On Fri, 20 Oct 2017 06:31:27 -0700
Kees Cook <keesc...@chromium.org> wrote:

> The jprobe subsystem is being removed, so convert to using kprobe instead.
> 

Looks good to me:)

Acked-by: Masami Hiramatsu <mhira...@kernel.org>

Thanks,

> Cc: Masami Hiramatsu <mhira...@kernel.org>
> Signed-off-by: Kees Cook <keesc...@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 <mhira...@kernel.org>

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