From: Alexei Starovoitov <ast@fb•com>
To: "David S . Miller" <davem@davemloft•net>
Cc: Daniel Borkmann <daniel@iogearbox•net>, <netdev@vger•kernel.org>,
<kernel-team@fb•com>
Subject: [PATCH net-next 3/9] bpf: teach verifier to track stack depth
Date: Tue, 30 May 2017 13:31:29 -0700 [thread overview]
Message-ID: <20170530203135.3642768-4-ast@fb.com> (raw)
In-Reply-To: <20170530203135.3642768-1-ast@fb.com>
teach verifier to track bpf program stack depth
Signed-off-by: Alexei Starovoitov <ast@kernel•org>
Acked-by: Daniel Borkmann <daniel@iogearbox•net>
---
include/linux/bpf.h | 1 +
kernel/bpf/verifier.c | 10 +++++++++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 6bb38d76faf4..fcc80ca11045 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -171,6 +171,7 @@ struct bpf_prog_aux {
atomic_t refcnt;
u32 used_map_cnt;
u32 max_ctx_offset;
+ u32 stack_depth;
struct latch_tree_node ksym_tnode;
struct list_head ksym_lnode;
const struct bpf_verifier_ops *ops;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 28113d0e8e92..d96f27ff9f6f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -926,6 +926,10 @@ static int check_mem_access(struct bpf_verifier_env *env, u32 regno, int off,
verbose("invalid stack off=%d size=%d\n", off, size);
return -EACCES;
}
+
+ if (env->prog->aux->stack_depth < -off)
+ env->prog->aux->stack_depth = -off;
+
if (t == BPF_WRITE) {
if (!env->allow_ptr_leaks &&
state->stack_slot_type[MAX_BPF_STACK + off] == STACK_SPILL &&
@@ -1032,6 +1036,9 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
return -EACCES;
}
+ if (env->prog->aux->stack_depth < -off)
+ env->prog->aux->stack_depth = -off;
+
if (meta && meta->raw_mode) {
meta->access_size = access_size;
meta->regno = regno;
@@ -3167,7 +3174,8 @@ static int do_check(struct bpf_verifier_env *env)
insn_idx++;
}
- verbose("processed %d insns\n", insn_processed);
+ verbose("processed %d insns, stack depth %d\n",
+ insn_processed, env->prog->aux->stack_depth);
return 0;
}
--
2.9.3
next prev parent reply other threads:[~2017-05-30 20:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-30 20:31 [PATCH net-next 0/9] bpf: stack depth tracking Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 1/9] bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 2/9] bpf: split bpf core interpreter Alexei Starovoitov
2017-05-30 20:31 ` Alexei Starovoitov [this message]
2017-05-30 20:31 ` [PATCH net-next 4/9] bpf: reconcile bpf_tail_call and stack_depth Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 5/9] bpf: track stack depth of classic bpf programs Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 6/9] bpf: fix stack_depth usage by test_bpf.ko Alexei Starovoitov
2017-05-31 18:15 ` David Miller
2017-05-31 18:39 ` Alexei Starovoitov
2017-05-31 18:43 ` David Miller
2017-05-31 18:45 ` Alexei Starovoitov
2017-05-31 22:41 ` Alexei Starovoitov
2017-05-31 23:30 ` David Miller
2017-06-06 10:19 ` Daniel Borkmann
2017-05-30 20:31 ` [PATCH net-next 7/9] bpf: use different interpreter depending on required stack size Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 8/9] bpf: change x86 JITed program stack layout Alexei Starovoitov
2017-05-30 20:31 ` [PATCH net-next 9/9] bpf: take advantage of stack_depth tracking in x64 JIT Alexei Starovoitov
2017-05-31 23:30 ` [PATCH net-next 0/9] bpf: stack depth tracking David Miller
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