perf top: Fix window dimensions change handling

The stdio perf top crashes when we change the terminal
window size. The reason is that we assumed we get the
perf_top pointer as a signal handler argument which is
not the case.

Changing the SIGWINCH handler logic to change global
resize variable, which is checked in the main thread
loop.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ysuzwz77oev1ftgvdscn9bpu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 1b01c277bab95f2e1d93ec4515be684c6c2b5116..48957388393612e994940c803af4cc7573683cab 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -77,6 +77,7 @@
 #include "sane_ctype.h"
 
 static volatile int done;
+static volatile int resize;
 
 #define HEADER_LINE_NR  5
 
@@ -86,10 +87,13 @@ static void perf_top__update_print_entries(struct perf_top *top)
 }
 
 static void perf_top__sig_winch(int sig __maybe_unused,
-                               siginfo_t *info __maybe_unused, void *arg)
+                               siginfo_t *info __maybe_unused, void *arg __maybe_unused)
 {
-       struct perf_top *top = arg;
+       resize = 1;
+}
 
+static void perf_top__resize(struct perf_top *top)
+{
        get_term_dimensions(&top->winsize);
        perf_top__update_print_entries(top);
 }
@@ -477,7 +481,7 @@ static bool perf_top__handle_keypress(struct perf_top *top, int c)
                                        .sa_sigaction = perf_top__sig_winch,
                                        .sa_flags     = SA_SIGINFO,
                                };
-                               perf_top__sig_winch(SIGWINCH, NULL, top);
+                               perf_top__resize(top);
                                sigaction(SIGWINCH, &act, NULL);
                        } else {
                                signal(SIGWINCH, SIG_DFL);
@@ -1032,6 +1036,11 @@ static int __cmd_top(struct perf_top *top)
 
                if (hits == top->samples)
                        ret = perf_evlist__poll(top->evlist, 100);
+
+               if (resize) {
+                       perf_top__resize(top);
+                       resize = 0;
+               }
        }
 
        ret = 0;