[PATCH AUTOSEL for 4.14 015/100] perf top: Fix window dimensions change handling

Sasha Levin
2018-01-28T23:16:48Z

From: Jiri Olsa <jolsa@kernel.org>

[ Upstream commit 89d0aeab4252adc2a7ea693637dd21c588bfa2d1 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
tools/perf/builtin-top.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ee954bde7e3e..dd57978b2096 100644
--- 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);
@@ -1022,6 +1026,11 @@ 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;
--
2.11.0