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author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2012-06-05 19:28:20 +0900 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2012-07-31 10:29:56 -0400 |
commit | f7fa6ef0ded995aad68650a877198f70e44b7621 (patch) | |
tree | c4f211caf1b11d437cc078df8a0917ad205cb3cf | |
parent | 72ef3794c5cd5f5f0e6355c24a529224c449cd14 (diff) | |
download | linux-stable-f7fa6ef0ded995aad68650a877198f70e44b7621.tar.gz linux-stable-f7fa6ef0ded995aad68650a877198f70e44b7621.tar.bz2 linux-stable-f7fa6ef0ded995aad68650a877198f70e44b7621.zip |
kprobes: cleanup to separate probe-able check
Separate probe-able address checking code from
register_kprobe().
Link: http://lkml.kernel.org/r/20120605102820.27845.90133.stgit@localhost.localdomain
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | kernel/kprobes.c | 82 |
1 files changed, 45 insertions, 37 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 7a8a1222c7b1..6137fe32b4b8 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1313,67 +1313,80 @@ static inline int check_kprobe_rereg(struct kprobe *p) return ret; } -int __kprobes register_kprobe(struct kprobe *p) +static __kprobes int check_kprobe_address_safe(struct kprobe *p, + struct module **probed_mod) { int ret = 0; - struct kprobe *old_p; - struct module *probed_mod; - kprobe_opcode_t *addr; - - addr = kprobe_addr(p); - if (IS_ERR(addr)) - return PTR_ERR(addr); - p->addr = addr; - - ret = check_kprobe_rereg(p); - if (ret) - return ret; jump_label_lock(); preempt_disable(); + + /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || in_kprobes_functions((unsigned long) p->addr) || ftrace_text_reserved(p->addr, p->addr) || jump_label_text_reserved(p->addr, p->addr)) { ret = -EINVAL; - goto cannot_probe; + goto out; } - /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ - p->flags &= KPROBE_FLAG_DISABLED; - - /* - * Check if are we probing a module. - */ - probed_mod = __module_text_address((unsigned long) p->addr); - if (probed_mod) { - /* Return -ENOENT if fail. */ - ret = -ENOENT; + /* Check if are we probing a module */ + *probed_mod = __module_text_address((unsigned long) p->addr); + if (*probed_mod) { /* * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. */ - if (unlikely(!try_module_get(probed_mod))) - goto cannot_probe; + if (unlikely(!try_module_get(*probed_mod))) { + ret = -ENOENT; + goto out; + } /* * If the module freed .init.text, we couldn't insert * kprobes in there. */ - if (within_module_init((unsigned long)p->addr, probed_mod) && - probed_mod->state != MODULE_STATE_COMING) { - module_put(probed_mod); - goto cannot_probe; + if (within_module_init((unsigned long)p->addr, *probed_mod) && + (*probed_mod)->state != MODULE_STATE_COMING) { + module_put(*probed_mod); + *probed_mod = NULL; + ret = -ENOENT; } - /* ret will be updated by following code */ } +out: preempt_enable(); jump_label_unlock(); + return ret; +} + +int __kprobes register_kprobe(struct kprobe *p) +{ + int ret; + struct kprobe *old_p; + struct module *probed_mod; + kprobe_opcode_t *addr; + + /* Adjust probe address from symbol */ + addr = kprobe_addr(p); + if (IS_ERR(addr)) + return PTR_ERR(addr); + p->addr = addr; + + ret = check_kprobe_rereg(p); + if (ret) + return ret; + + /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ + p->flags &= KPROBE_FLAG_DISABLED; p->nmissed = 0; INIT_LIST_HEAD(&p->list); - mutex_lock(&kprobe_mutex); + ret = check_kprobe_address_safe(p, &probed_mod); + if (ret) + return ret; + + mutex_lock(&kprobe_mutex); jump_label_lock(); /* needed to call jump_label_text_reserved() */ get_online_cpus(); /* For avoiding text_mutex deadlock. */ @@ -1410,11 +1423,6 @@ out: module_put(probed_mod); return ret; - -cannot_probe: - preempt_enable(); - jump_label_unlock(); - return ret; } EXPORT_SYMBOL_GPL(register_kprobe); |