From 46881159583318cf84e9210d794ae820f7196dca Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 28 Sep 2020 22:11:35 +0200 Subject: [PATCH] perf python scripting: Fix printable strings in python3 scripts commit 6fcd5ddc3b1467b3586972ef785d0d926ae4cdf4 upstream. Hagen reported broken strings in python3 tracepoint scripts: make PYTHON=python3 perf record -e sched:sched_switch -a -- sleep 5 perf script --gen-script py perf script -s ./perf-script.py [..] sched__sched_switch 7 563231.759525792 0 swapper prev_comm=bytearray(b'swapper/7\x00\x00\x00\x00\x00\x00\x00'), prev_pid=0, prev_prio=120, prev_state=, next_comm=bytearray(b'mutex-thread-co\x00'), The problem is in the is_printable_array function that does not take the zero byte into account and claim such string as not printable, so the code will create byte array instead of string. Committer testing: After this fix: sched__sched_switch 3 484522.497072626 1158680 kworker/3:0-eve prev_comm=kworker/3:0, prev_pid=1158680, prev_prio=120, prev_state=I, next_comm=swapper/3, next_pid=0, next_prio=120 Sample: {addr=0, cpu=3, datasrc=84410401, datasrc_decode=N/A|SNP N/A|TLB N/A|LCK N/A, ip=18446744071841817196, period=1, phys_addr=0, pid=1158680, tid=1158680, time=484522497072626, transaction=0, values=[(0, 0)], weight=0} sched__sched_switch 4 484522.497085610 1225814 perf prev_comm=perf, prev_pid=1225814, prev_prio=120, prev_state=, next_comm=migration/4, next_pid=30, next_prio=0 Sample: {addr=0, cpu=4, datasrc=84410401, datasrc_decode=N/A|SNP N/A|TLB N/A|LCK N/A, ip=18446744071841817196, period=1, phys_addr=0, pid=1225814, tid=1225814, time=484522497085610, transaction=0, values=[(0, 0)], weight=0} Fixes: 249de6e07458 ("perf script python: Fix string vs byte array resolving") Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Tested-by: Hagen Paul Pfeifer Cc: Alexander Shishkin Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/20200928201135.3633850-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/print_binary.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/print_binary.c b/tools/perf/util/print_binary.c index 599a1543871de..13fdc51c61d96 100644 --- a/tools/perf/util/print_binary.c +++ b/tools/perf/util/print_binary.c @@ -50,7 +50,7 @@ int is_printable_array(char *p, unsigned int len) len--; - for (i = 0; i < len; i++) { + for (i = 0; i < len && p[i]; i++) { if (!isprint(p[i]) && !isspace(p[i])) return 0; }