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 <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Hewenliang <[email protected]>
Signed-off-by: yaowenbin <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions