[dpdk-dev] ebpf issues with secondary process.

[Stephen Hemminger]

Trying to use the existing BPF code in BPF for packet filter is possible.
But one road block is that capture wants to allow a secondary process to
insert a packet filter. The current code in bpf_load() won't work for that.
The BPF program needs to be in shared area to allow secondary process
to work.

Why does the code use mmap() as an allocator instead of rte_malloc?

Something like the diff below (untested). JIT would have the same problem
but you would have issues with the mprotect stuff with huge pages.

I also noticed that bpf code is not using rte_memcpy and it has unnecessary
casts to void *.


diff --git a/lib/librte_bpf/bpf.c b/lib/librte_bpf/bpf.c
index 7e1879ffa5b5..d6995bbf0ba9 100644
--- a/lib/librte_bpf/bpf.c
+++ b/lib/librte_bpf/bpf.c
@@ -22,7 +22,7 @@ rte_bpf_destroy(struct rte_bpf *bpf)
        if (bpf != NULL) {
                if (bpf->jit.func != NULL)
                        munmap(bpf->jit.func, bpf->jit.sz);
-               munmap(bpf, bpf->sz);
+               rte_free(bpf);
        }
 }
 
diff --git a/lib/librte_bpf/bpf_load.c b/lib/librte_bpf/bpf_load.c
index 2a3b901d74c3..9a8e438a8963 100644
--- a/lib/librte_bpf/bpf_load.c
+++ b/lib/librte_bpf/bpf_load.c
@@ -32,9 +32,8 @@ bpf_load(const struct rte_bpf_prm *prm)
        bsz = sizeof(bpf[0]);
        sz = insz + xsz + bsz;
 
-       buf = mmap(NULL, sz, PROT_READ | PROT_WRITE,
-               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-       if (buf == MAP_FAILED)
+       buf = rte_malloc("bpf", sz, 0);
+       if (buf == NULL)
                return NULL;
 
        bpf = (void *)buf;

-- 
2.20.1