kernel/gcov: checkout to 4.19-q

* Samsung got this from 4.19-stable, but for us it'll cause conflicts as we're merging 4.19-stable over 4.19-q. So reset it.

Signed-off-by: ExtremeXT <75576145+ExtremeXT@users.noreply.github.com>

kernel/gcov/Kconfig

@@ -53,23 +53,16 @@ config GCOV_PROFILE_ALL
 choice
 	prompt "Specify GCOV format"
 	depends on GCOV_KERNEL
-	default GCOV_FORMAT_AUTODETECT
 	---help---
-	The gcov format is usually determined by the GCC version, but there are
+	The gcov format is usually determined by the GCC version, and the
+	default is chosen according to your GCC version. However, there are
 	exceptions where format changes are integrated in lower-version GCCs.
-	In such a case use this option to adjust the format used in the kernel
-	accordingly.
-
-	If unsure, choose "Autodetect".
-
-config GCOV_FORMAT_AUTODETECT
-	bool "Autodetect"
-	---help---
-	Select this option to use the format that corresponds to your GCC
-	version.
+	In such a case, change this option to adjust the format used in the
+	kernel accordingly.
 
 config GCOV_FORMAT_3_4
 	bool "GCC 3.4 format"
+	depends on CC_IS_GCC && GCC_VERSION < 40700
 	---help---
 	Select this option to use the format defined by GCC 3.4.
 

kernel/gcov/Makefile

@@ -1,12 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"'
 
-ifeq ($(cc-name),clang)
-obj-y := base.o fs.o clang.o
-else
 obj-y := base.o fs.o
-obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_base.o gcc_3_4.o
-obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_base.o gcc_4_7.o
-obj-$(CONFIG_GCOV_FORMAT_AUTODETECT) += $(call cc-ifversion, -lt, 0407, \
-							gcc_base.o gcc_3_4.o, gcc_base.o gcc_4_7.o)
-endif
+obj-$(CONFIG_GCOV_FORMAT_3_4) += gcc_3_4.o
+obj-$(CONFIG_GCOV_FORMAT_4_7) += gcc_4_7.o

kernel/gcov/base.c

@@ -22,8 +22,88 @@
 #include <linux/sched.h>
 #include "gcov.h"
 
-int gcov_events_enabled;
-DEFINE_MUTEX(gcov_lock);
+static int gcov_events_enabled;
+static DEFINE_MUTEX(gcov_lock);
+
+/*
+ * __gcov_init is called by gcc-generated constructor code for each object
+ * file compiled with -fprofile-arcs.
+ */
+void __gcov_init(struct gcov_info *info)
+{
+	static unsigned int gcov_version;
+
+	mutex_lock(&gcov_lock);
+	if (gcov_version == 0) {
+		gcov_version = gcov_info_version(info);
+		/*
+		 * Printing gcc's version magic may prove useful for debugging
+		 * incompatibility reports.
+		 */
+		pr_info("version magic: 0x%x\n", gcov_version);
+	}
+	/*
+	 * Add new profiling data structure to list and inform event
+	 * listener.
+	 */
+	gcov_info_link(info);
+	if (gcov_events_enabled)
+		gcov_event(GCOV_ADD, info);
+	mutex_unlock(&gcov_lock);
+}
+EXPORT_SYMBOL(__gcov_init);
+
+/*
+ * These functions may be referenced by gcc-generated profiling code but serve
+ * no function for kernel profiling.
+ */
+void __gcov_flush(void)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_flush);
+
+void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_add);
+
+void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_single);
+
+void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_delta);
+
+void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_ior);
+
+void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_time_profile);
+
+void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_icall_topn);
+
+void __gcov_exit(void)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_exit);
 
 /**
  * gcov_enable_events - enable event reporting through gcov_event()
@@ -64,7 +144,7 @@ static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
 
 	/* Remove entries located in module from linked list. */
 	while ((info = gcov_info_next(info))) {
-		if (gcov_info_within_module(info, mod)) {
+		if (within_module((unsigned long)info, mod)) {
 			gcov_info_unlink(prev, info);
 			if (gcov_events_enabled)
 				gcov_event(GCOV_REMOVE, info);

kernel/gcov/fs.c

@@ -64,6 +64,7 @@ struct gcov_node {
 static const char objtree[] = OBJTREE;
 static const char srctree[] = SRCTREE;
 static struct gcov_node root_node;
+static struct dentry *reset_dentry;
 static LIST_HEAD(all_head);
 static DEFINE_MUTEX(node_lock);
 
@@ -386,6 +387,8 @@ static void add_links(struct gcov_node *node, struct dentry *parent)
 			goto out_err;
 		node->links[i] = debugfs_create_symlink(deskew(basename),
 							parent,	target);
+		if (!node->links[i])
+			goto out_err;
 		kfree(target);
 	}
 
@@ -447,6 +450,11 @@ static struct gcov_node *new_node(struct gcov_node *parent,
 					parent->dentry, node, &gcov_data_fops);
 	} else
 		node->dentry = debugfs_create_dir(node->name, parent->dentry);
+	if (!node->dentry) {
+		pr_warn("could not create file\n");
+		kfree(node);
+		return NULL;
+	}
 	if (info)
 		add_links(node, parent->dentry);
 	list_add(&node->list, &parent->children);
@@ -753,20 +761,32 @@ void gcov_event(enum gcov_action action, struct gcov_info *info)
 /* Create debugfs entries. */
 static __init int gcov_fs_init(void)
 {
+	int rc = -EIO;
+
 	init_node(&root_node, NULL, NULL, NULL);
 	/*
 	 * /sys/kernel/debug/gcov will be parent for the reset control file
 	 * and all profiling files.
 	 */
 	root_node.dentry = debugfs_create_dir("gcov", NULL);
+	if (!root_node.dentry)
+		goto err_remove;
 	/*
 	 * Create reset file which resets all profiling counts when written
 	 * to.
 	 */
-	debugfs_create_file("reset", 0600, root_node.dentry, NULL,
-			    &gcov_reset_fops);
+	reset_dentry = debugfs_create_file("reset", 0600, root_node.dentry,
+					   NULL, &gcov_reset_fops);
+	if (!reset_dentry)
+		goto err_remove;
 	/* Replay previous events to get our fs hierarchy up-to-date. */
 	gcov_enable_events();
 	return 0;
+
+err_remove:
+	pr_err("init failed\n");
+	debugfs_remove(root_node.dentry);
+
+	return rc;
 }
 device_initcall(gcov_fs_init);

kernel/gcov/gcc_3_4.c

@@ -137,18 +137,6 @@ void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
 		gcov_info_head = info->next;
 }
 
-/**
- * gcov_info_within_module - check if a profiling data set belongs to a module
- * @info: profiling data set
- * @mod: module
- *
- * Returns true if profiling data belongs module, false otherwise.
- */
-bool gcov_info_within_module(struct gcov_info *info, struct module *mod)
-{
-	return within_module((unsigned long)info, mod);
-}
-
 /* Symbolic links to be created for each profiling data file. */
 const struct gcov_link gcov_link[] = {
 	{ OBJ_TREE, "gcno" },	/* Link to .gcno file in $(objtree). */
@@ -257,7 +245,8 @@ struct gcov_info *gcov_info_dup(struct gcov_info *info)
 
 	/* Duplicate gcov_info. */
 	active = num_counter_active(info);
-	dup = kzalloc(struct_size(dup, counts, active), GFP_KERNEL);
+	dup = kzalloc(sizeof(struct gcov_info) +
+		      sizeof(struct gcov_ctr_info) * active, GFP_KERNEL);
 	if (!dup)
 		return NULL;
 	dup->version		= info->version;
@@ -375,7 +364,8 @@ struct gcov_iterator *gcov_iter_new(struct gcov_info *info)
 {
 	struct gcov_iterator *iter;
 
-	iter = kzalloc(struct_size(iter, type_info, num_counter_active(info)),
+	iter = kzalloc(sizeof(struct gcov_iterator) +
+		       num_counter_active(info) * sizeof(struct type_info),
 		       GFP_KERNEL);
 	if (iter)
 		iter->info = info;

kernel/gcov/gcc_4_7.c

@@ -150,18 +150,6 @@ void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info)
 		gcov_info_head = info->next;
 }
 
-/**
- * gcov_info_within_module - check if a profiling data set belongs to a module
- * @info: profiling data set
- * @mod: module
- *
- * Returns true if profiling data belongs module, false otherwise.
- */
-bool gcov_info_within_module(struct gcov_info *info, struct module *mod)
-{
-	return within_module((unsigned long)info, mod);
-}
-
 /* Symbolic links to be created for each profiling data file. */
 const struct gcov_link gcov_link[] = {
 	{ OBJ_TREE, "gcno" },	/* Link to .gcno file in $(objtree). */

kernel/gcov/gcov.h

@@ -15,7 +15,6 @@
 #ifndef GCOV_H
 #define GCOV_H GCOV_H
 
-#include <linux/module.h>
 #include <linux/types.h>
 
 /*
@@ -47,7 +46,6 @@ unsigned int gcov_info_version(struct gcov_info *info);
 struct gcov_info *gcov_info_next(struct gcov_info *info);
 void gcov_info_link(struct gcov_info *info);
 void gcov_info_unlink(struct gcov_info *prev, struct gcov_info *info);
-bool gcov_info_within_module(struct gcov_info *info, struct module *mod);
 
 /* Base interface. */
 enum gcov_action {
@@ -85,7 +83,4 @@ struct gcov_link {
 };
 extern const struct gcov_link gcov_link[];
 
-extern int gcov_events_enabled;
-extern struct mutex gcov_lock;
-
 #endif /* GCOV_H */