From: Andrea Righi <righi.andrea@gmail.com>
Date: Tue, 12 Feb 2019 16:15:34 +0000 (+0900)
Subject: kprobes: Prohibit probing on bsearch()
X-Git-Tag: v3.18.139~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9bac786e36abc14f3d1a2a32b53a37b6ecfe0bc6;p=thirdparty%2Fkernel%2Fstable.git

kprobes: Prohibit probing on bsearch()

[ Upstream commit 02106f883cd745523f7766d90a739f983f19e650 ]

Since kprobe breakpoing handler is using bsearch(), probing on this
routine can cause recursive breakpoint problem.

int3
 ->do_int3()
   ->ftrace_int3_handler()
     ->ftrace_location()
       ->ftrace_location_range()
         ->bsearch() -> int3

Prohibit probing on bsearch().

Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/154998813406.31052.8791425358974650922.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/lib/bsearch.c b/lib/bsearch.c
index e33c179089dbf..d50048446b77d 100644
--- a/lib/bsearch.c
+++ b/lib/bsearch.c
@@ -11,6 +11,7 @@
 
 #include <linux/export.h>
 #include <linux/bsearch.h>
+#include <linux/kprobes.h>
 
 /*
  * bsearch - binary search an array of elements
@@ -51,3 +52,4 @@ void *bsearch(const void *key, const void *base, size_t num, size_t size,
 	return NULL;
 }
 EXPORT_SYMBOL(bsearch);
+NOKPROBE_SYMBOL(bsearch);