kprobes: Check probe address is reserved

Check whether the address of new probe is already reserved by
ftrace or alternatives (on x86) when registering new probe.
If reserved, it returns an error and not register the probe.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Jason Baron <jbaron@redhat.com>
LKML-Reference: <20100202214918.4694.94179.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 9453815138fa86cc5289cffdd79ed279c3231a4b..5de9f4a9c3fd0e77edc96ed1ed46b055d7a18bdc 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -337,6 +337,9 @@ static void __kprobes arch_copy_kprobe(struct kprobe *p)
 
 int __kprobes arch_prepare_kprobe(struct kprobe *p)
 {
+       if (alternatives_text_reserved(p->addr, p->addr))
+               return -EINVAL;
+
        if (!can_probe((unsigned long)p->addr))
                return -EILSEQ;
        /* insn: must be on special executable page on x86. */

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 9907a03c29f62e16a1f58dff1c711c185571ea0c..c3340e836c37bbb8c59abe4c09e856ae05383669 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -44,6 +44,7 @@
 #include <linux/debugfs.h>
 #include <linux/kdebug.h>
 #include <linux/memory.h>
+#include <linux/ftrace.h>
 
 #include <asm-generic/sections.h>
 #include <asm/cacheflush.h>
@@ -703,7 +704,8 @@ int __kprobes register_kprobe(struct kprobe *p)
 
        preempt_disable();
        if (!kernel_text_address((unsigned long) p->addr) ||
-           in_kprobes_functions((unsigned long) p->addr)) {
+           in_kprobes_functions((unsigned long) p->addr) ||
+           ftrace_text_reserved(p->addr, p->addr)) {
                preempt_enable();
                return -EINVAL;
        }