From 071c44e4278156f18a6a56958617223b6bffa6ab Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Mon, 13 Feb 2023 23:05:58 -0800
Subject: sched/idle: Mark arch_cpu_idle_dead() __noreturn

Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead()
return"), in Xen, when a previously offlined CPU was brought back
online, it unexpectedly resumed execution where it left off in the
middle of the idle loop.

There were some hacks to make that work, but the behavior was surprising
as do_idle() doesn't expect an offlined CPU to return from the dead (in
arch_cpu_idle_dead()).

Now that Xen has been fixed, and the arch-specific implementations of
arch_cpu_idle_dead() also don't return, give it a __noreturn attribute.

This will cause the compiler to complain if an arch-specific
implementation might return.  It also improves code generation for both
caller and callee.

Also fixes the following warning:

  vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index f937be1afe65..37c36dc1d868 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -202,6 +202,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"__reiserfs_panic",
 		"__stack_chk_fail",
 		"__ubsan_handle_builtin_unreachable",
+		"arch_cpu_idle_dead",
 		"cpu_bringup_and_idle",
 		"cpu_startup_entry",
 		"do_exit",
-- 
cgit v1.2.3


From f7515d9fe8fc4b80754cd4d98a5fcaee84adeebb Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 1 Mar 2023 07:13:07 -0800
Subject: objtool: Add objtool_types.h

Reduce the amount of header sync churn by splitting the shared objtool.h
types into a new file.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/dec622720851210ceafa12d4f4c5f9e73c832152.1677683419.git.jpoimboe@kernel.org
---
 tools/objtool/check.c       | 2 +-
 tools/objtool/orc_dump.c    | 2 +-
 tools/objtool/orc_gen.c     | 2 +-
 tools/objtool/sync-check.sh | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 37c36dc1d868..efc2baa02883 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -17,7 +17,7 @@
 #include <objtool/warn.h>
 #include <objtool/endianness.h>
 
-#include <linux/objtool.h>
+#include <linux/objtool_types.h>
 #include <linux/hashtable.h>
 #include <linux/kernel.h>
 #include <linux/static_call_types.h>
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index 2d8ebdcd1db3..9f6c528c26f2 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -4,7 +4,7 @@
  */
 
 #include <unistd.h>
-#include <linux/objtool.h>
+#include <linux/objtool_types.h>
 #include <asm/orc_types.h>
 #include <objtool/objtool.h>
 #include <objtool/warn.h>
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 57a4527d5988..f49630a21e0f 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -6,7 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <linux/objtool.h>
+#include <linux/objtool_types.h>
 #include <asm/orc_types.h>
 
 #include <objtool/check.h>
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index 105a291ff8e7..81d120d05442 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -6,7 +6,7 @@ if [ -z "$SRCARCH" ]; then
 	exit 1
 fi
 
-FILES="include/linux/objtool.h"
+FILES="include/linux/objtool_types.h"
 
 if [ "$SRCARCH" = "x86" ]; then
 FILES="$FILES
-- 
cgit v1.2.3


From f902cfdd46aedd2afb3e8033223312dbf5fbb675 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 1 Mar 2023 07:13:10 -0800
Subject: x86,objtool: Introduce ORC_TYPE_*

Unwind hints and ORC entry types are two distinct things.  Separate them
out more explicitly.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/cc879d38fff8a43f8f7beb2fd56e35a5a384d7cd.1677683419.git.jpoimboe@kernel.org
---
 tools/objtool/orc_dump.c |  7 +++----
 tools/objtool/orc_gen.c  | 19 +++++++++++++++++--
 2 files changed, 20 insertions(+), 6 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index 9f6c528c26f2..97ecbb8b9034 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -4,7 +4,6 @@
  */
 
 #include <unistd.h>
-#include <linux/objtool_types.h>
 #include <asm/orc_types.h>
 #include <objtool/objtool.h>
 #include <objtool/warn.h>
@@ -39,11 +38,11 @@ static const char *reg_name(unsigned int reg)
 static const char *orc_type_name(unsigned int type)
 {
 	switch (type) {
-	case UNWIND_HINT_TYPE_CALL:
+	case ORC_TYPE_CALL:
 		return "call";
-	case UNWIND_HINT_TYPE_REGS:
+	case ORC_TYPE_REGS:
 		return "regs";
-	case UNWIND_HINT_TYPE_REGS_PARTIAL:
+	case ORC_TYPE_REGS_PARTIAL:
 		return "regs (partial)";
 	default:
 		return "?";
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index f49630a21e0f..e85bbb996f6c 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -26,6 +26,22 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		return 0;
 	}
 
+	switch (cfi->type) {
+	case UNWIND_HINT_TYPE_CALL:
+		orc->type = ORC_TYPE_CALL;
+		break;
+	case UNWIND_HINT_TYPE_REGS:
+		orc->type = ORC_TYPE_REGS;
+		break;
+	case UNWIND_HINT_TYPE_REGS_PARTIAL:
+		orc->type = ORC_TYPE_REGS_PARTIAL;
+		break;
+	default:
+		WARN_FUNC("unknown unwind hint type %d",
+			  insn->sec, insn->offset, cfi->type);
+		return -1;
+	}
+
 	orc->end = cfi->end;
 	orc->signal = cfi->signal;
 
@@ -83,7 +99,6 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 
 	orc->sp_offset = cfi->cfa.offset;
 	orc->bp_offset = bp->offset;
-	orc->type = cfi->type;
 
 	return 0;
 }
@@ -151,7 +166,7 @@ int orc_create(struct objtool_file *file)
 	struct orc_entry null = {
 		.sp_reg  = ORC_REG_UNDEFINED,
 		.bp_reg  = ORC_REG_UNDEFINED,
-		.type    = UNWIND_HINT_TYPE_CALL,
+		.type    = ORC_TYPE_CALL,
 	};
 
 	/* Build a deduplicated list of ORC entries: */
-- 
cgit v1.2.3


From 4708ea14bef314fc901857eefd65678236a9f2d9 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 1 Mar 2023 07:13:11 -0800
Subject: x86,objtool: Separate unret validation from unwind hints

The ENTRY unwind hint type is serving double duty as both an empty
unwind hint and an unret validation annotation.

Unret validation is unrelated to unwinding. Separate it out into its own
annotation.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ff7448d492ea21b86d8a90264b105fbd0d751077.1677683419.git.jpoimboe@kernel.org
---
 tools/objtool/check.c                 | 65 ++++++++++++++++++++++++-----------
 tools/objtool/include/objtool/check.h |  4 +--
 2 files changed, 47 insertions(+), 22 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index efc2baa02883..10be80b3fe67 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2307,16 +2307,9 @@ static int read_unwind_hints(struct objtool_file *file)
 					WARN_FUNC("UNWIND_HINT_IRET_REGS without ENDBR",
 						  insn->sec, insn->offset);
 				}
-
-				insn->entry = 1;
 			}
 		}
 
-		if (hint->type == UNWIND_HINT_TYPE_ENTRY) {
-			hint->type = UNWIND_HINT_TYPE_CALL;
-			insn->entry = 1;
-		}
-
 		if (hint->type == UNWIND_HINT_TYPE_FUNC) {
 			insn->cfi = &func_cfi;
 			continue;
@@ -2449,6 +2442,34 @@ static int read_instr_hints(struct objtool_file *file)
 	return 0;
 }
 
+static int read_validate_unret_hints(struct objtool_file *file)
+{
+	struct section *sec;
+	struct instruction *insn;
+	struct reloc *reloc;
+
+	sec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
+	if (!sec)
+		return 0;
+
+	list_for_each_entry(reloc, &sec->reloc_list, list) {
+		if (reloc->sym->type != STT_SECTION) {
+			WARN("unexpected relocation symbol type in %s", sec->name);
+			return -1;
+		}
+
+		insn = find_insn(file, reloc->sym->sec, reloc->addend);
+		if (!insn) {
+			WARN("bad .discard.instr_end entry");
+			return -1;
+		}
+		insn->unret = 1;
+	}
+
+	return 0;
+}
+
+
 static int read_intra_function_calls(struct objtool_file *file)
 {
 	struct instruction *insn;
@@ -2667,6 +2688,10 @@ static int decode_sections(struct objtool_file *file)
 	if (ret)
 		return ret;
 
+	ret = read_validate_unret_hints(file);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
@@ -3863,10 +3888,10 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
 /*
  * Validate rethunk entry constraint: must untrain RET before the first RET.
  *
- * Follow every branch (intra-function) and ensure ANNOTATE_UNRET_END comes
+ * Follow every branch (intra-function) and ensure VALIDATE_UNRET_END comes
  * before an actual RET instruction.
  */
-static int validate_entry(struct objtool_file *file, struct instruction *insn)
+static int validate_unret(struct objtool_file *file, struct instruction *insn)
 {
 	struct instruction *next, *dest;
 	int ret, warnings = 0;
@@ -3874,10 +3899,10 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn)
 	for (;;) {
 		next = next_insn_to_validate(file, insn);
 
-		if (insn->visited & VISITED_ENTRY)
+		if (insn->visited & VISITED_UNRET)
 			return 0;
 
-		insn->visited |= VISITED_ENTRY;
+		insn->visited |= VISITED_UNRET;
 
 		if (!insn->ignore_alts && insn->alts) {
 			struct alternative *alt;
@@ -3887,7 +3912,7 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn)
 				if (alt->skip_orig)
 					skip_orig = true;
 
-				ret = validate_entry(file, alt->insn);
+				ret = validate_unret(file, alt->insn);
 				if (ret) {
 				        if (opts.backtrace)
 						BT_FUNC("(alt)", insn);
@@ -3915,7 +3940,7 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn)
 						  insn->sec, insn->offset);
 					return -1;
 				}
-				ret = validate_entry(file, insn->jump_dest);
+				ret = validate_unret(file, insn->jump_dest);
 				if (ret) {
 					if (opts.backtrace) {
 						BT_FUNC("(branch%s)", insn,
@@ -3940,7 +3965,7 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn)
 				return -1;
 			}
 
-			ret = validate_entry(file, dest);
+			ret = validate_unret(file, dest);
 			if (ret) {
 				if (opts.backtrace)
 					BT_FUNC("(call)", insn);
@@ -3976,19 +4001,19 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn)
 }
 
 /*
- * Validate that all branches starting at 'insn->entry' encounter UNRET_END
- * before RET.
+ * Validate that all branches starting at VALIDATE_UNRET_BEGIN encounter
+ * VALIDATE_UNRET_END before RET.
  */
-static int validate_unret(struct objtool_file *file)
+static int validate_unrets(struct objtool_file *file)
 {
 	struct instruction *insn;
 	int ret, warnings = 0;
 
 	for_each_insn(file, insn) {
-		if (!insn->entry)
+		if (!insn->unret)
 			continue;
 
-		ret = validate_entry(file, insn);
+		ret = validate_unret(file, insn);
 		if (ret < 0) {
 			WARN_FUNC("Failed UNRET validation", insn->sec, insn->offset);
 			return ret;
@@ -4607,7 +4632,7 @@ int check(struct objtool_file *file)
 		 * Must be after validate_branch() and friends, it plays
 		 * further games with insn->visited.
 		 */
-		ret = validate_unret(file);
+		ret = validate_unrets(file);
 		if (ret < 0)
 			return ret;
 		warnings += ret;
diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h
index 3e7c7004f7df..daa46f1f0965 100644
--- a/tools/objtool/include/objtool/check.h
+++ b/tools/objtool/include/objtool/check.h
@@ -61,7 +61,7 @@ struct instruction {
 	    restore		: 1,
 	    retpoline_safe	: 1,
 	    noendbr		: 1,
-	    entry		: 1,
+	    unret		: 1,
 	    visited		: 4,
 	    no_reloc		: 1;
 		/* 10 bit hole */
@@ -92,7 +92,7 @@ static inline struct symbol *insn_func(struct instruction *insn)
 #define VISITED_BRANCH		0x01
 #define VISITED_BRANCH_UACCESS	0x02
 #define VISITED_BRANCH_MASK	0x03
-#define VISITED_ENTRY		0x04
+#define VISITED_UNRET		0x04
 
 static inline bool is_static_jump(struct instruction *insn)
 {
-- 
cgit v1.2.3


From fb799447ae2974a07907906dff5bd4b9e47b7123 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 1 Mar 2023 07:13:12 -0800
Subject: x86,objtool: Split UNWIND_HINT_EMPTY in two

Mark reported that the ORC unwinder incorrectly marks an unwind as
reliable when the unwind terminates prematurely in the dark corners of
return_to_handler() due to lack of information about the next frame.

The problem is UNWIND_HINT_EMPTY is used in two different situations:

  1) The end of the kernel stack unwind before hitting user entry, boot
     code, or fork entry

  2) A blind spot in ORC coverage where the unwinder has to bail due to
     lack of information about the next frame

The ORC unwinder has no way to tell the difference between the two.
When it encounters an undefined stack state with 'end=1', it blindly
marks the stack reliable, which can break the livepatch consistency
model.

Fix it by splitting UNWIND_HINT_EMPTY into UNWIND_HINT_UNDEFINED and
UNWIND_HINT_END_OF_STACK.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/fd6212c8b450d3564b855e1cb48404d6277b4d9f.1677683419.git.jpoimboe@kernel.org
---
 tools/objtool/check.c    |  2 +-
 tools/objtool/orc_dump.c |  8 ++++++--
 tools/objtool/orc_gen.c  | 26 +++++++++++++-------------
 3 files changed, 20 insertions(+), 16 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 10be80b3fe67..cae6ac6ff246 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2243,6 +2243,7 @@ static void set_func_state(struct cfi_state *state)
 	memcpy(&state->regs, &initial_func_cfi.regs,
 	       CFI_NUM_REGS * sizeof(struct cfi_reg));
 	state->stack_size = initial_func_cfi.cfa.offset;
+	state->type = UNWIND_HINT_TYPE_CALL;
 }
 
 static int read_unwind_hints(struct objtool_file *file)
@@ -2327,7 +2328,6 @@ static int read_unwind_hints(struct objtool_file *file)
 		cfi.cfa.offset = bswap_if_needed(file->elf, hint->sp_offset);
 		cfi.type = hint->type;
 		cfi.signal = hint->signal;
-		cfi.end = hint->end;
 
 		insn->cfi = cfi_hash_find_or_add(&cfi);
 	}
diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index 97ecbb8b9034..0e183bb1c720 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -38,6 +38,10 @@ static const char *reg_name(unsigned int reg)
 static const char *orc_type_name(unsigned int type)
 {
 	switch (type) {
+	case ORC_TYPE_UNDEFINED:
+		return "(und)";
+	case ORC_TYPE_END_OF_STACK:
+		return "end";
 	case ORC_TYPE_CALL:
 		return "call";
 	case ORC_TYPE_REGS:
@@ -201,6 +205,7 @@ int orc_dump(const char *_objname)
 			printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
 		}
 
+		printf("type:%s", orc_type_name(orc[i].type));
 
 		printf(" sp:");
 
@@ -210,8 +215,7 @@ int orc_dump(const char *_objname)
 
 		print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset));
 
-		printf(" type:%s signal:%d end:%d\n",
-		       orc_type_name(orc[i].type), orc[i].signal, orc[i].end);
+		printf(" signal:%d\n", orc[i].signal);
 	}
 
 	elf_end(elf);
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e85bbb996f6c..b327f9ccfe73 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -21,12 +21,22 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 	memset(orc, 0, sizeof(*orc));
 
 	if (!cfi) {
-		orc->end = 0;
-		orc->sp_reg = ORC_REG_UNDEFINED;
+		/*
+		 * This is usually either unreachable nops/traps (which don't
+		 * trigger unreachable instruction warnings), or
+		 * STACK_FRAME_NON_STANDARD functions.
+		 */
+		orc->type = ORC_TYPE_UNDEFINED;
 		return 0;
 	}
 
 	switch (cfi->type) {
+	case UNWIND_HINT_TYPE_UNDEFINED:
+		orc->type = ORC_TYPE_UNDEFINED;
+		return 0;
+	case UNWIND_HINT_TYPE_END_OF_STACK:
+		orc->type = ORC_TYPE_END_OF_STACK;
+		return 0;
 	case UNWIND_HINT_TYPE_CALL:
 		orc->type = ORC_TYPE_CALL;
 		break;
@@ -42,14 +52,8 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		return -1;
 	}
 
-	orc->end = cfi->end;
 	orc->signal = cfi->signal;
 
-	if (cfi->cfa.base == CFI_UNDEFINED) {
-		orc->sp_reg = ORC_REG_UNDEFINED;
-		return 0;
-	}
-
 	switch (cfi->cfa.base) {
 	case CFI_SP:
 		orc->sp_reg = ORC_REG_SP;
@@ -163,11 +167,7 @@ int orc_create(struct objtool_file *file)
 	struct orc_list_entry *entry;
 	struct list_head orc_list;
 
-	struct orc_entry null = {
-		.sp_reg  = ORC_REG_UNDEFINED,
-		.bp_reg  = ORC_REG_UNDEFINED,
-		.type    = ORC_TYPE_CALL,
-	};
+	struct orc_entry null = { .type = ORC_TYPE_UNDEFINED };
 
 	/* Build a deduplicated list of ORC entries: */
 	INIT_LIST_HEAD(&orc_list);
-- 
cgit v1.2.3


From e18398e80c73e3cc7d9c3d2e0bc06a4af8f4f1cb Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 10:29:01 -0700
Subject: Revert "objtool: Support addition to set CFA base"

Commit 468af56a7bba ("objtool: Support addition to set CFA base") was
added as a preparatory patch for arm64 support, but that support never
came.  It triggers a false positive warning on x86, so just revert it
for now.

Fixes the following warning:

  vmlinux.o: warning: objtool: cdce925_regmap_i2c_write+0xdb: stack state mismatch: cfa1=4+120 cfa2=5+40

Fixes: 468af56a7bba ("objtool: Support addition to set CFA base")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/oe-kbuild-all/202304080538.j5G6h1AB-lkp@intel.com/
---
 tools/objtool/check.c | 11 -----------
 1 file changed, 11 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index cae6ac6ff246..9440b07cd3b6 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3002,17 +3002,6 @@ static int update_cfi_state(struct instruction *insn,
 				break;
 			}
 
-			if (!cfi->drap && op->src.reg == CFI_SP &&
-			    op->dest.reg == CFI_BP && cfa->base == CFI_SP &&
-			    check_reg_frame_pos(&regs[CFI_BP], -cfa->offset + op->src.offset)) {
-
-				/* lea disp(%rsp), %rbp */
-				cfa->base = CFI_BP;
-				cfa->offset -= op->src.offset;
-				cfi->bp_scratch = false;
-				break;
-			}
-
 			if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
 
 				/* drap: lea disp(%rsp), %drap */
-- 
cgit v1.2.3


From 7f530fba1123edcad00d59e1a73019814935f0c1 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 10:29:35 -0700
Subject: objtool: Add stackleak instrumentation to uaccess safe list

If a function has a large stack frame, the stackleak plugin adds a call
to stackleak_track_stack() after the prologue.

This function may be called in uaccess-enabled code.  Add it to the
uaccess safe list.

Fixes the following warning:

  vmlinux.o: warning: objtool: kasan_report+0x12: call to stackleak_track_stack() with UACCESS enabled

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/42e9b487ef89e9b237fd5220ad1c7cf1a2ad7eb8.1681320562.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9440b07cd3b6..4c8ef8173a79 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1279,6 +1279,8 @@ static const char *uaccess_safe_builtin[] = {
 	"__ubsan_handle_type_mismatch_v1",
 	"__ubsan_handle_shift_out_of_bounds",
 	"__ubsan_handle_load_invalid_value",
+	/* STACKLEAK */
+	"stackleak_track_stack",
 	/* misc */
 	"csum_partial_copy_generic",
 	"copy_mc_fragile",
-- 
cgit v1.2.3


From 246b2c85487a7bc5f6a09098e18a96506b1b55df Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 12:03:17 -0700
Subject: objtool: Add WARN_INSN()

It's easier to use and also gives easy access to the instruction's
containing function, which is useful for printing that function's
symbol.  It will also be useful in the future for rate-limiting and
disassembly of warned functions.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/2eaa3155c90fba683d8723599f279c46025b75f3.1681325924.git.jpoimboe@kernel.org
---
 tools/objtool/check.c                | 171 +++++++++++++----------------------
 tools/objtool/include/objtool/warn.h |   5 +
 tools/objtool/orc_gen.c              |   9 +-
 3 files changed, 70 insertions(+), 115 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4c8ef8173a79..7d1a42b31f60 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1446,7 +1446,7 @@ static void annotate_call_site(struct objtool_file *file,
 
 	if (opts.mcount && sym->fentry) {
 		if (sibling)
-			WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
+			WARN_INSN(insn, "tail call to __fentry__ !?!?");
 		if (opts.mnop) {
 			if (reloc) {
 				reloc->type = R_NONE;
@@ -1648,9 +1648,8 @@ static int add_jump_destinations(struct objtool_file *file)
 				continue;
 			}
 
-			WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
-				  insn->sec, insn->offset, dest_sec->name,
-				  dest_off);
+			WARN_INSN(insn, "can't find jump dest instruction at %s+0x%lx",
+				  dest_sec->name, dest_off);
 			return -1;
 		}
 
@@ -1733,13 +1732,12 @@ static int add_call_destinations(struct objtool_file *file)
 				continue;
 
 			if (!insn_call_dest(insn)) {
-				WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset);
+				WARN_INSN(insn, "unannotated intra-function call");
 				return -1;
 			}
 
 			if (insn_func(insn) && insn_call_dest(insn)->type != STT_FUNC) {
-				WARN_FUNC("unsupported call to non-function",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "unsupported call to non-function");
 				return -1;
 			}
 
@@ -1747,10 +1745,8 @@ static int add_call_destinations(struct objtool_file *file)
 			dest_off = arch_dest_reloc_offset(reloc->addend);
 			dest = find_call_destination(reloc->sym->sec, dest_off);
 			if (!dest) {
-				WARN_FUNC("can't find call dest symbol at %s+0x%lx",
-					  insn->sec, insn->offset,
-					  reloc->sym->sec->name,
-					  dest_off);
+				WARN_INSN(insn, "can't find call dest symbol at %s+0x%lx",
+					  reloc->sym->sec->name, dest_off);
 				return -1;
 			}
 
@@ -1810,8 +1806,7 @@ static int handle_group_alt(struct objtool_file *file,
 	} else {
 		if (orig_alt_group->last_insn->offset + orig_alt_group->last_insn->len -
 		    orig_alt_group->first_insn->offset != special_alt->orig_len) {
-			WARN_FUNC("weirdly overlapping alternative! %ld != %d",
-				  orig_insn->sec, orig_insn->offset,
+			WARN_INSN(orig_insn, "weirdly overlapping alternative! %ld != %d",
 				  orig_alt_group->last_insn->offset +
 				  orig_alt_group->last_insn->len -
 				  orig_alt_group->first_insn->offset,
@@ -1880,8 +1875,7 @@ static int handle_group_alt(struct objtool_file *file,
 		if (alt_reloc && arch_pc_relative_reloc(alt_reloc) &&
 		    !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
 
-			WARN_FUNC("unsupported relocation in alternatives section",
-				  insn->sec, insn->offset);
+			WARN_INSN(insn, "unsupported relocation in alternatives section");
 			return -1;
 		}
 
@@ -1895,8 +1889,7 @@ static int handle_group_alt(struct objtool_file *file,
 		if (dest_off == special_alt->new_off + special_alt->new_len) {
 			insn->jump_dest = next_insn_same_sec(file, orig_alt_group->last_insn);
 			if (!insn->jump_dest) {
-				WARN_FUNC("can't find alternative jump destination",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "can't find alternative jump destination");
 				return -1;
 			}
 		}
@@ -1930,8 +1923,7 @@ static int handle_jump_alt(struct objtool_file *file,
 	if (orig_insn->type != INSN_JUMP_UNCONDITIONAL &&
 	    orig_insn->type != INSN_NOP) {
 
-		WARN_FUNC("unsupported instruction at jump label",
-			  orig_insn->sec, orig_insn->offset);
+		WARN_INSN(orig_insn, "unsupported instruction at jump label");
 		return -1;
 	}
 
@@ -2010,8 +2002,7 @@ static int add_special_section_alts(struct objtool_file *file)
 
 		if (special_alt->group) {
 			if (!special_alt->orig_len) {
-				WARN_FUNC("empty alternative entry",
-					  orig_insn->sec, orig_insn->offset);
+				WARN_INSN(orig_insn, "empty alternative entry");
 				continue;
 			}
 
@@ -2102,8 +2093,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
 	}
 
 	if (!prev_offset) {
-		WARN_FUNC("can't find switch jump table",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "can't find switch jump table");
 		return -1;
 	}
 
@@ -2307,8 +2297,7 @@ static int read_unwind_hints(struct objtool_file *file)
 
 			if (sym && sym->bind == STB_GLOBAL) {
 				if (opts.ibt && insn->type != INSN_ENDBR && !insn->noendbr) {
-					WARN_FUNC("UNWIND_HINT_IRET_REGS without ENDBR",
-						  insn->sec, insn->offset);
+					WARN_INSN(insn, "UNWIND_HINT_IRET_REGS without ENDBR");
 				}
 			}
 		}
@@ -2322,8 +2311,7 @@ static int read_unwind_hints(struct objtool_file *file)
 			cfi = *(insn->cfi);
 
 		if (arch_decode_hint_reg(hint->sp_reg, &cfi.cfa.base)) {
-			WARN_FUNC("unsupported unwind_hint sp base reg %d",
-				  insn->sec, insn->offset, hint->sp_reg);
+			WARN_INSN(insn, "unsupported unwind_hint sp base reg %d", hint->sp_reg);
 			return -1;
 		}
 
@@ -2386,8 +2374,7 @@ static int read_retpoline_hints(struct objtool_file *file)
 		    insn->type != INSN_CALL_DYNAMIC &&
 		    insn->type != INSN_RETURN &&
 		    insn->type != INSN_NOP) {
-			WARN_FUNC("retpoline_safe hint not an indirect jump/call/ret/nop",
-				  insn->sec, insn->offset);
+			WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
 			return -1;
 		}
 
@@ -2498,8 +2485,7 @@ static int read_intra_function_calls(struct objtool_file *file)
 		}
 
 		if (insn->type != INSN_CALL) {
-			WARN_FUNC("intra_function_call not a direct call",
-				  insn->sec, insn->offset);
+			WARN_INSN(insn, "intra_function_call not a direct call");
 			return -1;
 		}
 
@@ -2513,8 +2499,7 @@ static int read_intra_function_calls(struct objtool_file *file)
 		dest_off = arch_jump_destination(insn);
 		insn->jump_dest = find_insn(file, insn->sec, dest_off);
 		if (!insn->jump_dest) {
-			WARN_FUNC("can't find call dest at %s+0x%lx",
-				  insn->sec, insn->offset,
+			WARN_INSN(insn, "can't find call dest at %s+0x%lx",
 				  insn->sec->name, dest_off);
 			return -1;
 		}
@@ -2855,7 +2840,7 @@ static int update_cfi_state(struct instruction *insn,
 	/* stack operations don't make sense with an undefined CFA */
 	if (cfa->base == CFI_UNDEFINED) {
 		if (insn_func(insn)) {
-			WARN_FUNC("undefined stack state", insn->sec, insn->offset);
+			WARN_INSN(insn, "undefined stack state");
 			return -1;
 		}
 		return 0;
@@ -3038,8 +3023,7 @@ static int update_cfi_state(struct instruction *insn,
 			}
 
 			if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) {
-				WARN_FUNC("unsupported stack register modification",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "unsupported stack register modification");
 				return -1;
 			}
 
@@ -3049,8 +3033,7 @@ static int update_cfi_state(struct instruction *insn,
 			if (op->dest.reg != CFI_SP ||
 			    (cfi->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) ||
 			    (cfi->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) {
-				WARN_FUNC("unsupported stack pointer realignment",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "unsupported stack pointer realignment");
 				return -1;
 			}
 
@@ -3145,8 +3128,7 @@ static int update_cfi_state(struct instruction *insn,
 			break;
 
 		default:
-			WARN_FUNC("unknown stack-related instruction",
-				  insn->sec, insn->offset);
+			WARN_INSN(insn, "unknown stack-related instruction");
 			return -1;
 		}
 
@@ -3235,8 +3217,7 @@ static int update_cfi_state(struct instruction *insn,
 
 	case OP_DEST_MEM:
 		if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) {
-			WARN_FUNC("unknown stack-related memory operation",
-				  insn->sec, insn->offset);
+			WARN_INSN(insn, "unknown stack-related memory operation");
 			return -1;
 		}
 
@@ -3248,8 +3229,7 @@ static int update_cfi_state(struct instruction *insn,
 		break;
 
 	default:
-		WARN_FUNC("unknown stack-related instruction",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "unknown stack-related instruction");
 		return -1;
 	}
 
@@ -3288,8 +3268,7 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn
 			struct alt_group *orig_group = insn->alt_group->orig_group ?: insn->alt_group;
 			struct instruction *orig = orig_group->first_insn;
 			char *where = offstr(insn->sec, insn->offset);
-			WARN_FUNC("stack layout conflict in alternatives: %s",
-				  orig->sec, orig->offset, where);
+			WARN_INSN(orig, "stack layout conflict in alternatives: %s", where);
 			free(where);
 			return -1;
 		}
@@ -3316,8 +3295,7 @@ static int handle_insn_ops(struct instruction *insn,
 			if (!state->uaccess_stack) {
 				state->uaccess_stack = 1;
 			} else if (state->uaccess_stack >> 31) {
-				WARN_FUNC("PUSHF stack exhausted",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "PUSHF stack exhausted");
 				return 1;
 			}
 			state->uaccess_stack <<= 1;
@@ -3349,8 +3327,7 @@ static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
 
 	if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) {
 
-		WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
-			  insn->sec, insn->offset,
+		WARN_INSN(insn, "stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
 			  cfi1->cfa.base, cfi1->cfa.offset,
 			  cfi2->cfa.base, cfi2->cfa.offset);
 
@@ -3360,8 +3337,7 @@ static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
 				    sizeof(struct cfi_reg)))
 				continue;
 
-			WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
-				  insn->sec, insn->offset,
+			WARN_INSN(insn, "stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
 				  i, cfi1->regs[i].base, cfi1->regs[i].offset,
 				  i, cfi2->regs[i].base, cfi2->regs[i].offset);
 			break;
@@ -3369,15 +3345,14 @@ static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
 
 	} else if (cfi1->type != cfi2->type) {
 
-		WARN_FUNC("stack state mismatch: type1=%d type2=%d",
-			  insn->sec, insn->offset, cfi1->type, cfi2->type);
+		WARN_INSN(insn, "stack state mismatch: type1=%d type2=%d",
+			  cfi1->type, cfi2->type);
 
 	} else if (cfi1->drap != cfi2->drap ||
 		   (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) ||
 		   (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) {
 
-		WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
-			  insn->sec, insn->offset,
+		WARN_INSN(insn, "stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
 			  cfi1->drap, cfi1->drap_reg, cfi1->drap_offset,
 			  cfi2->drap, cfi2->drap_reg, cfi2->drap_offset);
 
@@ -3485,20 +3460,17 @@ static int validate_call(struct objtool_file *file,
 {
 	if (state->noinstr && state->instr <= 0 &&
 	    !noinstr_call_dest(file, insn, insn_call_dest(insn))) {
-		WARN_FUNC("call to %s() leaves .noinstr.text section",
-				insn->sec, insn->offset, call_dest_name(insn));
+		WARN_INSN(insn, "call to %s() leaves .noinstr.text section", call_dest_name(insn));
 		return 1;
 	}
 
 	if (state->uaccess && !func_uaccess_safe(insn_call_dest(insn))) {
-		WARN_FUNC("call to %s() with UACCESS enabled",
-				insn->sec, insn->offset, call_dest_name(insn));
+		WARN_INSN(insn, "call to %s() with UACCESS enabled", call_dest_name(insn));
 		return 1;
 	}
 
 	if (state->df) {
-		WARN_FUNC("call to %s() with DF set",
-				insn->sec, insn->offset, call_dest_name(insn));
+		WARN_INSN(insn, "call to %s() with DF set", call_dest_name(insn));
 		return 1;
 	}
 
@@ -3510,8 +3482,7 @@ static int validate_sibling_call(struct objtool_file *file,
 				 struct insn_state *state)
 {
 	if (insn_func(insn) && has_modified_stack_frame(insn, state)) {
-		WARN_FUNC("sibling call from callable instruction with modified stack frame",
-				insn->sec, insn->offset);
+		WARN_INSN(insn, "sibling call from callable instruction with modified stack frame");
 		return 1;
 	}
 
@@ -3521,38 +3492,32 @@ static int validate_sibling_call(struct objtool_file *file,
 static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
 {
 	if (state->noinstr && state->instr > 0) {
-		WARN_FUNC("return with instrumentation enabled",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "return with instrumentation enabled");
 		return 1;
 	}
 
 	if (state->uaccess && !func_uaccess_safe(func)) {
-		WARN_FUNC("return with UACCESS enabled",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "return with UACCESS enabled");
 		return 1;
 	}
 
 	if (!state->uaccess && func_uaccess_safe(func)) {
-		WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "return with UACCESS disabled from a UACCESS-safe function");
 		return 1;
 	}
 
 	if (state->df) {
-		WARN_FUNC("return with DF set",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "return with DF set");
 		return 1;
 	}
 
 	if (func && has_modified_stack_frame(insn, state)) {
-		WARN_FUNC("return with modified stack frame",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "return with modified stack frame");
 		return 1;
 	}
 
 	if (state->cfi.bp_scratch) {
-		WARN_FUNC("BP used as a scratch register",
-			  insn->sec, insn->offset);
+		WARN_INSN(insn, "BP used as a scratch register");
 		return 1;
 	}
 
@@ -3624,8 +3589,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 		}
 
 		if (func && insn->ignore) {
-			WARN_FUNC("BUG: why am I validating an ignored function?",
-				  sec, insn->offset);
+			WARN_INSN(insn, "BUG: why am I validating an ignored function?");
 			return 1;
 		}
 
@@ -3658,14 +3622,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 				}
 
 				if (!save_insn) {
-					WARN_FUNC("no corresponding CFI save for CFI restore",
-						  sec, insn->offset);
+					WARN_INSN(insn, "no corresponding CFI save for CFI restore");
 					return 1;
 				}
 
 				if (!save_insn->visited) {
-					WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
-						  sec, insn->offset);
+					WARN_INSN(insn, "objtool isn't smart enough to handle this CFI save/restore combo");
 					return 1;
 				}
 
@@ -3725,8 +3687,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 			if (opts.stackval && func && !is_fentry_call(insn) &&
 			    !has_valid_stack_frame(&state)) {
-				WARN_FUNC("call without frame pointer save/setup",
-					  sec, insn->offset);
+				WARN_INSN(insn, "call without frame pointer save/setup");
 				return 1;
 			}
 
@@ -3772,15 +3733,14 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 		case INSN_CONTEXT_SWITCH:
 			if (func && (!next_insn || !next_insn->hint)) {
-				WARN_FUNC("unsupported instruction in callable function",
-					  sec, insn->offset);
+				WARN_INSN(insn, "unsupported instruction in callable function");
 				return 1;
 			}
 			return 0;
 
 		case INSN_STAC:
 			if (state.uaccess) {
-				WARN_FUNC("recursive UACCESS enable", sec, insn->offset);
+				WARN_INSN(insn, "recursive UACCESS enable");
 				return 1;
 			}
 
@@ -3789,12 +3749,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 		case INSN_CLAC:
 			if (!state.uaccess && func) {
-				WARN_FUNC("redundant UACCESS disable", sec, insn->offset);
+				WARN_INSN(insn, "redundant UACCESS disable");
 				return 1;
 			}
 
 			if (func_uaccess_safe(func) && !state.uaccess_stack) {
-				WARN_FUNC("UACCESS-safe disables UACCESS", sec, insn->offset);
+				WARN_INSN(insn, "UACCESS-safe disables UACCESS");
 				return 1;
 			}
 
@@ -3803,7 +3763,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 		case INSN_STD:
 			if (state.df) {
-				WARN_FUNC("recursive STD", sec, insn->offset);
+				WARN_INSN(insn, "recursive STD");
 				return 1;
 			}
 
@@ -3812,7 +3772,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 
 		case INSN_CLD:
 			if (!state.df && func) {
-				WARN_FUNC("redundant CLD", sec, insn->offset);
+				WARN_INSN(insn, "redundant CLD");
 				return 1;
 			}
 
@@ -3920,15 +3880,14 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
 		case INSN_CALL_DYNAMIC:
 		case INSN_JUMP_DYNAMIC:
 		case INSN_JUMP_DYNAMIC_CONDITIONAL:
-			WARN_FUNC("early indirect call", insn->sec, insn->offset);
+			WARN_INSN(insn, "early indirect call");
 			return 1;
 
 		case INSN_JUMP_UNCONDITIONAL:
 		case INSN_JUMP_CONDITIONAL:
 			if (!is_sibling_call(insn)) {
 				if (!insn->jump_dest) {
-					WARN_FUNC("unresolved jump target after linking?!?",
-						  insn->sec, insn->offset);
+					WARN_INSN(insn, "unresolved jump target after linking?!?");
 					return -1;
 				}
 				ret = validate_unret(file, insn->jump_dest);
@@ -3969,7 +3928,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
 			return 0;
 
 		case INSN_RETURN:
-			WARN_FUNC("RET before UNTRAIN", insn->sec, insn->offset);
+			WARN_INSN(insn, "RET before UNTRAIN");
 			return 1;
 
 		case INSN_NOP:
@@ -3982,7 +3941,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
 		}
 
 		if (!next) {
-			WARN_FUNC("teh end!", insn->sec, insn->offset);
+			WARN_INSN(insn, "teh end!");
 			return -1;
 		}
 		insn = next;
@@ -4006,7 +3965,7 @@ static int validate_unrets(struct objtool_file *file)
 
 		ret = validate_unret(file, insn);
 		if (ret < 0) {
-			WARN_FUNC("Failed UNRET validation", insn->sec, insn->offset);
+			WARN_INSN(insn, "Failed UNRET validation");
 			return ret;
 		}
 		warnings += ret;
@@ -4034,13 +3993,11 @@ static int validate_retpoline(struct objtool_file *file)
 
 		if (insn->type == INSN_RETURN) {
 			if (opts.rethunk) {
-				WARN_FUNC("'naked' return found in RETHUNK build",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "'naked' return found in RETHUNK build");
 			} else
 				continue;
 		} else {
-			WARN_FUNC("indirect %s found in RETPOLINE build",
-				  insn->sec, insn->offset,
+			WARN_INSN(insn, "indirect %s found in RETPOLINE build",
 				  insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
 		}
 
@@ -4419,9 +4376,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
 		if (noendbr_range(file, dest))
 			continue;
 
-		WARN_FUNC("relocation to !ENDBR: %s",
-			  insn->sec, insn->offset,
-			  offstr(dest->sec, dest->offset));
+		WARN_INSN(insn, "relocation to !ENDBR: %s", offstr(dest->sec, dest->offset));
 
 		warnings++;
 	}
@@ -4523,16 +4478,14 @@ static int validate_sls(struct objtool_file *file)
 		switch (insn->type) {
 		case INSN_RETURN:
 			if (!next_insn || next_insn->type != INSN_TRAP) {
-				WARN_FUNC("missing int3 after ret",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "missing int3 after ret");
 				warnings++;
 			}
 
 			break;
 		case INSN_JUMP_DYNAMIC:
 			if (!next_insn || next_insn->type != INSN_TRAP) {
-				WARN_FUNC("missing int3 after indirect jump",
-					  insn->sec, insn->offset);
+				WARN_INSN(insn, "missing int3 after indirect jump");
 				warnings++;
 			}
 			break;
@@ -4555,7 +4508,7 @@ static int validate_reachable_instructions(struct objtool_file *file)
 		if (insn->visited || ignore_unreachable_insn(file, insn))
 			continue;
 
-		WARN_FUNC("unreachable instruction", insn->sec, insn->offset);
+		WARN_INSN(insn, "unreachable instruction");
 		return 1;
 	}
 
diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h
index a3e79ae75f2e..b1c920dc9516 100644
--- a/tools/objtool/include/objtool/warn.h
+++ b/tools/objtool/include/objtool/warn.h
@@ -53,6 +53,11 @@ static inline char *offstr(struct section *sec, unsigned long offset)
 	free(_str);					\
 })
 
+#define WARN_INSN(insn, format, ...)					\
+({									\
+	WARN_FUNC(format, insn->sec, insn->offset,  ##__VA_ARGS__);	\
+})
+
 #define BT_FUNC(format, insn, ...)			\
 ({							\
 	struct instruction *_insn = (insn);		\
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index b327f9ccfe73..48efd1e2f00d 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -47,8 +47,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->type = ORC_TYPE_REGS_PARTIAL;
 		break;
 	default:
-		WARN_FUNC("unknown unwind hint type %d",
-			  insn->sec, insn->offset, cfi->type);
+		WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
 		return -1;
 	}
 
@@ -80,8 +79,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->sp_reg = ORC_REG_DX;
 		break;
 	default:
-		WARN_FUNC("unknown CFA base reg %d",
-			  insn->sec, insn->offset, cfi->cfa.base);
+		WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
 		return -1;
 	}
 
@@ -96,8 +94,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->bp_reg = ORC_REG_BP;
 		break;
 	default:
-		WARN_FUNC("unknown BP base reg %d",
-			  insn->sec, insn->offset, bp->base);
+		WARN_INSN(insn, "unknown BP base reg %d", bp->base);
 		return -1;
 	}
 
-- 
cgit v1.2.3


From 9290e772baccecec324ae9f2e0b470f870c097de Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 12:03:19 -0700
Subject: objtool: Add symbol iteration helpers

Add [sec_]for_each_sym() and use them.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/59023e5886ab125aa30702e633be7732b1acaa7e.1681325924.git.jpoimboe@kernel.org
---
 tools/objtool/check.c               | 98 ++++++++++++++++---------------------
 tools/objtool/elf.c                 |  2 +-
 tools/objtool/include/objtool/elf.h |  9 ++++
 3 files changed, 51 insertions(+), 58 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 7d1a42b31f60..9de3972a9b1c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -470,7 +470,7 @@ static int decode_instructions(struct objtool_file *file)
 
 //		printf("%s: last chunk used: %d\n", sec->name, (int)idx);
 
-		list_for_each_entry(func, &sec->symbol_list, list) {
+		sec_for_each_sym(sec, func) {
 			if (func->type != STT_NOTYPE && func->type != STT_FUNC)
 				continue;
 
@@ -924,7 +924,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
 
 static int create_cfi_sections(struct objtool_file *file)
 {
-	struct section *sec, *s;
+	struct section *sec;
 	struct symbol *sym;
 	unsigned int *loc;
 	int idx;
@@ -937,19 +937,14 @@ static int create_cfi_sections(struct objtool_file *file)
 	}
 
 	idx = 0;
-	for_each_sec(file, s) {
-		if (!s->text)
+	for_each_sym(file, sym) {
+		if (sym->type != STT_FUNC)
 			continue;
 
-		list_for_each_entry(sym, &s->symbol_list, list) {
-			if (sym->type != STT_FUNC)
-				continue;
-
-			if (strncmp(sym->name, "__cfi_", 6))
-				continue;
+		if (strncmp(sym->name, "__cfi_", 6))
+			continue;
 
-			idx++;
-		}
+		idx++;
 	}
 
 	sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx);
@@ -957,28 +952,23 @@ static int create_cfi_sections(struct objtool_file *file)
 		return -1;
 
 	idx = 0;
-	for_each_sec(file, s) {
-		if (!s->text)
+	for_each_sym(file, sym) {
+		if (sym->type != STT_FUNC)
 			continue;
 
-		list_for_each_entry(sym, &s->symbol_list, list) {
-			if (sym->type != STT_FUNC)
-				continue;
-
-			if (strncmp(sym->name, "__cfi_", 6))
-				continue;
+		if (strncmp(sym->name, "__cfi_", 6))
+			continue;
 
-			loc = (unsigned int *)sec->data->d_buf + idx;
-			memset(loc, 0, sizeof(unsigned int));
+		loc = (unsigned int *)sec->data->d_buf + idx;
+		memset(loc, 0, sizeof(unsigned int));
 
-			if (elf_add_reloc_to_insn(file->elf, sec,
-						  idx * sizeof(unsigned int),
-						  R_X86_64_PC32,
-						  s, sym->offset))
-				return -1;
+		if (elf_add_reloc_to_insn(file->elf, sec,
+					  idx * sizeof(unsigned int),
+					  R_X86_64_PC32,
+					  sym->sec, sym->offset))
+			return -1;
 
-			idx++;
-		}
+		idx++;
 	}
 
 	return 0;
@@ -2207,23 +2197,20 @@ static int add_func_jump_tables(struct objtool_file *file,
  */
 static int add_jump_table_alts(struct objtool_file *file)
 {
-	struct section *sec;
 	struct symbol *func;
 	int ret;
 
 	if (!file->rodata)
 		return 0;
 
-	for_each_sec(file, sec) {
-		list_for_each_entry(func, &sec->symbol_list, list) {
-			if (func->type != STT_FUNC)
-				continue;
+	for_each_sym(file, func) {
+		if (func->type != STT_FUNC)
+			continue;
 
-			mark_func_jump_tables(file, func);
-			ret = add_func_jump_tables(file, func);
-			if (ret)
-				return ret;
-		}
+		mark_func_jump_tables(file, func);
+		ret = add_func_jump_tables(file, func);
+		if (ret)
+			return ret;
 	}
 
 	return 0;
@@ -2535,30 +2522,27 @@ static bool is_profiling_func(const char *name)
 
 static int classify_symbols(struct objtool_file *file)
 {
-	struct section *sec;
 	struct symbol *func;
 
-	for_each_sec(file, sec) {
-		list_for_each_entry(func, &sec->symbol_list, list) {
-			if (func->bind != STB_GLOBAL)
-				continue;
+	for_each_sym(file, func) {
+		if (func->bind != STB_GLOBAL)
+			continue;
 
-			if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
-				     strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
-				func->static_call_tramp = true;
+		if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+			     strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
+			func->static_call_tramp = true;
 
-			if (arch_is_retpoline(func))
-				func->retpoline_thunk = true;
+		if (arch_is_retpoline(func))
+			func->retpoline_thunk = true;
 
-			if (arch_is_rethunk(func))
-				func->return_thunk = true;
+		if (arch_is_rethunk(func))
+			func->return_thunk = true;
 
-			if (arch_ftrace_match(func->name))
-				func->fentry = true;
+		if (arch_ftrace_match(func->name))
+			func->fentry = true;
 
-			if (is_profiling_func(func->name))
-				func->profiling_func = true;
-		}
+		if (is_profiling_func(func->name))
+			func->profiling_func = true;
 	}
 
 	return 0;
@@ -4213,7 +4197,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 	struct symbol *func;
 	int warnings = 0;
 
-	list_for_each_entry(func, &sec->symbol_list, list) {
+	sec_for_each_sym(sec, func) {
 		if (func->type != STT_FUNC)
 			continue;
 
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 6806ce01d933..500e92979a31 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -474,7 +474,7 @@ static int read_symbols(struct elf *elf)
 
 	/* Create parent/child links for any cold subfunctions */
 	list_for_each_entry(sec, &elf->sections, list) {
-		list_for_each_entry(sym, &sec->symbol_list, list) {
+		sec_for_each_sym(sec, sym) {
 			char pname[MAX_NAME_LEN + 1];
 			size_t pnamelen;
 			if (sym->type != STT_FUNC)
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index ad0024da262b..e1ca588eb69d 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -188,4 +188,13 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset);
 #define for_each_sec(file, sec)						\
 	list_for_each_entry(sec, &file->elf->sections, list)
 
+#define sec_for_each_sym(sec, sym)					\
+	list_for_each_entry(sym, &sec->symbol_list, list)
+
+#define for_each_sym(file, sym)						\
+	for (struct section *__sec, *__fake = (struct section *)1;	\
+	     __fake; __fake = NULL)					\
+		for_each_sec(file, __sec)				\
+			sec_for_each_sym(__sec, sym)
+
 #endif /* _OBJTOOL_ELF_H */
-- 
cgit v1.2.3


From 6126ed5dfbc656374e851bfdfb128f3aa9e1263a Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 12:03:22 -0700
Subject: objtool: Remove superfluous dead_end_function() check

annotate_call_site() already sets 'insn->dead_end' for calls to dead end
functions.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/5d603a301e9a8b1036b61503385907e154867ace.1681325924.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9de3972a9b1c..1cf2e2841c47 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4078,8 +4078,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 	 * It may also insert a UD2 after calling a __noreturn function.
 	 */
 	prev_insn = prev_insn_same_sec(file, insn);
-	if ((prev_insn->dead_end ||
-	     dead_end_function(file, insn_call_dest(prev_insn))) &&
+	if (prev_insn->dead_end &&
 	    (insn->type == INSN_BUG ||
 	     (insn->type == INSN_JUMP_UNCONDITIONAL &&
 	      insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
-- 
cgit v1.2.3


From bd456a1bedd20cebd37493f8cb0291294a7356ea Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 13:26:13 -0700
Subject: objtool: Separate prefix code from stack validation code

Simplify the prefix code by moving it after
validate_reachable_instructions().

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/d7f31ac2de462d0cd7b1db01b7ecb525c057c8f6.1681331135.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 88 +++++++++++++++++++++++++++++----------------------
 1 file changed, 50 insertions(+), 38 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 1cf2e2841c47..8ee4d51de6fa 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4114,54 +4114,61 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 	return false;
 }
 
-static int add_prefix_symbol(struct objtool_file *file, struct symbol *func,
-			     struct instruction *insn)
+static int add_prefix_symbol(struct objtool_file *file, struct symbol *func)
 {
-	if (!opts.prefix)
-		return 0;
+	struct instruction *insn, *prev;
 
-	for (;;) {
-		struct instruction *prev = prev_insn_same_sec(file, insn);
-		u64 offset;
+	insn = find_insn(file, func->sec, func->offset);
+	if (!insn)
+		return -1;
 
-		if (!prev)
-			break;
+	for (prev = prev_insn_same_sec(file, insn);
+	     prev;
+	     prev = prev_insn_same_sec(file, prev)) {
+		u64 offset;
 
 		if (prev->type != INSN_NOP)
-			break;
+			return -1;
 
 		offset = func->offset - prev->offset;
-		if (offset >= opts.prefix) {
-			if (offset == opts.prefix) {
-				/*
-				 * Since the sec->symbol_list is ordered by
-				 * offset (see elf_add_symbol()) the added
-				 * symbol will not be seen by the iteration in
-				 * validate_section().
-				 *
-				 * Hence the lack of list_for_each_entry_safe()
-				 * there.
-				 *
-				 * The direct concequence is that prefix symbols
-				 * don't get visited (because pointless), except
-				 * for the logic in ignore_unreachable_insn()
-				 * that needs the terminating insn to be visited
-				 * otherwise it will report the hole.
-				 *
-				 * Hence mark the first instruction of the
-				 * prefix symbol as visisted.
-				 */
-				prev->visited |= VISITED_BRANCH;
-				elf_create_prefix_symbol(file->elf, func, opts.prefix);
-			}
-			break;
-		}
-		insn = prev;
+
+		if (offset > opts.prefix)
+			return -1;
+
+		if (offset < opts.prefix)
+			continue;
+
+		elf_create_prefix_symbol(file->elf, func, opts.prefix);
+		break;
 	}
 
+	if (!prev)
+		return -1;
+
 	return 0;
 }
 
+static int add_prefix_symbols(struct objtool_file *file)
+{
+	struct section *sec;
+	struct symbol *func;
+	int warnings = 0;
+
+	for_each_sec(file, sec) {
+		if (!(sec->sh.sh_flags & SHF_EXECINSTR))
+			continue;
+
+		sec_for_each_sym(sec, func) {
+			if (func->type != STT_FUNC)
+				continue;
+
+			add_prefix_symbol(file, func);
+		}
+	}
+
+	return warnings;
+}
+
 static int validate_symbol(struct objtool_file *file, struct section *sec,
 			   struct symbol *sym, struct insn_state *state)
 {
@@ -4180,8 +4187,6 @@ static int validate_symbol(struct objtool_file *file, struct section *sec,
 	if (!insn || insn->ignore || insn->visited)
 		return 0;
 
-	add_prefix_symbol(file, sym, insn);
-
 	state->uaccess = sym->uaccess_safe;
 
 	ret = validate_branch(file, insn_func(insn), insn, *state);
@@ -4621,6 +4626,13 @@ int check(struct objtool_file *file)
 		warnings += ret;
 	}
 
+	if (opts.prefix) {
+		ret = add_prefix_symbols(file);
+		if (ret < 0)
+			return ret;
+		warnings += ret;
+	}
+
 	if (opts.ibt) {
 		ret = create_ibt_endbr_seal_sections(file);
 		if (ret < 0)
-- 
cgit v1.2.3


From 5743654f5e2ebd56df99f56fca5ba4b23fe3c815 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 13:26:15 -0700
Subject: objtool: Generate ORC data for __pfx code

Allow unwinding from prefix code by copying the CFI from the starting
instruction of the corresponding function.  Even when the NOPs are
replaced, they're still stack-invariant instructions so the same ORC
entry can be reused everywhere.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/bc3344e51f3e87102f1301a0be0f72a7689ea4a4.1681331135.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 8ee4d51de6fa..df634dafefc4 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4117,6 +4117,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 static int add_prefix_symbol(struct objtool_file *file, struct symbol *func)
 {
 	struct instruction *insn, *prev;
+	struct cfi_state *cfi;
 
 	insn = find_insn(file, func->sec, func->offset);
 	if (!insn)
@@ -4145,6 +4146,19 @@ static int add_prefix_symbol(struct objtool_file *file, struct symbol *func)
 	if (!prev)
 		return -1;
 
+	if (!insn->cfi) {
+		/*
+		 * This can happen if stack validation isn't enabled or the
+		 * function is annotated with STACK_FRAME_NON_STANDARD.
+		 */
+		return 0;
+	}
+
+	/* Propagate insn->cfi to the prefix code */
+	cfi = cfi_hash_find_or_add(insn->cfi);
+	for (; prev != insn; prev = next_insn_same_sec(file, prev))
+		prev->cfi = cfi;
+
 	return 0;
 }
 
-- 
cgit v1.2.3


From 9ea7e6b62c2bd2f7bbfc3f10099df803002dd33b Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:31 -0700
Subject: init: Mark [arch_call_]rest_init() __noreturn

In preparation for improving objtool's handling of weak noreturn
functions, mark start_kernel(), arch_call_rest_init(), and rest_init()
__noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/7194ed8a989a85b98d92e62df660f4a90435a723.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index df634dafefc4..3d7227f0ea2a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -202,6 +202,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"__reiserfs_panic",
 		"__stack_chk_fail",
 		"__ubsan_handle_builtin_unreachable",
+		"arch_call_rest_init",
 		"arch_cpu_idle_dead",
 		"cpu_bringup_and_idle",
 		"cpu_startup_entry",
@@ -217,6 +218,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"machine_real_restart",
 		"make_task_dead",
 		"panic",
+		"rest_init",
 		"rewind_stack_and_make_dead",
 		"sev_es_terminate",
 		"snp_abort",
-- 
cgit v1.2.3


From 25a6917ca63ad4470bf88535c56f0dec72b570fe Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:32 -0700
Subject: init: Mark start_kernel() __noreturn

Now that arch_call_rest_init() is __noreturn, mark its caller
start_kernel() __noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/7069acf026a195f26a88061227fba5a3b0337b9a.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 3d7227f0ea2a..9aaad9dc6c20 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -222,6 +222,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"rewind_stack_and_make_dead",
 		"sev_es_terminate",
 		"snp_abort",
+		"start_kernel",
 		"stop_this_cpu",
 		"usercopy_abort",
 		"xen_cpu_bringup_again",
-- 
cgit v1.2.3


From 4208d2d79837ef70f260d6170e3ac7fd6fde7788 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:33 -0700
Subject: x86/head: Mark *_start_kernel() __noreturn

Now that start_kernel() is __noreturn, mark its chain of callers
__noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/c2525f96b88be98ee027ee0291d58003036d4120.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9aaad9dc6c20..a436bc1e63d9 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -225,6 +225,8 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"start_kernel",
 		"stop_this_cpu",
 		"usercopy_abort",
+		"x86_64_start_kernel",
+		"x86_64_start_reservations",
 		"xen_cpu_bringup_again",
 		"xen_start_kernel",
 	};
-- 
cgit v1.2.3


From 7412a60decec2a6744cf773280ff17a0f89e8395 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:35 -0700
Subject: cpu: Mark panic_smp_self_stop() __noreturn

In preparation for improving objtool's handling of weak noreturn
functions, mark panic_smp_self_stop() __noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/92d76ab5c8bf660f04fdcd3da1084519212de248.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index a436bc1e63d9..4b52ed6bff66 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -218,6 +218,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"machine_real_restart",
 		"make_task_dead",
 		"panic",
+		"panic_smp_self_stop",
 		"rest_init",
 		"rewind_stack_and_make_dead",
 		"sev_es_terminate",
-- 
cgit v1.2.3


From 27dea14c7f05106f39850a9239874cd38703b405 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:36 -0700
Subject: cpu: Mark nmi_panic_self_stop() __noreturn

In preparation for improving objtool's handling of weak noreturn
functions, mark nmi_panic_self_stop() __noreturn.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/316fc6dfab5a8c4e024c7185484a1ee5fb0afb79.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4b52ed6bff66..8d073bfd7d7f 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -217,6 +217,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"lbug_with_loc",
 		"machine_real_restart",
 		"make_task_dead",
+		"nmi_panic_self_stop",
 		"panic",
 		"panic_smp_self_stop",
 		"rest_init",
-- 
cgit v1.2.3


From 1c47c8758a11345ac643fa68cb70b708a6668883 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:37 -0700
Subject: objtool: Include weak functions in global_noreturns check

If a global function doesn't return, and its prototype has the
__noreturn attribute, its weak counterpart must also not return so that
it matches the prototype and meets call site expectations.

To properly follow the compiled control flow at the call sites, change
the global_noreturns check to include both global and weak functions.

On the other hand, if a weak function isn't in global_noreturns, assume
the prototype doesn't have __noreturn.  Even if the weak function
doesn't return, call sites treat it like a returnable function.

Fixes the following warning:

  kernel/sched/build_policy.o: warning: objtool: do_idle() falls through to next function play_idle_precise()

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/ede3460d63f4a65d282c86f1175bd2662c2286ba.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 8d073bfd7d7f..ae0c94285124 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -236,14 +236,14 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 	if (!func)
 		return false;
 
-	if (func->bind == STB_WEAK)
-		return false;
-
-	if (func->bind == STB_GLOBAL)
+	if (func->bind == STB_GLOBAL || func->bind == STB_WEAK)
 		for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
 			if (!strcmp(func->name, global_noreturns[i]))
 				return true;
 
+	if (func->bind == STB_WEAK)
+		return false;
+
 	if (!func->len)
 		return false;
 
-- 
cgit v1.2.3


From 09c5ae30d007514a1be870fa5873ad55c3319f3a Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:38 -0700
Subject: btrfs: Mark btrfs_assertfail() __noreturn

Fixes a bunch of warnings including:

  vmlinux.o: warning: objtool: select_reloc_root+0x314: unreachable instruction
  vmlinux.o: warning: objtool: finish_inode_if_needed+0x15b1: unreachable instruction
  vmlinux.o: warning: objtool: get_bio_sector_nr+0x259: unreachable instruction
  vmlinux.o: warning: objtool: raid_wait_read_end_io+0xc26: unreachable instruction
  vmlinux.o: warning: objtool: raid56_parity_alloc_scrub_rbio+0x37b: unreachable instruction
  ...

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/960bd9c0c9e3cfc409ba9c35a17644b11b832956.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ae0c94285124..ceb98489d718 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -204,6 +204,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"__ubsan_handle_builtin_unreachable",
 		"arch_call_rest_init",
 		"arch_cpu_idle_dead",
+		"btrfs_assertfail",
 		"cpu_bringup_and_idle",
 		"cpu_startup_entry",
 		"do_exit",
-- 
cgit v1.2.3


From 52668badd34b4b346f32c33a9bcba069a06c3caa Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:39 -0700
Subject: x86/cpu: Mark {hlt,resume}_play_dead() __noreturn

Fixes the following warning:

  vmlinux.o: warning: objtool: resume_play_dead+0x21: unreachable instruction

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ce1407c4bf88b1334fe40413126343792a77ca50.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ceb98489d718..724a63bdc412 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -212,6 +212,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"do_task_dead",
 		"ex_handler_msr_mce",
 		"fortify_panic",
+		"hlt_play_dead",
 		"kthread_complete_and_exit",
 		"kthread_exit",
 		"kunit_try_catch_throw",
@@ -222,6 +223,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"panic",
 		"panic_smp_self_stop",
 		"rest_init",
+		"resume_play_dead",
 		"rewind_stack_and_make_dead",
 		"sev_es_terminate",
 		"snp_abort",
-- 
cgit v1.2.3


From 6e36a56a5f617262c0e8ae7e961487361c720b9e Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: Wed, 12 Apr 2023 16:49:40 -0700
Subject: scsi: message: fusion: Mark mpt_halt_firmware() __noreturn

mpt_halt_firmware() doesn't return.  Mark it as such.

Fixes the following warnings:

  vmlinux.o: warning: objtool: mptscsih_abort+0x7f4: unreachable instruction
  vmlinux.o: warning: objtool: mptctl_timeout_expired+0x310: unreachable instruction

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Debugged-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/d8129817423422355bf30e90dadc6764261b53e0.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 724a63bdc412..e1b01ea6ad1b 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -219,6 +219,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"lbug_with_loc",
 		"machine_real_restart",
 		"make_task_dead",
+		"mpt_halt_firmware",
 		"nmi_panic_self_stop",
 		"panic",
 		"panic_smp_self_stop",
-- 
cgit v1.2.3


From 611d4c716db0141cfc436994dc5aff1d69c924ad Mon Sep 17 00:00:00 2001
From: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Date: Wed, 12 Apr 2023 16:49:41 -0700
Subject: x86/hyperv: Mark hv_ghcb_terminate() as noreturn

Annotate the function prototype and definition as noreturn to prevent
objtool warnings like:

vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction

Also, as per Josh's suggestion, add it to the global_noreturns list.
As a comparison, an objdump output without the annotation:

[...]
1b63:  mov    $0x1,%esi
1b68:  xor    %edi,%edi
1b6a:  callq  ffffffff8102f680 <hv_ghcb_terminate>
1b6f:  jmpq   ffffffff82f217ec <hyperv_init+0x9c> # unreachable
1b74:  cmpq   $0xffffffffffffffff,-0x702a24(%rip)
[...]

Now, after adding the __noreturn to the function prototype:

[...]
17df:  callq  ffffffff8102f6d0 <hv_ghcb_negotiate_protocol>
17e4:  test   %al,%al
17e6:  je     ffffffff82f21bb9 <hyperv_init+0x469>
[...]  <many insns>
1bb9:  mov    $0x1,%esi
1bbe:  xor    %edi,%edi
1bc0:  callq  ffffffff8102f680 <hv_ghcb_terminate>
1bc5:  nopw   %cs:0x0(%rax,%rax,1) # end of function

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/32453a703dfcf0d007b473c9acbf70718222b74b.1681342859.git.jpoimboe@kernel.org
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/objtool')

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e1b01ea6ad1b..5b600bbf2389 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -213,6 +213,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"ex_handler_msr_mce",
 		"fortify_panic",
 		"hlt_play_dead",
+		"hv_ghcb_terminate",
 		"kthread_complete_and_exit",
 		"kthread_exit",
 		"kunit_try_catch_throw",
-- 
cgit v1.2.3