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-rw-r--r--common/recipes-kernel/linux/linux-yocto-4.9.21/0044-bpf-refactor-fixup_bpf_calls.patch125
1 files changed, 125 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0044-bpf-refactor-fixup_bpf_calls.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0044-bpf-refactor-fixup_bpf_calls.patch
new file mode 100644
index 00000000..bd75a23a
--- /dev/null
+++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0044-bpf-refactor-fixup_bpf_calls.patch
@@ -0,0 +1,125 @@
+From 9db9c08ce79c7ca4b0038faf03e31078f0b5dd4c Mon Sep 17 00:00:00 2001
+From: Alexei Starovoitov <ast@fb.com>
+Date: Wed, 15 Mar 2017 18:26:40 -0700
+Subject: [PATCH 044/103] bpf: refactor fixup_bpf_calls()
+
+commit 79741b3bdec01a8628368fbcfccc7d189ed606cb upstream.
+
+reduce indent and make it iterate over instructions similar to
+convert_ctx_accesses(). Also convert hard BUG_ON into soft verifier error.
+
+Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+Acked-by: Daniel Borkmann <daniel@iogearbox.net>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Cc: Jiri Slaby <jslaby@suse.cz>
+[Backported to 4.9.y - gregkh]
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/bpf/verifier.c | 73 ++++++++++++++++++++++++---------------------------
+ 1 file changed, 34 insertions(+), 39 deletions(-)
+
+diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
+index 1176556..3f24718 100644
+--- a/kernel/bpf/verifier.c
++++ b/kernel/bpf/verifier.c
+@@ -3119,55 +3119,50 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
+ return 0;
+ }
+
+-/* fixup insn->imm field of bpf_call instructions:
+- * if (insn->imm == BPF_FUNC_map_lookup_elem)
+- * insn->imm = bpf_map_lookup_elem - __bpf_call_base;
+- * else if (insn->imm == BPF_FUNC_map_update_elem)
+- * insn->imm = bpf_map_update_elem - __bpf_call_base;
+- * else ...
++/* fixup insn->imm field of bpf_call instructions
+ *
+ * this function is called after eBPF program passed verification
+ */
+-static void fixup_bpf_calls(struct bpf_prog *prog)
++static int fixup_bpf_calls(struct bpf_verifier_env *env)
+ {
++ struct bpf_prog *prog = env->prog;
++ struct bpf_insn *insn = prog->insnsi;
+ const struct bpf_func_proto *fn;
++ const int insn_cnt = prog->len;
+ int i;
+
+- for (i = 0; i < prog->len; i++) {
+- struct bpf_insn *insn = &prog->insnsi[i];
++ for (i = 0; i < insn_cnt; i++, insn++) {
++ if (insn->code != (BPF_JMP | BPF_CALL))
++ continue;
+
+- if (insn->code == (BPF_JMP | BPF_CALL)) {
+- /* we reach here when program has bpf_call instructions
+- * and it passed bpf_check(), means that
+- * ops->get_func_proto must have been supplied, check it
+- */
+- BUG_ON(!prog->aux->ops->get_func_proto);
+-
+- if (insn->imm == BPF_FUNC_get_route_realm)
+- prog->dst_needed = 1;
+- if (insn->imm == BPF_FUNC_get_prandom_u32)
+- bpf_user_rnd_init_once();
+- if (insn->imm == BPF_FUNC_tail_call) {
+- /* mark bpf_tail_call as different opcode
+- * to avoid conditional branch in
+- * interpeter for every normal call
+- * and to prevent accidental JITing by
+- * JIT compiler that doesn't support
+- * bpf_tail_call yet
+- */
+- insn->imm = 0;
+- insn->code |= BPF_X;
+- continue;
+- }
++ if (insn->imm == BPF_FUNC_get_route_realm)
++ prog->dst_needed = 1;
++ if (insn->imm == BPF_FUNC_get_prandom_u32)
++ bpf_user_rnd_init_once();
++ if (insn->imm == BPF_FUNC_tail_call) {
++ /* mark bpf_tail_call as different opcode to avoid
++ * conditional branch in the interpeter for every normal
++ * call and to prevent accidental JITing by JIT compiler
++ * that doesn't support bpf_tail_call yet
++ */
++ insn->imm = 0;
++ insn->code |= BPF_X;
++ continue;
++ }
+
+- fn = prog->aux->ops->get_func_proto(insn->imm);
+- /* all functions that have prototype and verifier allowed
+- * programs to call them, must be real in-kernel functions
+- */
+- BUG_ON(!fn->func);
+- insn->imm = fn->func - __bpf_call_base;
++ fn = prog->aux->ops->get_func_proto(insn->imm);
++ /* all functions that have prototype and verifier allowed
++ * programs to call them, must be real in-kernel functions
++ */
++ if (!fn->func) {
++ verbose("kernel subsystem misconfigured func %d\n",
++ insn->imm);
++ return -EFAULT;
+ }
++ insn->imm = fn->func - __bpf_call_base;
+ }
++
++ return 0;
+ }
+
+ static void free_states(struct bpf_verifier_env *env)
+@@ -3269,7 +3264,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
+ ret = convert_ctx_accesses(env);
+
+ if (ret == 0)
+- fixup_bpf_calls(env->prog);
++ ret = fixup_bpf_calls(env);
+
+ if (log_level && log_len >= log_size - 1) {
+ BUG_ON(log_len >= log_size);
+--
+2.7.4
+