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Unable to fetch data using bpf_map_lookup_elem()
I am trying to write a code for XDP where a user space program will populate a bpf map and then later the Kernel will look into the map. For creating the map I have added a SEC(".maps") in t...
Rishab
Votes: 0
Answers: 1
Why eBPF requires two memory copies for look up elememnts?
I am reading Linux kernel 5.18 and find out that Linux requires two memory copies for bpf(BPF_LOOKUP_ELEM..) system call. BPF_LOOKUP_ELEM calls map_lookup_elem defined at linux/bpf/syscall.c. In map_l...
JHAhn
Votes: 0
Answers: 0
What is the difference between syscalls openat and sys_enter_openat?
I see for python BCC implementation the syscall __x64_sys_openat is used to attach a kprobe, however in libbpf implementation a kprobe is attached to sys_enter_openat. It seems both capture openat() s...
phoxd
Votes: 0
Answers: 1
BPF / XDP: 'bpftool batch file' returns 'Error: reading batch file failed: Operation not permitted'
I have a docker container with an XDP program loaded on it. I also have a batch file for the bpftool to run. When I run bpftool batch file tmp_bpftool.txt, I get Error: reading batch file failed: Oper...
Ferrar
Votes: 0
Answers: 1