releases/4.19.34/kprobes-prohibit-probing-on-bsearch.patch

   1 From b86843d11b3a9cd286198f193dffa9266ca3fb49 Mon Sep 17 00:00:00 2001
   2 From: Andrea Righi <righi.andrea@gmail.com>
   3 Date: Wed, 13 Feb 2019 01:15:34 +0900
   4 Subject: kprobes: Prohibit probing on bsearch()
   5
   6 [ Upstream commit 02106f883cd745523f7766d90a739f983f19e650 ]
   7
   8 Since kprobe breakpoing handler is using bsearch(), probing on this
   9 routine can cause recursive breakpoint problem.
  10
  11 int3
  12  ->do_int3()
  13    ->ftrace_int3_handler()
  14      ->ftrace_location()
  15        ->ftrace_location_range()
  16          ->bsearch() -> int3
  17
  18 Prohibit probing on bsearch().
  19
  20 Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
  21 Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
  22 Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
  23 Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
  24 Cc: Jiri Olsa <jolsa@redhat.com>
  25 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  26 Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  27 Cc: Peter Zijlstra <peterz@infradead.org>
  28 Cc: Steven Rostedt <rostedt@goodmis.org>
  29 Cc: Thomas Gleixner <tglx@linutronix.de>
  30 Link: http://lkml.kernel.org/r/154998813406.31052.8791425358974650922.stgit@devbox
  31 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  32 Signed-off-by: Sasha Levin <sashal@kernel.org>
  33 ---
  34  lib/bsearch.c | 2 ++
  35  1 file changed, 2 insertions(+)
  36
  37 diff --git a/lib/bsearch.c b/lib/bsearch.c
  38 index 18b445b010c3..82512fe7b33c 100644
  39 --- a/lib/bsearch.c
  40 +++ b/lib/bsearch.c
  41 @@ -11,6 +11,7 @@
  42
  43  #include <linux/export.h>
  44  #include <linux/bsearch.h>
  45 +#include <linux/kprobes.h>
  46
  47  /*
  48   * bsearch - binary search an array of elements
  49 @@ -53,3 +54,4 @@ void *bsearch(const void *key, const void *base, size_t num, size_t size,
  50         return NULL;
  51  }
  52  EXPORT_SYMBOL(bsearch);
  53 +NOKPROBE_SYMBOL(bsearch);
  54 --
  55 2.19.1
  56