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Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c55
1 files changed, 52 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4ec1d1aa25ea..b6664d0f6914 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -579,6 +579,13 @@ static bool is_cmpxchg_insn(const struct bpf_insn *insn)
insn->imm == BPF_CMPXCHG;
}
+static bool is_atomic_load_insn(const struct bpf_insn *insn)
+{
+ return BPF_CLASS(insn->code) == BPF_STX &&
+ BPF_MODE(insn->code) == BPF_ATOMIC &&
+ insn->imm == BPF_LOAD_ACQ;
+}
+
static int __get_spi(s32 off)
{
return (-off - 1) / BPF_REG_SIZE;
@@ -3567,7 +3574,7 @@ static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
}
if (class == BPF_STX) {
- /* BPF_STX (including atomic variants) has multiple source
+ /* BPF_STX (including atomic variants) has one or more source
* operands, one of which is a ptr. Check whether the caller is
* asking about it.
*/
@@ -4181,7 +4188,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
* dreg still needs precision before this insn
*/
}
- } else if (class == BPF_LDX) {
+ } else if (class == BPF_LDX || is_atomic_load_insn(insn)) {
if (!bt_is_reg_set(bt, dreg))
return 0;
bt_clear_reg(bt, dreg);
@@ -7766,6 +7773,32 @@ static int check_atomic_rmw(struct bpf_verifier_env *env,
return 0;
}
+static int check_atomic_load(struct bpf_verifier_env *env,
+ struct bpf_insn *insn)
+{
+ if (!atomic_ptr_type_ok(env, insn->src_reg, insn)) {
+ verbose(env, "BPF_ATOMIC loads from R%d %s is not allowed\n",
+ insn->src_reg,
+ reg_type_str(env, reg_state(env, insn->src_reg)->type));
+ return -EACCES;
+ }
+
+ return check_load_mem(env, insn, true, false, false, "atomic_load");
+}
+
+static int check_atomic_store(struct bpf_verifier_env *env,
+ struct bpf_insn *insn)
+{
+ if (!atomic_ptr_type_ok(env, insn->dst_reg, insn)) {
+ verbose(env, "BPF_ATOMIC stores into R%d %s is not allowed\n",
+ insn->dst_reg,
+ reg_type_str(env, reg_state(env, insn->dst_reg)->type));
+ return -EACCES;
+ }
+
+ return check_store_reg(env, insn, true);
+}
+
static int check_atomic(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
switch (insn->imm) {
@@ -7780,6 +7813,20 @@ static int check_atomic(struct bpf_verifier_env *env, struct bpf_insn *insn)
case BPF_XCHG:
case BPF_CMPXCHG:
return check_atomic_rmw(env, insn);
+ case BPF_LOAD_ACQ:
+ if (BPF_SIZE(insn->code) == BPF_DW && BITS_PER_LONG != 64) {
+ verbose(env,
+ "64-bit load-acquires are only supported on 64-bit arches\n");
+ return -EOPNOTSUPP;
+ }
+ return check_atomic_load(env, insn);
+ case BPF_STORE_REL:
+ if (BPF_SIZE(insn->code) == BPF_DW && BITS_PER_LONG != 64) {
+ verbose(env,
+ "64-bit store-releases are only supported on 64-bit arches\n");
+ return -EOPNOTSUPP;
+ }
+ return check_atomic_store(env, insn);
default:
verbose(env, "BPF_ATOMIC uses invalid atomic opcode %02x\n",
insn->imm);
@@ -20605,7 +20652,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
insn->code == (BPF_ST | BPF_MEM | BPF_W) ||
insn->code == (BPF_ST | BPF_MEM | BPF_DW)) {
type = BPF_WRITE;
- } else if ((insn->code == (BPF_STX | BPF_ATOMIC | BPF_W) ||
+ } else if ((insn->code == (BPF_STX | BPF_ATOMIC | BPF_B) ||
+ insn->code == (BPF_STX | BPF_ATOMIC | BPF_H) ||
+ insn->code == (BPF_STX | BPF_ATOMIC | BPF_W) ||
insn->code == (BPF_STX | BPF_ATOMIC | BPF_DW)) &&
env->insn_aux_data[i + delta].ptr_type == PTR_TO_ARENA) {
insn->code = BPF_STX | BPF_PROBE_ATOMIC | BPF_SIZE(insn->code);