linux_dsm_epyc7002/drivers/misc/lkdtm.c

1024 lines
23 KiB
C
Raw Normal View History

/*
* Kprobe module for testing crash dumps
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2006
*
* Author: Ankita Garg <ankita@in.ibm.com>
*
* This module induces system failures at predefined crashpoints to
* evaluate the reliability of crash dumps obtained using different dumping
* solutions.
*
* 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.txt for instructions
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.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/interrupt.h>
#include <linux/hrtimer.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 15:04:11 +07:00
#include <linux/slab.h>
#include <scsi/scsi_cmnd.h>
#include <linux/debugfs.h>
#include <linux/vmalloc.h>
#include <linux/mman.h>
#include <asm/cacheflush.h>
#ifdef CONFIG_IDE
#include <linux/ide.h>
#endif
/*
* Make sure our attempts to over run the kernel stack doesn't trigger
* a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
* recurse past the end of THREAD_SIZE by default.
*/
#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
#else
#define REC_STACK_SIZE (THREAD_SIZE / 8)
#endif
#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
#define DEFAULT_COUNT 10
#define EXEC_SIZE 64
enum cname {
CN_INVALID,
CN_INT_HARDWARE_ENTRY,
CN_INT_HW_IRQ_EN,
CN_INT_TASKLET_ENTRY,
CN_FS_DEVRW,
CN_MEM_SWAPOUT,
CN_TIMERADD,
CN_SCSI_DISPATCH_CMD,
CN_IDE_CORE_CP,
CN_DIRECT,
};
enum ctype {
CT_NONE,
CT_PANIC,
CT_BUG,
CT_WARNING,
CT_EXCEPTION,
CT_LOOP,
CT_OVERFLOW,
CT_CORRUPT_STACK,
CT_UNALIGNED_LOAD_STORE_WRITE,
CT_OVERWRITE_ALLOCATION,
CT_WRITE_AFTER_FREE,
CT_READ_AFTER_FREE,
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
CT_WRITE_BUDDY_AFTER_FREE,
CT_READ_BUDDY_AFTER_FREE,
CT_SOFTLOCKUP,
CT_HARDLOCKUP,
CT_SPINLOCKUP,
CT_HUNG_TASK,
CT_EXEC_DATA,
CT_EXEC_STACK,
CT_EXEC_KMALLOC,
CT_EXEC_VMALLOC,
CT_EXEC_USERSPACE,
CT_ACCESS_USERSPACE,
CT_WRITE_RO,
CT_WRITE_RO_AFTER_INIT,
CT_WRITE_KERN,
lkdtm: add test for atomic_t underflow/overflow dmesg output of running this LKDTM test with PaX: [187095.475573] lkdtm: No crash points registered, enable through debugfs [187118.020257] lkdtm: Performing direct entry WRAP_ATOMIC [187118.030045] lkdtm: attempting atomic underflow [187118.030929] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.071667] PAX: refcount overflow occured at: lkdtm_do_action+0x19e/0x400 [lkdtm] [187118.081423] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.083403] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.102596] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.111321] RIP: 0010:[<ffffffffc00fc2fe>] [<ffffffffc00fc2fe>] lkdtm_do_action+0x19e/0x400 [lkdtm] ... [187118.128074] lkdtm: attempting atomic overflow [187118.128080] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.128082] PAX: refcount overflow occured at: lkdtm_do_action+0x1b6/0x400 [lkdtm] [187118.128085] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.128086] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.128088] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.128092] RIP: 0010:[<ffffffffc00fc316>] [<ffffffffc00fc316>] lkdtm_do_action+0x1b6/0x400 [lkdtm] Signed-off-by: David Windsor <dave@progbits.org> [cleaned up whitespacing, keescook] Signed-off-by: Kees Cook <keescook@chromium.org>
2015-12-17 12:56:36 +07:00
CT_WRAP_ATOMIC
};
static char* cp_name[] = {
"INT_HARDWARE_ENTRY",
"INT_HW_IRQ_EN",
"INT_TASKLET_ENTRY",
"FS_DEVRW",
"MEM_SWAPOUT",
"TIMERADD",
"SCSI_DISPATCH_CMD",
"IDE_CORE_CP",
"DIRECT",
};
static char* cp_type[] = {
"PANIC",
"BUG",
"WARNING",
"EXCEPTION",
"LOOP",
"OVERFLOW",
"CORRUPT_STACK",
"UNALIGNED_LOAD_STORE_WRITE",
"OVERWRITE_ALLOCATION",
"WRITE_AFTER_FREE",
"READ_AFTER_FREE",
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
"WRITE_BUDDY_AFTER_FREE",
"READ_BUDDY_AFTER_FREE",
"SOFTLOCKUP",
"HARDLOCKUP",
"SPINLOCKUP",
"HUNG_TASK",
"EXEC_DATA",
"EXEC_STACK",
"EXEC_KMALLOC",
"EXEC_VMALLOC",
"EXEC_USERSPACE",
"ACCESS_USERSPACE",
"WRITE_RO",
"WRITE_RO_AFTER_INIT",
"WRITE_KERN",
lkdtm: add test for atomic_t underflow/overflow dmesg output of running this LKDTM test with PaX: [187095.475573] lkdtm: No crash points registered, enable through debugfs [187118.020257] lkdtm: Performing direct entry WRAP_ATOMIC [187118.030045] lkdtm: attempting atomic underflow [187118.030929] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.071667] PAX: refcount overflow occured at: lkdtm_do_action+0x19e/0x400 [lkdtm] [187118.081423] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.083403] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.102596] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.111321] RIP: 0010:[<ffffffffc00fc2fe>] [<ffffffffc00fc2fe>] lkdtm_do_action+0x19e/0x400 [lkdtm] ... [187118.128074] lkdtm: attempting atomic overflow [187118.128080] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.128082] PAX: refcount overflow occured at: lkdtm_do_action+0x1b6/0x400 [lkdtm] [187118.128085] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.128086] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.128088] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.128092] RIP: 0010:[<ffffffffc00fc316>] [<ffffffffc00fc316>] lkdtm_do_action+0x1b6/0x400 [lkdtm] Signed-off-by: David Windsor <dave@progbits.org> [cleaned up whitespacing, keescook] Signed-off-by: Kees Cook <keescook@chromium.org>
2015-12-17 12:56:36 +07:00
"WRAP_ATOMIC"
};
static struct jprobe lkdtm;
static int lkdtm_parse_commandline(void);
static void lkdtm_handler(void);
static char* cpoint_name;
static char* cpoint_type;
static int cpoint_count = DEFAULT_COUNT;
static int recur_count = REC_NUM_DEFAULT;
static enum cname cpoint = CN_INVALID;
static enum ctype cptype = CT_NONE;
static int count = DEFAULT_COUNT;
static DEFINE_SPINLOCK(count_lock);
static DEFINE_SPINLOCK(lock_me_up);
static u8 data_area[EXEC_SIZE];
static const unsigned long rodata = 0xAA55AA55;
static unsigned long ro_after_init __ro_after_init = 0x55AA5500;
module_param(recur_count, int, 0644);
MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
module_param(cpoint_name, charp, 0444);
MODULE_PARM_DESC(cpoint_name, " Crash Point, where kernel is to be crashed");
module_param(cpoint_type, charp, 0444);
MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\
"hitting the crash point");
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");
static unsigned int jp_do_irq(unsigned int irq)
{
lkdtm_handler();
jprobe_return();
return 0;
}
static irqreturn_t jp_handle_irq_event(unsigned int irq,
struct irqaction *action)
{
lkdtm_handler();
jprobe_return();
return 0;
}
static void jp_tasklet_action(struct softirq_action *a)
{
lkdtm_handler();
jprobe_return();
}
static void jp_ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
{
lkdtm_handler();
jprobe_return();
}
struct scan_control;
static unsigned long jp_shrink_inactive_list(unsigned long max_scan,
struct zone *zone,
struct scan_control *sc)
{
lkdtm_handler();
jprobe_return();
return 0;
}
static int jp_hrtimer_start(struct hrtimer *timer, ktime_t tim,
const enum hrtimer_mode mode)
{
lkdtm_handler();
jprobe_return();
return 0;
}
static int jp_scsi_dispatch_cmd(struct scsi_cmnd *cmd)
{
lkdtm_handler();
jprobe_return();
return 0;
}
#ifdef CONFIG_IDE
static int jp_generic_ide_ioctl(ide_drive_t *drive, struct file *file,
struct block_device *bdev, unsigned int cmd,
unsigned long arg)
{
lkdtm_handler();
jprobe_return();
return 0;
}
#endif
/* Return the crashpoint number or NONE if the name is invalid */
static enum ctype parse_cp_type(const char *what, size_t count)
{
int i;
for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
if (!strcmp(what, cp_type[i]))
return i + 1;
}
return CT_NONE;
}
static const char *cp_type_to_str(enum ctype type)
{
if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
return "None";
return cp_type[type - 1];
}
static const char *cp_name_to_str(enum cname name)
{
if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
return "INVALID";
return cp_name[name - 1];
}
static int lkdtm_parse_commandline(void)
{
int i;
unsigned long flags;
if (cpoint_count < 1 || recur_count < 1)
return -EINVAL;
spin_lock_irqsave(&count_lock, flags);
count = cpoint_count;
spin_unlock_irqrestore(&count_lock, flags);
/* No special parameters */
if (!cpoint_type && !cpoint_name)
return 0;
/* Neither or both of these need to be set */
if (!cpoint_type || !cpoint_name)
return -EINVAL;
cptype = parse_cp_type(cpoint_type, strlen(cpoint_type));
if (cptype == CT_NONE)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
if (!strcmp(cpoint_name, cp_name[i])) {
cpoint = i + 1;
return 0;
}
}
/* Could not find a valid crash point */
return -EINVAL;
}
static int recursive_loop(int remaining)
{
char buf[REC_STACK_SIZE];
/* Make sure compiler does not optimize this away. */
memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
if (!remaining)
return 0;
else
return recursive_loop(remaining - 1);
}
static void do_nothing(void)
{
return;
}
/* Must immediately follow do_nothing for size calculuations to work out. */
static void do_overwritten(void)
{
pr_info("do_overwritten wasn't overwritten!\n");
return;
}
static noinline void corrupt_stack(void)
{
/* Use default char array length that triggers stack protection. */
char data[8];
memset((void *)data, 0, 64);
}
static void noinline execute_location(void *dst)
{
void (*func)(void) = dst;
pr_info("attempting ok execution at %p\n", do_nothing);
do_nothing();
memcpy(dst, do_nothing, EXEC_SIZE);
flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE);
pr_info("attempting bad execution at %p\n", func);
func();
}
static void execute_user_location(void *dst)
{
/* Intentionally crossing kernel/user memory boundary. */
void (*func)(void) = dst;
pr_info("attempting ok execution at %p\n", do_nothing);
do_nothing();
if (copy_to_user((void __user *)dst, do_nothing, EXEC_SIZE))
return;
flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE);
pr_info("attempting bad execution at %p\n", func);
func();
}
static void lkdtm_do_action(enum ctype which)
{
switch (which) {
case CT_PANIC:
panic("dumptest");
break;
case CT_BUG:
BUG();
break;
case CT_WARNING:
WARN_ON(1);
break;
case CT_EXCEPTION:
*((int *) 0) = 0;
break;
case CT_LOOP:
for (;;)
;
break;
case CT_OVERFLOW:
(void) recursive_loop(recur_count);
break;
case CT_CORRUPT_STACK:
corrupt_stack();
break;
case CT_UNALIGNED_LOAD_STORE_WRITE: {
static u8 data[5] __attribute__((aligned(4))) = {1, 2,
3, 4, 5};
u32 *p;
u32 val = 0x12345678;
p = (u32 *)(data + 1);
if (*p == 0)
val = 0x87654321;
*p = val;
break;
}
case CT_OVERWRITE_ALLOCATION: {
size_t len = 1020;
u32 *data = kmalloc(len, GFP_KERNEL);
data[1024 / sizeof(u32)] = 0x12345678;
kfree(data);
break;
}
case CT_WRITE_AFTER_FREE: {
int *base, *again;
size_t len = 1024;
/*
* The slub allocator uses the first word to store the free
* pointer in some configurations. Use the middle of the
* allocation to avoid running into the freelist
*/
size_t offset = (len / sizeof(*base)) / 2;
base = kmalloc(len, GFP_KERNEL);
pr_info("Allocated memory %p-%p\n", base, &base[offset * 2]);
pr_info("Attempting bad write to freed memory at %p\n",
&base[offset]);
kfree(base);
base[offset] = 0x0abcdef0;
/* Attempt to notice the overwrite. */
again = kmalloc(len, GFP_KERNEL);
kfree(again);
if (again != base)
pr_info("Hmm, didn't get the same memory range.\n");
break;
}
case CT_READ_AFTER_FREE: {
int *base, *val, saw;
size_t len = 1024;
/*
* The slub allocator uses the first word to store the free
* pointer in some configurations. Use the middle of the
* allocation to avoid running into the freelist
*/
size_t offset = (len / sizeof(*base)) / 2;
base = kmalloc(len, GFP_KERNEL);
if (!base)
break;
val = kmalloc(len, GFP_KERNEL);
if (!val) {
kfree(base);
break;
}
*val = 0x12345678;
base[offset] = *val;
pr_info("Value in memory before free: %x\n", base[offset]);
kfree(base);
pr_info("Attempting bad read from freed memory\n");
saw = base[offset];
if (saw != *val) {
/* Good! Poisoning happened, so declare a win. */
pr_info("Memory correctly poisoned (%x)\n", saw);
BUG();
}
pr_info("Memory was not poisoned\n");
kfree(val);
break;
}
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
case CT_WRITE_BUDDY_AFTER_FREE: {
unsigned long p = __get_free_page(GFP_KERNEL);
if (!p)
break;
pr_info("Writing to the buddy page before free\n");
memset((void *)p, 0x3, PAGE_SIZE);
free_page(p);
schedule();
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
pr_info("Attempting bad write to the buddy page after free\n");
memset((void *)p, 0x78, PAGE_SIZE);
/* Attempt to notice the overwrite. */
p = __get_free_page(GFP_KERNEL);
free_page(p);
schedule();
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
break;
}
case CT_READ_BUDDY_AFTER_FREE: {
unsigned long p = __get_free_page(GFP_KERNEL);
int saw, *val;
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
int *base;
if (!p)
break;
val = kmalloc(1024, GFP_KERNEL);
if (!val) {
free_page(p);
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
break;
}
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
base = (int *)p;
*val = 0x12345678;
base[0] = *val;
pr_info("Value in memory before free: %x\n", base[0]);
free_page(p);
pr_info("Attempting to read from freed memory\n");
saw = base[0];
if (saw != *val) {
/* Good! Poisoning happened, so declare a win. */
pr_info("Memory correctly poisoned (%x)\n", saw);
lkdtm: Add read/write after free tests for buddy memory The current tests for read/write after free work on slab allocated memory. Memory straight from the buddy allocator may behave slightly differently and have a different set of parameters to test. Add tests for those cases as well. On a basic x86 boot: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 22.291950] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 22.292983] lkdtm: Writing to the buddy page before free [ 22.293950] lkdtm: Attempting bad write to the buddy page after free # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 32.375601] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 32.379896] lkdtm: Value in memory before free: 12345678 [ 32.383854] lkdtm: Attempting to read from freed memory [ 32.389309] lkdtm: Buddy page was not poisoned On x86 with CONFIG_DEBUG_PAGEALLOC and debug_pagealloc=on: # echo WRITE_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 17.475533] lkdtm: Performing direct entry WRITE_BUDDY_AFTER_FREE [ 17.477360] lkdtm: Writing to the buddy page before free [ 17.479089] lkdtm: Attempting bad write to the buddy page after free [ 17.480904] BUG: unable to handle kernel paging request at ffff88000ebd8000 # echo READ_BUDDY_AFTER_FREE > /sys/kernel/debug/provoke-crash/DIRECT [ 14.606433] lkdtm: Performing direct entry READ_BUDDY_AFTER_FREE [ 14.607447] lkdtm: Value in memory before free: 12345678 [ 14.608161] lkdtm: Attempting to read from freed memory [ 14.608860] BUG: unable to handle kernel paging request at ffff88000eba3000 Note that arches without ARCH_SUPPORTS_DEBUG_PAGEALLOC may not produce the same crash. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-02-26 07:36:44 +07:00
BUG();
}
pr_info("Buddy page was not poisoned\n");
kfree(val);
break;
}
case CT_SOFTLOCKUP:
preempt_disable();
for (;;)
cpu_relax();
break;
case CT_HARDLOCKUP:
local_irq_disable();
for (;;)
cpu_relax();
break;
case CT_SPINLOCKUP:
/* Must be called twice to trigger. */
spin_lock(&lock_me_up);
/* Let sparse know we intended to exit holding the lock. */
__release(&lock_me_up);
break;
case CT_HUNG_TASK:
set_current_state(TASK_UNINTERRUPTIBLE);
schedule();
break;
case CT_EXEC_DATA:
execute_location(data_area);
break;
case CT_EXEC_STACK: {
u8 stack_area[EXEC_SIZE];
execute_location(stack_area);
break;
}
case CT_EXEC_KMALLOC: {
u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
execute_location(kmalloc_area);
kfree(kmalloc_area);
break;
}
case CT_EXEC_VMALLOC: {
u32 *vmalloc_area = vmalloc(EXEC_SIZE);
execute_location(vmalloc_area);
vfree(vmalloc_area);
break;
}
case CT_EXEC_USERSPACE: {
unsigned long user_addr;
user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_ANONYMOUS | MAP_PRIVATE, 0);
if (user_addr >= TASK_SIZE) {
pr_warn("Failed to allocate user memory\n");
return;
}
execute_user_location((void *)user_addr);
vm_munmap(user_addr, PAGE_SIZE);
break;
}
case CT_ACCESS_USERSPACE: {
unsigned long user_addr, tmp = 0;
unsigned long *ptr;
user_addr = vm_mmap(NULL, 0, PAGE_SIZE,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_ANONYMOUS | MAP_PRIVATE, 0);
if (user_addr >= TASK_SIZE) {
pr_warn("Failed to allocate user memory\n");
return;
}
if (copy_to_user((void __user *)user_addr, &tmp, sizeof(tmp))) {
pr_warn("copy_to_user failed\n");
vm_munmap(user_addr, PAGE_SIZE);
return;
}
ptr = (unsigned long *)user_addr;
pr_info("attempting bad read at %p\n", ptr);
tmp = *ptr;
tmp += 0xc0dec0de;
pr_info("attempting bad write at %p\n", ptr);
*ptr = tmp;
vm_munmap(user_addr, PAGE_SIZE);
break;
}
case CT_WRITE_RO: {
/* Explicitly cast away "const" for the test. */
unsigned long *ptr = (unsigned long *)&rodata;
pr_info("attempting bad rodata write at %p\n", ptr);
*ptr ^= 0xabcd1234;
break;
}
case CT_WRITE_RO_AFTER_INIT: {
unsigned long *ptr = &ro_after_init;
/*
* Verify we were written to during init. Since an Oops
* is considered a "success", a failure is to just skip the
* real test.
*/
if ((*ptr & 0xAA) != 0xAA) {
pr_info("%p was NOT written during init!?\n", ptr);
break;
}
pr_info("attempting bad ro_after_init write at %p\n", ptr);
*ptr ^= 0xabcd1234;
break;
}
case CT_WRITE_KERN: {
size_t size;
unsigned char *ptr;
size = (unsigned long)do_overwritten -
(unsigned long)do_nothing;
ptr = (unsigned char *)do_overwritten;
pr_info("attempting bad %zu byte write at %p\n", size, ptr);
memcpy(ptr, (unsigned char *)do_nothing, size);
flush_icache_range((unsigned long)ptr,
(unsigned long)(ptr + size));
do_overwritten();
break;
}
lkdtm: add test for atomic_t underflow/overflow dmesg output of running this LKDTM test with PaX: [187095.475573] lkdtm: No crash points registered, enable through debugfs [187118.020257] lkdtm: Performing direct entry WRAP_ATOMIC [187118.030045] lkdtm: attempting atomic underflow [187118.030929] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.071667] PAX: refcount overflow occured at: lkdtm_do_action+0x19e/0x400 [lkdtm] [187118.081423] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.083403] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.102596] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.111321] RIP: 0010:[<ffffffffc00fc2fe>] [<ffffffffc00fc2fe>] lkdtm_do_action+0x19e/0x400 [lkdtm] ... [187118.128074] lkdtm: attempting atomic overflow [187118.128080] PAX: refcount overflow detected in: bash:1790, uid/euid: 0/0 [187118.128082] PAX: refcount overflow occured at: lkdtm_do_action+0x1b6/0x400 [lkdtm] [187118.128085] CPU: 3 PID: 1790 Comm: bash Not tainted 4.2.6-pax-refcount-split+ #2 [187118.128086] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [187118.128088] task: ffff8800da8de040 ti: ffff8800da8e4000 task.ti: ffff8800da8e4000 [187118.128092] RIP: 0010:[<ffffffffc00fc316>] [<ffffffffc00fc316>] lkdtm_do_action+0x1b6/0x400 [lkdtm] Signed-off-by: David Windsor <dave@progbits.org> [cleaned up whitespacing, keescook] Signed-off-by: Kees Cook <keescook@chromium.org>
2015-12-17 12:56:36 +07:00
case CT_WRAP_ATOMIC: {
atomic_t under = ATOMIC_INIT(INT_MIN);
atomic_t over = ATOMIC_INIT(INT_MAX);
pr_info("attempting atomic underflow\n");
atomic_dec(&under);
pr_info("attempting atomic overflow\n");
atomic_inc(&over);
return;
}
case CT_NONE:
default:
break;
}
}
static void lkdtm_handler(void)
{
unsigned long flags;
bool do_it = false;
spin_lock_irqsave(&count_lock, flags);
count--;
pr_info("Crash point %s of type %s hit, trigger in %d rounds\n",
cp_name_to_str(cpoint), cp_type_to_str(cptype), count);
if (count == 0) {
do_it = true;
count = cpoint_count;
}
spin_unlock_irqrestore(&count_lock, flags);
if (do_it)
lkdtm_do_action(cptype);
}
static int lkdtm_register_cpoint(enum cname which)
{
int ret;
cpoint = CN_INVALID;
if (lkdtm.entry != NULL)
unregister_jprobe(&lkdtm);
switch (which) {
case CN_DIRECT:
lkdtm_do_action(cptype);
return 0;
case CN_INT_HARDWARE_ENTRY:
lkdtm.kp.symbol_name = "do_IRQ";
lkdtm.entry = (kprobe_opcode_t*) jp_do_irq;
break;
case CN_INT_HW_IRQ_EN:
lkdtm.kp.symbol_name = "handle_IRQ_event";
lkdtm.entry = (kprobe_opcode_t*) jp_handle_irq_event;
break;
case CN_INT_TASKLET_ENTRY:
lkdtm.kp.symbol_name = "tasklet_action";
lkdtm.entry = (kprobe_opcode_t*) jp_tasklet_action;
break;
case CN_FS_DEVRW:
lkdtm.kp.symbol_name = "ll_rw_block";
lkdtm.entry = (kprobe_opcode_t*) jp_ll_rw_block;
break;
case CN_MEM_SWAPOUT:
lkdtm.kp.symbol_name = "shrink_inactive_list";
lkdtm.entry = (kprobe_opcode_t*) jp_shrink_inactive_list;
break;
case CN_TIMERADD:
lkdtm.kp.symbol_name = "hrtimer_start";
lkdtm.entry = (kprobe_opcode_t*) jp_hrtimer_start;
break;
case CN_SCSI_DISPATCH_CMD:
lkdtm.kp.symbol_name = "scsi_dispatch_cmd";
lkdtm.entry = (kprobe_opcode_t*) jp_scsi_dispatch_cmd;
break;
case CN_IDE_CORE_CP:
#ifdef CONFIG_IDE
lkdtm.kp.symbol_name = "generic_ide_ioctl";
lkdtm.entry = (kprobe_opcode_t*) jp_generic_ide_ioctl;
#else
pr_info("Crash point not available\n");
return -EINVAL;
#endif
break;
default:
pr_info("Invalid Crash Point\n");
return -EINVAL;
}
cpoint = which;
if ((ret = register_jprobe(&lkdtm)) < 0) {
pr_info("Couldn't register jprobe\n");
cpoint = CN_INVALID;
}
return ret;
}
static ssize_t do_register_entry(enum cname which, struct file *f,
const char __user *user_buf, size_t count, loff_t *off)
{
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);
cptype = parse_cp_type(buf, count);
free_page((unsigned long) buf);
if (cptype == CT_NONE)
return -EINVAL;
err = lkdtm_register_cpoint(which);
if (err < 0)
return err;
*off += count;
return count;
}
/* 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)
{
char *buf;
int i, n, out;
buf = (char *)__get_free_page(GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
n = snprintf(buf, PAGE_SIZE, "Available crash types:\n");
for (i = 0; i < ARRAY_SIZE(cp_type); i++)
n += snprintf(buf + n, PAGE_SIZE - n, "%s\n", cp_type[i]);
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;
}
static ssize_t int_hardware_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_INT_HARDWARE_ENTRY, f, buf, count, off);
}
static ssize_t int_hw_irq_en(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_INT_HW_IRQ_EN, f, buf, count, off);
}
static ssize_t int_tasklet_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_INT_TASKLET_ENTRY, f, buf, count, off);
}
static ssize_t fs_devrw_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_FS_DEVRW, f, buf, count, off);
}
static ssize_t mem_swapout_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_MEM_SWAPOUT, f, buf, count, off);
}
static ssize_t timeradd_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_TIMERADD, f, buf, count, off);
}
static ssize_t scsi_dispatch_cmd_entry(struct file *f,
const char __user *buf, size_t count, loff_t *off)
{
return do_register_entry(CN_SCSI_DISPATCH_CMD, f, buf, count, off);
}
static ssize_t ide_core_cp_entry(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
return do_register_entry(CN_IDE_CORE_CP, f, buf, count, off);
}
/* 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)
{
enum ctype type;
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);
type = parse_cp_type(buf, count);
free_page((unsigned long) buf);
if (type == CT_NONE)
return -EINVAL;
pr_info("Performing direct entry %s\n", cp_type_to_str(type));
lkdtm_do_action(type);
*off += count;
return count;
}
struct crash_entry {
const char *name;
const struct file_operations fops;
};
static const struct crash_entry crash_entries[] = {
{"DIRECT", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = direct_entry} },
{"INT_HARDWARE_ENTRY", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = int_hardware_entry} },
{"INT_HW_IRQ_EN", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = int_hw_irq_en} },
{"INT_TASKLET_ENTRY", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = int_tasklet_entry} },
{"FS_DEVRW", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = fs_devrw_entry} },
{"MEM_SWAPOUT", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = mem_swapout_entry} },
{"TIMERADD", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = timeradd_entry} },
{"SCSI_DISPATCH_CMD", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = scsi_dispatch_cmd_entry} },
{"IDE_CORE_CP", {.read = lkdtm_debugfs_read,
.llseek = generic_file_llseek,
.open = lkdtm_debugfs_open,
.write = ide_core_cp_entry} },
};
static struct dentry *lkdtm_debugfs_root;
static int __init lkdtm_module_init(void)
{
int ret = -EINVAL;
int n_debugfs_entries = 1; /* Assume only the direct entry */
int i;
/* Make sure we can write to __ro_after_init values during __init */
ro_after_init |= 0xAA;
/* Register debugfs interface */
lkdtm_debugfs_root = debugfs_create_dir("provoke-crash", NULL);
if (!lkdtm_debugfs_root) {
pr_err("creating root dir failed\n");
return -ENODEV;
}
#ifdef CONFIG_KPROBES
n_debugfs_entries = ARRAY_SIZE(crash_entries);
#endif
for (i = 0; i < n_debugfs_entries; i++) {
const struct crash_entry *cur = &crash_entries[i];
struct dentry *de;
de = debugfs_create_file(cur->name, 0644, lkdtm_debugfs_root,
NULL, &cur->fops);
if (de == NULL) {
pr_err("could not create %s\n", cur->name);
goto out_err;
}
}
if (lkdtm_parse_commandline() == -EINVAL) {
pr_info("Invalid command\n");
goto out_err;
}
if (cpoint != CN_INVALID && cptype != CT_NONE) {
ret = lkdtm_register_cpoint(cpoint);
if (ret < 0) {
pr_info("Invalid crash point %d\n", cpoint);
goto out_err;
}
pr_info("Crash point %s of type %s registered\n",
cpoint_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);
unregister_jprobe(&lkdtm);
pr_info("Crash point unregistered\n");
}
module_init(lkdtm_module_init);
module_exit(lkdtm_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Kprobe module for testing crash dumps");