From c952b35f4b15dd1b83e952718dec3307256383ef Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 19 Jun 2019 18:04:53 -0700 Subject: [PATCH] perf header: Assign proper ff->ph in perf_event__synthesize_features() bpf/btf write_* functions need ff->ph->env. With this missing, pipe-mode (perf record -o -) would crash like: Program terminated with signal SIGSEGV, Segmentation fault. This patch assign proper ph value to ff. Committer testing: (gdb) run record -o - Starting program: /root/bin/perf record -o - PERFILE2 Thread 1 "perf" received signal SIGSEGV, Segmentation fault. __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126 126 memcpy(ff->buf + ff->offset, buf, size); (gdb) bt #0 __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126 #1 do_write (ff=ff@entry=0x7fffffff8f80, buf=buf@entry=0x160, size=4) at util/header.c:137 #2 0x00000000004eddba in write_bpf_prog_info (ff=0x7fffffff8f80, evlist=) at util/header.c:912 #3 0x00000000004f69d7 in perf_event__synthesize_features (tool=tool@entry=0x97cc00 , session=session@entry=0x7fffe9c6d010, evlist=0x7fffe9cae010, process=process@entry=0x4435d0 ) at util/header.c:3695 #4 0x0000000000443c79 in record__synthesize (tail=tail@entry=false, rec=0x97cc00 ) at builtin-record.c:1214 #5 0x0000000000444ec9 in __cmd_record (rec=0x97cc00 , argv=, argc=0) at builtin-record.c:1435 #6 cmd_record (argc=0, argv=) at builtin-record.c:2450 #7 0x00000000004ae3e9 in run_builtin (p=p@entry=0x98e058 , argc=argc@entry=3, argv=0x7fffffffd670) at perf.c:304 #8 0x000000000042eded in handle_internal_command (argv=, argc=) at perf.c:356 #9 run_argv (argcp=, argv=) at perf.c:400 #10 main (argc=3, argv=) at perf.c:522 (gdb) After the patch the SEGSEGV is gone. Reported-by: David Carrillo Cisneros Signed-off-by: Song Liu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: kernel-team@fb.com Cc: stable@vger.kernel.org # v5.1+ Fixes: 606f972b1361 ("perf bpf: Save bpf_prog_info information as headers to perf.data") Link: http://lkml.kernel.org/r/20190620010453.4118689-1-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 847ae51..fb0aa66 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -3602,6 +3602,7 @@ int perf_event__synthesize_features(struct perf_tool *tool, return -ENOMEM; ff.size = sz - sz_hdr; + ff.ph = &session->header; for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) { if (!feat_ops[feat].synthesize) { -- 2.7.4