From: Avi Kivity <avi@scylladb.com>
To: linux-perf-users@vger.kernel.org
Subject: Infinite recursion in `perf record`
Date: Mon, 16 May 2022 18:22:35 +0300 [thread overview]
Message-ID: <f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com> (raw)
In bpf-event.c we have:
struct btf * __weak btf__load_from_kernel_by_id(__u32 id)
{
struct btf *btf;
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
int err = btf__get_from_id(id, &btf);
#pragma GCC diagnostic pop
return err ? ERR_PTR(err) : btf;
}
and in btf.c we have:
int btf__get_from_id(__u32 id, struct btf **btf)
{
struct btf *res;
int err;
*btf = NULL;
res = btf__load_from_kernel_by_id(id);
err = libbpf_get_error(res);
if (err)
return libbpf_err(err);
*btf = res;
return 0;
}
Obviously, if the first weak symbol isn't overridden we get into an
infinite recursion, which is what I see immediately on running perf record:
(gdb) bt
#0 0x00007f3d94c26d76 in btf__get_from_id (id=282,
btf=btf@entry=0x7ffc1dab4010) at btf.c:1410
#1 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#2 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4060) at btf.c:1411
#3 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#4 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab40b0) at btf.c:1411
#5 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#6 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4100) at btf.c:1411
#7 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#8 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4150) at btf.c:1411
#9 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#10 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab41a0) at btf.c:1411
#11 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#12 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab41f0) at btf.c:1411
#13 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#14 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4240) at btf.c:1411
#15 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#16 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4290) at btf.c:1411
#17 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#18 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab42e0) at btf.c:1411
#19 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#20 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4330) at btf.c:1411
#21 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#22 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4380) at btf.c:1411
#23 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#24 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab43d0) at btf.c:1411
#25 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#26 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4420) at btf.c:1411
#27 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#28 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4470) at btf.c:1411
#29 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#30 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab44c0) at btf.c:1411
#31 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#32 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4510) at btf.c:1411
#33 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#34 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4560) at btf.c:1411
#35 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#36 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab45b0) at btf.c:1411
#37 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#38 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4600) at btf.c:1411
#39 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#40 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4650) at btf.c:1411
#41 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#42 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab46a0) at btf.c:1411
#43 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#44 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab46f0) at btf.c:1411
#45 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#46 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4740) at btf.c:1411
#47 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#48 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4790) at btf.c:1411
#49 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#50 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab47e0) at btf.c:1411
#51 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#52 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4830) at btf.c:1411
#53 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#54 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4880) at btf.c:1411
#55 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#56 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab48d0) at btf.c:1411
#57 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#58 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4920) at btf.c:1411
#59 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#60 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4970) at btf.c:1411
#61 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#62 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab49c0) at btf.c:1411
#63 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#64 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4a10) at btf.c:1411
#65 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#66 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4a60) at btf.c:1411
#67 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#68 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4ab0) at btf.c:1411
#69 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#70 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4b00) at btf.c:1411
#71 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#72 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4b50) at btf.c:1411
#73 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#74 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4ba0) at btf.c:1411
#75 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#76 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4bf0) at btf.c:1411
#77 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
#78 0x00007f3d94c26d8d in btf__get_from_id (id=<optimized out>,
btf=btf@entry=0x7ffc1dab4c40) at btf.c:1411
#79 0x000055f3ff6d5004 in btf__load_from_kernel_by_id (id=<optimized
out>) at util/bpf-event.c:30
--Type <RET> for more, q to quit, c to continue without paging--
(rest of infinite stack trace omitted)
I guess I should load some library or other, but I have no idea which,
and in any case this is quite a fragile interface.
perf-5.17.6-300.fc36.x86_64
next reply other threads:[~2022-05-16 15:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 15:22 Avi Kivity [this message]
2022-05-16 22:04 ` Infinite recursion in `perf record` Ian Rogers
2022-05-17 13:23 ` Avi Kivity
2022-05-17 14:52 ` Arnaldo Carvalho de Melo
2022-05-17 14:59 ` Avi Kivity
2022-05-17 21:17 ` Arnaldo Carvalho de Melo
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