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-rw-r--r--kernel/bpf/bpf_iter.c6
-rw-r--r--kernel/bpf/cgroup_iter.c8
-rw-r--r--kernel/bpf/cpumask.c6
-rw-r--r--kernel/bpf/helpers.c39
-rw-r--r--kernel/bpf/map_iter.c6
-rw-r--r--kernel/bpf/task_iter.c24
-rw-r--r--kernel/bpf/verifier.c33
7 files changed, 70 insertions, 52 deletions
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 833faa04461b..0fae79164187 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -782,9 +782,7 @@ struct bpf_iter_num_kern {
int end; /* final value, exclusive */
} __aligned(8);
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end)
{
@@ -843,4 +841,4 @@ __bpf_kfunc void bpf_iter_num_destroy(struct bpf_iter_num *it)
s->cur = s->end = 0;
}
-__diag_pop();
+__bpf_kfunc_end_defs();
diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
index 209e5135f9fb..f04a468cf6a7 100644
--- a/kernel/bpf/cgroup_iter.c
+++ b/kernel/bpf/cgroup_iter.c
@@ -282,7 +282,7 @@ static struct bpf_iter_reg bpf_cgroup_reg_info = {
.ctx_arg_info_size = 1,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__cgroup, cgroup),
- PTR_TO_BTF_ID_OR_NULL },
+ PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
},
.seq_info = &cgroup_iter_seq_info,
};
@@ -305,9 +305,7 @@ struct bpf_iter_css_kern {
unsigned int flags;
} __attribute__((aligned(8)));
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc int bpf_iter_css_new(struct bpf_iter_css *it,
struct cgroup_subsys_state *start, unsigned int flags)
@@ -358,4 +356,4 @@ __bpf_kfunc void bpf_iter_css_destroy(struct bpf_iter_css *it)
{
}
-__diag_pop(); \ No newline at end of file
+__bpf_kfunc_end_defs();
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 6983af8e093c..e01c741e54e7 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -34,9 +34,7 @@ static bool cpu_valid(u32 cpu)
return cpu < nr_cpu_ids;
}
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global kfuncs as their definitions will be in BTF");
+__bpf_kfunc_start_defs();
/**
* bpf_cpumask_create() - Create a mutable BPF cpumask.
@@ -407,7 +405,7 @@ __bpf_kfunc u32 bpf_cpumask_any_and_distribute(const struct cpumask *src1,
return cpumask_any_and_distribute(src1, src2);
}
-__diag_pop();
+__bpf_kfunc_end_defs();
BTF_SET8_START(cpumask_kfunc_btf_ids)
BTF_ID_FLAGS(func, bpf_cpumask_create, KF_ACQUIRE | KF_RET_NULL)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index e46ac288a108..56b0c1f678ee 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1177,13 +1177,6 @@ BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map
ret = -EBUSY;
goto out;
}
- if (!atomic64_read(&map->usercnt)) {
- /* maps with timers must be either held by user space
- * or pinned in bpffs.
- */
- ret = -EPERM;
- goto out;
- }
/* allocate hrtimer via map_kmalloc to use memcg accounting */
t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node);
if (!t) {
@@ -1196,7 +1189,21 @@ BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map
rcu_assign_pointer(t->callback_fn, NULL);
hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
t->timer.function = bpf_timer_cb;
- timer->timer = t;
+ WRITE_ONCE(timer->timer, t);
+ /* Guarantee the order between timer->timer and map->usercnt. So
+ * when there are concurrent uref release and bpf timer init, either
+ * bpf_timer_cancel_and_free() called by uref release reads a no-NULL
+ * timer or atomic64_read() below returns a zero usercnt.
+ */
+ smp_mb();
+ if (!atomic64_read(&map->usercnt)) {
+ /* maps with timers must be either held by user space
+ * or pinned in bpffs.
+ */
+ WRITE_ONCE(timer->timer, NULL);
+ kfree(t);
+ ret = -EPERM;
+ }
out:
__bpf_spin_unlock_irqrestore(&timer->lock);
return ret;
@@ -1374,7 +1381,7 @@ void bpf_timer_cancel_and_free(void *val)
/* The subsequent bpf_timer_start/cancel() helpers won't be able to use
* this timer, since it won't be initialized.
*/
- timer->timer = NULL;
+ WRITE_ONCE(timer->timer, NULL);
out:
__bpf_spin_unlock_irqrestore(&timer->lock);
if (!t)
@@ -1886,9 +1893,7 @@ void bpf_rb_root_free(const struct btf_field *field, void *rb_root,
}
}
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
{
@@ -2505,7 +2510,7 @@ __bpf_kfunc void bpf_throw(u64 cookie)
WARN(1, "A call to BPF exception callback should never return\n");
}
-__diag_pop();
+__bpf_kfunc_end_defs();
BTF_SET8_START(generic_btf_ids)
#ifdef CONFIG_KEXEC_CORE
@@ -2564,15 +2569,17 @@ BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_iter_task_vma_new, KF_ITER_NEW | KF_RCU)
BTF_ID_FLAGS(func, bpf_iter_task_vma_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_task_vma_destroy, KF_ITER_DESTROY)
+#ifdef CONFIG_CGROUPS
BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_iter_css_task_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
-BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
-BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL)
-BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_iter_css_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
BTF_ID_FLAGS(func, bpf_iter_css_next, KF_ITER_NEXT | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_iter_css_destroy, KF_ITER_DESTROY)
+#endif
+BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS | KF_RCU_PROTECTED)
+BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY)
BTF_ID_FLAGS(func, bpf_dynptr_adjust)
BTF_ID_FLAGS(func, bpf_dynptr_is_null)
BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index 6fc9dae9edc8..6abd7c5df4b3 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -193,9 +193,7 @@ static int __init bpf_map_iter_init(void)
late_initcall(bpf_map_iter_init);
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
{
@@ -213,7 +211,7 @@ __bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
return ret;
}
-__diag_pop();
+__bpf_kfunc_end_defs();
BTF_SET8_START(bpf_map_iter_kfunc_ids)
BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index 654601dd6b49..26082b97894d 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -704,7 +704,7 @@ static struct bpf_iter_reg task_reg_info = {
.ctx_arg_info_size = 1,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__task, task),
- PTR_TO_BTF_ID_OR_NULL },
+ PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
},
.seq_info = &task_seq_info,
.fill_link_info = bpf_iter_fill_link_info,
@@ -822,9 +822,7 @@ struct bpf_iter_task_vma_kern {
struct bpf_iter_task_vma_kern_data *data;
} __attribute__((aligned(8)));
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc int bpf_iter_task_vma_new(struct bpf_iter_task_vma *it,
struct task_struct *task, u64 addr)
@@ -890,7 +888,9 @@ __bpf_kfunc void bpf_iter_task_vma_destroy(struct bpf_iter_task_vma *it)
}
}
-__diag_pop();
+__bpf_kfunc_end_defs();
+
+#ifdef CONFIG_CGROUPS
struct bpf_iter_css_task {
__u64 __opaque[1];
@@ -900,9 +900,7 @@ struct bpf_iter_css_task_kern {
struct css_task_iter *css_it;
} __attribute__((aligned(8)));
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc int bpf_iter_css_task_new(struct bpf_iter_css_task *it,
struct cgroup_subsys_state *css, unsigned int flags)
@@ -948,7 +946,9 @@ __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it)
bpf_mem_free(&bpf_global_ma, kit->css_it);
}
-__diag_pop();
+__bpf_kfunc_end_defs();
+
+#endif /* CONFIG_CGROUPS */
struct bpf_iter_task {
__u64 __opaque[3];
@@ -969,9 +969,7 @@ enum {
BPF_TASK_ITER_PROC_THREADS
};
-__diag_push();
-__diag_ignore_all("-Wmissing-prototypes",
- "Global functions as their definitions will be in vmlinux BTF");
+__bpf_kfunc_start_defs();
__bpf_kfunc int bpf_iter_task_new(struct bpf_iter_task *it,
struct task_struct *task__nullable, unsigned int flags)
@@ -1041,7 +1039,7 @@ __bpf_kfunc void bpf_iter_task_destroy(struct bpf_iter_task *it)
{
}
-__diag_pop();
+__bpf_kfunc_end_defs();
DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 857d76694517..bd1c42eb540f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3742,7 +3742,12 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
if (class == BPF_ALU || class == BPF_ALU64) {
if (!bt_is_reg_set(bt, dreg))
return 0;
- if (opcode == BPF_MOV) {
+ if (opcode == BPF_END || opcode == BPF_NEG) {
+ /* sreg is reserved and unused
+ * dreg still need precision before this insn
+ */
+ return 0;
+ } else if (opcode == BPF_MOV) {
if (BPF_SRC(insn->code) == BPF_X) {
/* dreg = sreg or dreg = (s8, s16, s32)sreg
* dreg needs precision after this insn
@@ -4674,7 +4679,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
insn->imm != 0 && env->bpf_capable) {
struct bpf_reg_state fake_reg = {};
- __mark_reg_known(&fake_reg, (u32)insn->imm);
+ __mark_reg_known(&fake_reg, insn->imm);
fake_reg.type = SCALAR_VALUE;
save_register_state(state, spi, &fake_reg, size);
} else if (reg && is_spillable_regtype(reg->type)) {
@@ -5388,7 +5393,9 @@ static bool in_rcu_cs(struct bpf_verifier_env *env)
/* Once GCC supports btf_type_tag the following mechanism will be replaced with tag check */
BTF_SET_START(rcu_protected_types)
BTF_ID(struct, prog_test_ref_kfunc)
+#ifdef CONFIG_CGROUPS
BTF_ID(struct, cgroup)
+#endif
BTF_ID(struct, bpf_cpumask)
BTF_ID(struct, task_struct)
BTF_SET_END(rcu_protected_types)
@@ -10835,7 +10842,9 @@ BTF_ID(func, bpf_dynptr_clone)
BTF_ID(func, bpf_percpu_obj_new_impl)
BTF_ID(func, bpf_percpu_obj_drop_impl)
BTF_ID(func, bpf_throw)
+#ifdef CONFIG_CGROUPS
BTF_ID(func, bpf_iter_css_task_new)
+#endif
BTF_SET_END(special_kfunc_set)
BTF_ID_LIST(special_kfunc_list)
@@ -10861,7 +10870,11 @@ BTF_ID(func, bpf_dynptr_clone)
BTF_ID(func, bpf_percpu_obj_new_impl)
BTF_ID(func, bpf_percpu_obj_drop_impl)
BTF_ID(func, bpf_throw)
+#ifdef CONFIG_CGROUPS
BTF_ID(func, bpf_iter_css_task_new)
+#else
+BTF_ID_UNUSED
+#endif
static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta)
{
@@ -11394,6 +11407,12 @@ static int process_kf_arg_ptr_to_rbtree_node(struct bpf_verifier_env *env,
&meta->arg_rbtree_root.field);
}
+/*
+ * css_task iter allowlist is needed to avoid dead locking on css_set_lock.
+ * LSM hooks and iters (both sleepable and non-sleepable) are safe.
+ * Any sleepable progs are also safe since bpf_check_attach_target() enforce
+ * them can only be attached to some specific hook points.
+ */
static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env)
{
enum bpf_prog_type prog_type = resolve_prog_type(env->prog);
@@ -11401,10 +11420,12 @@ static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env)
switch (prog_type) {
case BPF_PROG_TYPE_LSM:
return true;
- case BPF_TRACE_ITER:
- return env->prog->aux->sleepable;
+ case BPF_PROG_TYPE_TRACING:
+ if (env->prog->expected_attach_type == BPF_TRACE_ITER)
+ return true;
+ fallthrough;
default:
- return false;
+ return env->prog->aux->sleepable;
}
}
@@ -11663,7 +11684,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_
case KF_ARG_PTR_TO_ITER:
if (meta->func_id == special_kfunc_list[KF_bpf_iter_css_task_new]) {
if (!check_css_task_iter_allowlist(env)) {
- verbose(env, "css_task_iter is only allowed in bpf_lsm and bpf iter-s\n");
+ verbose(env, "css_task_iter is only allowed in bpf_lsm, bpf_iter and sleepable progs\n");
return -EINVAL;
}
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-02 03:21:02 +0300