fentry and fexit programs are similar to kprobe and kretprobe, but they
are newer and they have practically zero overhead to call before or
after kernel function. Also, fexit programs are focused on access to
arguments rather than the return value.
Those kind of programs were introduced in the following patchset:
https://lwn.net/Articles/804112/
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
This commit ensures that if no attach type is provided, that we use the
cgroup/skb section. If an attach type is provided we use the
cgroup_skb/$attach_type section.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This is necessary since the context is used in many other program types
and not just in SK_SKB programs.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This change adds support for the following program types:
* raw tracepoint
* LSM
Supporting LSM programs involved a necessity of supporting more
load_attrs for the BPF_PROG_LOAD operation, concretely:
* expected_attach_type - for LSM programs, it has always to be set to
BPF_LSM_MAC
* attach_btf_obj_fd - it's often used to reference the file descriptor of
program's BTF info, altough in case of LSM programs, it only has to
contain the value 0, which means the vmlinux object file (usually
/sys/kernel/btf/vmlinux)
* attach_btf_id - ID of the BTF object, which in case of LSM programs is
the ID of the function (the LSM hook)
The example of LSM program using that functionality can be found here:
https://github.com/vadorovsky/aya-example-lsmFixes: #9
Signed-off-by: William Findlay <william@williamfindlay.com>
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Alessandro Decina
William Findlay
Michal Rostecki
Dave Tucker
Markus Stange
Tw