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Subject[PATCH] lkdtm: Convert from jprobe to kprobe
The jprobe subsystem is being removed, so convert to using kprobe instead.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/lkdtm_core.c | 154 ++++++++++++++--------------------------------
1 file changed, 45 insertions(+), 109 deletions(-)

diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index 981b3ef71e47..ed7f0c61c59a 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -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
};
@@ -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;

@@ -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();
}

@@ -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;
}
@@ -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--;
@@ -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,
@@ -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");
}
--
2.7.4

--
Kees Cook
Pixel Security

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