hi,
Martynas reported kprobe _multi link does not resolve symbols
from kernel modules, which attach by address works.
In addition while fixing that I realized we do not take module
reference if the module has kprobe_multi link on top of it and
can be removed.
There's mo crash related to this, it will silently disappear from
ftrace tables, while kprobe_multi link stays up with no data.
This patchset has fixes for both issues.
thanks,
jirka
---
Jiri Olsa (8):
kallsyms: Make module_kallsyms_on_each_symbol generally available
ftrace: Add support to resolve module symbols in ftrace_lookup_symbols
bpf: Rename __bpf_kprobe_multi_cookie_cmp to bpf_kprobe_multi_addrs_cmp
bpf: Take module reference on kprobe_multi link
selftests/bpf: Add load_kallsyms_refresh function
selftests/bpf: Add bpf_testmod_fentry_* functions
selftests/bpf: Add kprobe_multi kmod link api tests
selftests/bpf: Add kprobe_multi check to module attach test
include/linux/module.h | 9 ++++++++
kernel/module/kallsyms.c | 2 --
kernel/trace/bpf_trace.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
kernel/trace/ftrace.c | 11 +++++----
tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 24 +++++++++++++++++++
tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
tools/testing/selftests/bpf/prog_tests/module_attach.c | 7 ++++++
tools/testing/selftests/bpf/progs/kprobe_multi.c | 51 ++++++++++++++++++++++++++++++++++++++++
tools/testing/selftests/bpf/progs/test_module_attach.c | 6 +++++
tools/testing/selftests/bpf/trace_helpers.c | 20 ++++++++++------
tools/testing/selftests/bpf/trace_helpers.h | 2 ++
11 files changed, 315 insertions(+), 17 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c
