Re: [PATCH] perf machine: Initialize srcline string member in add_location struct
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: 2021-09-09 13:21:47
Em Mon, Jul 19, 2021 at 04:53:32PM +0200, Michael Petlan escreveu:
It's later supposed to be either a correct address or NULL. Without the initialization, it may contain an undefined value which results in the following segmentation fault: # perf top --sort comm -g --ignore-callees=do_idle
Later where? The backtrace below is unresolved, I couldn't reproduce it here, that al variable is local to add_callchain_ip(), and is then passed to several places where I couldn't find al->srcline being used, can you state where it is used and causes the segfault? - Arnaldo
quoted hunk ↗ jump to hunk
terminates with perf: Segmentation fault -------- backtrace -------- perf(+0x417b26)[0x557794f1fb26] /lib64/libc.so.6(+0x37400)[0x7f62a0194400] /lib64/libc.so.6(+0x15d685)[0x7f62a02ba685] /lib64/libc.so.6(__strdup+0x12)[0x7f62a01e6802] perf(+0x3769d9)[0x557794e7e9d9] perf(+0x376d3a)[0x557794e7ed3a] perf(+0x377284)[0x557794e7f284] perf(+0x3773e0)[0x557794e7f3e0] perf(hist_entry_iter__add+0xc4)[0x557794e80114] perf(+0x2799aa)[0x557794d819aa] perf(+0x354ec8)[0x557794e5cec8] perf(+0x279341)[0x557794d81341] /lib64/libpthread.so.0(+0x814a)[0x7f62a27b514a] /lib64/libc.so.6(clone+0x43)[0x7f62a0259dc3] Fixes: 1fb7d06a509e ("perf report: Use srcline from callchain for hist entries") Signed-off-by: Michael Petlan <redacted> Reported-by: Juri Lelli <redacted> CC: Milian Wolff <redacted> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <redacted> --- tools/perf/util/machine.c | 1 + 1 file changed, 1 insertion(+)diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index da19be7da284..44e40bad0e33 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c@@ -2149,6 +2149,7 @@ static int add_callchain_ip(struct thread *thread, al.filtered = 0; al.sym = NULL; + al.srcline = NULL; if (!cpumode) { thread__find_cpumode_addr_location(thread, ip, &al); } else {-- 2.18.4
-- - Arnaldo