![Juerg Haefliger](/assets/img/avatar_default.png)
No jprobe is registered when the module is loaded without specifying a crashpoint that uses a jprobe. At the moment, we unconditionally try to unregister the jprobe on module unload which results in an Oops. Add a check to fix this. Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
549 lines
13 KiB
C
549 lines
13 KiB
C
/*
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* Linux Kernel Dump Test Module for testing kernel crashes conditions:
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* induces system failures at predefined crashpoints and under predefined
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* operational conditions in order to evaluate the reliability of kernel
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* sanity checking and crash dumps obtained using different dumping
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* solutions.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright (C) IBM Corporation, 2006
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*
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* Author: Ankita Garg <ankita@in.ibm.com>
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*
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* It is adapted from the Linux Kernel Dump Test Tool by
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* Fernando Luis Vazquez Cao <http://lkdtt.sourceforge.net>
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*
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* Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
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*
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* See Documentation/fault-injection/provoke-crashes.txt for instructions
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*/
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#include "lkdtm.h"
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/buffer_head.h>
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#include <linux/kprobes.h>
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#include <linux/list.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/hrtimer.h>
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#include <linux/slab.h>
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#include <scsi/scsi_cmnd.h>
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#include <linux/debugfs.h>
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#ifdef CONFIG_IDE
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#include <linux/ide.h>
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#endif
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#define DEFAULT_COUNT 10
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static int lkdtm_debugfs_open(struct inode *inode, struct file *file);
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static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
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size_t count, loff_t *off);
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static ssize_t direct_entry(struct file *f, const char __user *user_buf,
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size_t count, loff_t *off);
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#ifdef CONFIG_KPROBES
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static void lkdtm_handler(void);
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static ssize_t lkdtm_debugfs_entry(struct file *f,
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const char __user *user_buf,
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size_t count, loff_t *off);
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/* jprobe entry point handlers. */
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static unsigned int jp_do_irq(unsigned int irq)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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static irqreturn_t jp_handle_irq_event(unsigned int irq,
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struct irqaction *action)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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static void jp_tasklet_action(struct softirq_action *a)
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{
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lkdtm_handler();
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jprobe_return();
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}
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static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
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{
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lkdtm_handler();
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jprobe_return();
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}
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struct scan_control;
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static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
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struct zone *zone,
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struct scan_control *sc)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
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const enum hrtimer_mode mode)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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# ifdef CONFIG_IDE
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static int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
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struct block_device *bdev, unsigned int cmd,
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unsigned long arg)
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{
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lkdtm_handler();
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jprobe_return();
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return 0;
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}
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# endif
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#endif
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/* Crash points */
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struct crashpoint {
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const char *name;
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const struct file_operations fops;
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struct jprobe jprobe;
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};
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#define CRASHPOINT(_name, _write, _symbol, _entry) \
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{ \
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.name = _name, \
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.fops = { \
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.read = lkdtm_debugfs_read, \
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.llseek = generic_file_llseek, \
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.open = lkdtm_debugfs_open, \
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.write = _write, \
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}, \
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.jprobe = { \
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.kp.symbol_name = _symbol, \
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.entry = (kprobe_opcode_t *)_entry, \
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}, \
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}
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/* Define the possible places where we can trigger a crash point. */
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struct crashpoint crashpoints[] = {
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CRASHPOINT("DIRECT", direct_entry,
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NULL, NULL),
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#ifdef CONFIG_KPROBES
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CRASHPOINT("INT_HARDWARE_ENTRY", lkdtm_debugfs_entry,
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"do_IRQ", jp_do_irq),
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CRASHPOINT("INT_HW_IRQ_EN", lkdtm_debugfs_entry,
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"handle_IRQ_event", jp_handle_irq_event),
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CRASHPOINT("INT_TASKLET_ENTRY", lkdtm_debugfs_entry,
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"tasklet_action", jp_tasklet_action),
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CRASHPOINT("FS_DEVRW", lkdtm_debugfs_entry,
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"ll_rw_block", jp_ll_rw_block),
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CRASHPOINT("MEM_SWAPOUT", lkdtm_debugfs_entry,
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"shrink_inactive_list", jp_shrink_inactive_list),
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CRASHPOINT("TIMERADD", lkdtm_debugfs_entry,
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"hrtimer_start", jp_hrtimer_start),
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CRASHPOINT("SCSI_DISPATCH_CMD", lkdtm_debugfs_entry,
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"scsi_dispatch_cmd", jp_scsi_dispatch_cmd),
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# ifdef CONFIG_IDE
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CRASHPOINT("IDE_CORE_CP", lkdtm_debugfs_entry,
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"generic_ide_ioctl", jp_generic_ide_ioctl),
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# endif
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#endif
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};
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/* Crash types. */
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struct crashtype {
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const char *name;
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void (*func)(void);
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};
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#define CRASHTYPE(_name) \
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{ \
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.name = __stringify(_name), \
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.func = lkdtm_ ## _name, \
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}
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/* Define the possible types of crashes that can be triggered. */
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struct crashtype crashtypes[] = {
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CRASHTYPE(PANIC),
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CRASHTYPE(BUG),
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CRASHTYPE(WARNING),
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CRASHTYPE(EXCEPTION),
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CRASHTYPE(LOOP),
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CRASHTYPE(OVERFLOW),
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CRASHTYPE(CORRUPT_LIST_ADD),
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CRASHTYPE(CORRUPT_LIST_DEL),
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CRASHTYPE(CORRUPT_STACK),
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CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
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CRASHTYPE(OVERWRITE_ALLOCATION),
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CRASHTYPE(WRITE_AFTER_FREE),
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CRASHTYPE(READ_AFTER_FREE),
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CRASHTYPE(WRITE_BUDDY_AFTER_FREE),
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CRASHTYPE(READ_BUDDY_AFTER_FREE),
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CRASHTYPE(SOFTLOCKUP),
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CRASHTYPE(HARDLOCKUP),
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CRASHTYPE(SPINLOCKUP),
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CRASHTYPE(HUNG_TASK),
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CRASHTYPE(EXEC_DATA),
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CRASHTYPE(EXEC_STACK),
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CRASHTYPE(EXEC_KMALLOC),
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CRASHTYPE(EXEC_VMALLOC),
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CRASHTYPE(EXEC_RODATA),
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CRASHTYPE(EXEC_USERSPACE),
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CRASHTYPE(ACCESS_USERSPACE),
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CRASHTYPE(WRITE_RO),
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CRASHTYPE(WRITE_RO_AFTER_INIT),
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CRASHTYPE(WRITE_KERN),
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CRASHTYPE(ATOMIC_UNDERFLOW),
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CRASHTYPE(ATOMIC_OVERFLOW),
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CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
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CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
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CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
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CRASHTYPE(USERCOPY_HEAP_FLAG_FROM),
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CRASHTYPE(USERCOPY_STACK_FRAME_TO),
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CRASHTYPE(USERCOPY_STACK_FRAME_FROM),
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CRASHTYPE(USERCOPY_STACK_BEYOND),
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CRASHTYPE(USERCOPY_KERNEL),
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};
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/* Global jprobe entry and crashtype. */
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static struct jprobe *lkdtm_jprobe;
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struct crashpoint *lkdtm_crashpoint;
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struct crashtype *lkdtm_crashtype;
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/* Module parameters */
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static int recur_count = -1;
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module_param(recur_count, int, 0644);
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MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
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static char* cpoint_name;
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module_param(cpoint_name, charp, 0444);
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MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
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static char* cpoint_type;
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module_param(cpoint_type, charp, 0444);
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MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
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"hitting the crash point");
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static int cpoint_count = DEFAULT_COUNT;
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module_param(cpoint_count, int, 0644);
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MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\
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"crash point is to be hit to trigger action");
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/* Return the crashtype number or NULL if the name is invalid */
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static struct crashtype *find_crashtype(const char *name)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
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if (!strcmp(name, crashtypes[i].name))
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return &crashtypes[i];
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}
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return NULL;
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}
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/*
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* This is forced noinline just so it distinctly shows up in the stackdump
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* which makes validation of expected lkdtm crashes easier.
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*/
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static noinline void lkdtm_do_action(struct crashtype *crashtype)
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{
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BUG_ON(!crashtype || !crashtype->func);
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crashtype->func();
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}
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static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
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struct crashtype *crashtype)
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{
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int ret;
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/* If this doesn't have a symbol, just call immediately. */
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if (!crashpoint->jprobe.kp.symbol_name) {
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lkdtm_do_action(crashtype);
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return 0;
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}
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if (lkdtm_jprobe != NULL)
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unregister_jprobe(lkdtm_jprobe);
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lkdtm_crashpoint = crashpoint;
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lkdtm_crashtype = crashtype;
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lkdtm_jprobe = &crashpoint->jprobe;
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ret = register_jprobe(lkdtm_jprobe);
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if (ret < 0) {
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pr_info("Couldn't register jprobe %s\n",
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crashpoint->jprobe.kp.symbol_name);
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lkdtm_jprobe = NULL;
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lkdtm_crashpoint = NULL;
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lkdtm_crashtype = NULL;
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}
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return ret;
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}
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#ifdef CONFIG_KPROBES
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/* Global crash counter and spinlock. */
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static int crash_count = DEFAULT_COUNT;
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static DEFINE_SPINLOCK(crash_count_lock);
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/* Called by jprobe entry points. */
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static void lkdtm_handler(void)
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{
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unsigned long flags;
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bool do_it = false;
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BUG_ON(!lkdtm_crashpoint || !lkdtm_crashtype);
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spin_lock_irqsave(&crash_count_lock, flags);
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crash_count--;
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pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
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lkdtm_crashpoint->name, lkdtm_crashtype->name, crash_count);
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if (crash_count == 0) {
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do_it = true;
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crash_count = cpoint_count;
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}
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spin_unlock_irqrestore(&crash_count_lock, flags);
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if (do_it)
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lkdtm_do_action(lkdtm_crashtype);
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}
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static ssize_t lkdtm_debugfs_entry(struct file *f,
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const char __user *user_buf,
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size_t count, loff_t *off)
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{
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struct crashpoint *crashpoint = file_inode(f)->i_private;
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struct crashtype *crashtype = NULL;
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char *buf;
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int err;
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if (count >= PAGE_SIZE)
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return -EINVAL;
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buf = (char *)__get_free_page(GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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if (copy_from_user(buf, user_buf, count)) {
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free_page((unsigned long) buf);
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return -EFAULT;
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}
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/* NULL-terminate and remove enter */
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buf[count] = '\0';
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strim(buf);
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crashtype = find_crashtype(buf);
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free_page((unsigned long)buf);
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if (!crashtype)
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return -EINVAL;
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err = lkdtm_register_cpoint(crashpoint, crashtype);
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if (err < 0)
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return err;
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*off += count;
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return count;
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}
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#endif
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/* Generic read callback that just prints out the available crash types */
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static ssize_t lkdtm_debugfs_read(struct file *f, char __user *user_buf,
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size_t count, loff_t *off)
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{
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char *buf;
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int i, n, out;
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buf = (char *)__get_free_page(GFP_KERNEL);
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if (buf == NULL)
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return -ENOMEM;
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n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
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for (i = 0; i < ARRAY_SIZE(crashtypes); i++) {
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n += snprintf(buf + n, PAGE_SIZE - n, "%s\n",
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crashtypes[i].name);
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}
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buf[n] = '\0';
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out = simple_read_from_buffer(user_buf, count, off,
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buf, n);
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free_page((unsigned long) buf);
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return out;
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}
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static int lkdtm_debugfs_open(struct inode *inode, struct file *file)
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{
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return 0;
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}
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/* Special entry to just crash directly. Available without KPROBEs */
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static ssize_t direct_entry(struct file *f, const char __user *user_buf,
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size_t count, loff_t *off)
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{
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struct crashtype *crashtype;
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char *buf;
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if (count >= PAGE_SIZE)
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return -EINVAL;
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if (count < 1)
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return -EINVAL;
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buf = (char *)__get_free_page(GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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if (copy_from_user(buf, user_buf, count)) {
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free_page((unsigned long) buf);
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return -EFAULT;
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}
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/* NULL-terminate and remove enter */
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buf[count] = '\0';
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strim(buf);
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crashtype = find_crashtype(buf);
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free_page((unsigned long) buf);
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if (!crashtype)
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return -EINVAL;
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pr_info("Performing direct entry %s\n", crashtype->name);
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lkdtm_do_action(crashtype);
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*off += count;
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return count;
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}
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static struct dentry *lkdtm_debugfs_root;
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static int __init lkdtm_module_init(void)
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{
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struct crashpoint *crashpoint = NULL;
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struct crashtype *crashtype = NULL;
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int ret = -EINVAL;
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int i;
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/* Neither or both of these need to be set */
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if ((cpoint_type || cpoint_name) && !(cpoint_type && cpoint_name)) {
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pr_err("Need both cpoint_type and cpoint_name or neither\n");
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return -EINVAL;
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}
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if (cpoint_type) {
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crashtype = find_crashtype(cpoint_type);
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if (!crashtype) {
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pr_err("Unknown crashtype '%s'\n", cpoint_type);
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return -EINVAL;
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}
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}
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if (cpoint_name) {
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for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
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if (!strcmp(cpoint_name, crashpoints[i].name))
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crashpoint = &crashpoints[i];
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}
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/* Refuse unknown crashpoints. */
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if (!crashpoint) {
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pr_err("Invalid crashpoint %s\n", cpoint_name);
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return -EINVAL;
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}
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}
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#ifdef CONFIG_KPROBES
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/* Set crash count. */
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crash_count = cpoint_count;
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#endif
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/* Handle test-specific initialization. */
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lkdtm_bugs_init(&recur_count);
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lkdtm_perms_init();
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lkdtm_usercopy_init();
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/* Register debugfs interface */
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lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
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if (!lkdtm_debugfs_root) {
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pr_err("creating root dir failed\n");
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return -ENODEV;
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}
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/* Install debugfs trigger files. */
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for (i = 0; i < ARRAY_SIZE(crashpoints); i++) {
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struct crashpoint *cur = &crashpoints[i];
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struct dentry *de;
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de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
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cur, &cur->fops);
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if (de == NULL) {
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pr_err("could not create crashpoint %s\n", cur->name);
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
/* 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_usercopy_exit();
|
|
|
|
if (lkdtm_jprobe != NULL)
|
|
unregister_jprobe(lkdtm_jprobe);
|
|
|
|
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");
|