From 346fd59bab28093276be102632f72691a2c243fe Mon Sep 17 00:00:00 2001 From: Srinivasa Ds Date: Tue, 20 Feb 2007 13:57:54 -0800 Subject: [PATCH] kprobes: list all active probes in the system This patch lists all active probes in the system by scanning through kprobe_table[]. It takes care of aggregate handlers and prints the type of the probe. Letter "k" for kprobes, "j" for jprobes, "r" for kretprobes. It also lists address of the instruction,its symbolic name(function name + offset) and the module name. One can access this file through /sys/kernel/debug/kprobes/list. Output looks like this ===================== llm40:~/a # cat /sys/kernel/debug/kprobes/list c0169ae3 r sys_read+0x0 c0169ae3 k sys_read+0x0 c01694c8 k vfs_write+0x0 c0167d20 r sys_open+0x0 f8e658a6 k reiserfs_delete_inode+0x0 reiserfs c0120f4a k do_fork+0x0 c0120f4a j do_fork+0x0 c0169b4a r sys_write+0x0 c0169b4a k sys_write+0x0 c0169622 r vfs_read+0x0 ================================= [akpm@linux-foundation.org: cleanup] [ananth@in.ibm.com: sparc build fix] Signed-off-by: Srinivasa DS Cc: Prasanna S Panchamukhi Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kprobes.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 111 insertions(+), 2 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 6fcf8dd148d0..d25a9ada3f8e 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -39,6 +39,8 @@ #include #include #include +#include +#include #include #include #include @@ -778,6 +780,12 @@ int __kprobes register_kretprobe(struct kretprobe *rp) return -ENOSYS; } +static int __kprobes pre_handler_kretprobe(struct kprobe *p, + struct pt_regs *regs) +{ + return 0; +} + #endif /* ARCH_SUPPORTS_KRETPROBES */ void __kprobes unregister_kretprobe(struct kretprobe *rp) @@ -815,7 +823,109 @@ static int __init init_kprobes(void) return err; } -__initcall(init_kprobes); +#ifdef CONFIG_DEBUG_FS +static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, + const char *sym, int offset,char *modname) +{ + char *kprobe_type; + + if (p->pre_handler == pre_handler_kretprobe) + kprobe_type = "r"; + else if (p->pre_handler == setjmp_pre_handler) + kprobe_type = "j"; + else + kprobe_type = "k"; + if (sym) + seq_printf(pi, "%p %s %s+0x%x %s\n", p->addr, kprobe_type, + sym, offset, (modname ? modname : " ")); + else + seq_printf(pi, "%p %s %p\n", p->addr, kprobe_type, p->addr); +} + +static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) +{ + return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; +} + +static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) +{ + (*pos)++; + if (*pos >= KPROBE_TABLE_SIZE) + return NULL; + return pos; +} + +static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) +{ + /* Nothing to do */ +} + +static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) +{ + struct hlist_head *head; + struct hlist_node *node; + struct kprobe *p, *kp; + const char *sym = NULL; + unsigned int i = *(loff_t *) v; + unsigned long size, offset = 0; + char *modname, namebuf[128]; + + head = &kprobe_table[i]; + preempt_disable(); + hlist_for_each_entry_rcu(p, node, head, hlist) { + sym = kallsyms_lookup((unsigned long)p->addr, &size, + &offset, &modname, namebuf); + if (p->pre_handler == aggr_pre_handler) { + list_for_each_entry_rcu(kp, &p->list, list) + report_probe(pi, kp, sym, offset, modname); + } else + report_probe(pi, p, sym, offset, modname); + } + preempt_enable(); + return 0; +} + +static struct seq_operations kprobes_seq_ops = { + .start = kprobe_seq_start, + .next = kprobe_seq_next, + .stop = kprobe_seq_stop, + .show = show_kprobe_addr +}; + +static int __kprobes kprobes_open(struct inode *inode, struct file *filp) +{ + return seq_open(filp, &kprobes_seq_ops); +} + +static struct file_operations debugfs_kprobes_operations = { + .open = kprobes_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __kprobes debugfs_kprobe_init(void) +{ + struct dentry *dir, *file; + + dir = debugfs_create_dir("kprobes", NULL); + if (!dir) + return -ENOMEM; + + file = debugfs_create_file("list", 0444, dir , 0 , + &debugfs_kprobes_operations); + if (!file) { + debugfs_remove(dir); + return -ENOMEM; + } + + return 0; +} + +late_initcall(debugfs_kprobe_init); +#endif /* CONFIG_DEBUG_FS */ + +module_init(init_kprobes); EXPORT_SYMBOL_GPL(register_kprobe); EXPORT_SYMBOL_GPL(unregister_kprobe); @@ -824,4 +934,3 @@ EXPORT_SYMBOL_GPL(unregister_jprobe); EXPORT_SYMBOL_GPL(jprobe_return); EXPORT_SYMBOL_GPL(register_kretprobe); EXPORT_SYMBOL_GPL(unregister_kretprobe); - -- cgit v1.2.3