From 64f18d2d043015b3f835ce4c9f3beb97cfd19b6e Mon Sep 17 00:00:00 2001 From: yaowenbin Date: Wed, 29 Dec 2021 16:55:19 +0800 Subject: perf top: Fix TUI exit screen refresh race condition When the following command is executed several times, a coredump file is generated. $ timeout -k 9 5 perf top -e task-clock ******* ******* ******* 0.01% [kernel] [k] __do_softirq 0.01% libpthread-2.28.so [.] __pthread_mutex_lock 0.01% [kernel] [k] __ll_sc_atomic64_sub_return double free or corruption (!prev) perf top --sort comm,dso timeout: the monitored command dumped core When we terminate "perf top" using sending signal method, SLsmg_reset_smg() called. SLsmg_reset_smg() resets the SLsmg screen management routines by freeing all memory allocated while it was active. However SLsmg_reinit_smg() maybe be called by another thread. SLsmg_reinit_smg() will free the same memory accessed by SLsmg_reset_smg(), thus it results in a double free. SLsmg_reinit_smg() is called already protected by ui__lock, so we fix the problem by adding pthread_mutex_trylock of ui__lock when calling SLsmg_reset_smg(). Signed-off-by: Wenyu Liu Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: wuxu.wu@huawei.com Link: http://lore.kernel.org/lkml/a91e3943-7ddc-f5c0-a7f5-360f073c20e6@huawei.com Signed-off-by: Hewenliang Signed-off-by: yaowenbin Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/ui/tui/setup.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/ui/tui/setup.c b/tools/perf/ui/tui/setup.c index e9bfe856a5de..b1be59b4e2a4 100644 --- a/tools/perf/ui/tui/setup.c +++ b/tools/perf/ui/tui/setup.c @@ -170,9 +170,11 @@ void ui__exit(bool wait_for_ok) "Press any key...", 0); SLtt_set_cursor_visibility(1); - SLsmg_refresh(); - SLsmg_reset_smg(); + if (!pthread_mutex_trylock(&ui__lock)) { + SLsmg_refresh(); + SLsmg_reset_smg(); + pthread_mutex_unlock(&ui__lock); + } SLang_reset_tty(); - perf_error__unregister(&perf_tui_eops); } -- cgit v1.2.3-59-g8ed1b