From 22c3d58079688b697f36d670616e463cbb14d058 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:53 +0100
Subject: objtool: Convert ANNOTATE_NOENDBR to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.042140333@infradead.org
---
 include/linux/objtool_types.h | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'include/linux/objtool_types.h')

diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 453a4f4ef39d..4884f8cf8429 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -54,4 +54,9 @@ struct unwind_hint {
 #define UNWIND_HINT_TYPE_SAVE		6
 #define UNWIND_HINT_TYPE_RESTORE	7
 
+/*
+ * Annotate types
+ */
+#define ANNOTYPE_NOENDBR		1
+
 #endif /* _LINUX_OBJTOOL_TYPES_H */
-- 
cgit v1.3


From bf5febebd99fddfc6226a94e937d38a8d470b24e Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:54 +0100
Subject: objtool: Convert ANNOTATE_RETPOLINE_SAFE to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.145275669@infradead.org
---
 arch/x86/include/asm/nospec-branch.h | 13 ++-------
 include/linux/objtool_types.h        |  1 +
 tools/include/linux/objtool_types.h  |  1 +
 tools/objtool/check.c                | 52 +++++++++++++-----------------------
 4 files changed, 22 insertions(+), 45 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 96b410b1d4e8..50340a125953 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -184,12 +184,7 @@
  * objtool the subsequent indirect jump/call is vouched safe for retpoline
  * builds.
  */
-.macro ANNOTATE_RETPOLINE_SAFE
-.Lhere_\@:
-	.pushsection .discard.retpoline_safe
-	.long .Lhere_\@
-	.popsection
-.endm
+#define ANNOTATE_RETPOLINE_SAFE	ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
 
 /*
  * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
@@ -350,11 +345,7 @@
 
 #else /* __ASSEMBLY__ */
 
-#define ANNOTATE_RETPOLINE_SAFE					\
-	"999:\n\t"						\
-	".pushsection .discard.retpoline_safe\n\t"		\
-	".long 999b\n\t"					\
-	".popsection\n\t"
+#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
 
 typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
 extern retpoline_thunk_t __x86_indirect_thunk_array[];
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 4884f8cf8429..1b348361ad1d 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
  * Annotate types
  */
 #define ANNOTYPE_NOENDBR		1
+#define ANNOTYPE_RETPOLINE_SAFE		2
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 4884f8cf8429..1b348361ad1d 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
  * Annotate types
  */
 #define ANNOTYPE_NOENDBR		1
+#define ANNOTYPE_RETPOLINE_SAFE		2
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index a74ff26860f7..c5b52309b80d 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2373,12 +2373,12 @@ static int read_unwind_hints(struct objtool_file *file)
 	return 0;
 }
 
-static int read_annotate(struct objtool_file *file, void (*func)(int type, struct instruction *insn))
+static int read_annotate(struct objtool_file *file, int (*func)(int type, struct instruction *insn))
 {
 	struct section *sec;
 	struct instruction *insn;
 	struct reloc *reloc;
-	int type;
+	int type, ret;
 
 	sec = find_section_by_name(file->elf, ".discard.annotate_insn");
 	if (!sec)
@@ -2406,53 +2406,37 @@ static int read_annotate(struct objtool_file *file, void (*func)(int type, struc
 			return -1;
 		}
 
-		func(type, insn);
+		ret = func(type, insn);
+		if (ret < 0)
+			return ret;
 	}
 
 	return 0;
 }
 
-static void __annotate_noendbr(int type, struct instruction *insn)
+static int __annotate_noendbr(int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_NOENDBR)
-		return;
+		return 0;
 
 	insn->noendbr = 1;
+	return 0;
 }
 
-static int read_retpoline_hints(struct objtool_file *file)
+static int __annotate_retpoline_safe(int type, struct instruction *insn)
 {
-	struct section *rsec;
-	struct instruction *insn;
-	struct reloc *reloc;
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
-	if (!rsec)
+	if (type != ANNOTYPE_RETPOLINE_SAFE)
 		return 0;
 
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.retpoline_safe entry");
-			return -1;
-		}
-
-		if (insn->type != INSN_JUMP_DYNAMIC &&
-		    insn->type != INSN_CALL_DYNAMIC &&
-		    insn->type != INSN_RETURN &&
-		    insn->type != INSN_NOP) {
-			WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
-			return -1;
-		}
-
-		insn->retpoline_safe = true;
+	if (insn->type != INSN_JUMP_DYNAMIC &&
+	    insn->type != INSN_CALL_DYNAMIC &&
+	    insn->type != INSN_RETURN &&
+	    insn->type != INSN_NOP) {
+		WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
+		return -1;
 	}
 
+	insn->retpoline_safe = true;
 	return 0;
 }
 
@@ -2742,7 +2726,7 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
-	ret = read_retpoline_hints(file);
+	ret = read_annotate(file, __annotate_retpoline_safe);
 	if (ret)
 		return ret;
 
-- 
cgit v1.3


From 317f2a64618c528539d17fe6957a64106087fbd2 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:55 +0100
Subject: objtool: Convert instrumentation_{begin,end}() to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.245980207@infradead.org
---
 include/linux/instrumentation.h     | 11 ++++-----
 include/linux/objtool.h             | 12 ++++++---
 include/linux/objtool_types.h       |  2 ++
 tools/include/linux/objtool_types.h |  2 ++
 tools/objtool/check.c               | 49 ++++++++-----------------------------
 5 files changed, 28 insertions(+), 48 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h
index bc7babe91b2e..c8f866cf02d8 100644
--- a/include/linux/instrumentation.h
+++ b/include/linux/instrumentation.h
@@ -4,14 +4,14 @@
 
 #ifdef CONFIG_NOINSTR_VALIDATION
 
+#include <linux/objtool.h>
 #include <linux/stringify.h>
 
 /* Begin/end of an instrumentation safe region */
 #define __instrumentation_begin(c) ({					\
 	asm volatile(__stringify(c) ": nop\n\t"				\
-		     ".pushsection .discard.instr_begin\n\t"		\
-		     ".long " __stringify(c) "b - .\n\t"		\
-		     ".popsection\n\t" : : "i" (c));			\
+		     __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_BEGIN)\
+		     : : "i" (c));					\
 })
 #define instrumentation_begin() __instrumentation_begin(__COUNTER__)
 
@@ -48,9 +48,8 @@
  */
 #define __instrumentation_end(c) ({					\
 	asm volatile(__stringify(c) ": nop\n\t"				\
-		     ".pushsection .discard.instr_end\n\t"		\
-		     ".long " __stringify(c) "b - .\n\t"		\
-		     ".popsection\n\t" : : "i" (c));			\
+		     __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_END)	\
+		     : : "i" (c));					\
 })
 #define instrumentation_end() __instrumentation_end(__COUNTER__)
 #else /* !CONFIG_NOINSTR_VALIDATION */
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index b5e9c0ab4048..89c67cd7eebe 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -51,13 +51,18 @@
 	".long 998b\n\t"						\
 	".popsection\n\t"
 
-#define ASM_ANNOTATE(type)						\
-	"911:\n\t"							\
+#define __ASM_BREF(label)	label ## b
+
+#define __ASM_ANNOTATE(label, type)					\
 	".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t"	\
-	".long 911b - .\n\t"						\
+	".long " __stringify(label) " - .\n\t"			\
 	".long " __stringify(type) "\n\t"				\
 	".popsection\n\t"
 
+#define ASM_ANNOTATE(type)						\
+	"911:\n\t"						\
+	__ASM_ANNOTATE(911b, type)
+
 #define ANNOTATE_NOENDBR	ASM_ANNOTATE(ANNOTYPE_NOENDBR)
 
 #else /* __ASSEMBLY__ */
@@ -161,6 +166,7 @@
 #define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"
 #define STACK_FRAME_NON_STANDARD(func)
 #define STACK_FRAME_NON_STANDARD_FP(func)
+#define __ASM_ANNOTATE(label, type)
 #define ASM_ANNOTATE(type)
 #define ANNOTATE_NOENDBR
 #define ASM_REACHABLE
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 1b348361ad1d..d4d68dd36f7a 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -59,5 +59,7 @@ struct unwind_hint {
  */
 #define ANNOTYPE_NOENDBR		1
 #define ANNOTYPE_RETPOLINE_SAFE		2
+#define ANNOTYPE_INSTR_BEGIN		3
+#define ANNOTYPE_INSTR_END		4
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 1b348361ad1d..d4d68dd36f7a 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -59,5 +59,7 @@ struct unwind_hint {
  */
 #define ANNOTYPE_NOENDBR		1
 #define ANNOTYPE_RETPOLINE_SAFE		2
+#define ANNOTYPE_INSTR_BEGIN		3
+#define ANNOTYPE_INSTR_END		4
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index c5b52309b80d..8e39c7f484d8 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2440,48 +2440,19 @@ static int __annotate_retpoline_safe(int type, struct instruction *insn)
 	return 0;
 }
 
-static int read_instr_hints(struct objtool_file *file)
+static int __annotate_instr(int type, struct instruction *insn)
 {
-	struct section *rsec;
-	struct instruction *insn;
-	struct reloc *reloc;
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.instr_end");
-	if (!rsec)
-		return 0;
-
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.instr_end entry");
-			return -1;
-		}
+	switch (type) {
+	case ANNOTYPE_INSTR_BEGIN:
+		insn->instr++;
+		break;
 
+	case ANNOTYPE_INSTR_END:
 		insn->instr--;
-	}
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
-	if (!rsec)
-		return 0;
-
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.instr_begin entry");
-			return -1;
-		}
+		break;
 
-		insn->instr++;
+	default:
+		break;
 	}
 
 	return 0;
@@ -2730,7 +2701,7 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
-	ret = read_instr_hints(file);
+	ret = read_annotate(file, __annotate_instr);
 	if (ret)
 		return ret;
 
-- 
cgit v1.3


From 18aa6118a1689b4d73c5ebbd917ae3f20c9c0db1 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:56 +0100
Subject: objtool: Convert VALIDATE_UNRET_BEGIN to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.358508242@infradead.org
---
 include/linux/objtool.h             |  9 +++------
 include/linux/objtool_types.h       |  1 +
 tools/include/linux/objtool_types.h |  1 +
 tools/objtool/check.c               | 28 +++++-----------------------
 4 files changed, 10 insertions(+), 29 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 89c67cd7eebe..5f0bf8052dc7 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -130,15 +130,12 @@
  * NOTE: The macro must be used at the beginning of a global symbol, otherwise
  * it will be ignored.
  */
-.macro VALIDATE_UNRET_BEGIN
 #if defined(CONFIG_NOINSTR_VALIDATION) && \
 	(defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))
-.Lhere_\@:
-	.pushsection .discard.validate_unret
-	.long	.Lhere_\@ - .
-	.popsection
+#define VALIDATE_UNRET_BEGIN	ANNOTATE type=ANNOTYPE_UNRET_BEGIN
+#else
+#define VALIDATE_UNRET_BEGIN
 #endif
-.endm
 
 .macro REACHABLE
 .Lhere_\@:
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index d4d68dd36f7a..16236a56364b 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -61,5 +61,6 @@ struct unwind_hint {
 #define ANNOTYPE_RETPOLINE_SAFE		2
 #define ANNOTYPE_INSTR_BEGIN		3
 #define ANNOTYPE_INSTR_END		4
+#define ANNOTYPE_UNRET_BEGIN		5
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index d4d68dd36f7a..16236a56364b 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -61,5 +61,6 @@ struct unwind_hint {
 #define ANNOTYPE_RETPOLINE_SAFE		2
 #define ANNOTYPE_INSTR_BEGIN		3
 #define ANNOTYPE_INSTR_END		4
+#define ANNOTYPE_UNRET_BEGIN		5
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 8e39c7f484d8..2a703748cad1 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2458,33 +2458,15 @@ static int __annotate_instr(int type, struct instruction *insn)
 	return 0;
 }
 
-static int read_validate_unret_hints(struct objtool_file *file)
+static int __annotate_unret(int type, struct instruction *insn)
 {
-	struct section *rsec;
-	struct instruction *insn;
-	struct reloc *reloc;
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
-	if (!rsec)
+	if (type != ANNOTYPE_UNRET_BEGIN)
 		return 0;
 
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.instr_end entry");
-			return -1;
-		}
-		insn->unret = 1;
-	}
-
+	insn->unret = 1;
 	return 0;
-}
 
+}
 
 static int read_intra_function_calls(struct objtool_file *file)
 {
@@ -2705,7 +2687,7 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
-	ret = read_validate_unret_hints(file);
+	ret = read_annotate(file, __annotate_unret);
 	if (ret)
 		return ret;
 
-- 
cgit v1.3


From f0cd57c35a75f152d3b31b9be3f7f413b96a6d3f Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:57 +0100
Subject: objtool: Convert ANNOTATE_IGNORE_ALTERNATIVE to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.465691316@infradead.org
---
 arch/x86/include/asm/alternative.h  | 14 +++---------
 include/linux/objtool_types.h       |  1 +
 tools/include/linux/objtool_types.h |  1 +
 tools/objtool/check.c               | 45 +++++++++----------------------------
 4 files changed, 15 insertions(+), 46 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index dc03a647776d..595695f85f80 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -4,6 +4,7 @@
 
 #include <linux/types.h>
 #include <linux/stringify.h>
+#include <linux/objtool.h>
 #include <asm/asm.h>
 
 #define ALT_FLAGS_SHIFT		16
@@ -58,11 +59,7 @@
  * objtool annotation to ignore the alternatives and only consider the original
  * instruction(s).
  */
-#define ANNOTATE_IGNORE_ALTERNATIVE				\
-	"999:\n\t"						\
-	".pushsection .discard.ignore_alts\n\t"			\
-	".long 999b\n\t"					\
-	".popsection\n\t"
+#define ANNOTATE_IGNORE_ALTERNATIVE	ASM_ANNOTATE(ANNOTYPE_IGNORE_ALTS)
 
 /*
  * The patching flags are part of the upper bits of the @ft_flags parameter when
@@ -314,12 +311,7 @@ void nop_func(void);
  * objtool annotation to ignore the alternatives and only consider the original
  * instruction(s).
  */
-.macro ANNOTATE_IGNORE_ALTERNATIVE
-	.Lannotate_\@:
-	.pushsection .discard.ignore_alts
-	.long .Lannotate_\@
-	.popsection
-.endm
+#define ANNOTATE_IGNORE_ALTERNATIVE ANNOTATE type=ANNOTYPE_IGNORE_ALTS
 
 /*
  * Issue one struct alt_instr descriptor entry (need to put it into
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 16236a56364b..eab15dbe1cb7 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -62,5 +62,6 @@ struct unwind_hint {
 #define ANNOTYPE_INSTR_BEGIN		3
 #define ANNOTYPE_INSTR_END		4
 #define ANNOTYPE_UNRET_BEGIN		5
+#define ANNOTYPE_IGNORE_ALTS		6
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 16236a56364b..eab15dbe1cb7 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -62,5 +62,6 @@ struct unwind_hint {
 #define ANNOTYPE_INSTR_BEGIN		3
 #define ANNOTYPE_INSTR_END		4
 #define ANNOTYPE_UNRET_BEGIN		5
+#define ANNOTYPE_IGNORE_ALTS		6
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 2a703748cad1..ba2cb9b69399 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1309,40 +1309,6 @@ static void add_uaccess_safe(struct objtool_file *file)
 	}
 }
 
-/*
- * FIXME: For now, just ignore any alternatives which add retpolines.  This is
- * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline.
- * But it at least allows objtool to understand the control flow *around* the
- * retpoline.
- */
-static int add_ignore_alternatives(struct objtool_file *file)
-{
-	struct section *rsec;
-	struct reloc *reloc;
-	struct instruction *insn;
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
-	if (!rsec)
-		return 0;
-
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.ignore_alts entry");
-			return -1;
-		}
-
-		insn->ignore_alts = true;
-	}
-
-	return 0;
-}
-
 /*
  * Symbols that replace INSN_CALL_DYNAMIC, every (tail) call to such a symbol
  * will be added to the .retpoline_sites section.
@@ -2414,6 +2380,15 @@ static int read_annotate(struct objtool_file *file, int (*func)(int type, struct
 	return 0;
 }
 
+static int __annotate_ignore_alts(int type, struct instruction *insn)
+{
+	if (type != ANNOTYPE_IGNORE_ALTS)
+		return 0;
+
+	insn->ignore_alts = true;
+	return 0;
+}
+
 static int __annotate_noendbr(int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_NOENDBR)
@@ -2626,7 +2601,7 @@ static int decode_sections(struct objtool_file *file)
 	add_ignores(file);
 	add_uaccess_safe(file);
 
-	ret = add_ignore_alternatives(file);
+	ret = read_annotate(file, __annotate_ignore_alts);
 	if (ret)
 		return ret;
 
-- 
cgit v1.3


From 112765ca1cb9353e71b4f5af4e6e6c4a69c28d99 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:38:58 +0100
Subject: objtool: Convert ANNOTATE_INTRA_FUNCTION_CALL to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.584892071@infradead.org
---
 include/linux/objtool.h             | 16 +++----
 include/linux/objtool_types.h       |  1 +
 tools/include/linux/objtool_types.h |  1 +
 tools/objtool/check.c               | 96 +++++++++++++++----------------------
 4 files changed, 47 insertions(+), 67 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 5f0bf8052dc7..42287c1e32ce 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -67,16 +67,6 @@
 
 #else /* __ASSEMBLY__ */
 
-/*
- * This macro indicates that the following intra-function call is valid.
- * Any non-annotated intra-function call will cause objtool to issue a warning.
- */
-#define ANNOTATE_INTRA_FUNCTION_CALL				\
-	999:							\
-	.pushsection .discard.intra_function_calls;		\
-	.long 999b;						\
-	.popsection;
-
 /*
  * In asm, there are two kinds of code: normal C-type callable functions and
  * the rest.  The normal callable functions can be called by other code, and
@@ -154,6 +144,12 @@
 
 #define ANNOTATE_NOENDBR	ANNOTATE type=ANNOTYPE_NOENDBR
 
+/*
+ * This macro indicates that the following intra-function call is valid.
+ * Any non-annotated intra-function call will cause objtool to issue a warning.
+ */
+#define ANNOTATE_INTRA_FUNCTION_CALL ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL
+
 #endif /* __ASSEMBLY__ */
 
 #else /* !CONFIG_OBJTOOL */
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index eab15dbe1cb7..23d6fb6d04c7 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -63,5 +63,6 @@ struct unwind_hint {
 #define ANNOTYPE_INSTR_END		4
 #define ANNOTYPE_UNRET_BEGIN		5
 #define ANNOTYPE_IGNORE_ALTS		6
+#define ANNOTYPE_INTRA_FUNCTION_CALL	7
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index eab15dbe1cb7..23d6fb6d04c7 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -63,5 +63,6 @@ struct unwind_hint {
 #define ANNOTYPE_INSTR_END		4
 #define ANNOTYPE_UNRET_BEGIN		5
 #define ANNOTYPE_IGNORE_ALTS		6
+#define ANNOTYPE_INTRA_FUNCTION_CALL	7
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ba2cb9b69399..2222fe710832 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2339,7 +2339,8 @@ static int read_unwind_hints(struct objtool_file *file)
 	return 0;
 }
 
-static int read_annotate(struct objtool_file *file, int (*func)(int type, struct instruction *insn))
+static int read_annotate(struct objtool_file *file,
+			 int (*func)(struct objtool_file *file, int type, struct instruction *insn))
 {
 	struct section *sec;
 	struct instruction *insn;
@@ -2372,7 +2373,7 @@ static int read_annotate(struct objtool_file *file, int (*func)(int type, struct
 			return -1;
 		}
 
-		ret = func(type, insn);
+		ret = func(file, type, insn);
 		if (ret < 0)
 			return ret;
 	}
@@ -2380,7 +2381,7 @@ static int read_annotate(struct objtool_file *file, int (*func)(int type, struct
 	return 0;
 }
 
-static int __annotate_ignore_alts(int type, struct instruction *insn)
+static int __annotate_ignore_alts(struct objtool_file *file, int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_IGNORE_ALTS)
 		return 0;
@@ -2389,7 +2390,7 @@ static int __annotate_ignore_alts(int type, struct instruction *insn)
 	return 0;
 }
 
-static int __annotate_noendbr(int type, struct instruction *insn)
+static int __annotate_noendbr(struct objtool_file *file, int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_NOENDBR)
 		return 0;
@@ -2398,7 +2399,37 @@ static int __annotate_noendbr(int type, struct instruction *insn)
 	return 0;
 }
 
-static int __annotate_retpoline_safe(int type, struct instruction *insn)
+static int __annotate_ifc(struct objtool_file *file, int type, struct instruction *insn)
+{
+	unsigned long dest_off;
+
+	if (type != ANNOTYPE_INTRA_FUNCTION_CALL)
+		return 0;
+
+	if (insn->type != INSN_CALL) {
+		WARN_INSN(insn, "intra_function_call not a direct call");
+		return -1;
+	}
+
+	/*
+	 * Treat intra-function CALLs as JMPs, but with a stack_op.
+	 * See add_call_destinations(), which strips stack_ops from
+	 * normal CALLs.
+	 */
+	insn->type = INSN_JUMP_UNCONDITIONAL;
+
+	dest_off = arch_jump_destination(insn);
+	insn->jump_dest = find_insn(file, insn->sec, dest_off);
+	if (!insn->jump_dest) {
+		WARN_INSN(insn, "can't find call dest at %s+0x%lx",
+			  insn->sec->name, dest_off);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int __annotate_retpoline_safe(struct objtool_file *file, int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_RETPOLINE_SAFE)
 		return 0;
@@ -2415,7 +2446,7 @@ static int __annotate_retpoline_safe(int type, struct instruction *insn)
 	return 0;
 }
 
-static int __annotate_instr(int type, struct instruction *insn)
+static int __annotate_instr(struct objtool_file *file, int type, struct instruction *insn)
 {
 	switch (type) {
 	case ANNOTYPE_INSTR_BEGIN:
@@ -2433,7 +2464,7 @@ static int __annotate_instr(int type, struct instruction *insn)
 	return 0;
 }
 
-static int __annotate_unret(int type, struct instruction *insn)
+static int __annotate_unret(struct objtool_file *file, int type, struct instruction *insn)
 {
 	if (type != ANNOTYPE_UNRET_BEGIN)
 		return 0;
@@ -2443,55 +2474,6 @@ static int __annotate_unret(int type, struct instruction *insn)
 
 }
 
-static int read_intra_function_calls(struct objtool_file *file)
-{
-	struct instruction *insn;
-	struct section *rsec;
-	struct reloc *reloc;
-
-	rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
-	if (!rsec)
-		return 0;
-
-	for_each_reloc(rsec, reloc) {
-		unsigned long dest_off;
-
-		if (reloc->sym->type != STT_SECTION) {
-			WARN("unexpected relocation symbol type in %s",
-			     rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-		if (!insn) {
-			WARN("bad .discard.intra_function_call entry");
-			return -1;
-		}
-
-		if (insn->type != INSN_CALL) {
-			WARN_INSN(insn, "intra_function_call not a direct call");
-			return -1;
-		}
-
-		/*
-		 * Treat intra-function CALLs as JMPs, but with a stack_op.
-		 * See add_call_destinations(), which strips stack_ops from
-		 * normal CALLs.
-		 */
-		insn->type = INSN_JUMP_UNCONDITIONAL;
-
-		dest_off = arch_jump_destination(insn);
-		insn->jump_dest = find_insn(file, insn->sec, dest_off);
-		if (!insn->jump_dest) {
-			WARN_INSN(insn, "can't find call dest at %s+0x%lx",
-				  insn->sec->name, dest_off);
-			return -1;
-		}
-	}
-
-	return 0;
-}
-
 /*
  * Return true if name matches an instrumentation function, where calls to that
  * function from noinstr code can safely be removed, but compilers won't do so.
@@ -2630,7 +2612,7 @@ static int decode_sections(struct objtool_file *file)
 	 * Must be before add_call_destination(); it changes INSN_CALL to
 	 * INSN_JUMP.
 	 */
-	ret = read_intra_function_calls(file);
+	ret = read_annotate(file, __annotate_ifc);
 	if (ret)
 		return ret;
 
-- 
cgit v1.3


From e7a174fb43d24adca066e82d1cb9fdee092d48d1 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 28 Nov 2024 10:39:05 +0100
Subject: objtool: Convert {.UN}REACHABLE to ANNOTATE

Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094312.353431347@infradead.org
---
 arch/loongarch/include/asm/bug.h    |  2 +-
 arch/x86/entry/entry_64.S           |  4 +-
 arch/x86/include/asm/bug.h          |  2 +-
 arch/x86/include/asm/irq_stack.h    |  2 +-
 include/linux/objtool.h             | 18 ++++----
 include/linux/objtool_types.h       |  1 +
 tools/include/linux/objtool_types.h |  1 +
 tools/objtool/check.c               | 82 ++++++++++---------------------------
 8 files changed, 36 insertions(+), 76 deletions(-)

(limited to 'include/linux/objtool_types.h')

diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h
index 561ac1bf79e2..e25404a93882 100644
--- a/arch/loongarch/include/asm/bug.h
+++ b/arch/loongarch/include/asm/bug.h
@@ -45,7 +45,7 @@
 #define __WARN_FLAGS(flags)					\
 do {								\
 	instrumentation_begin();				\
-	__BUG_FLAGS(BUGFLAG_WARNING|(flags), ASM_REACHABLE);	\
+	__BUG_FLAGS(BUGFLAG_WARNING|(flags), ANNOTATE_REACHABLE);\
 	instrumentation_end();					\
 } while (0)
 
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1b5be07f8669..9248660ad409 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -311,7 +311,7 @@ SYM_CODE_END(xen_error_entry)
 	call	\cfunc
 
 	/* For some configurations \cfunc ends up being a noreturn. */
-	REACHABLE
+	ANNOTATE_REACHABLE
 
 	jmp	error_return
 .endm
@@ -532,7 +532,7 @@ SYM_CODE_START(\asmsym)
 	call	\cfunc
 
 	/* For some configurations \cfunc ends up being a noreturn. */
-	REACHABLE
+	ANNOTATE_REACHABLE
 
 	jmp	paranoid_exit
 
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 806649c7f23d..dd8fb1779d97 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -92,7 +92,7 @@ do {								\
 do {								\
 	__auto_type __flags = BUGFLAG_WARNING|(flags);		\
 	instrumentation_begin();				\
-	_BUG_FLAGS(ASM_UD2, __flags, ASM_REACHABLE);		\
+	_BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE);	\
 	instrumentation_end();					\
 } while (0)
 
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h
index b71ad173f877..5455747ed918 100644
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -101,7 +101,7 @@
 
 #define ASM_CALL_ARG0							\
 	"call %c[__func]				\n"		\
-	ASM_REACHABLE
+	ANNOTATE_REACHABLE
 
 #define ASM_CALL_ARG1							\
 	"movq	%[arg1], %%rdi				\n"		\
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index fd487d466bb2..e3cb13583fba 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -111,14 +111,6 @@
 #endif
 .endm
 
-
-.macro REACHABLE
-.Lhere_\@:
-	.pushsection .discard.reachable
-	.long	.Lhere_\@
-	.popsection
-.endm
-
 .macro ANNOTATE type:req
 .Lhere_\@:
 	.pushsection .discard.annotate_insn,"M",@progbits,8
@@ -138,14 +130,11 @@
 #define STACK_FRAME_NON_STANDARD_FP(func)
 #define __ASM_ANNOTATE(label, type)
 #define ASM_ANNOTATE(type)
-#define ASM_REACHABLE
 #else
 .macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
 .endm
 .macro STACK_FRAME_NON_STANDARD func:req
 .endm
-.macro REACHABLE
-.endm
 .macro ANNOTATE type:req
 .endm
 #endif
@@ -187,6 +176,12 @@
  * it will be ignored.
  */
 #define ANNOTATE_UNRET_BEGIN		ASM_ANNOTATE(ANNOTYPE_UNRET_BEGIN)
+/*
+ * This should be used directly after an instruction that is considered
+ * terminating, like a noreturn CALL or UD2 when we know they are not -- eg
+ * WARN using UD2.
+ */
+#define ANNOTATE_REACHABLE		ASM_ANNOTATE(ANNOTYPE_REACHABLE)
 
 #else
 #define ANNOTATE_NOENDBR		ANNOTATE type=ANNOTYPE_NOENDBR
@@ -196,6 +191,7 @@
 #define ANNOTATE_IGNORE_ALTERNATIVE	ANNOTATE type=ANNOTYPE_IGNORE_ALTS
 #define ANNOTATE_INTRA_FUNCTION_CALL	ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL
 #define ANNOTATE_UNRET_BEGIN		ANNOTATE type=ANNOTYPE_UNRET_BEGIN
+#define ANNOTATE_REACHABLE		ANNOTATE type=ANNOTYPE_REACHABLE
 #endif
 
 #if defined(CONFIG_NOINSTR_VALIDATION) && \
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 23d6fb6d04c7..df5d9fa84dba 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -64,5 +64,6 @@ struct unwind_hint {
 #define ANNOTYPE_UNRET_BEGIN		5
 #define ANNOTYPE_IGNORE_ALTS		6
 #define ANNOTYPE_INTRA_FUNCTION_CALL	7
+#define ANNOTYPE_REACHABLE		8
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 23d6fb6d04c7..df5d9fa84dba 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -64,5 +64,6 @@ struct unwind_hint {
 #define ANNOTYPE_UNRET_BEGIN		5
 #define ANNOTYPE_IGNORE_ALTS		6
 #define ANNOTYPE_INTRA_FUNCTION_CALL	7
+#define ANNOTYPE_REACHABLE		8
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 798cff5bffc4..27d0c4153582 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -627,56 +627,6 @@ static struct instruction *find_last_insn(struct objtool_file *file,
 	return insn;
 }
 
-/*
- * Mark "ud2" instructions and manually annotated dead ends.
- */
-static int add_dead_ends(struct objtool_file *file)
-{
-	struct section *rsec;
-	struct reloc *reloc;
-	struct instruction *insn;
-	uint64_t offset;
-
-	/*
-	 * UD2 defaults to being a dead-end, allow them to be annotated for
-	 * non-fatal, eg WARN.
-	 */
-	rsec = find_section_by_name(file->elf, ".rela.discard.reachable");
-	if (!rsec)
-		return 0;
-
-	for_each_reloc(rsec, reloc) {
-		if (reloc->sym->type == STT_SECTION) {
-			offset = reloc_addend(reloc);
-		} else if (reloc->sym->local_label) {
-			offset = reloc->sym->offset;
-		} else {
-			WARN("unexpected relocation symbol type in %s", rsec->name);
-			return -1;
-		}
-
-		insn = find_insn(file, reloc->sym->sec, offset);
-		if (insn)
-			insn = prev_insn_same_sec(file, insn);
-		else if (offset == reloc->sym->sec->sh.sh_size) {
-			insn = find_last_insn(file, reloc->sym->sec);
-			if (!insn) {
-				WARN("can't find reachable insn at %s+0x%" PRIx64,
-				     reloc->sym->sec->name, offset);
-				return -1;
-			}
-		} else {
-			WARN("can't find reachable insn at %s+0x%" PRIx64,
-			     reloc->sym->sec->name, offset);
-			return -1;
-		}
-
-		insn->dead_end = false;
-	}
-
-	return 0;
-}
-
 static int create_static_call_sections(struct objtool_file *file)
 {
 	struct static_call_site *site;
@@ -2306,6 +2256,7 @@ static int read_annotate(struct objtool_file *file,
 	struct section *sec;
 	struct instruction *insn;
 	struct reloc *reloc;
+	uint64_t offset;
 	int type, ret;
 
 	sec = find_section_by_name(file->elf, ".discard.annotate_insn");
@@ -2327,8 +2278,19 @@ static int read_annotate(struct objtool_file *file,
 	for_each_reloc(sec->rsec, reloc) {
 		type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4);
 
-		insn = find_insn(file, reloc->sym->sec,
-				 reloc->sym->offset + reloc_addend(reloc));
+		offset = reloc->sym->offset + reloc_addend(reloc);
+		insn = find_insn(file, reloc->sym->sec, offset);
+
+		/*
+		 * Reachable annotations are 'funneh' and act on the previous instruction :/
+		 */
+		if (type == ANNOTYPE_REACHABLE) {
+			if (insn)
+				insn = prev_insn_same_sec(file, insn);
+			else if (offset == reloc->sym->sec->sh.sh_size)
+				insn = find_last_insn(file, reloc->sym->sec);
+		}
+
 		if (!insn) {
 			WARN("bad .discard.annotate_insn entry: %d of type %d", reloc_idx(reloc), type);
 			return -1;
@@ -2420,6 +2382,10 @@ static int __annotate_late(struct objtool_file *file, int type, struct instructi
 		insn->unret = 1;
 		break;
 
+	case ANNOTYPE_REACHABLE:
+		insn->dead_end = false;
+		break;
+
 	default:
 		break;
 	}
@@ -2566,14 +2532,6 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
-	/*
-	 * Must be after add_call_destinations() such that it can override
-	 * dead_end_function() marks.
-	 */
-	ret = add_dead_ends(file);
-	if (ret)
-		return ret;
-
 	ret = add_jump_table_alts(file);
 	if (ret)
 		return ret;
@@ -2582,6 +2540,10 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
+	/*
+	 * Must be after add_call_destinations() such that it can override
+	 * dead_end_function() marks.
+	 */
 	ret = read_annotate(file, __annotate_late);
 	if (ret)
 		return ret;
-- 
cgit v1.3