linux/tools/perf/ui/tui/setup.c
yaowenbin 64f18d2d04 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 <liuwenyu7@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: wuxu.wu@huawei.com
Link: http://lore.kernel.org/lkml/a91e3943-7ddc-f5c0-a7f5-360f073c20e6@huawei.com
Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Signed-off-by: yaowenbin <yaowenbin1@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-01-02 11:46:44 -03:00

181 lines
3.2 KiB
C

#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/kernel.h>
#ifdef HAVE_BACKTRACE_SUPPORT
#include <execinfo.h>
#endif
#include "../../util/debug.h"
#include "../../perf.h"
#include "../browser.h"
#include "../helpline.h"
#include "../ui.h"
#include "../util.h"
#include "../libslang.h"
#include "../keysyms.h"
#include "tui.h"
static volatile int ui__need_resize;
extern struct perf_error_ops perf_tui_eops;
extern bool tui_helpline__set;
extern void hist_browser__init_hpp(void);
void ui__refresh_dimensions(bool force)
{
if (force || ui__need_resize) {
ui__need_resize = 0;
pthread_mutex_lock(&ui__lock);
SLtt_get_screen_size();
SLsmg_reinit_smg();
pthread_mutex_unlock(&ui__lock);
}
}
static void ui__sigwinch(int sig __maybe_unused)
{
ui__need_resize = 1;
}
static void ui__setup_sigwinch(void)
{
static bool done;
if (done)
return;
done = true;
pthread__unblock_sigwinch();
signal(SIGWINCH, ui__sigwinch);
}
int ui__getch(int delay_secs)
{
struct timeval timeout, *ptimeout = delay_secs ? &timeout : NULL;
fd_set read_set;
int err, key;
ui__setup_sigwinch();
FD_ZERO(&read_set);
FD_SET(0, &read_set);
if (delay_secs) {
timeout.tv_sec = delay_secs;
timeout.tv_usec = 0;
}
err = select(1, &read_set, NULL, NULL, ptimeout);
if (err == 0)
return K_TIMER;
if (err == -1) {
if (errno == EINTR)
return K_RESIZE;
return K_ERROR;
}
key = SLang_getkey();
if (key != K_ESC)
return key;
FD_ZERO(&read_set);
FD_SET(0, &read_set);
timeout.tv_sec = 0;
timeout.tv_usec = 20;
err = select(1, &read_set, NULL, NULL, &timeout);
if (err == 0)
return K_ESC;
SLang_ungetkey(key);
return SLkp_getkey();
}
#ifdef HAVE_BACKTRACE_SUPPORT
static void ui__signal_backtrace(int sig)
{
void *stackdump[32];
size_t size;
ui__exit(false);
psignal(sig, "perf");
printf("-------- backtrace --------\n");
size = backtrace(stackdump, ARRAY_SIZE(stackdump));
backtrace_symbols_fd(stackdump, size, STDOUT_FILENO);
exit(0);
}
#else
# define ui__signal_backtrace ui__signal
#endif
static void ui__signal(int sig)
{
ui__exit(false);
psignal(sig, "perf");
exit(0);
}
int ui__init(void)
{
int err;
SLutf8_enable(-1);
SLtt_get_terminfo();
SLtt_get_screen_size();
err = SLsmg_init_smg();
if (err < 0)
goto out;
err = SLang_init_tty(-1, 0, 0);
if (err < 0)
goto out;
err = SLkp_init();
if (err < 0) {
pr_err("TUI initialization failed.\n");
goto out;
}
SLkp_define_keysym((char *)"^(kB)", SL_KEY_UNTAB);
signal(SIGSEGV, ui__signal_backtrace);
signal(SIGFPE, ui__signal_backtrace);
signal(SIGINT, ui__signal);
signal(SIGQUIT, ui__signal);
signal(SIGTERM, ui__signal);
perf_error__register(&perf_tui_eops);
ui_helpline__init();
ui_browser__init();
tui_progress__init();
hist_browser__init_hpp();
out:
return err;
}
void ui__exit(bool wait_for_ok)
{
if (wait_for_ok && tui_helpline__set)
ui__question_window("Fatal Error",
ui_helpline__last_msg,
"Press any key...", 0);
SLtt_set_cursor_visibility(1);
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);
}