[ 29/68] kprobes: return proper error code from register_kprobe()
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-03-09 20:04:52
Also in:
lkml
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Prashanth Nageshappa <redacted>
commit f986a499ef6f317d906e6f6f281be966e1237a10 upstream.
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 <redacted>
Signed-off-by: Prashanth K Nageshappa <redacted>
Acked-by: Masami Hiramatsu <redacted>
Cc: Jason Baron <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/kprobes.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c@@ -1324,8 +1324,10 @@ int __kprobes register_kprobe(struct kpr 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;
@@ -1340,7 +1342,7 @@ int __kprobes register_kprobe(struct kpr * 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
@@ -1349,7 +1351,7 @@ int __kprobes register_kprobe(struct kpr 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; } } preempt_enable();
@@ -1396,7 +1398,7 @@ out: return ret; -fail_with_jump_label: +cannot_probe: preempt_enable(); jump_label_unlock(); return -EINVAL;