From: Masami Hiramatsu <mhiramat@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lkdtm: Convert from jprobe to kprobe
Date: Sat, 21 Oct 2017 14:59:39 +0900 [thread overview]
Message-ID: <20171021145939.0af9f7f9129e60228f3b686a@kernel.org> (raw)
In-Reply-To: <20171020133127.GA18360@beast>
On Fri, 20 Oct 2017 06:31:27 -0700
Kees Cook <keescook@chromium.org> wrote:
> The jprobe subsystem is being removed, so convert to using kprobe instead.
>
Looks good to me:)
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Thanks,
> 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
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2017-10-21 5:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-20 13:31 [PATCH] lkdtm: Convert from jprobe to kprobe Kees Cook
2017-10-21 5:59 ` Masami Hiramatsu [this message]
2017-10-23 12:45 ` [tip:perf/core] lkdtm, kprobes: Convert from jprobes to kprobes tip-bot for Kees Cook
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