFLAGS_REMOVE		+= -fstack-protector-strong
 endif
 
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
 PURGATORY_CFLAGS_REMOVE		+= $(RETPOLINE_CFLAGS)
 endif
 

include/linux/compiler-gcc.h

···
 	(typeof(ptr)) (__ptr + (off));					\
 })
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 #define __noretpoline __attribute__((__indirect_branch__("keep")))
 #endif
 

include/linux/indirect_call_wrapper.h

···
 #ifndef _LINUX_INDIRECT_CALL_WRAPPER_H
 #define _LINUX_INDIRECT_CALL_WRAPPER_H
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 
 /*
  * INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin

include/linux/module.h

···
 static inline void module_bug_cleanup(struct module *mod) {}
 #endif	/* CONFIG_GENERIC_BUG */
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 extern bool retpoline_module_ok(bool has_retpoline);
 #else
 static inline bool retpoline_module_ok(bool has_retpoline)

include/net/netfilter/nf_tables_core.h

···
 extern const struct nft_set_type nft_set_pipapo_type;
 extern const struct nft_set_type nft_set_pipapo_avx2_type;
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 bool nft_rhash_lookup(const struct net *net, const struct nft_set *set,
 		      const u32 *key, const struct nft_set_ext **ext);
 bool nft_rbtree_lookup(const struct net *net, const struct nft_set *set,

include/net/tc_wrapper.h

···
 
 #include <net/pkt_cls.h>
 
-#if IS_ENABLED(CONFIG_RETPOLINE)
+#if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)
 
 #include <linux/cpufeature.h>
 #include <linux/static_key.h>

kernel/trace/ring_buffer.c

···
 	u64 ts;
 
 	/* Skip retpolines :-( */
-	if (IS_ENABLED(CONFIG_RETPOLINE) && likely(buffer->clock == trace_clock_local))
+	if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && likely(buffer->clock == trace_clock_local))
 		ts = trace_clock_local();
 	else
 		ts = buffer->clock();

net/netfilter/Makefile

···
 endif
 
 ifdef CONFIG_NFT_CT
-ifdef CONFIG_RETPOLINE
+ifdef CONFIG_MITIGATION_RETPOLINE
 nf_tables-objs += nft_ct_fast.o
 endif
 endif

net/netfilter/nf_tables_core.c

···
 #include <net/netfilter/nf_log.h>
 #include <net/netfilter/nft_meta.h>
 
-#if defined(CONFIG_RETPOLINE) && defined(CONFIG_X86)
+#if defined(CONFIG_MITIGATION_RETPOLINE) && defined(CONFIG_X86)
 
 static struct static_key_false nf_tables_skip_direct_calls;
 
···
 			       struct nft_regs *regs,
 			       struct nft_pktinfo *pkt)
 {
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 	unsigned long e;
 
 	if (nf_skip_indirect_calls())
···
 	X(e, nft_objref_map_eval);
 #undef  X
 indirect_call:
-#endif /* CONFIG_RETPOLINE */
+#endif /* CONFIG_MITIGATION_RETPOLINE */
 	expr->ops->eval(expr, regs, pkt);
 }
 

net/netfilter/nft_ct.c

···
 	return false;
 }
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 static const struct nft_expr_ops nft_ct_get_fast_ops = {
 	.type		= &nft_ct_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_ct)),
···
 		return ERR_PTR(-EINVAL);
 
 	if (tb[NFTA_CT_DREG]) {
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 		u32 k = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
 
 		switch (k) {

net/netfilter/nft_lookup.c

···
 	struct nft_set_binding		binding;
 };
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 bool nft_set_do_lookup(const struct net *net, const struct nft_set *set,
 		       const u32 *key, const struct nft_set_ext **ext)
 {

net/sched/sch_api.c

···
 	.exit = psched_net_exit,
 };
 
-#if IS_ENABLED(CONFIG_RETPOLINE)
+#if IS_ENABLED(CONFIG_MITIGATION_RETPOLINE)
 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper);
 #endif
 

scripts/Makefile.lib

···
 objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT)		+= --mnop
 endif
 objtool-args-$(CONFIG_UNWINDER_ORC)			+= --orc
-objtool-args-$(CONFIG_RETPOLINE)			+= --retpoline
+objtool-args-$(CONFIG_MITIGATION_RETPOLINE)		+= --retpoline
 objtool-args-$(CONFIG_RETHUNK)				+= --rethunk
 objtool-args-$(CONFIG_SLS)				+= --sls
 objtool-args-$(CONFIG_STACK_VALIDATION)			+= --stackval

scripts/generate_rust_target.rs

···
             "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
         );
         let mut features = "-3dnow,-3dnowa,-mmx,+soft-float".to_string();
-        if cfg.has("RETPOLINE") {
+        if cfg.has("MITIGATION_RETPOLINE") {
             features += ",+retpoline-external-thunk";
         }
         ts.push("features", features);

scripts/mod/modpost.c

···
 
 	buf_printf(b,
 		   "\n"
-		   "#ifdef CONFIG_RETPOLINE\n"
+		   "#ifdef CONFIG_MITIGATION_RETPOLINE\n"
 		   "MODULE_INFO(retpoline, \"Y\");\n"
 		   "#endif\n");
 

tools/arch/x86/include/asm/disabled-features.h

···
 # define DISABLE_PTI		(1 << (X86_FEATURE_PTI & 31))
 #endif
 
-#ifdef CONFIG_RETPOLINE
+#ifdef CONFIG_MITIGATION_RETPOLINE
 # define DISABLE_RETPOLINE	0
 #else
 # define DISABLE_RETPOLINE	((1 << (X86_FEATURE_RETPOLINE & 31)) | \

tools/objtool/arch/x86/special.c

···
  *    TODO: Once we have DWARF CFI and smarter instruction decoding logic,
  *    ensure the same register is used in the mov and jump instructions.
  *
- *    NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ *    NOTE: MITIGATION_RETPOLINE made it harder still to decode dynamic jumps.
  */
 struct reloc *arch_find_switch_table(struct objtool_file *file,
 				    struct instruction *insn)

tools/objtool/check.c

···
 			} else
 				continue;
 		} else {
-			WARN_INSN(insn, "indirect %s found in RETPOLINE build",
+			WARN_INSN(insn, "indirect %s found in MITIGATION_RETPOLINE build",
 				  insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
 		}