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lkdtm, kprobes: Convert from jprobes to kprobes
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The jprobes subsystem is being removed, so convert to using kprobes instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171020133127.GA18360@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kees Cook authored and Ingo Molnar committed Oct 23, 2017
1 parent 9b17374 commit 8776fe7
Showing 1 changed file with 45 additions and 109 deletions.
154 changes: 45 additions & 109 deletions drivers/misc/lkdtm_core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,122 +56,54 @@ static ssize_t direct_entry(struct file *f, const char __user *user_buf,
size_t count, loff_t *off);

#ifdef CONFIG_KPROBES
static void lkdtm_handler(void);
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);


/* jprobe entry point handlers. */
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
# 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 jprobe jprobe;
struct kprobe kprobe;
};

#define CRASHPOINT(_name, _write, _symbol, _entry) \
#define CRASHPOINT(_name, _symbol) \
{ \
.name = _name, \
.fops = { \
.read = lkdtm_debugfs_read, \
.llseek = generic_file_llseek, \
.open = lkdtm_debugfs_open, \
.write = _write, \
}, \
.jprobe = { \
.kp.symbol_name = _symbol, \
.entry = (kprobe_opcode_t *)_entry, \
.write = CRASHPOINT_WRITE(_symbol) \
}, \
CRASHPOINT_KPROBE(_symbol) \
}

/* Define the possible places where we can trigger a crash point. */
struct crashpoint crashpoints[] = {
CRASHPOINT("DIRECT", direct_entry,
NULL, NULL),
static struct crashpoint crashpoints[] = {
CRASHPOINT("DIRECT", NULL),
#ifdef CONFIG_KPROBES
CRASHPOINT("INT_HARDWARE_ENTRY", lkdtm_debugfs_entry,
"do_IRQ", jp_do_irq),
CRASHPOINT("INT_HW_IRQ_EN", lkdtm_debugfs_entry,
"handle_IRQ_event", jp_handle_irq_event),
CRASHPOINT("INT_TASKLET_ENTRY", lkdtm_debugfs_entry,
"tasklet_action", jp_tasklet_action),
CRASHPOINT("FS_DEVRW", lkdtm_debugfs_entry,
"ll_rw_block", jp_ll_rw_block),
CRASHPOINT("MEM_SWAPOUT", lkdtm_debugfs_entry,
"shrink_inactive_list", jp_shrink_inactive_list),
CRASHPOINT("TIMERADD", lkdtm_debugfs_entry,
"hrtimer_start", jp_hrtimer_start),
CRASHPOINT("SCSI_DISPATCH_CMD", lkdtm_debugfs_entry,
"scsi_dispatch_cmd", jp_scsi_dispatch_cmd),
CRASHPOINT("INT_HARDWARE_ENTRY", "do_IRQ"),
CRASHPOINT("INT_HW_IRQ_EN", "handle_IRQ_event"),
CRASHPOINT("INT_TASKLET_ENTRY", "tasklet_action"),
CRASHPOINT("FS_DEVRW", "ll_rw_block"),
CRASHPOINT("MEM_SWAPOUT", "shrink_inactive_list"),
CRASHPOINT("TIMERADD", "hrtimer_start"),
CRASHPOINT("SCSI_DISPATCH_CMD", "scsi_dispatch_cmd"),
# ifdef CONFIG_IDE
CRASHPOINT("IDE_CORE_CP", lkdtm_debugfs_entry,
"generic_ide_ioctl", jp_generic_ide_ioctl),
CRASHPOINT("IDE_CORE_CP", "generic_ide_ioctl"),
# endif
#endif
};
Expand Down Expand Up @@ -254,8 +186,8 @@ struct crashtype crashtypes[] = {
};


/* Global jprobe entry and crashtype. */
static struct jprobe *lkdtm_jprobe;
/* Global kprobe entry and crashtype. */
static struct kprobe *lkdtm_kprobe;
struct crashpoint *lkdtm_crashpoint;
struct crashtype *lkdtm_crashtype;

Expand Down Expand Up @@ -298,7 +230,8 @@ static struct crashtype *find_crashtype(const char *name)
*/
static noinline void lkdtm_do_action(struct crashtype *crashtype)
{
BUG_ON(!crashtype || !crashtype->func);
if (WARN_ON(!crashtype || !crashtype->func))
return;
crashtype->func();
}

Expand All @@ -308,22 +241,22 @@ static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
int ret;

/* If this doesn't have a symbol, just call immediately. */
if (!crashpoint->jprobe.kp.symbol_name) {
if (!crashpoint->kprobe.symbol_name) {
lkdtm_do_action(crashtype);
return 0;
}

if (lkdtm_jprobe != NULL)
unregister_jprobe(lkdtm_jprobe);
if (lkdtm_kprobe != NULL)
unregister_kprobe(lkdtm_kprobe);

lkdtm_crashpoint = crashpoint;
lkdtm_crashtype = crashtype;
lkdtm_jprobe = &crashpoint->jprobe;
ret = register_jprobe(lkdtm_jprobe);
lkdtm_kprobe = &crashpoint->kprobe;
ret = register_kprobe(lkdtm_kprobe);
if (ret < 0) {
pr_info("Couldn't register jprobe %s\n",
crashpoint->jprobe.kp.symbol_name);
lkdtm_jprobe = NULL;
pr_info("Couldn't register kprobe %s\n",
crashpoint->kprobe.symbol_name);
lkdtm_kprobe = NULL;
lkdtm_crashpoint = NULL;
lkdtm_crashtype = NULL;
}
Expand All @@ -336,13 +269,14 @@ static int lkdtm_register_cpoint(struct crashpoint *crashpoint,
static int crash_count = DEFAULT_COUNT;
static DEFINE_SPINLOCK(crash_count_lock);

/* Called by jprobe entry points. */
static void lkdtm_handler(void)
/* Called by kprobe entry points. */
static int lkdtm_kprobe_handler(struct kprobe *kp, struct pt_regs *regs)
{
unsigned long flags;
bool do_it = false;

BUG_ON(!lkdtm_crashpoint || !lkdtm_crashtype);
if (WARN_ON(!lkdtm_crashpoint || !lkdtm_crashtype))
return 0;

spin_lock_irqsave(&crash_count_lock, flags);
crash_count--;
Expand All @@ -357,6 +291,8 @@ static void lkdtm_handler(void)

if (do_it)
lkdtm_do_action(lkdtm_crashtype);

return 0;
}

static ssize_t lkdtm_debugfs_entry(struct file *f,
Expand Down Expand Up @@ -556,8 +492,8 @@ static void __exit lkdtm_module_exit(void)
/* Handle test-specific clean-up. */
lkdtm_usercopy_exit();

if (lkdtm_jprobe != NULL)
unregister_jprobe(lkdtm_jprobe);
if (lkdtm_kprobe != NULL)
unregister_kprobe(lkdtm_kprobe);

pr_info("Crash point unregistered\n");
}
Expand Down

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