Similar to classic bpf, support saving original ebpf instructions
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
include/linux/filter.h | 5 ++++-
kernel/bpf/syscall.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index e4eb2546339a..86b1e3624463 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -391,7 +391,10 @@ struct compat_sock_fprog {
struct sock_fprog_kern {
u16 len;
- struct sock_filter *filter;
+ union {
+ struct sock_filter *filter;
+ struct bpf_insn *insn;
+ };
};
struct bpf_binary_header {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 08a4d287226b..95e640a3ed99 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -694,11 +694,43 @@ static void bpf_prog_uncharge_memlock(struct bpf_prog
*prog)
free_uid(user);
}
+static int bpf_prog_store_orig_insn(struct bpf_prog *prog)
+{
+ u32 isize = bpf_prog_insn_size(prog);
+ struct sock_fprog_kern *fkprog;
+
+ prog->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL);
+ if (!prog->orig_prog)
+ return -ENOMEM;
+
+ fkprog = prog->orig_prog;
+ fkprog->len = prog->len;
+
+ fkprog->insn = kmemdup(prog->insnsi, isize, GFP_KERNEL | __GFP_NOWARN);
+ if (!fkprog->insn) {
+ kfree(prog->orig_prog);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void bpf_release_orig_insn(struct bpf_prog *fp)
+{
+ struct sock_fprog_kern *fprog = fp->orig_prog;
+
+ if (fprog) {
+ kfree(fprog->insn);
+ kfree(fprog);
+ }
+}
+
static void __bpf_prog_put_rcu(struct rcu_head *rcu)
{
struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
free_used_maps(aux);
+ bpf_release_orig_insn(aux->prog);
bpf_prog_uncharge_memlock(aux->prog);
bpf_prog_free(aux->prog);
}
@@ -885,6 +917,10 @@ static int bpf_prog_load(union bpf_attr *attr)
if (err < 0)
goto free_prog;
+ err = bpf_prog_store_orig_insn(prog);
+ if (err < 0)
+ goto free_prog;
+
/* run eBPF verifier */
err = bpf_check(&prog, attr);
if (err < 0)
--
2.1.4
