[RFC bpf-next v2 06/12] bpf: verifier: record original instruction index
From: Jakub Kicinski <hidden>
Date: 2018-12-28 00:55:56
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
The communication between the verifier and advanced JITs is based on instruction indexes. We have to keep them stable throughout the optimizations otherwise referring to a particular instruction gets messy quickly. Signed-off-by: Jakub Kicinski <redacted> Reviewed-by: Quentin Monnet <redacted> --- include/linux/bpf_verifier.h | 1 + kernel/bpf/verifier.c | 8 +++++--- 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index c233efc106c6..414d1aeba897 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h@@ -176,6 +176,7 @@ struct bpf_insn_aux_data { int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ int sanitize_stack_off; /* stack slot to be cleared */ bool seen; /* this insn was processed by the verifier */ + unsigned int orig_idx; /* original instruction index */ }; #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a92b9eeff79c..dea4f70250c8 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -7142,7 +7142,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, { struct bpf_verifier_env *env; struct bpf_verifier_log *log; - int ret = -EINVAL; + int i, len, ret = -EINVAL; bool is_priv; /* no program is valid */
@@ -7157,12 +7157,14 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, return -ENOMEM; log = &env->log; + len = (*prog)->len; env->insn_aux_data = - vzalloc(array_size(sizeof(struct bpf_insn_aux_data), - (*prog)->len)); + vzalloc(array_size(sizeof(struct bpf_insn_aux_data), len)); ret = -ENOMEM; if (!env->insn_aux_data) goto err_free_env; + for (i = 0; i < len; i++) + env->insn_aux_data[i].orig_idx = i; env->prog = *prog; env->ops = bpf_verifier_ops[env->prog->type];
--
2.19.2