3 files changed, 0 insertions, 118 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 3c3f8037ebed..c645bb453f3b 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -449,20 +449,6 @@ config ACPI_HED
 	  which is used to report some hardware errors notified via
 	  SCI, mainly the corrected errors.
 
-config ACPI_CUSTOM_METHOD
-	tristate "Allow ACPI methods to be inserted/replaced at run time"
-	depends on DEBUG_FS
-	help
-	  This debug facility allows ACPI AML methods to be inserted and/or
-	  replaced without rebooting the system. For details refer to:
-	  Documentation/firmware-guide/acpi/method-customizing.rst.
-
-	  NOTE: This option is security sensitive, because it allows arbitrary
-	  kernel memory to be written to by root (uid=0) users, allowing them
-	  to bypass certain security measures (e.g. if root is not allowed to
-	  load additional kernel modules after boot, this feature may be used
-	  to override that restriction).
-
 config ACPI_BGRT
 	bool "Boottime Graphics Resource Table support"
 	depends on EFI && (X86 || ARM64)
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 12ef8180d272..8cc8c0d9c873 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -101,7 +101,6 @@ obj-$(CONFIG_ACPI_SBS)		+= sbshc.o
 obj-$(CONFIG_ACPI_SBS)		+= sbs.o
 obj-$(CONFIG_ACPI_HED)		+= hed.o
 obj-$(CONFIG_ACPI_EC_DEBUGFS)	+= ec_sys.o
-obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
 obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o
 obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
deleted file mode 100644
index d39a9b474727..000000000000
--- a/drivers/acpi/custom_method.c
+++ /dev/null
@@ -1,103 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * custom_method.c - debugfs interface for customizing ACPI control method
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/uaccess.h>
-#include <linux/debugfs.h>
-#include <linux/acpi.h>
-#include <linux/security.h>
-
-#include "internal.h"
-
-MODULE_LICENSE("GPL");
-
-static struct dentry *cm_dentry;
-
-/* /sys/kernel/debug/acpi/custom_method */
-
-static ssize_t cm_write(struct file *file, const char __user *user_buf,
-			size_t count, loff_t *ppos)
-{
-	static char *buf;
-	static u32 max_size;
-	static u32 uncopied_bytes;
-
-	struct acpi_table_header table;
-	acpi_status status;
-	int ret;
-
-	ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
-	if (ret)
-		return ret;
-
-	if (!(*ppos)) {
-		/* parse the table header to get the table length */
-		if (count <= sizeof(struct acpi_table_header))
-			return -EINVAL;
-		if (copy_from_user(&table, user_buf,
-				   sizeof(struct acpi_table_header)))
-			return -EFAULT;
-		uncopied_bytes = max_size = table.length;
-		/* make sure the buf is not allocated */
-		kfree(buf);
-		buf = kzalloc(max_size, GFP_KERNEL);
-		if (!buf)
-			return -ENOMEM;
-	}
-
-	if (buf == NULL)
-		return -EINVAL;
-
-	if ((*ppos > max_size) ||
-	    (*ppos + count > max_size) ||
-	    (*ppos + count < count) ||
-	    (count > uncopied_bytes)) {
-		kfree(buf);
-		buf = NULL;
-		return -EINVAL;
-	}
-
-	if (copy_from_user(buf + (*ppos), user_buf, count)) {
-		kfree(buf);
-		buf = NULL;
-		return -EFAULT;
-	}
-
-	uncopied_bytes -= count;
-	*ppos += count;
-
-	if (!uncopied_bytes) {
-		status = acpi_install_method(buf);
-		kfree(buf);
-		buf = NULL;
-		if (ACPI_FAILURE(status))
-			return -EINVAL;
-		add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
-	}
-
-	return count;
-}
-
-static const struct file_operations cm_fops = {
-	.write = cm_write,
-	.llseek = default_llseek,
-};
-
-static int __init acpi_custom_method_init(void)
-{
-	cm_dentry = debugfs_create_file("custom_method", S_IWUSR,
-					acpi_debugfs_dir, NULL, &cm_fops);
-	return 0;
-}
-
-static void __exit acpi_custom_method_exit(void)
-{
-	debugfs_remove(cm_dentry);
-}
-
-module_init(acpi_custom_method_init);
-module_exit(acpi_custom_method_exit);