Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Tiezhu Yang <> | Subject | [PATCH] perf top: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set | Date | Tue, 18 Aug 2020 20:30:37 +0800 |
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When I execute perf top without HAVE_LIBBPF_SUPPORT, there exists the following segmentation fault, skip the side-band event setup to fix it, this is similar with commit 1101c872c8c7 ("perf record: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set").
[yangtiezhu@linux perf]$ ./perf top
<SNIP> perf: Segmentation fault Obtained 6 stack frames. ./perf(sighandler_dump_stack+0x5c) [0x12011b604] [0xffffffc010] ./perf(perf_mmap__read_init+0x3e) [0x1201feeae] ./perf() [0x1200d715c] /lib64/libpthread.so.0(+0xab9c) [0xffee10ab9c] /lib64/libc.so.6(+0x128f4c) [0xffedc08f4c] Segmentation fault
I use git bisect to find commit b38d85ef49cf ("perf bpf: Decouple creating the evlist from adding the SB event") is the first bad commit, so also add the Fixes tag.
Fixes: b38d85ef49cf ("perf bpf: Decouple creating the evlist from adding the SB event") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> --- tools/perf/builtin-top.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 994c230..7c64134 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1746,6 +1746,7 @@ int cmd_top(int argc, const char **argv) goto out_delete_evlist; } +#ifdef HAVE_LIBBPF_SUPPORT if (!top.record_opts.no_bpf_event) { top.sb_evlist = evlist__new(); @@ -1759,6 +1760,7 @@ int cmd_top(int argc, const char **argv) goto out_delete_evlist; } } +#endif if (perf_evlist__start_sb_thread(top.sb_evlist, target)) { pr_debug("Couldn't start the BPF side band thread:\nBPF programs starting from now on won't be annotatable\n"); -- 2.1.0
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