diff options
Diffstat (limited to 'kernel/bpf/helpers.c')
| -rw-r--r-- | kernel/bpf/helpers.c | 109 |
1 files changed, 97 insertions, 12 deletions
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 8bd3812fb8df..e46ac288a108 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -22,6 +22,7 @@ #include <linux/security.h> #include <linux/btf_ids.h> #include <linux/bpf_mem_alloc.h> +#include <linux/kasan.h> #include "../../lib/kstrtox.h" @@ -1271,7 +1272,7 @@ BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, fla if (in_nmi()) return -EOPNOTSUPP; - if (flags > BPF_F_TIMER_ABS) + if (flags & ~(BPF_F_TIMER_ABS | BPF_F_TIMER_CPU_PIN)) return -EINVAL; __bpf_spin_lock_irqsave(&timer->lock); t = timer->timer; @@ -1285,6 +1286,9 @@ BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, fla else mode = HRTIMER_MODE_REL_SOFT; + if (flags & BPF_F_TIMER_CPU_PIN) + mode |= HRTIMER_MODE_PINNED; + hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode); out: __bpf_spin_unlock_irqrestore(&timer->lock); @@ -1807,8 +1811,6 @@ bpf_base_func_proto(enum bpf_func_id func_id) } } -void __bpf_obj_drop_impl(void *p, const struct btf_record *rec); - void bpf_list_head_free(const struct btf_field *field, void *list_head, struct bpf_spin_lock *spin_lock) { @@ -1840,7 +1842,7 @@ unlock: * bpf_list_head which needs to be freed. */ migrate_disable(); - __bpf_obj_drop_impl(obj, field->graph_root.value_rec); + __bpf_obj_drop_impl(obj, field->graph_root.value_rec, false); migrate_enable(); } } @@ -1879,7 +1881,7 @@ void bpf_rb_root_free(const struct btf_field *field, void *rb_root, migrate_disable(); - __bpf_obj_drop_impl(obj, field->graph_root.value_rec); + __bpf_obj_drop_impl(obj, field->graph_root.value_rec, false); migrate_enable(); } } @@ -1902,9 +1904,19 @@ __bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign) return p; } +__bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign) +{ + u64 size = local_type_id__k; + + /* The verifier has ensured that meta__ign must be NULL */ + return bpf_mem_alloc(&bpf_global_percpu_ma, size); +} + /* Must be called under migrate_disable(), as required by bpf_mem_free */ -void __bpf_obj_drop_impl(void *p, const struct btf_record *rec) +void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu) { + struct bpf_mem_alloc *ma; + if (rec && rec->refcount_off >= 0 && !refcount_dec_and_test((refcount_t *)(p + rec->refcount_off))) { /* Object is refcounted and refcount_dec didn't result in 0 @@ -1916,10 +1928,14 @@ void __bpf_obj_drop_impl(void *p, const struct btf_record *rec) if (rec) bpf_obj_free_fields(rec, p); + if (percpu) + ma = &bpf_global_percpu_ma; + else + ma = &bpf_global_ma; if (rec && rec->refcount_off >= 0) - bpf_mem_free_rcu(&bpf_global_ma, p); + bpf_mem_free_rcu(ma, p); else - bpf_mem_free(&bpf_global_ma, p); + bpf_mem_free(ma, p); } __bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) @@ -1927,7 +1943,13 @@ __bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign) struct btf_struct_meta *meta = meta__ign; void *p = p__alloc; - __bpf_obj_drop_impl(p, meta ? meta->record : NULL); + __bpf_obj_drop_impl(p, meta ? meta->record : NULL, false); +} + +__bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign) +{ + /* The verifier has ensured that meta__ign must be NULL */ + bpf_mem_free_rcu(&bpf_global_percpu_ma, p__alloc); } __bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign) @@ -1965,7 +1987,7 @@ static int __bpf_list_add(struct bpf_list_node_kern *node, */ if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) { /* Only called from BPF prog, no need to migrate_disable */ - __bpf_obj_drop_impl((void *)n - off, rec); + __bpf_obj_drop_impl((void *)n - off, rec, false); return -EINVAL; } @@ -2064,7 +2086,7 @@ static int __bpf_rbtree_add(struct bpf_rb_root *root, */ if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) { /* Only called from BPF prog, no need to migrate_disable */ - __bpf_obj_drop_impl((void *)n - off, rec); + __bpf_obj_drop_impl((void *)n - off, rec, false); return -EINVAL; } @@ -2197,7 +2219,12 @@ __bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid) __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, struct cgroup *ancestor) { - return task_under_cgroup_hierarchy(task, ancestor); + long ret; + + rcu_read_lock(); + ret = task_under_cgroup_hierarchy(task, ancestor); + rcu_read_unlock(); + return ret; } #endif /* CONFIG_CGROUPS */ @@ -2435,6 +2462,49 @@ __bpf_kfunc void bpf_rcu_read_unlock(void) rcu_read_unlock(); } +struct bpf_throw_ctx { + struct bpf_prog_aux *aux; + u64 sp; + u64 bp; + int cnt; +}; + +static bool bpf_stack_walker(void *cookie, u64 ip, u64 sp, u64 bp) +{ + struct bpf_throw_ctx *ctx = cookie; + struct bpf_prog *prog; + + if (!is_bpf_text_address(ip)) + return !ctx->cnt; + prog = bpf_prog_ksym_find(ip); + ctx->cnt++; + if (bpf_is_subprog(prog)) + return true; + ctx->aux = prog->aux; + ctx->sp = sp; + ctx->bp = bp; + return false; +} + +__bpf_kfunc void bpf_throw(u64 cookie) +{ + struct bpf_throw_ctx ctx = {}; + + arch_bpf_stack_walk(bpf_stack_walker, &ctx); + WARN_ON_ONCE(!ctx.aux); + if (ctx.aux) + WARN_ON_ONCE(!ctx.aux->exception_boundary); + WARN_ON_ONCE(!ctx.bp); + WARN_ON_ONCE(!ctx.cnt); + /* Prevent KASAN false positives for CONFIG_KASAN_STACK by unpoisoning + * deeper stack depths than ctx.sp as we do not return from bpf_throw, + * which skips compiler generated instrumentation to do the same. + */ + kasan_unpoison_task_stack_below((void *)(long)ctx.sp); + ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp); + WARN(1, "A call to BPF exception callback should never return\n"); +} + __diag_pop(); BTF_SET8_START(generic_btf_ids) @@ -2442,7 +2512,9 @@ BTF_SET8_START(generic_btf_ids) BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) #endif BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_percpu_obj_new_impl, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_percpu_obj_drop_impl, KF_RELEASE) BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_list_push_front_impl) BTF_ID_FLAGS(func, bpf_list_push_back_impl) @@ -2462,6 +2534,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_throw) BTF_SET8_END(generic_btf_ids) static const struct btf_kfunc_id_set generic_kfunc_set = { @@ -2488,6 +2561,18 @@ BTF_ID_FLAGS(func, bpf_dynptr_slice_rdwr, KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_num_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_num_next, KF_ITER_NEXT | KF_RET_NULL) 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) +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) BTF_ID_FLAGS(func, bpf_dynptr_adjust) BTF_ID_FLAGS(func, bpf_dynptr_is_null) BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly) |