From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Wed, 23 Jan 2019 06:45:23 +0000 (-0800)
Subject: bpf: verifier: record original instruction index
X-Git-Tag: v5.1-rc1~178^2~404^2~9^2~6
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=9e4c24e7ee7dfd3898269519103e823892b730d8;p=linux.git

bpf: verifier: record original instruction index

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 <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 573cca00a0e6..f3ae00ee5516 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -187,6 +187,7 @@ struct bpf_insn_aux_data {
 	int sanitize_stack_off; /* stack slot to be cleared */
 	bool seen; /* this insn was processed by the verifier */
 	u8 alu_state; /* used in combination with alu_limit */
+	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 f39bca188a5c..f2c49b4235df 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7371,7 +7371,7 @@ 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 */
@@ -7386,12 +7386,14 @@ 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];