Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 488 insertions, 0 deletions

diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
new file mode 100644
index 000000000..0772e4a47
--- /dev/null
+++ b/drivers/misc/lkdtm/core.c
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux Kernel Dump Test Module for testing kernel crashes conditions:
+ * induces system failures at predefined crashpoints and under predefined
+ * operational conditions in order to evaluate the reliability of kernel
+ * sanity checking and crash dumps obtained using different dumping
+ * solutions.
+ *
+ * Copyright (C) IBM Corporation, 2006
+ *
+ * Author: Ankita Garg <ankita@in.ibm.com>
+ *
+ * It is adapted from the Linux Kernel Dump Test Tool by
+ * Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
+ *
+ * Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
+ *
+ * See Documentation/fault-injection/provoke-crashes.rst for instructions
+ */
+#include "lkdtm.h"
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/kprobes.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <linux/utsname.h>
+
+#define DEFAULT_COUNT 10
+
+static int lkdtm_debugfs_open(struct inode *inode, struct file *file);
+static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
+		size_t count, loff_t *off);
+static ssize_t direct_entry(struct file *f, const char __user *user_buf,
+			    size_t count, loff_t *off);
+
+#ifdef CONFIG_KPROBES
+static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs);
+static ssize_t lkdtm_debugfs_entry(struct file *f,
+				   const char __user *user_buf,
+				   size_t count, loff_t *off);
+# define CRASHPOINT_KPROBE(_symbol)				\
+		.kprobe = {					\
+			.symbol_name = (_symbol),		\
+			.pre_handler = lkdtm_kprobe_handler,	\
+		},
+# define CRASHPOINT_WRITE(_symbol)				\
+		(_symbol) ? lkdtm_debugfs_entry : direct_entry
+#else
+# define CRASHPOINT_KPROBE(_symbol)
+# define CRASHPOINT_WRITE(_symbol)		direct_entry
+#endif
+
+/* Crash points */
+struct crashpoint {
+	const char *name;
+	const struct file_operations fops;
+	struct kprobe kprobe;
+};
+
+#define CRASHPOINT(_name, _symbol)				\
+	{							\
+		.name = _name,					\
+		.fops = {					\
+			.read	= lkdtm_debugfs_read,		\
+			.llseek	= generic_file_llseek,		\
+			.open	= lkdtm_debugfs_open,		\
+			.write	= CRASHPOINT_WRITE(_symbol)	\
+		},						\
+		CRASHPOINT_KPROBE(_symbol)			\
+	}
+
+/* Define the possible places where we can trigger a crash point. */
+static struct crashpoint crashpoints[] = {
+	CRASHPOINT("DIRECT",		 NULL),
+#ifdef CONFIG_KPROBES
+	CRASHPOINT("INT_HARDWARE_ENTRY", "do_IRQ"),
+	CRASHPOINT("INT_HW_IRQ_EN",	 "handle_irq_event"),
+	CRASHPOINT("INT_TASKLET_ENTRY",	 "tasklet_action"),
+	CRASHPOINT("FS_SUBMIT_BH",		 "submit_bh"),
+	CRASHPOINT("MEM_SWAPOUT",	 "shrink_inactive_list"),
+	CRASHPOINT("TIMERADD",		 "hrtimer_start"),
+	CRASHPOINT("SCSI_QUEUE_RQ",	 "scsi_queue_rq"),
+#endif
+};
+
+/* List of possible types for crashes that can be triggered. */
+static const struct crashtype_category *crashtype_categories[] = {
+	&bugs_crashtypes,
+	&heap_crashtypes,
+	&perms_crashtypes,
+	&refcount_crashtypes,
+	&usercopy_crashtypes,
+	&stackleak_crashtypes,
+	&cfi_crashtypes,
+	&fortify_crashtypes,
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	&powerpc_crashtypes,
+#endif
+};
+
+/* Global kprobe entry and crashtype. */
+static struct kprobe *lkdtm_kprobe;
+static struct crashpoint *lkdtm_crashpoint;
+static const struct crashtype *lkdtm_crashtype;
+
+/* Module parameters */
+static int recur_count = -1;
+module_param(recur_count, int, 0644);
+MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
+
+static char* cpoint_name;
+module_param(cpoint_name, charp, 0444);
+MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
+
+static char* cpoint_type;
+module_param(cpoint_type, charp, 0444);
+MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
+				"hitting the crash point");
+
+static int cpoint_count = DEFAULT_COUNT;
+module_param(cpoint_count, int, 0644);
+MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
+				"crash point is to be hit to trigger action");
+
+/*
+ * For test debug reporting when CI systems provide terse summaries.
+ * TODO: Remove this once reasonable reporting exists in most CI systems:
+ * https://lore.kernel.org/lkml/CAHk-=wiFvfkoFixTapvvyPMN9pq5G-+Dys2eSyBa1vzDGAO5+A@mail.gmail.com
+ */
+char *lkdtm_kernel_info;
+
+/* Return the crashtype number or NULL if the name is invalid */
+static const struct crashtype *find_crashtype(const char *name)
+{
+	int cat, idx;
+
+	for (cat = 0; cat < ARRAY_SIZE(crashtype_categories); cat++) {
+		for (idx = 0; idx < crashtype_categories[cat]->len; idx++) {
+			struct crashtype *crashtype;
+
+			crashtype = &crashtype_categories[cat]->crashtypes[idx];
+			if (!strcmp(name, crashtype->name))
+				return crashtype;
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * This is forced noinline just so it distinctly shows up in the stackdump
+ * which makes validation of expected lkdtm crashes easier.
+ */
+static noinline void lkdtm_do_action(const struct crashtype *crashtype)
+{
+	if (WARN_ON(!crashtype || !crashtype->func))
+		return;
+	crashtype->func();
+}
+
+static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
+				 const struct crashtype *crashtype)
+{
+	int ret;
+
+	/* If this doesn't have a symbol, just call immediately. */
+	if (!crashpoint->kprobe.symbol_name) {
+		lkdtm_do_action(crashtype);
+		return 0;
+	}
+
+	if (lkdtm_kprobe != NULL)
+		unregister_kprobe(lkdtm_kprobe);
+
+	lkdtm_crashpoint = crashpoint;
+	lkdtm_crashtype = crashtype;
+	lkdtm_kprobe = &crashpoint->kprobe;
+	ret = register_kprobe(lkdtm_kprobe);
+	if (ret < 0) {
+		pr_info("Couldn't register kprobe %s\n",
+			crashpoint->kprobe.symbol_name);
+		lkdtm_kprobe = NULL;
+		lkdtm_crashpoint = NULL;
+		lkdtm_crashtype = NULL;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_KPROBES
+/* Global crash counter and spinlock. */
+static int crash_count = DEFAULT_COUNT;
+static DEFINE_SPINLOCK(crash_count_lock);
+
+/* Called by kprobe entry points. */
+static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
+{
+	unsigned long flags;
+	bool do_it = false;
+
+	if (WARN_ON(!lkdtm_crashpoint || !lkdtm_crashtype))
+		return 0;
+
+	spin_lock_irqsave(&crash_count_lock, flags);
+	crash_count--;
+	pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
+		lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);
+
+	if (crash_count == 0) {
+		do_it = true;
+		crash_count = cpoint_count;
+	}
+	spin_unlock_irqrestore(&crash_count_lock, flags);
+
+	if (do_it)
+		lkdtm_do_action(lkdtm_crashtype);
+
+	return 0;
+}
+
+static ssize_t lkdtm_debugfs_entry(struct file *f,
+				   const char __user *user_buf,
+				   size_t count, loff_t *off)
+{
+	struct crashpoint *crashpoint = file_inode(f)->i_private;
+	const struct crashtype *crashtype = NULL;
+	char *buf;
+	int err;
+
+	if (count >= PAGE_SIZE)
+		return -EINVAL;
+
+	buf = (char *)__get_free_page(GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	if (copy_from_user(buf, user_buf, count)) {
+		free_page((unsigned long) buf);
+		return -EFAULT;
+	}
+	/* NULL-terminate and remove enter */
+	buf[count] = '\0';
+	strim(buf);
+
+	crashtype = find_crashtype(buf);
+	free_page((unsigned long)buf);
+
+	if (!crashtype)
+		return -EINVAL;
+
+	err = lkdtm_register_cpoint(crashpoint, crashtype);
+	if (err < 0)
+		return err;
+
+	*off += count;
+
+	return count;
+}
+#endif
+
+/* Generic read callback that just prints out the available crash types */
+static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
+		size_t count, loff_t *off)
+{
+	int n, cat, idx;
+	ssize_t out;
+	char *buf;
+
+	buf = (char *)__get_free_page(GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	n = scnprintf(buf, PAGE_SIZE, "Available crash types:\n");
+
+	for (cat = 0; cat < ARRAY_SIZE(crashtype_categories); cat++) {
+		for (idx = 0; idx < crashtype_categories[cat]->len; idx++) {
+			struct crashtype *crashtype;
+
+			crashtype = &crashtype_categories[cat]->crashtypes[idx];
+			n += scnprintf(buf + n, PAGE_SIZE - n, "%s\n",
+				      crashtype->name);
+		}
+	}
+	buf[n] = '\0';
+
+	out = simple_read_from_buffer(user_buf, count, off,
+				      buf, n);
+	free_page((unsigned long) buf);
+
+	return out;
+}
+
+static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+/* Special entry to just crash directly. Available without KPROBEs */
+static ssize_t direct_entry(struct file *f, const char __user *user_buf,
+		size_t count, loff_t *off)
+{
+	const struct crashtype *crashtype;
+	char *buf;
+
+	if (count >= PAGE_SIZE)
+		return -EINVAL;
+	if (count < 1)
+		return -EINVAL;
+
+	buf = (char *)__get_free_page(GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	if (copy_from_user(buf, user_buf, count)) {
+		free_page((unsigned long) buf);
+		return -EFAULT;
+	}
+	/* NULL-terminate and remove enter */
+	buf[count] = '\0';
+	strim(buf);
+
+	crashtype = find_crashtype(buf);
+	free_page((unsigned long) buf);
+	if (!crashtype)
+		return -EINVAL;
+
+	pr_info("Performing direct entry %s\n", crashtype->name);
+	lkdtm_do_action(crashtype);
+	*off += count;
+
+	return count;
+}
+
+#ifndef MODULE
+/*
+ * To avoid needing to export parse_args(), just don't use this code
+ * when LKDTM is built as a module.
+ */
+struct check_cmdline_args {
+	const char *param;
+	int value;
+};
+
+static int lkdtm_parse_one(char *param, char *val,
+			   const char *unused, void *arg)
+{
+	struct check_cmdline_args *args = arg;
+
+	/* short circuit if we already found a value. */
+	if (args->value != -ESRCH)
+		return 0;
+	if (strncmp(param, args->param, strlen(args->param)) == 0) {
+		bool bool_result;
+		int ret;
+
+		ret = kstrtobool(val, &bool_result);
+		if (ret == 0)
+			args->value = bool_result;
+	}
+	return 0;
+}
+
+int lkdtm_check_bool_cmdline(const char *param)
+{
+	char *command_line;
+	struct check_cmdline_args args = {
+		.param = param,
+		.value = -ESRCH,
+	};
+
+	command_line = kstrdup(saved_command_line, GFP_KERNEL);
+	if (!command_line)
+		return -ENOMEM;
+
+	parse_args("Setting sysctl args", command_line,
+		   NULL, 0, -1, -1, &args, lkdtm_parse_one);
+
+	kfree(command_line);
+
+	return args.value;
+}
+#endif
+
+static struct dentry *lkdtm_debugfs_root;
+
+static int __init lkdtm_module_init(void)
+{
+	struct crashpoint *crashpoint = NULL;
+	const struct crashtype *crashtype = NULL;
+	int ret;
+	int i;
+
+	/* Neither or both of these need to be set */
+	if ((cpoint_type || cpoint_name) && !(cpoint_type && cpoint_name)) {
+		pr_err("Need both cpoint_type and cpoint_name or neither\n");
+		return -EINVAL;
+	}
+
+	if (cpoint_type) {
+		crashtype = find_crashtype(cpoint_type);
+		if (!crashtype) {
+			pr_err("Unknown crashtype '%s'\n", cpoint_type);
+			return -EINVAL;
+		}
+	}
+
+	if (cpoint_name) {
+		for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
+			if (!strcmp(cpoint_name, crashpoints[i].name))
+				crashpoint = &crashpoints[i];
+		}
+
+		/* Refuse unknown crashpoints. */
+		if (!crashpoint) {
+			pr_err("Invalid crashpoint %s\n", cpoint_name);
+			return -EINVAL;
+		}
+	}
+
+#ifdef CONFIG_KPROBES
+	/* Set crash count. */
+	crash_count = cpoint_count;
+#endif
+
+	/* Common initialization. */
+	lkdtm_kernel_info = kasprintf(GFP_KERNEL, "kernel (%s %s)",
+				      init_uts_ns.name.release,
+				      init_uts_ns.name.machine);
+
+	/* Handle test-specific initialization. */
+	lkdtm_bugs_init(&recur_count);
+	lkdtm_perms_init();
+	lkdtm_usercopy_init();
+	lkdtm_heap_init();
+
+	/* Register debugfs interface */
+	lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
+
+	/* Install debugfs trigger files. */
+	for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
+		struct crashpoint *cur = &crashpoints[i];
+
+		debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root, cur,
+				    &cur->fops);
+	}
+
+	/* Install crashpoint if one was selected. */
+	if (crashpoint) {
+		ret = lkdtm_register_cpoint(crashpoint, crashtype);
+		if (ret < 0) {
+			pr_info("Invalid crashpoint %s\n", crashpoint->name);
+			goto out_err;
+		}
+		pr_info("Crash point %s of type %s registered\n",
+			crashpoint->name, cpoint_type);
+	} else {
+		pr_info("No crash points registered, enable through debugfs\n");
+	}
+
+	return 0;
+
+out_err:
+	debugfs_remove_recursive(lkdtm_debugfs_root);
+	return ret;
+}
+
+static void __exit lkdtm_module_exit(void)
+{
+	debugfs_remove_recursive(lkdtm_debugfs_root);
+
+	/* Handle test-specific clean-up. */
+	lkdtm_heap_exit();
+	lkdtm_usercopy_exit();
+
+	if (lkdtm_kprobe != NULL)
+		unregister_kprobe(lkdtm_kprobe);
+
+	kfree(lkdtm_kernel_info);
+
+	pr_info("Crash point unregistered\n");
+}
+
+module_init(lkdtm_module_init);
+module_exit(lkdtm_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Kernel crash testing module");