path: root/tools/perf/builtin-top.c
diff options
authorTommi Rantala <tommi.t.rantala@nokia.com>2020-03-05 10:37:12 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-03-06 08:30:47 -0300
commit29b4f5f188571c112713c35cc87eefb46efee612 (patch)
tree17b88ffd4b1cc19a14cc131c43fd29a6a49df96d /tools/perf/builtin-top.c
parentperf diff: Fix undefined string comparision spotted by clang's -Wstring-compare (diff)
perf top: Fix stdio interface input handling with glibc 2.28+
Since glibc 2.28 when running 'perf top --stdio', input handling no longer works, but hitting any key always just prints the "Mapped keys" help text. To fix it, call clearerr() in the display_thread() loop to clear any EOF sticky errors, as instructed in the glibc NEWS file (https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS): * All stdio functions now treat end-of-file as a sticky condition. If you read from a file until EOF, and then the file is enlarged by another process, you must call clearerr or another function with the same effect (e.g. fseek, rewind) before you can read the additional data. This corrects a longstanding C99 conformance bug. It is most likely to affect programs that use stdio to read interactive input from a terminal. (Bug #1190.) Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.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> Link: http://lore.kernel.org/lkml/20200305083714.9381-2-tommi.t.rantala@nokia.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to '')
1 files changed, 3 insertions, 1 deletions
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index f6dd1a63f159..d2539b793f9d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -684,7 +684,9 @@ repeat:
delay_msecs = top->delay_secs * MSEC_PER_SEC;
/* trash return*/
- getc(stdin);
+ clearerr(stdin);
+ if (poll(&stdin_poll, 1, 0) > 0)
+ getc(stdin);
while (!done) {