TESTING: drivers/staging: add module for testing code taggingmemalloc_prof_v2

Test:
echo 0 > /proc/sys/kernel/panic_on_warn
insmod ctagmod.ko
echo 64 > /sys/kernel/mm/ctagmod/kmalloc_size
echo 4097 > /sys/kernel/mm/ctagmod/pgalloc_size
cat /proc/allocinfo
rmmod ctagmod.ko <-- should generate a warning about leaks
cat /proc/allocinfo

Signed-off-by: Suren Baghdasaryan <surenb@google.com>

6 files changed, 139 insertions, 0 deletions

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 784b9f673ead..0c303e5a0052 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -74,4 +74,6 @@ source "drivers/staging/fieldbus/Kconfig"
 
 source "drivers/staging/vme_user/Kconfig"
 
+source "drivers/staging/ctagmod/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 2ea99c7b05d9..35225df29842 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -26,3 +26,4 @@ obj-$(CONFIG_BCM2835_VCHIQ)	+= vc04_services/
 obj-$(CONFIG_PI433)		+= pi433/
 obj-$(CONFIG_XIL_AXIS_FIFO)	+= axis-fifo/
 obj-$(CONFIG_FIELDBUS_DEV)     += fieldbus/
+obj-$(CONFIG_CTAGMOD)		+= ctagmod/
diff --git a/drivers/staging/ctagmod/Kconfig b/drivers/staging/ctagmod/Kconfig
new file mode 100644
index 000000000000..e66394482888
--- /dev/null
+++ b/drivers/staging/ctagmod/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+config CTAGMOD
+	tristate "Code tagging test module"
+	depends on CODE_TAGGING
+	default m
+	help
+	  Code tagging test module.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called ctagmod.
diff --git a/drivers/staging/ctagmod/Makefile b/drivers/staging/ctagmod/Makefile
new file mode 100644
index 000000000000..63342b42d82c
--- /dev/null
+++ b/drivers/staging/ctagmod/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CTAGMOD) += ctagmod.o
diff --git a/drivers/staging/ctagmod/ctagmod.c b/drivers/staging/ctagmod/ctagmod.c
new file mode 100644
index 000000000000..af41dfbdd411
--- /dev/null
+++ b/drivers/staging/ctagmod/ctagmod.c
@@ -0,0 +1,115 @@
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+MODULE_LICENSE("GPL");
+
+static int kmalloc_sz;
+static void *kmalloc_ptr;
+static int pgalloc_sz;
+static struct page *pgalloc_ptr;
+
+static ssize_t parse_size(const char *buf)
+{
+	unsigned long sz;
+	int err;
+
+	err = kstrtoul(buf, 0, &sz);
+	if (err)
+		return err;
+	return sz;
+}
+
+static ssize_t kmalloc_size_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", kmalloc_sz);
+}
+
+static ssize_t kmalloc_size_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	ssize_t sz = parse_size(buf);
+
+	if (sz < 0)
+		return sz;
+
+	if (kmalloc_sz)
+		kfree(kmalloc_ptr);
+	if (sz > 0) {
+		kmalloc_ptr = kmalloc(sz, GFP_KERNEL);
+		if (unlikely(!kmalloc_ptr)) {
+			printk(KERN_ERR "kmalloc failed!\n");
+			return -ENOMEM;
+		}
+	}
+	kmalloc_sz = sz;
+
+	return count;
+}
+
+static struct kobj_attribute dev_attr_kmalloc_size = __ATTR_RW_MODE(kmalloc_size, 0600);
+
+static ssize_t pgalloc_size_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", pgalloc_sz);
+}
+
+static ssize_t pgalloc_size_store(struct kobject *kobj, struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	ssize_t sz = parse_size(buf);
+
+	if (sz < 0)
+		return sz;
+
+	if (pgalloc_sz)
+		free_pages((unsigned long)page_address(pgalloc_ptr), get_order(pgalloc_sz));
+	if (sz > 0) {
+		pgalloc_ptr = alloc_pages(GFP_KERNEL, get_order(sz));
+		if (unlikely(!pgalloc_ptr)) {
+			printk(KERN_ERR "alloc_pages failed!\n");
+			return -ENOMEM;
+		}
+	}
+	pgalloc_sz = sz;
+
+	return count;
+}
+
+static struct kobj_attribute dev_attr_pgalloc_size = __ATTR_RW_MODE(pgalloc_size, 0600);
+
+static struct attribute *ctagmod_attributes[] = {
+	&dev_attr_kmalloc_size.attr,
+	&dev_attr_pgalloc_size.attr,
+	NULL
+};
+
+static struct attribute_group ctagmod_attr_group = {
+	.name = "ctagmod",
+	.attrs = ctagmod_attributes,
+};
+
+static int __init ctagmod_start(void)
+{
+	printk(KERN_INFO "Loading ctagmod module\n");
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	if (sysfs_create_group(mm_kobj, &ctagmod_attr_group))
+		pr_err("ctagmod: failed to create sysfs group\n");
+#else
+	printk(KERN_INFO "CONFIG_MEM_ALLOC_PROFILING is undefined\n");
+#endif
+	return 0;
+}
+
+static void __exit ctagmod_end(void)
+{
+	printk(KERN_INFO "Unloading ctagmod module\n");
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	sysfs_remove_group(mm_kobj, &ctagmod_attr_group);
+#endif
+}
+
+module_init(ctagmod_start);
+module_exit(ctagmod_end);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 0e49984826a6..f1093c6f4843 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -998,6 +998,15 @@ config MEM_ALLOC_PROFILING_DEBUG
 	  Adds warnings with helpful error messages for memory allocation
 	  profiling.
 
+config CODE_TAG_TESTING
+	bool "Enable code tag testing"
+	default y
+	select MEM_ALLOC_PROFILING
+	select MEM_ALLOC_PROFILING_DEBUG
+	select STAGING
+	help
+	  Enable to test code tagging.
+
 source "lib/Kconfig.kasan"
 source "lib/Kconfig.kfence"
 source "lib/Kconfig.kmsan"