clang 6.0 and onwards, for the external function call generates
BPF_PSEUDO_CALL instruction:
call pseudo +-off -> call another bpf function.
More details about that change: https://lwn.net/Articles/741773/
DPDK BPF implementation right now doesn't support multiple BPF
functions per module.
To overcome that problem, and preserve existing functionality
(ability to call allowed by user external functions),
bpf_elf_load() clears EBPF_PSEUDO_CALL value.
For details how to reproduce the issue:
https://bugs.dpdk.org/show_bug.cgi?id=259
Fixes: 5dba93ae5f ("bpf: add ability to load eBPF program from ELF object file")
Cc: stable@dpdk.org
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Extend struct rte_bpf_xsym with new fields to provide information about:
- for variables - type and size
- for functions - number of arguments and type/size of each argument
and return value
Such information would allow validate code to perform
more extensive checking on input BPF program and catch
misbehaving BPF code.
That change would cause ABI/API breakage for librte_bpf.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Introduce rte_bpf_elf_load() function to provide ability to
load eBPF program from ELF object file.
It also adds dependency on libelf.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
