From 375a4f4ea719ad68e305373cfe0f77ecd1378531 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:54 +0900
Subject: [PATCH 01/16] kconfig: qconf: remove unnecessary lastWindowClosed()
 signal connection

The default value of the quitOnLastWindowClosed property is true.

Hence, the application implicitly quits when the last window is closed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 120090fa4ac9..49a3d0365c39 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1863,7 +1863,6 @@ int main(int ac, char** av)
 	v = new ConfigMainWindow();
 
 	//zconfdump(stdout);
-	configApp->connect(configApp, SIGNAL(lastWindowClosed()), SLOT(quit()));
 	configApp->connect(configApp, SIGNAL(aboutToQuit()), v, SLOT(saveSettings()));
 
 	v->show();
-- 
2.51.0


From b6962d8694963620401c24f051999678943a7123 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:55 +0900
Subject: [PATCH 02/16] kconfig: qconf: convert the last old connection syntax
 to Qt5 style

Commit a2574c12df0d ("kconfig: qconf: convert to Qt5 new signal/slot
connection syntax") converted most of the old string-based connections,
but one more instance still remains. Convert it to the new style.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 49a3d0365c39..c922c34621a4 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1475,6 +1475,9 @@ ConfigMainWindow::ConfigMainWindow(void)
 	connect(helpText, &ConfigInfoView::menuSelected,
 		this, &ConfigMainWindow::setMenuLink);
 
+	connect(configApp, &QApplication::aboutToQuit,
+		this, &ConfigMainWindow::saveSettings);
+
 	conf_read(NULL);
 
 	QString listMode = configSettings->value("/listMode", "symbol").toString();
@@ -1863,7 +1866,6 @@ int main(int ac, char** av)
 	v = new ConfigMainWindow();
 
 	//zconfdump(stdout);
-	configApp->connect(configApp, SIGNAL(aboutToQuit()), v, SLOT(saveSettings()));
 
 	v->show();
 	configApp->exec();
-- 
2.51.0


From 76567f93b3454cae3a3eaa23a3b28c94b70ee013 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:56 +0900
Subject: [PATCH 03/16] kconfig: qconf: do not show goParent button in split
 view

When a menu is selected in the split view, the right pane displays the
goParent button, but it is never functional.

This is unnecessary, as you can select a menu from the menu tree in the
left pane.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index c922c34621a4..7c844c4a119e 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -436,8 +436,7 @@ void ConfigList::updateList()
 		return;
 	}
 
-	if (rootEntry != &rootmenu && (mode == singleMode ||
-	    (mode == symbolMode && rootEntry->parent != &rootmenu))) {
+	if (rootEntry != &rootmenu && mode == singleMode) {
 		item = (ConfigItem *)topLevelItem(0);
 		if (!item)
 			item = new ConfigItem(this, 0, true);
-- 
2.51.0


From 511ff539c31d89e3f7132a61dae2ebcb0c4b2912 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:57 +0900
Subject: [PATCH 04/16] kconfig: qconf: remove ConfigItem::visible member

The " (NEW)" string should be displayed regardless of the visibility
of the associated menu.

The ConfigItem::visible member is not used for any other purpose.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 28 +++++++++++-----------------
 scripts/kconfig/qconf.h  | 15 +++++++--------
 2 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 7c844c4a119e..5b1237bf085a 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -175,17 +175,16 @@ void ConfigItem::updateMenu(void)
 		setText(dataColIdx, sym_get_string_value(sym));
 		break;
 	}
-	if (!sym_has_value(sym) && visible)
+	if (!sym_has_value(sym))
 		prompt += " (NEW)";
 set_prompt:
 	setText(promptColIdx, prompt);
 }
 
-void ConfigItem::testUpdateMenu(bool v)
+void ConfigItem::testUpdateMenu(void)
 {
 	ConfigItem* i;
 
-	visible = v;
 	if (!menu)
 		return;
 
@@ -429,7 +428,7 @@ void ConfigList::updateList()
 			item = (ConfigItem*)(*it);
 			if (!item->menu)
 				continue;
-			item->testUpdateMenu(menu_is_visible(item->menu));
+			item->testUpdateMenu();
 
 			++it;
 		}
@@ -439,16 +438,16 @@ void ConfigList::updateList()
 	if (rootEntry != &rootmenu && mode == singleMode) {
 		item = (ConfigItem *)topLevelItem(0);
 		if (!item)
-			item = new ConfigItem(this, 0, true);
+			item = new ConfigItem(this, 0);
 		last = item;
 	}
 	if ((mode == singleMode || (mode == symbolMode && !(rootEntry->flags & MENU_ROOT))) &&
 	    rootEntry->sym && rootEntry->prompt) {
 		item = last ? last->nextSibling() : nullptr;
 		if (!item)
-			item = new ConfigItem(this, last, rootEntry, true);
+			item = new ConfigItem(this, last, rootEntry);
 		else
-			item->testUpdateMenu(true);
+			item->testUpdateMenu();
 
 		updateMenuList(item, rootEntry);
 		update();
@@ -597,7 +596,6 @@ void ConfigList::updateMenuList(ConfigItem *parent, struct menu* menu)
 	struct menu* child;
 	ConfigItem* item;
 	ConfigItem* last;
-	bool visible;
 	enum prop_type type;
 
 	if (!menu) {
@@ -629,14 +627,13 @@ void ConfigList::updateMenuList(ConfigItem *parent, struct menu* menu)
 			break;
 		}
 
-		visible = menu_is_visible(child);
 		if (!menuSkip(child)) {
 			if (!child->sym && !child->list && !child->prompt)
 				continue;
 			if (!item || item->menu != child)
-				item = new ConfigItem(parent, last, child, visible);
+				item = new ConfigItem(parent, last, child);
 			else
-				item->testUpdateMenu(visible);
+				item->testUpdateMenu();
 
 			if (mode == fullMode || mode == menuMode || type != P_MENU)
 				updateMenuList(item, child);
@@ -662,7 +659,6 @@ void ConfigList::updateMenuList(struct menu *menu)
 	struct menu* child;
 	ConfigItem* item;
 	ConfigItem* last;
-	bool visible;
 	enum prop_type type;
 
 	if (!menu) {
@@ -694,14 +690,13 @@ void ConfigList::updateMenuList(struct menu *menu)
 			break;
 		}
 
-		visible = menu_is_visible(child);
 		if (!menuSkip(child)) {
 			if (!child->sym && !child->list && !child->prompt)
 				continue;
 			if (!item || item->menu != child)
-				item = new ConfigItem(this, last, child, visible);
+				item = new ConfigItem(this, last, child);
 			else
-				item->testUpdateMenu(visible);
+				item->testUpdateMenu();
 
 			if (mode == fullMode || mode == menuMode || type != P_MENU)
 				updateMenuList(item, child);
@@ -1274,8 +1269,7 @@ void ConfigSearchWindow::search(void)
 		return;
 	for (p = result; *p; p++) {
 		for_all_prompts((*p), prop)
-			lastItem = new ConfigItem(list, lastItem, prop->menu,
-						  menu_is_visible(prop->menu));
+			lastItem = new ConfigItem(list, lastItem, prop->menu);
 	}
 }
 
diff --git a/scripts/kconfig/qconf.h b/scripts/kconfig/qconf.h
index 0b62fb26821a..62ab3286d04f 100644
--- a/scripts/kconfig/qconf.h
+++ b/scripts/kconfig/qconf.h
@@ -114,25 +114,25 @@ public:
 class ConfigItem : public QTreeWidgetItem {
 	typedef class QTreeWidgetItem Parent;
 public:
-	ConfigItem(ConfigList *parent, ConfigItem *after, struct menu *m, bool v)
-	: Parent(parent, after), nextItem(0), menu(m), visible(v), goParent(false)
+	ConfigItem(ConfigList *parent, ConfigItem *after, struct menu *m)
+	: Parent(parent, after), nextItem(0), menu(m), goParent(false)
 	{
 		init();
 	}
-	ConfigItem(ConfigItem *parent, ConfigItem *after, struct menu *m, bool v)
-	: Parent(parent, after), nextItem(0), menu(m), visible(v), goParent(false)
+	ConfigItem(ConfigItem *parent, ConfigItem *after, struct menu *m)
+	: Parent(parent, after), nextItem(0), menu(m), goParent(false)
 	{
 		init();
 	}
-	ConfigItem(ConfigList *parent, ConfigItem *after, bool v)
-	: Parent(parent, after), nextItem(0), menu(0), visible(v), goParent(true)
+	ConfigItem(ConfigList *parent, ConfigItem *after)
+	: Parent(parent, after), nextItem(0), menu(0), goParent(true)
 	{
 		init();
 	}
 	~ConfigItem(void);
 	void init(void);
 	void updateMenu(void);
-	void testUpdateMenu(bool v);
+	void testUpdateMenu(void);
 	ConfigList* listView() const
 	{
 		return (ConfigList*)Parent::treeWidget();
@@ -159,7 +159,6 @@ public:
 
 	ConfigItem* nextItem;
 	struct menu *menu;
-	bool visible;
 	bool goParent;
 
 	static QIcon symbolYesIcon, symbolModIcon, symbolNoIcon;
-- 
2.51.0


From 572cd1d2a9a68b66af98a60f4aad4f01d6589447 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:58 +0900
Subject: [PATCH 05/16] kconfig: qconf: avoid unnecessary parentSelected() when
 ESC is pressed

When the ESC key is pressed, the parentSelected() signal is currently
emitted for singleMode, menuMode, and symbolMode.

However, parentSelected() signal is functional only for singleMode.

In menuMode, the signal is connected to the goBack() slot, but nothing
occurs because configList->rootEntry is always &rootmenu.

In symbolMode (in the right pane), the parentSelected() signal is not
connected to any slot.

This commit prevents the unnecessary emission of the parentSelected()
signal.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 5b1237bf085a..1948cda048d2 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -724,7 +724,7 @@ void ConfigList::keyPressEvent(QKeyEvent* ev)
 	struct menu *menu;
 	enum prop_type type;
 
-	if (ev->key() == Qt::Key_Escape && mode != fullMode && mode != listMode) {
+	if (ev->key() == Qt::Key_Escape && mode == singleMode) {
 		emit parentSelected();
 		ev->accept();
 		return;
-- 
2.51.0


From 8e8ce9531e09376d987ff0e09491bea82a0f6411 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:17:59 +0900
Subject: [PATCH 06/16] kconfig: qconf: remove redundant check in goBack()

The same check is performed in the configList->setParentMenu() call.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index 1948cda048d2..acbc4331ebc5 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1616,9 +1616,6 @@ void ConfigMainWindow::listFocusChanged(void)
 
 void ConfigMainWindow::goBack(void)
 {
-	if (configList->rootEntry == &rootmenu)
-		return;
-
 	configList->setParentMenu();
 }
 
-- 
2.51.0


From 929ce506d60ede917f241fb40e0bed6ab3e52999 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:18:00 +0900
Subject: [PATCH 07/16] kconfig: qconf: remove non-functional href="m..." tag

The only functional tag is href="s<symbol_name>".

Commit c4f7398bee9c ("kconfig: qconf: make debug links work again")
changed prop->name to sym->name for this reference, but it missed to
change the tag "m" to "s".

This tag is not functional at all.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index acbc4331ebc5..a208ef33128f 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1065,9 +1065,9 @@ QString ConfigInfoView::debug_info(struct symbol *sym)
 		switch (prop->type) {
 		case P_PROMPT:
 		case P_MENU:
-			stream << "prompt: <a href=\"m" << sym->name << "\">";
+			stream << "prompt: ";
 			stream << print_filter(prop->text);
-			stream << "</a><br>";
+			stream << "<br>";
 			break;
 		case P_DEFAULT:
 		case P_SELECT:
-- 
2.51.0


From bce590f1020742d81e9fbfe3b045538973111c11 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:18:01 +0900
Subject: [PATCH 08/16] kconfig: add sym_get_prompt_menu() helper function

Split out the code that retrieves the menu entry with a prompt, so it
can be reused in other functions.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/lkc_proto.h |  1 +
 scripts/kconfig/symbol.c    | 26 +++++++++++++++++++-------
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 63519cd24bc7..8914b4e8f2a8 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -34,6 +34,7 @@ bool sym_string_valid(struct symbol *sym, const char *newval);
 bool sym_string_within_range(struct symbol *sym, const char *str);
 bool sym_set_string_value(struct symbol *sym, const char *newval);
 bool sym_is_changeable(const struct symbol *sym);
+struct menu *sym_get_prompt_menu(const struct symbol *sym);
 struct menu *sym_get_choice_menu(const struct symbol *sym);
 const char * sym_get_string_value(struct symbol *sym);
 
diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index a3af93aaaf32..89b84bf8e21f 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -70,6 +70,24 @@ const char *sym_type_name(enum symbol_type type)
 	return "???";
 }
 
+/**
+ * sym_get_prompt_menu - get the menu entry with a prompt
+ *
+ * @sym: a symbol pointer
+ *
+ * Return: the menu entry with a prompt.
+ */
+struct menu *sym_get_prompt_menu(const struct symbol *sym)
+{
+	struct menu *m;
+
+	list_for_each_entry(m, &sym->menus, link)
+		if (m->prompt)
+			return m;
+
+	return NULL;
+}
+
 /**
  * sym_get_choice_menu - get the parent choice menu if present
  *
@@ -80,18 +98,12 @@ const char *sym_type_name(enum symbol_type type)
 struct menu *sym_get_choice_menu(const struct symbol *sym)
 {
 	struct menu *menu = NULL;
-	struct menu *m;
 
 	/*
 	 * Choice members must have a prompt. Find a menu entry with a prompt,
 	 * and assume it resides inside a choice block.
 	 */
-	list_for_each_entry(m, &sym->menus, link)
-		if (m->prompt) {
-			menu = m;
-			break;
-		}
-
+	menu = sym_get_prompt_menu(sym);
 	if (!menu)
 		return NULL;
 
-- 
2.51.0


From a914032b71f0a74e9c9114ff9be8babb55bbca67 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:18:02 +0900
Subject: [PATCH 09/16] kconfig: qconf: refactor ConfigInfoView::clicked()

Most of the code in ConfigInfoView::clicked() is unnecessary.
There is no need to use the regular expression to search for a symbol.
Calling sym_find() is simpler and faster.

The hyperlink always begins with the "s" tag, and there is no other
tag used. Remove it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 43 ++++++----------------------------------
 1 file changed, 6 insertions(+), 37 deletions(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index a208ef33128f..f59a9597f09b 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -1001,7 +1001,7 @@ void ConfigInfoView::menuInfo(void)
 			if (sym->name) {
 				stream << " (";
 				if (showDebug())
-					stream << "<a href=\"s" << sym->name << "\">";
+					stream << "<a href=\"" << sym->name << "\">";
 				stream << print_filter(sym->name);
 				if (showDebug())
 					stream << "</a>";
@@ -1010,7 +1010,7 @@ void ConfigInfoView::menuInfo(void)
 		} else if (sym->name) {
 			stream << "<big><b>";
 			if (showDebug())
-				stream << "<a href=\"s" << sym->name << "\">";
+				stream << "<a href=\"" << sym->name << "\">";
 			stream << print_filter(sym->name);
 			if (showDebug())
 				stream << "</a>";
@@ -1124,7 +1124,7 @@ void ConfigInfoView::expr_print_help(void *data, struct symbol *sym, const char
 	QTextStream *stream = reinterpret_cast<QTextStream *>(data);
 
 	if (sym && sym->name && !(sym->flags & SYMBOL_CONST)) {
-		*stream << "<a href=\"s" << sym->name << "\">";
+		*stream << "<a href=\"" << sym->name << "\">";
 		*stream << print_filter(str);
 		*stream << "</a>";
 	} else {
@@ -1134,39 +1134,11 @@ void ConfigInfoView::expr_print_help(void *data, struct symbol *sym, const char
 
 void ConfigInfoView::clicked(const QUrl &url)
 {
-	QByteArray str = url.toEncoded();
-	const std::size_t count = str.size();
-	char *data = new char[count + 2];  // '$' + '\0'
-	struct symbol **result;
-	struct menu *m = NULL;
+	struct menu *m;
 
-	if (count < 1) {
-		delete[] data;
-		return;
-	}
-
-	memcpy(data, str.constData(), count);
-	data[count] = '\0';
-
-	/* Seek for exact match */
-	data[0] = '^';
-	strcat(data, "$");
-	result = sym_re_search(data);
-	if (!result) {
-		delete[] data;
-		return;
-	}
-
-	sym = *result;
-
-	/* Seek for the menu which holds the symbol */
-	for (struct property *prop = sym->prop; prop; prop = prop->next) {
-		    if (prop->type != P_PROMPT && prop->type != P_MENU)
-			    continue;
-		    m = prop->menu;
-		    break;
-	}
+	sym = sym_find(url.toEncoded().constData());
 
+	m = sym_get_prompt_menu(sym);
 	if (!m) {
 		/* Symbol is not visible as a menu */
 		symbolInfo();
@@ -1174,9 +1146,6 @@ void ConfigInfoView::clicked(const QUrl &url)
 	} else {
 		emit menuSelected(m);
 	}
-
-	free(result);
-	delete[] data;
 }
 
 void ConfigInfoView::contextMenuEvent(QContextMenuEvent *event)
-- 
2.51.0


From d6a91e28d11902e6cd5715633ed6f9b6df75de32 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 03:18:03 +0900
Subject: [PATCH 10/16] kconfig: qconf: remove unnecessary mode check in
 ConfigItem::updateMenu()

The P_MENU entries ("menu" and "menuconfig") are never displayed in
symbolMode.

The condition, list->mode == symbolMode, is never met here.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/qconf.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/kconfig/qconf.cc b/scripts/kconfig/qconf.cc
index f59a9597f09b..6c92ef1e16ef 100644
--- a/scripts/kconfig/qconf.cc
+++ b/scripts/kconfig/qconf.cc
@@ -110,7 +110,7 @@ void ConfigItem::updateMenu(void)
 
 	if (prop) switch (prop->type) {
 	case P_MENU:
-		if (list->mode == singleMode || list->mode == symbolMode) {
+		if (list->mode == singleMode) {
 			/* a menuconfig entry is displayed differently
 			 * depending whether it's at the view root or a child.
 			 */
-- 
2.51.0


From a49401be4c780f3397ca19a070d7c38e6f032efa Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 24 Oct 2024 20:25:45 +0900
Subject: [PATCH 11/16] kconfig: document the positional argument in the help
 message

The positional argument specifies the top-level Kconfig. Include this
information in the help message.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/kconfig/conf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 3d7d454c54da..8abe57041955 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -628,7 +628,7 @@ static const struct option long_opts[] = {
 
 static void conf_usage(const char *progname)
 {
-	printf("Usage: %s [options] <kconfig-file>\n", progname);
+	printf("Usage: %s [options] kconfig_file\n", progname);
 	printf("\n");
 	printf("Generic options:\n");
 	printf("  -h, --help              Print this message and exit.\n");
@@ -653,6 +653,9 @@ static void conf_usage(const char *progname)
 	printf("  --mod2yesconfig         Change answers from mod to yes if possible\n");
 	printf("  --mod2noconfig          Change answers from mod to no if possible\n");
 	printf("  (If none of the above is given, --oldaskconfig is the default)\n");
+	printf("\n");
+	printf("Arguments:\n");
+	printf("  kconfig_file            Top-level Kconfig file.\n");
 }
 
 int main(int ac, char **av)
-- 
2.51.0


From 397a479b511df4e6e7c665d7d8991943645b4cab Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Fri, 25 Oct 2024 02:09:22 +0900
Subject: [PATCH 12/16] kbuild: simplify rustfmt target

There is no need to prune the rust/alloc directory because it was
removed by commit 9d0441bab775 ("rust: alloc: remove our fork of the
`alloc` crate").

There is no need to prune the rust/test directory because no '*.rs'
files are generated within it.

To avoid forking the 'grep -Fv generated' process, filter out generated
files using the option, ! -name '*generated*'.

Now that the '-path ... -prune' option is no longer used, there is no
need to use the absolute path. Searching in $(srctree), which can be
a relative path, is sufficient.

The comment mentions the use case where $(srctree) is '..', that is,
$(objtree) is a sub-directory of $(srctree). In this scenario, all
'*.rs' files under $(objtree) are generated files and filters out by
the '*generated*' pattern.

Add $(RCS_FIND_IGNORE) as a shortcut. Although I do not believe '*.rs'
files would exist under the .git directory, there is no need for the
'find' command to traverse it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
---
 Makefile | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/Makefile b/Makefile
index 855913b71e7a..266376f7f164 100644
--- a/Makefile
+++ b/Makefile
@@ -1754,18 +1754,9 @@ rusttest: prepare
 # Formatting targets
 PHONY += rustfmt rustfmtcheck
 
-# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
-#
-# We match using absolute paths since `find` does not resolve them
-# when matching, which is a problem when e.g. `srctree` is `..`.
-# We `grep` afterwards in order to remove the directory entry itself.
 rustfmt:
-	$(Q)find $(abs_srctree) -type f -name '*.rs' \
-		-o -path $(abs_srctree)/rust/alloc -prune \
-		-o -path $(abs_objtree)/rust/test -prune \
-		| grep -Fv $(abs_srctree)/rust/alloc \
-		| grep -Fv $(abs_objtree)/rust/test \
-		| grep -Fv generated \
+	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
+		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
 		| xargs $(RUSTFMT) $(rustfmt_flags)
 
 rustfmtcheck: rustfmt_flags = --check
-- 
2.51.0


From 315ad8780a129e82e2c5c65ee6e970d91a577acb Mon Sep 17 00:00:00 2001
From: Rong Xu <xur@google.com>
Date: Sat, 2 Nov 2024 10:51:08 -0700
Subject: [PATCH 13/16] kbuild: Add AutoFDO support for Clang build

Add the build support for using Clang's AutoFDO. Building the kernel
with AutoFDO does not reduce the optimization level from the
compiler. AutoFDO uses hardware sampling to gather information about
the frequency of execution of different code paths within a binary.
This information is then used to guide the compiler's optimization
decisions, resulting in a more efficient binary. Experiments
showed that the kernel can improve up to 10% in latency.

The support requires a Clang compiler after LLVM 17. This submission
is limited to x86 platforms that support PMU features like LBR on
Intel machines and AMD Zen3 BRS. Support for SPE on ARM 1,
 and BRBE on ARM 1 is part of planned future work.

Here is an example workflow for AutoFDO kernel:

1) Build the kernel on the host machine with LLVM enabled, for example,
       $ make menuconfig LLVM=1
    Turn on AutoFDO build config:
      CONFIG_AUTOFDO_CLANG=y
    With a configuration that has LLVM enabled, use the following
    command:
       scripts/config -e AUTOFDO_CLANG
    After getting the config, build with
      $ make LLVM=1

2) Install the kernel on the test machine.

3) Run the load tests. The '-c' option in perf specifies the sample
   event period. We suggest     using a suitable prime number,
   like 500009, for this purpose.
   For Intel platforms:
      $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \
        -o <perf_file> -- <loadtest>
   For AMD platforms:
      The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2
     For Zen3:
      $ cat proc/cpuinfo | grep " brs"
      For Zen4:
      $ cat proc/cpuinfo | grep amd_lbr_v2
      $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \
        -N -b -c <count> -o <perf_file> -- <loadtest>

4) (Optional) Download the raw perf file to the host machine.

5) To generate an AutoFDO profile, two offline tools are available:
   create_llvm_prof and llvm_profgen. The create_llvm_prof tool is part
   of the AutoFDO project and can be found on GitHub
   (https://github.com/google/autofdo), version v0.30.1 or later. The
   llvm_profgen tool is included in the LLVM compiler itself. It's
   important to note that the version of llvm_profgen doesn't need to
   match the version of Clang. It needs to be the LLVM 19 release or
   later, or from the LLVM trunk.
      $ llvm-profgen --kernel --binary=<vmlinux> --perfdata=<perf_file> \
        -o <profile_file>
   or
      $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \
        --format=extbinary --out=<profile_file>

   Note that multiple AutoFDO profile files can be merged into one via:
      $ llvm-profdata merge -o <profile_file>  <profile_1> ... <profile_n>

6) Rebuild the kernel using the AutoFDO profile file with the same config
   as step 1, (Note CONFIG_AUTOFDO_CLANG needs to be enabled):
      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<profile_file>

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Tested-by: Peter Jung <ptr1337@cachyos.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Documentation/dev-tools/autofdo.rst | 168 ++++++++++++++++++++++++++++
 Documentation/dev-tools/index.rst   |   1 +
 MAINTAINERS                         |   7 ++
 Makefile                            |   1 +
 arch/Kconfig                        |  20 ++++
 arch/x86/Kconfig                    |   1 +
 scripts/Makefile.autofdo            |  22 ++++
 scripts/Makefile.lib                |  10 ++
 tools/objtool/check.c               |   1 +
 9 files changed, 231 insertions(+)
 create mode 100644 Documentation/dev-tools/autofdo.rst
 create mode 100644 scripts/Makefile.autofdo

diff --git a/Documentation/dev-tools/autofdo.rst b/Documentation/dev-tools/autofdo.rst
new file mode 100644
index 000000000000..1f0a451e9ccd
--- /dev/null
+++ b/Documentation/dev-tools/autofdo.rst
@@ -0,0 +1,168 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================
+Using AutoFDO with the Linux kernel
+===================================
+
+This enables AutoFDO build support for the kernel when using
+the Clang compiler. AutoFDO (Auto-Feedback-Directed Optimization)
+is a type of profile-guided optimization (PGO) used to enhance the
+performance of binary executables. It gathers information about the
+frequency of execution of various code paths within a binary using
+hardware sampling. This data is then used to guide the compiler's
+optimization decisions, resulting in a more efficient binary. AutoFDO
+is a powerful optimization technique, and data indicates that it can
+significantly improve kernel performance. It's especially beneficial
+for workloads affected by front-end stalls.
+
+For AutoFDO builds, unlike non-FDO builds, the user must supply a
+profile. Acquiring an AutoFDO profile can be done in several ways.
+AutoFDO profiles are created by converting hardware sampling using
+the "perf" tool. It is crucial that the workload used to create these
+perf files is representative; they must exhibit runtime
+characteristics similar to the workloads that are intended to be
+optimized. Failure to do so will result in the compiler optimizing
+for the wrong objective.
+
+The AutoFDO profile often encapsulates the program's behavior. If the
+performance-critical codes are architecture-independent, the profile
+can be applied across platforms to achieve performance gains. For
+instance, using the profile generated on Intel architecture to build
+a kernel for AMD architecture can also yield performance improvements.
+
+There are two methods for acquiring a representative profile:
+(1) Sample real workloads using a production environment.
+(2) Generate the profile using a representative load test.
+When enabling the AutoFDO build configuration without providing an
+AutoFDO profile, the compiler only modifies the dwarf information in
+the kernel without impacting runtime performance. It's advisable to
+use a kernel binary built with the same AutoFDO configuration to
+collect the perf profile. While it's possible to use a kernel built
+with different options, it may result in inferior performance.
+
+One can collect profiles using AutoFDO build for the previous kernel.
+AutoFDO employs relative line numbers to match the profiles, offering
+some tolerance for source changes. This mode is commonly used in a
+production environment for profile collection.
+
+In a profile collection based on a load test, the AutoFDO collection
+process consists of the following steps:
+
+#. Initial build: The kernel is built with AutoFDO options
+   without a profile.
+
+#. Profiling: The above kernel is then run with a representative
+   workload to gather execution frequency data. This data is
+   collected using hardware sampling, via perf. AutoFDO is most
+   effective on platforms supporting advanced PMU features like
+   LBR on Intel machines.
+
+#. AutoFDO profile generation: Perf output file is converted to
+   the AutoFDO profile via offline tools.
+
+The support requires a Clang compiler LLVM 17 or later.
+
+Preparation
+===========
+
+Configure the kernel with::
+
+   CONFIG_AUTOFDO_CLANG=y
+
+Customization
+=============
+
+The default CONFIG_AUTOFDO_CLANG setting covers kernel space objects for
+AutoFDO builds. One can, however, enable or disable AutoFDO build for
+individual files and directories by adding a line similar to the following
+to the respective kernel Makefile:
+
+- For enabling a single file (e.g. foo.o) ::
+
+   AUTOFDO_PROFILE_foo.o := y
+
+- For enabling all files in one directory ::
+
+   AUTOFDO_PROFILE := y
+
+- For disabling one file ::
+
+   AUTOFDO_PROFILE_foo.o := n
+
+- For disabling all files in one directory ::
+
+   AUTOFDO_PROFILE := n
+
+Workflow
+========
+
+Here is an example workflow for AutoFDO kernel:
+
+1)  Build the kernel on the host machine with LLVM enabled,
+    for example, ::
+
+      $ make menuconfig LLVM=1
+
+    Turn on AutoFDO build config::
+
+      CONFIG_AUTOFDO_CLANG=y
+
+    With a configuration that with LLVM enabled, use the following command::
+
+      $ scripts/config -e AUTOFDO_CLANG
+
+    After getting the config, build with ::
+
+      $ make LLVM=1
+
+2) Install the kernel on the test machine.
+
+3) Run the load tests. The '-c' option in perf specifies the sample
+   event period. We suggest using a suitable prime number, like 500009,
+   for this purpose.
+
+   - For Intel platforms::
+
+      $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> -o <perf_file> -- <loadtest>
+
+   - For AMD platforms:
+
+     The supported systems are: Zen3 with BRS, or Zen4 with amd_lbr_v2. To check,
+
+     For Zen3::
+
+      $ cat proc/cpuinfo | grep " brs"
+
+     For Zen4::
+
+      $ cat proc/cpuinfo | grep amd_lbr_v2
+
+     The following command generated the perf data file::
+
+      $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a -N -b -c <count> -o <perf_file> -- <loadtest>
+
+4) (Optional) Download the raw perf file to the host machine.
+
+5) To generate an AutoFDO profile, two offline tools are available:
+   create_llvm_prof and llvm_profgen. The create_llvm_prof tool is part
+   of the AutoFDO project and can be found on GitHub
+   (https://github.com/google/autofdo), version v0.30.1 or later.
+   The llvm_profgen tool is included in the LLVM compiler itself. It's
+   important to note that the version of llvm_profgen doesn't need to match
+   the version of Clang. It needs to be the LLVM 19 release of Clang
+   or later, or just from the LLVM trunk. ::
+
+      $ llvm-profgen --kernel --binary=<vmlinux> --perfdata=<perf_file> -o <profile_file>
+
+   or ::
+
+      $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> --format=extbinary --out=<profile_file>
+
+   Note that multiple AutoFDO profile files can be merged into one via::
+
+      $ llvm-profdata merge -o <profile_file> <profile_1> <profile_2> ... <profile_n>
+
+6) Rebuild the kernel using the AutoFDO profile file with the same config as step 1,
+   (Note CONFIG_AUTOFDO_CLANG needs to be enabled)::
+
+      $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<profile_file>
diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
index 53d4d124f9c5..6945644f7008 100644
--- a/Documentation/dev-tools/index.rst
+++ b/Documentation/dev-tools/index.rst
@@ -34,6 +34,7 @@ Documentation/dev-tools/testing-overview.rst
    ktap
    checkuapi
    gpio-sloppy-logic-analyzer
+   autofdo
 
 
 .. only::  subproject and html
diff --git a/MAINTAINERS b/MAINTAINERS
index bdae0faf000c..1eba172ed532 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3665,6 +3665,13 @@ F:	kernel/audit*
 F:	lib/*audit.c
 K:	\baudit_[a-z_0-9]\+\b
 
+AUTOFDO BUILD
+M:	Rong Xu <xur@google.com>
+M:	Han Shen <shenhan@google.com>
+S:	Supported
+F:	Documentation/dev-tools/autofdo.rst
+F:	scripts/Makefile.autofdo
+
 AUXILIARY BUS DRIVER
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 R:	Dave Ertman <david.m.ertman@intel.com>
diff --git a/Makefile b/Makefile
index 266376f7f164..1f31c633a41d 100644
--- a/Makefile
+++ b/Makefile
@@ -1023,6 +1023,7 @@ include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
 include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
 include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
 include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
+include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
 include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
 
 include $(addprefix $(srctree)/, $(include-y))
diff --git a/arch/Kconfig b/arch/Kconfig
index bd9f095d69fa..8dca3b5e6ef5 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -811,6 +811,26 @@ config LTO_CLANG_THIN
 	  If unsure, say Y.
 endchoice
 
+config ARCH_SUPPORTS_AUTOFDO_CLANG
+	bool
+
+config AUTOFDO_CLANG
+	bool "Enable Clang's AutoFDO build (EXPERIMENTAL)"
+	depends on ARCH_SUPPORTS_AUTOFDO_CLANG
+	depends on CC_IS_CLANG && CLANG_VERSION >= 170000
+	help
+	  This option enables Clang’s AutoFDO build. When
+	  an AutoFDO profile is specified in variable
+	  CLANG_AUTOFDO_PROFILE during the build process,
+	  Clang uses the profile to optimize the kernel.
+
+	  If no profile is specified, AutoFDO options are
+	  still passed to Clang to facilitate the collection
+	  of perf data for creating an AutoFDO profile in
+	  subsequent builds.
+
+	  If unsure, say N.
+
 config ARCH_SUPPORTS_CFI_CLANG
 	bool
 	help
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 16354dfa6d96..9dc87661fb37 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -126,6 +126,7 @@ config X86
 	select ARCH_SUPPORTS_LTO_CLANG
 	select ARCH_SUPPORTS_LTO_CLANG_THIN
 	select ARCH_SUPPORTS_RT
+	select ARCH_SUPPORTS_AUTOFDO_CLANG
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
 	select ARCH_USE_MEMTEST
diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo
new file mode 100644
index 000000000000..ff96a63fea7c
--- /dev/null
+++ b/scripts/Makefile.autofdo
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Enable available and selected Clang AutoFDO features.
+
+CFLAGS_AUTOFDO_CLANG := -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true
+
+ifndef CONFIG_DEBUG_INFO
+  CFLAGS_AUTOFDO_CLANG += -gmlt
+endif
+
+ifdef CLANG_AUTOFDO_PROFILE
+  CFLAGS_AUTOFDO_CLANG += -fprofile-sample-use=$(CLANG_AUTOFDO_PROFILE)
+endif
+
+ifdef CONFIG_LTO_CLANG_THIN
+  ifdef CLANG_AUTOFDO_PROFILE
+    KBUILD_LDFLAGS += --lto-sample-profile=$(CLANG_AUTOFDO_PROFILE)
+  endif
+  KBUILD_LDFLAGS += --mllvm=-enable-fs-discriminator=true --mllvm=-improved-fs-discriminator=true -plugin-opt=thinlto
+endif
+
+export CFLAGS_AUTOFDO_CLANG
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 01a9f567d5af..2d0942c1a027 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -191,6 +191,16 @@ _c_flags += $(if $(patsubst n%,, \
 	-D__KCSAN_INSTRUMENT_BARRIERS__)
 endif
 
+#
+# Enable AutoFDO build flags except some files or directories we don't want to
+# enable (depends on variables AUTOFDO_PROFILE_obj.o and AUTOFDO_PROFILE).
+#
+ifeq ($(CONFIG_AUTOFDO_CLANG),y)
+_c_flags += $(if $(patsubst n%,, \
+	$(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(is-kernel-object)), \
+	$(CFLAGS_AUTOFDO_CLANG))
+endif
+
 # $(src) for including checkin headers from generated source files
 # $(obj) for including generated headers from checkin source files
 ifeq ($(KBUILD_EXTMOD),)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 6604f5d038aa..4c5229991e1e 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4557,6 +4557,7 @@ static int validate_ibt(struct objtool_file *file)
 		    !strcmp(sec->name, "__jump_table")			||
 		    !strcmp(sec->name, "__mcount_loc")			||
 		    !strcmp(sec->name, ".kcfi_traps")			||
+		    !strcmp(sec->name, ".llvm.call-graph-profile")	||
 		    strstr(sec->name, "__patchable_function_entries"))
 			continue;
 
-- 
2.51.0


From 18e885099f1c52755f054202525cb60d3edcda44 Mon Sep 17 00:00:00 2001
From: Rong Xu <xur@google.com>
Date: Sat, 2 Nov 2024 10:51:09 -0700
Subject: [PATCH 14/16] objtool: Fix unreachable instruction warnings for weak
 functions

In the presence of both weak and strong function definitions, the
linker drops the weak symbol in favor of a strong symbol, but
leaves the code in place. Code in ignore_unreachable_insn() has
some heuristics to suppress the warning, but it does not work when
-ffunction-sections is enabled.

Suppose function foo has both strong and weak definitions.
Case 1: The strong definition has an annotated section name,
like .init.text. Only the weak definition will be placed into
.text.foo. But since the section has no symbols, there will be no
"hole" in the section.

Case 2: Both sections are without an annotated section name.
Both will be placed into .text.foo section, but there will be only one
symbol (the strong one). If the weak code is before the strong code,
there is no "hole" as it fails to find the right-most symbol before
the offset.

The fix is to use the first node to compute the hole if hole.sym
is empty. If there is no symbol in the section, the first node
will be NULL, in which case, -1 is returned to skip the whole
section.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 tools/objtool/elf.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 3d27983dc908..6f64d611faea 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -224,12 +224,17 @@ int find_symbol_hole_containing(const struct section *sec, unsigned long offset)
 	if (n)
 		return 0; /* not a hole */
 
-	/* didn't find a symbol for which @offset is after it */
-	if (!hole.sym)
-		return 0; /* not a hole */
+	/*
+	 * @offset >= sym->offset + sym->len, find symbol after it.
+	 * When hole.sym is empty, use the first node to compute the hole.
+	 * If there is no symbol in the section, the first node will be NULL,
+	 * in which case, -1 is returned to skip the whole section.
+	 */
+	if (hole.sym)
+		n = rb_next(&hole.sym->node);
+	else
+		n = rb_first_cached(&sec->symbol_tree);
 
-	/* @offset >= sym->offset + sym->len, find symbol after it */
-	n = rb_next(&hole.sym->node);
 	if (!n)
 		return -1; /* until end of address space */
 
-- 
2.51.0


From 52892ed6b03a14b961c1df783ed05763758abc73 Mon Sep 17 00:00:00 2001
From: Rong Xu <xur@google.com>
Date: Tue, 26 Nov 2024 09:34:09 -0800
Subject: [PATCH 15/16] MIPS: Place __kernel_entry at the beginning of text
 section

Mark __kernel_entry as ".head.text" and place HEAD_TEXT before
TEXT_TEXT in the linker script. This ensures that __kernel_entry
will be placed at the beginning of text section.

Drop mips from scripts/head-object-list.txt.

Signed-off-by: Rong Xu <xur@google.com>
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Closes: https://lore.kernel.org/lkml/c6719149-8531-4174-824e-a3caf4bc6d0e@alliedtelesis.co.nz/T/
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 arch/mips/kernel/head.S        | 1 +
 arch/mips/kernel/vmlinux.lds.S | 1 +
 scripts/head-object-list.txt   | 1 -
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index b825ed4476c7..e3ff6179c99f 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -59,6 +59,7 @@
 #endif
 	.endm
 
+	__HEAD
 #ifndef CONFIG_NO_EXCEPT_FILL
 	/*
 	 * Reserved space for exception handlers.
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 9ff55cb80a64..2b708fac8d2c 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -61,6 +61,7 @@ SECTIONS
 	/* read-only */
 	_text = .;	/* Text and read-only data */
 	.text : {
+		HEAD_TEXT
 		TEXT_TEXT
 		SCHED_TEXT
 		LOCK_TEXT
diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
index fd5d00bac447..f12b4a7b8406 100644
--- a/scripts/head-object-list.txt
+++ b/scripts/head-object-list.txt
@@ -23,7 +23,6 @@ arch/m68k/coldfire/head.o
 arch/m68k/kernel/head.o
 arch/m68k/kernel/sun3-head.o
 arch/microblaze/kernel/head.o
-arch/mips/kernel/head.o
 arch/nios2/kernel/head.o
 arch/openrisc/kernel/head.o
 arch/parisc/kernel/head.o
-- 
2.51.0


From 0043ecea2399ffc8bfd99ed9dbbe766e7c79293c Mon Sep 17 00:00:00 2001
From: Rong Xu <xur@google.com>
Date: Sat, 2 Nov 2024 10:51:10 -0700
Subject: [PATCH 16/16] vmlinux.lds.h: Adjust symbol ordering in text output
 section
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

When the -ffunction-sections compiler option is enabled, each function
is placed in a separate section named .text.function_name rather than
putting all functions in a single .text section.

However, using -function-sections can cause problems with the
linker script. The comments included in include/asm-generic/vmlinux.lds.h
note these issues.:
  “TEXT_MAIN here will match .text.fixup and .text.unlikely if dead
   code elimination is enabled, so these sections should be converted
   to use ".." first.”

It is unclear whether there is a straightforward method for converting
a suffix to "..".

This patch modifies the order of subsections within the text output
section. Specifically, it changes current order:
  .text.hot, .text, .text_unlikely, .text.unknown, .text.asan
to the new order:
  .text.asan, .text.unknown, .text_unlikely, .text.hot, .text

Here is the rationale behind the new layout:

The majority of the code resides in three sections: .text.hot, .text,
and .text.unlikely, with .text.unknown containing a negligible amount.
.text.asan is only generated in ASAN builds.

The primary goal is to group code segments based on their execution
frequency (hotness).

First, we want to place .text.hot adjacent to .text. Since we cannot put
.text.hot after .text (Due to constraints with -ffunction-sections,
placing .text.hot after .text is problematic), we need to put
.text.hot before .text.

Then it comes to .text.unlikely, we cannot put it after .text (same
-ffunction-sections issue) . Therefore, we position .text.unlikely
before .text.hot.

.text.unknown and .tex.asan follow the same logic.

This revised ordering effectively reverses the original arrangement (for
.text.unlikely, .text.unknown, and .tex.asan), maintaining a similar level
of affinity between sections.

It also places .text.hot section at the beginning of a page to better
utilize the TLB entry.

Note that the limitation arises because the linker script employs glob
patterns instead of regular expressions for string matching. While there
is a method to maintain the current order using complex patterns, this
significantly complicates the pattern and increases the likelihood of
errors.

This patch also changes vmlinux.lds.S for the sparc64 architecture to
accommodate specific symbol placement requirements.

Co-developed-by: Han Shen <shenhan@google.com>
Signed-off-by: Han Shen <shenhan@google.com>
Signed-off-by: Rong Xu <xur@google.com>
Suggested-by: Sriraman Tallam <tmsriram@google.com>
Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com>
Tested-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Yabin Cui <yabinc@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 arch/sparc/kernel/vmlinux.lds.S   |  5 +++++
 include/asm-generic/vmlinux.lds.h | 19 ++++++++++++-------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index d317a843f7ea..f1b86eb30340 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -48,6 +48,11 @@ SECTIONS
 	{
 		_text = .;
 		HEAD_TEXT
+	        ALIGN_FUNCTION();
+#ifdef CONFIG_SPARC64
+	        /* Match text section symbols in head_64.S first */
+	        *head_64.o(.text)
+#endif
 		TEXT_TEXT
 		SCHED_TEXT
 		LOCK_TEXT
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index eeadbaeccf88..fd901951549c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -553,19 +553,24 @@
  * .text section. Map to function alignment to avoid address changes
  * during second ld run in second ld pass when generating System.map
  *
- * TEXT_MAIN here will match .text.fixup and .text.unlikely if dead
- * code elimination is enabled, so these sections should be converted
- * to use ".." first.
+ * TEXT_MAIN here will match symbols with a fixed pattern (for example,
+ * .text.hot or .text.unlikely) if dead code elimination or
+ * function-section is enabled. Match these symbols first before
+ * TEXT_MAIN to ensure they are grouped together.
+ *
+ * Also placing .text.hot section at the beginning of a page, this
+ * would help the TLB performance.
  */
 #define TEXT_TEXT							\
 		ALIGN_FUNCTION();					\
+		*(.text.asan.* .text.tsan.*)				\
+		*(.text.unknown .text.unknown.*)			\
+		*(.text.unlikely .text.unlikely.*)			\
+		. = ALIGN(PAGE_SIZE);					\
 		*(.text.hot .text.hot.*)				\
 		*(TEXT_MAIN .text.fixup)				\
-		*(.text.unlikely .text.unlikely.*)			\
-		*(.text.unknown .text.unknown.*)			\
 		NOINSTR_TEXT						\
-		*(.ref.text)						\
-		*(.text.asan.* .text.tsan.*)
+		*(.ref.text)
 
 
 /* sched.text is aling to function alignment to secure we have same
-- 
2.51.0