From: Li Bin <huawei.libin@huawei.com>

Date: Tue, 29 Aug 2017 20:57:23 +0800

Subject: perf probe: Fix kprobe blacklist checking condition

Git-commit: 2c29461e273abaf149cf8220c3403e9d67dd8b61

Patch-mainline: v4.14-rc1

References: bsc#1070010 (git-fixes)

Signed-off-By: Tony Jones <tonyj@suse.de>

​

The commit 9aaf5a5f479b ("perf probe: Check kprobes blacklist when

adding new events"), 'perf probe' supports checking the blacklist of the

fuctions which can not be probed.  But the checking condition is wrong,

that the end_addr of the symbol which is the start_addr of the next

symbol can't be included.

​

Committer notes:

​

IOW make it match its kernel counterpart in kernel/kprobes.c:

​

  bool within_kprobe_blacklist(unsigned long addr)

​

Each entry have as its end address not its end address, but the first

address _outside_ that symbol, which for related functions, is the first

address of the next symbol, like these from kernel/trace/trace_probe.c:

​

0xffffffffbd198df0-0xffffffffbd198e40   print_type_u8

0xffffffffbd198e40-0xffffffffbd198e90   print_type_u16

0xffffffffbd198e90-0xffffffffbd198ee0   print_type_u32

0xffffffffbd198ee0-0xffffffffbd198f30   print_type_u64

0xffffffffbd198f30-0xffffffffbd198f80   print_type_s8

0xffffffffbd198f80-0xffffffffbd198fd0   print_type_s16

0xffffffffbd198fd0-0xffffffffbd199020   print_type_s32

0xffffffffbd199020-0xffffffffbd199070   print_type_s64

0xffffffffbd199070-0xffffffffbd1990c0   print_type_x8

0xffffffffbd1990c0-0xffffffffbd199110   print_type_x16

0xffffffffbd199110-0xffffffffbd199160   print_type_x32

0xffffffffbd199160-0xffffffffbd1991b0   print_type_x64

​

But not always:

​

0xffffffffbd1997b0-0xffffffffbd1997c0   fetch_kernel_stack_address (kernel/trace/trace_probe.c)

0xffffffffbd1c57f0-0xffffffffbd1c58b0   __context_tracking_enter   (kernel/context_tracking.c)

​

Signed-off-by: Li Bin <huawei.libin@huawei.com>

Cc: Masami Hiramatsu <mhiramat@kernel.org>

Cc: Namhyung Kim <namhyung@kernel.org>

Cc: Peter Zijlstra <peterz@infradead.org>

Cc: Wang Nan <wangnan0@huawei.com>

Cc: zhangmengting@huawei.com

Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events")

Link: http://lkml.kernel.org/r/1504011443-7269-1-git-send-email-huawei.libin@huawei.com

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

---

 tools/perf/util/probe-event.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

​

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c

index d7cd1142f4c6..b7aaf9b2294d 100644

--- a/tools/perf/util/probe-event.c

+++ b/tools/perf/util/probe-event.c

@@ -2395,7 +2395,7 @@ kprobe_blacklist__find_by_address(struct list_head *blacklist,

    struct kprobe_blacklist_node *node;

    list_for_each_entry(node, blacklist, list) {

-       if (node->start <= address && address <= node->end)

+       if (node->start <= address && address < node->end)

            return node;

    }

​

​