The BPF_PROG_QUERY constant was introduced to Linux in
commit defd9c476fa6b01b4eb5450452bfd202138decb7
Author: Alexei Starovoitov <ast@kernel.org>
Date: Mon Oct 2 22:50:26 2017 -0700
libbpf: sync bpf.h
This is old enough that all our supported platforms can be assumed
to have this feature.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Currently, we are mixing: #if HAVE_BLAH with #if WITH_BLAH.
Things got way better with Pavel's work on meson, but apparently,
mixing these two lead to confusing and easy to miss bugs (see
31fb929eca for instance). While we were forced to use HAVE_
prefix with autotools, we are free to chose our own prefix with
meson and since WITH_ prefix appears to be more popular let's use
it everywhere.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The virbpf module wraps syscalls to BPF. However, if the kernel
headers used at the compile time don't have support for BPF the
module offers stubs which return a negative one to signal error
to the caller. But there is a slight discrepancy between real
functions and these stubs. While the former set errno and return
-1 the latter report an error (without setting the errno) and
return -1. This is not optimal because the caller might see stale
errno and overwrite the error message with a less accurate one.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
In functions implemented here we fill this attr union (type of
bpf_attr) and just pass it to syscall(2). Thing is that some of
the union members are type of __aligned_u64. This is not regular
uint64_t. This one is explicitly aligned to 8 bytes, while
uint64_t can be aligned to 4 bytes (on 32 bits). We've used
explicit typecast to uint64_t to shut compiler which would
otherwise complain of assigning a pointer into an integer. Well,
we have uintptr_t just for that.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There are some OSes which don't have syscall() nor
<sys/syscall.h>. We already check for the header file in
configure phase, so we just need to add check for
HAVE_SYS_SYSCALL_H to HAVE_DECL_BPF_PROG_QUERY.
While I'm at it, some header files we are including are not
needed, so their includes can be safely dropped.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In order to implement devices controller with cgroup v2 we need to
add support for BPF programs, cgroup v2 doesn't have devices controller.
This introduces required helpers wrapping linux syscalls.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
