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Message-Id: <20230301223555.84824-7-alexei.starovoitov@gmail.com>
Date: Wed, 1 Mar 2023 14:35:55 -0800
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: davem@...emloft.net
Cc: daniel@...earbox.net, andrii@...nel.org, martin.lau@...nel.org,
void@...ifault.com, davemarchevsky@...a.com, tj@...nel.org,
memxor@...il.com, netdev@...r.kernel.org, bpf@...r.kernel.org,
kernel-team@...com
Subject: [PATCH v4 bpf-next 6/6] bpf: Refactor RCU enforcement in the verifier.
From: Alexei Starovoitov <ast@...nel.org>
bpf_rcu_read_lock/unlock() are only available in clang compiled kernels. Lack
of such key mechanism makes it impossible for sleepable bpf programs to use RCU
pointers.
Allow bpf_rcu_read_lock/unlock() in GCC compiled kernels (though GCC doesn't
support btf_type_tag yet) and allowlist certain field dereferences in important
data structures like tast_struct, cgroup, socket that are used by sleepable
programs either as RCU pointer or full trusted pointer (which is valid outside
of RCU CS). Use BTF_TYPE_SAFE_RCU and BTF_TYPE_SAFE_TRUSTED macros for such
tagging. They will be removed once GCC supports btf_type_tag.
With that refactor check_ptr_to_btf_access(). Make it strict in enforcing
PTR_TRUSTED and PTR_UNTRUSTED while deprecating old PTR_TO_BTF_ID without
modifier flags. There is a chance that this strict enforcement might break
existing programs (especially on GCC compiled kernels), but this cleanup has to
start sooner than later. Note PTR_TO_CTX access still yields old deprecated
PTR_TO_BTF_ID. Once it's converted to strict PTR_TRUSTED or PTR_UNTRUSTED the
kfuncs and helpers will be able to default to KF_TRUSTED_ARGS. KF_RCU will
remain as a weaker version of KF_TRUSTED_ARGS where obj refcnt could be 0.
Signed-off-by: Alexei Starovoitov <ast@...nel.org>
---
include/linux/bpf.h | 2 +-
include/linux/bpf_verifier.h | 1 -
kernel/bpf/btf.c | 15 +-
kernel/bpf/cpumask.c | 40 ++--
kernel/bpf/verifier.c | 178 ++++++++++++------
.../bpf/prog_tests/cgrp_local_storage.c | 14 +-
.../selftests/bpf/prog_tests/rcu_read_lock.c | 16 +-
.../selftests/bpf/progs/cgrp_ls_sleepable.c | 4 +-
.../selftests/bpf/progs/cpumask_failure.c | 2 +-
.../bpf/progs/nested_trust_failure.c | 2 +-
.../selftests/bpf/progs/rcu_read_lock.c | 6 +-
tools/testing/selftests/bpf/verifier/calls.c | 2 +-
12 files changed, 172 insertions(+), 110 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 23ec684e660d..d3456804f7aa 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2279,7 +2279,7 @@ struct bpf_core_ctx {
bool btf_nested_type_is_trusted(struct bpf_verifier_log *log,
const struct bpf_reg_state *reg,
- int off);
+ int off, const char *suffix);
bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log,
const struct btf *reg_btf, u32 reg_id,
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index b26ff2a8f63b..18538bad2b8c 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -537,7 +537,6 @@ struct bpf_verifier_env {
bool bypass_spec_v1;
bool bypass_spec_v4;
bool seen_direct_write;
- bool rcu_tag_supported;
struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */
const struct bpf_line_info *prev_linfo;
struct bpf_verifier_log log;
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index c5e1d6955491..bae384728ec7 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6329,6 +6329,15 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
* of this field or inside of this struct
*/
if (btf_type_is_struct(mtype)) {
+ if (BTF_INFO_KIND(mtype->info) == BTF_KIND_UNION &&
+ btf_type_vlen(mtype) != 1)
+ /*
+ * walking unions yields untrusted pointers
+ * with exception of __bpf_md_ptr and others
+ * unions with a single member
+ */
+ *flag |= PTR_UNTRUSTED;
+
/* our field must be inside that union or struct */
t = mtype;
@@ -6373,7 +6382,7 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
stype = btf_type_skip_modifiers(btf, mtype->type, &id);
if (btf_type_is_struct(stype)) {
*next_btf_id = id;
- *flag = tmp_flag;
+ *flag |= tmp_flag;
return WALK_PTR;
}
}
@@ -8357,7 +8366,7 @@ int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo,
bool btf_nested_type_is_trusted(struct bpf_verifier_log *log,
const struct bpf_reg_state *reg,
- int off)
+ int off, const char *suffix)
{
struct btf *btf = reg->btf;
const struct btf_type *walk_type, *safe_type;
@@ -8374,7 +8383,7 @@ bool btf_nested_type_is_trusted(struct bpf_verifier_log *log,
tname = btf_name_by_offset(btf, walk_type->name_off);
- ret = snprintf(safe_tname, sizeof(safe_tname), "%s__safe_fields", tname);
+ ret = snprintf(safe_tname, sizeof(safe_tname), "%s%s", tname, suffix);
if (ret < 0)
return false;
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 2b3fbbfebdc5..2223562dd54e 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -427,26 +427,26 @@ BTF_ID_FLAGS(func, bpf_cpumask_create, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_cpumask_release, KF_RELEASE | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_cpumask_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_cpumask_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_cpumask_first, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_first_zero, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_set_cpu, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_clear_cpu, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_test_cpu, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_test_and_set_cpu, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_test_and_clear_cpu, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_setall, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_clear, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_and, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_or, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_xor, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_equal, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_intersects, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_subset, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_empty, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_full, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_copy, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_any, KF_TRUSTED_ARGS)
-BTF_ID_FLAGS(func, bpf_cpumask_any_and, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_cpumask_first, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_first_zero, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_set_cpu, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_clear_cpu, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_test_cpu, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_test_and_set_cpu, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_test_and_clear_cpu, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_setall, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_clear, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_and, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_or, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_xor, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_equal, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_intersects, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_subset, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_empty, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_full, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_copy, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_any, KF_TRUSTED_ARGS | KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_any_and, KF_TRUSTED_ARGS | KF_RCU)
BTF_SET8_END(cpumask_kfunc_btf_ids)
static const struct btf_kfunc_id_set cpumask_kfunc_set = {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a095055d7ef4..10d674e8154a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5073,29 +5073,76 @@ static int bpf_map_direct_read(struct bpf_map *map, int off, int size, u64 *val)
return 0;
}
-#define BTF_TYPE_SAFE_NESTED(__type) __PASTE(__type, __safe_fields)
+#define BTF_TYPE_SAFE_RCU(__type) __PASTE(__type, __safe_rcu)
+#define BTF_TYPE_SAFE_TRUSTED(__type) __PASTE(__type, __safe_trusted)
-BTF_TYPE_SAFE_NESTED(struct task_struct) {
+/*
+ * Allow list few fields as RCU trusted or full trusted.
+ * This logic doesn't allow mix tagging and will be removed once GCC supports
+ * btf_type_tag.
+ */
+
+/* RCU trusted: these fields are trusted in RCU CS and never NULL */
+BTF_TYPE_SAFE_RCU(struct task_struct) {
const cpumask_t *cpus_ptr;
struct css_set __rcu *cgroups;
+ struct task_struct __rcu *real_parent;
+ struct task_struct *group_leader;
};
-BTF_TYPE_SAFE_NESTED(struct css_set) {
+BTF_TYPE_SAFE_RCU(struct css_set) {
struct cgroup *dfl_cgrp;
};
-static bool nested_ptr_is_trusted(struct bpf_verifier_env *env,
- struct bpf_reg_state *reg,
- int off)
+/* full trusted: these fields are trusted even outside of RCU CS and never NULL */
+BTF_TYPE_SAFE_TRUSTED(struct bpf_iter_meta) {
+ __bpf_md_ptr(struct seq_file *, seq);
+};
+
+BTF_TYPE_SAFE_TRUSTED(struct bpf_iter__task) {
+ __bpf_md_ptr(struct bpf_iter_meta *, meta);
+ __bpf_md_ptr(struct task_struct *, task);
+};
+
+BTF_TYPE_SAFE_TRUSTED(struct linux_binprm) {
+ struct file *file;
+};
+
+BTF_TYPE_SAFE_TRUSTED(struct file) {
+ struct inode *f_inode;
+};
+
+BTF_TYPE_SAFE_TRUSTED(struct dentry) {
+ /* no negative dentry-s in places where bpf can see it */
+ struct inode *d_inode;
+};
+
+BTF_TYPE_SAFE_TRUSTED(struct socket) {
+ struct sock *sk;
+};
+
+static bool type_is_rcu(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ int off)
{
- /* If its parent is not trusted, it can't regain its trusted status. */
- if (!is_trusted_reg(reg))
- return false;
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct task_struct));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_RCU(struct css_set));
- BTF_TYPE_EMIT(BTF_TYPE_SAFE_NESTED(struct task_struct));
- BTF_TYPE_EMIT(BTF_TYPE_SAFE_NESTED(struct css_set));
+ return btf_nested_type_is_trusted(&env->log, reg, off, "__safe_rcu");
+}
- return btf_nested_type_is_trusted(&env->log, reg, off);
+static bool type_is_trusted(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ int off)
+{
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct bpf_iter_meta));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct bpf_iter__task));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct linux_binprm));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct file));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct dentry));
+ BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct socket));
+
+ return btf_nested_type_is_trusted(&env->log, reg, off, "__safe_trusted");
}
static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
@@ -5181,49 +5228,58 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env,
if (ret < 0)
return ret;
- /* If this is an untrusted pointer, all pointers formed by walking it
- * also inherit the untrusted flag.
- */
- if (type_flag(reg->type) & PTR_UNTRUSTED)
- flag |= PTR_UNTRUSTED;
+ if (ret != PTR_TO_BTF_ID) {
+ /* just mark; */
- /* By default any pointer obtained from walking a trusted pointer is no
- * longer trusted, unless the field being accessed has explicitly been
- * marked as inheriting its parent's state of trust.
- *
- * An RCU-protected pointer can also be deemed trusted if we are in an
- * RCU read region. This case is handled below.
- */
- if (nested_ptr_is_trusted(env, reg, off)) {
- flag |= PTR_TRUSTED;
- /*
- * task->cgroups is trusted. It provides a stronger guarantee
- * than __rcu tag on 'cgroups' field in 'struct task_struct'.
- * Clear MEM_RCU in such case.
+ } else if (type_flag(reg->type) & PTR_UNTRUSTED) {
+ /* If this is an untrusted pointer, all pointers formed by walking it
+ * also inherit the untrusted flag.
+ */
+ flag = PTR_UNTRUSTED;
+
+ } else if (is_trusted_reg(reg) || is_rcu_reg(reg)) {
+ /* By default any pointer obtained from walking a trusted pointer is no
+ * longer trusted, unless the field being accessed has explicitly been
+ * marked as inheriting its parent's state of trust (either full or RCU).
+ * For example:
+ * 'cgroups' pointer is untrusted if task->cgroups dereference
+ * happened in a sleepable program outside of bpf_rcu_read_lock()
+ * section. In a non-sleepable program it's trusted while in RCU CS (aka MEM_RCU).
+ * Note bpf_rcu_read_unlock() converts MEM_RCU pointers to PTR_UNTRUSTED.
+ *
+ * A regular RCU-protected pointer with __rcu tag can also be deemed
+ * trusted if we are in an RCU CS. Such pointer can be NULL.
*/
- flag &= ~MEM_RCU;
+ if (type_is_trusted(env, reg, off)) {
+ flag |= PTR_TRUSTED;
+ } else if (in_rcu_cs(env) && !type_may_be_null(reg->type)) {
+ if (type_is_rcu(env, reg, off)) {
+ /* ignore __rcu tag and mark it MEM_RCU */
+ flag |= MEM_RCU;
+ } else if (flag & MEM_RCU) {
+ /* __rcu tagged pointers can be NULL */
+ flag |= PTR_MAYBE_NULL;
+ } else if (flag & (MEM_PERCPU | MEM_USER)) {
+ /* keep as-is */
+ } else {
+ /* walking unknown pointers yields untrusted pointer */
+ flag = PTR_UNTRUSTED;
+ }
+ } else {
+ /*
+ * If not in RCU CS or MEM_RCU pointer can be NULL then
+ * aggressively mark as untrusted otherwise such
+ * pointers will be plain PTR_TO_BTF_ID without flags
+ * and will be allowed to be passed into helpers for
+ * compat reasons.
+ */
+ flag = PTR_UNTRUSTED;
+ }
} else {
+ /* Old compat. Deperecated */
flag &= ~PTR_TRUSTED;
}
- if (flag & MEM_RCU) {
- /* Mark value register as MEM_RCU only if it is protected by
- * bpf_rcu_read_lock() and the ptr reg is rcu or trusted. MEM_RCU
- * itself can already indicate trustedness inside the rcu
- * read lock region. Also mark rcu pointer as PTR_MAYBE_NULL since
- * it could be null in some cases.
- */
- if (in_rcu_cs(env) && (is_trusted_reg(reg) || is_rcu_reg(reg)))
- flag |= PTR_MAYBE_NULL;
- else
- flag &= ~MEM_RCU;
- } else if (reg->type & MEM_RCU) {
- /* ptr (reg) is marked as MEM_RCU, but the struct field is not tagged
- * with __rcu. Mark the flag as PTR_UNTRUSTED conservatively.
- */
- flag |= PTR_UNTRUSTED;
- }
-
if (atype == BPF_READ && value_regno >= 0)
mark_btf_ld_reg(env, regs, value_regno, ret, reg->btf, btf_id, flag);
@@ -10049,10 +10105,6 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
rcu_lock = is_kfunc_bpf_rcu_read_lock(&meta);
rcu_unlock = is_kfunc_bpf_rcu_read_unlock(&meta);
- if ((rcu_lock || rcu_unlock) && !env->rcu_tag_supported) {
- verbose(env, "no vmlinux btf rcu tag support for kfunc %s\n", func_name);
- return -EACCES;
- }
if (env->cur_state->active_rcu_lock) {
struct bpf_func_state *state;
@@ -14911,8 +14963,22 @@ static int do_check(struct bpf_verifier_env *env)
* src_reg == stack|map in some other branch.
* Reject it.
*/
- verbose(env, "same insn cannot be used with different pointers\n");
- return -EINVAL;
+ if (base_type(src_reg_type) == PTR_TO_BTF_ID &&
+ base_type(*prev_src_type) == PTR_TO_BTF_ID) {
+ /*
+ * Have to support a use case when one path through
+ * the program yields TRUSTED pointer while another
+ * is UNTRUSTED. Fallback to UNTRUSTED to generate
+ * BPF_PROBE_MEM.
+ */
+ *prev_src_type = PTR_TO_BTF_ID | PTR_UNTRUSTED;
+ } else {
+ verbose(env,
+ "The same insn cannot be used with different pointers: %s",
+ reg_type_str(env, src_reg_type));
+ verbose(env, " != %s\n", reg_type_str(env, *prev_src_type));
+ return -EINVAL;
+ }
}
} else if (class == BPF_STX) {
@@ -17984,8 +18050,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr)
env->bypass_spec_v1 = bpf_bypass_spec_v1();
env->bypass_spec_v4 = bpf_bypass_spec_v4();
env->bpf_capable = bpf_capable();
- env->rcu_tag_supported = btf_vmlinux &&
- btf_find_by_name_kind(btf_vmlinux, "rcu", BTF_KIND_TYPE_TAG) > 0;
if (is_priv)
env->test_state_freq = attr->prog_flags & BPF_F_TEST_STATE_FREQ;
diff --git a/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c b/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
index 2cc759956e3b..63e776f4176e 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgrp_local_storage.c
@@ -193,7 +193,7 @@ static void test_cgroup_iter_sleepable(int cgroup_fd, __u64 cgroup_id)
cgrp_ls_sleepable__destroy(skel);
}
-static void test_no_rcu_lock(__u64 cgroup_id)
+static void test_yes_rcu_lock(__u64 cgroup_id)
{
struct cgrp_ls_sleepable *skel;
int err;
@@ -204,7 +204,7 @@ static void test_no_rcu_lock(__u64 cgroup_id)
skel->bss->target_pid = syscall(SYS_gettid);
- bpf_program__set_autoload(skel->progs.no_rcu_lock, true);
+ bpf_program__set_autoload(skel->progs.yes_rcu_lock, true);
err = cgrp_ls_sleepable__load(skel);
if (!ASSERT_OK(err, "skel_load"))
goto out;
@@ -220,7 +220,7 @@ static void test_no_rcu_lock(__u64 cgroup_id)
cgrp_ls_sleepable__destroy(skel);
}
-static void test_rcu_lock(void)
+static void test_no_rcu_lock(void)
{
struct cgrp_ls_sleepable *skel;
int err;
@@ -229,7 +229,7 @@ static void test_rcu_lock(void)
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
- bpf_program__set_autoload(skel->progs.yes_rcu_lock, true);
+ bpf_program__set_autoload(skel->progs.no_rcu_lock, true);
err = cgrp_ls_sleepable__load(skel);
ASSERT_ERR(err, "skel_load");
@@ -256,10 +256,10 @@ void test_cgrp_local_storage(void)
test_negative();
if (test__start_subtest("cgroup_iter_sleepable"))
test_cgroup_iter_sleepable(cgroup_fd, cgroup_id);
+ if (test__start_subtest("yes_rcu_lock"))
+ test_yes_rcu_lock(cgroup_id);
if (test__start_subtest("no_rcu_lock"))
- test_no_rcu_lock(cgroup_id);
- if (test__start_subtest("rcu_lock"))
- test_rcu_lock();
+ test_no_rcu_lock();
close(cgroup_fd);
}
diff --git a/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c b/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
index 447d8560ecb6..3f1f58d3a729 100644
--- a/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
+++ b/tools/testing/selftests/bpf/prog_tests/rcu_read_lock.c
@@ -25,10 +25,10 @@ static void test_success(void)
bpf_program__set_autoload(skel->progs.get_cgroup_id, true);
bpf_program__set_autoload(skel->progs.task_succ, true);
- bpf_program__set_autoload(skel->progs.no_lock, true);
bpf_program__set_autoload(skel->progs.two_regions, true);
bpf_program__set_autoload(skel->progs.non_sleepable_1, true);
bpf_program__set_autoload(skel->progs.non_sleepable_2, true);
+ bpf_program__set_autoload(skel->progs.task_trusted_non_rcuptr, true);
err = rcu_read_lock__load(skel);
if (!ASSERT_OK(err, "skel_load"))
goto out;
@@ -69,6 +69,7 @@ static void test_rcuptr_acquire(void)
static const char * const inproper_region_tests[] = {
"miss_lock",
+ "no_lock",
"miss_unlock",
"non_sleepable_rcu_mismatch",
"inproper_sleepable_helper",
@@ -99,7 +100,6 @@ static void test_inproper_region(void)
}
static const char * const rcuptr_misuse_tests[] = {
- "task_untrusted_non_rcuptr",
"task_untrusted_rcuptr",
"cross_rcu_region",
};
@@ -128,17 +128,8 @@ static void test_rcuptr_misuse(void)
void test_rcu_read_lock(void)
{
- struct btf *vmlinux_btf;
int cgroup_fd;
- vmlinux_btf = btf__load_vmlinux_btf();
- if (!ASSERT_OK_PTR(vmlinux_btf, "could not load vmlinux BTF"))
- return;
- if (btf__find_by_name_kind(vmlinux_btf, "rcu", BTF_KIND_TYPE_TAG) < 0) {
- test__skip();
- goto out;
- }
-
cgroup_fd = test__join_cgroup("/rcu_read_lock");
if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /rcu_read_lock"))
goto out;
@@ -153,6 +144,5 @@ void test_rcu_read_lock(void)
if (test__start_subtest("negative_tests_rcuptr_misuse"))
test_rcuptr_misuse();
close(cgroup_fd);
-out:
- btf__free(vmlinux_btf);
+out:;
}
diff --git a/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
index 2d11ed528b6f..7615dc23d301 100644
--- a/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
+++ b/tools/testing/selftests/bpf/progs/cgrp_ls_sleepable.c
@@ -49,7 +49,7 @@ int no_rcu_lock(void *ctx)
if (task->pid != target_pid)
return 0;
- /* ptr_to_btf_id semantics. should work. */
+ /* task->cgroups is untrusted in sleepable prog outside of RCU CS */
cgrp = task->cgroups->dfl_cgrp;
ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0,
BPF_LOCAL_STORAGE_GET_F_CREATE);
@@ -71,7 +71,7 @@ int yes_rcu_lock(void *ctx)
bpf_rcu_read_lock();
cgrp = task->cgroups->dfl_cgrp;
- /* cgrp is untrusted and cannot pass to bpf_cgrp_storage_get() helper. */
+ /* cgrp is trusted under RCU CS */
ptr = bpf_cgrp_storage_get(&map_a, cgrp, 0, BPF_LOCAL_STORAGE_GET_F_CREATE);
if (ptr)
cgroup_id = cgrp->kn->id;
diff --git a/tools/testing/selftests/bpf/progs/cpumask_failure.c b/tools/testing/selftests/bpf/progs/cpumask_failure.c
index 33e8e86dd090..c16f7563b84e 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_failure.c
+++ b/tools/testing/selftests/bpf/progs/cpumask_failure.c
@@ -44,7 +44,7 @@ int BPF_PROG(test_alloc_double_release, struct task_struct *task, u64 clone_flag
}
SEC("tp_btf/task_newtask")
-__failure __msg("bpf_cpumask_acquire args#0 expected pointer to STRUCT bpf_cpumask")
+__failure __msg("must be referenced")
int BPF_PROG(test_acquire_wrong_cpumask, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *cpumask;
diff --git a/tools/testing/selftests/bpf/progs/nested_trust_failure.c b/tools/testing/selftests/bpf/progs/nested_trust_failure.c
index 14aff7676436..0d1aa6bbace4 100644
--- a/tools/testing/selftests/bpf/progs/nested_trust_failure.c
+++ b/tools/testing/selftests/bpf/progs/nested_trust_failure.c
@@ -17,7 +17,7 @@ char _license[] SEC("license") = "GPL";
*/
SEC("tp_btf/task_newtask")
-__failure __msg("R2 must be referenced or trusted")
+__failure __msg("R2 must be")
int BPF_PROG(test_invalid_nested_user_cpus, struct task_struct *task, u64 clone_flags)
{
bpf_cpumask_test_cpu(0, task->user_cpus_ptr);
diff --git a/tools/testing/selftests/bpf/progs/rcu_read_lock.c b/tools/testing/selftests/bpf/progs/rcu_read_lock.c
index 5cecbdbbb16e..7250bb76d18a 100644
--- a/tools/testing/selftests/bpf/progs/rcu_read_lock.c
+++ b/tools/testing/selftests/bpf/progs/rcu_read_lock.c
@@ -81,7 +81,7 @@ int no_lock(void *ctx)
{
struct task_struct *task, *real_parent;
- /* no bpf_rcu_read_lock(), old code still works */
+ /* old style ptr_to_btf_id is not allowed in sleepable */
task = bpf_get_current_task_btf();
real_parent = task->real_parent;
(void)bpf_task_storage_get(&map_a, real_parent, 0, 0);
@@ -286,13 +286,13 @@ int nested_rcu_region(void *ctx)
}
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
-int task_untrusted_non_rcuptr(void *ctx)
+int task_trusted_non_rcuptr(void *ctx)
{
struct task_struct *task, *group_leader;
task = bpf_get_current_task_btf();
bpf_rcu_read_lock();
- /* the pointer group_leader marked as untrusted */
+ /* the pointer group_leader is explicitly marked as trusted */
group_leader = task->real_parent->group_leader;
(void)bpf_task_storage_get(&map_a, group_leader, 0, 0);
bpf_rcu_read_unlock();
diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c
index 9a326a800e5c..5702fc9761ef 100644
--- a/tools/testing/selftests/bpf/verifier/calls.c
+++ b/tools/testing/selftests/bpf/verifier/calls.c
@@ -181,7 +181,7 @@
},
.result_unpriv = REJECT,
.result = REJECT,
- .errstr = "negative offset ptr_ ptr R1 off=-4 disallowed",
+ .errstr = "ptr R1 off=-4 disallowed",
},
{
"calls: invalid kfunc call: PTR_TO_BTF_ID with variable offset",
--
2.39.2
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