From f986a499ef6f317d906e6f6f281be966e1237a10 Mon Sep 17 00:00:00 2001 From: Prashanth Nageshappa Date: Mon, 5 Mar 2012 14:59:12 -0800 Subject: [PATCH] kprobes: return proper error code from register_kprobe() register_kprobe() aborts if the address of the new request falls in a prohibited area (such as ftrace pouch, __kprobes annotated functions, non-kernel text addresses, jump label text). We however don't return the right error on this abort, resulting in a silent failure - incorrect adding/reporting of kprobes ('perf probe do_fork+18' or 'perf probe mcount' for instance). In V2 we are incorporating Masami Hiramatsu's feedback. This patch fixes it by returning -EINVAL upon failure. While we are here, rename the label used for exit to be more appropriate. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Prashanth K Nageshappa Acked-by: Masami Hiramatsu Cc: Jason Baron Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kprobes.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 9788c0ec6f43..c62b8546cc90 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1334,8 +1334,10 @@ int __kprobes register_kprobe(struct kprobe *p) 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)) - goto fail_with_jump_label; + jump_label_text_reserved(p->addr, p->addr)) { + ret = -EINVAL; + goto cannot_probe; + } /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */ p->flags &= KPROBE_FLAG_DISABLED; @@ -1352,7 +1354,7 @@ int __kprobes register_kprobe(struct kprobe *p) * its code to prohibit unexpected unloading. */ if (unlikely(!try_module_get(probed_mod))) - goto fail_with_jump_label; + goto cannot_probe; /* * If the module freed .init.text, we couldn't insert @@ -1361,7 +1363,7 @@ int __kprobes register_kprobe(struct kprobe *p) if (within_module_init((unsigned long)p->addr, probed_mod) && probed_mod->state != MODULE_STATE_COMING) { module_put(probed_mod); - goto fail_with_jump_label; + goto cannot_probe; } /* ret will be updated by following code */ } @@ -1409,7 +1411,7 @@ int __kprobes register_kprobe(struct kprobe *p) return ret; -fail_with_jump_label: +cannot_probe: preempt_enable(); jump_label_unlock(); return ret;