diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/Makefile | 3 | ||||
| -rw-r--r-- | kernel/bpf/bpf_local_storage.c | 28 | ||||
| -rw-r--r-- | kernel/bpf/bpf_lsm.c | 4 | ||||
| -rw-r--r-- | kernel/bpf/bpf_task_storage.c | 43 | ||||
| -rw-r--r-- | kernel/fork.c | 5 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 4 |
6 files changed, 38 insertions, 49 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index d1249340fd6b..7f33098ca63f 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -9,8 +9,8 @@ CFLAGS_core.o += $(call cc-disable-warning, override-init) $(cflags-nogcse-yy) obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o +obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o -obj-${CONFIG_BPF_LSM} += bpf_task_storage.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o obj-$(CONFIG_BPF_JIT) += trampoline.o obj-$(CONFIG_BPF_SYSCALL) += btf.o @@ -18,7 +18,6 @@ obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o obj-$(CONFIG_BPF_SYSCALL) += cpumap.o -obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o obj-$(CONFIG_BPF_SYSCALL) += offload.o obj-$(CONFIG_BPF_SYSCALL) += net_namespace.o endif diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index dd5aedee99e7..9bd47ad2b26f 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -140,17 +140,18 @@ static void __bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem) { struct bpf_local_storage *local_storage; bool free_local_storage = false; + unsigned long flags; if (unlikely(!selem_linked_to_storage(selem))) /* selem has already been unlinked from sk */ return; local_storage = rcu_dereference(selem->local_storage); - raw_spin_lock_bh(&local_storage->lock); + raw_spin_lock_irqsave(&local_storage->lock, flags); if (likely(selem_linked_to_storage(selem))) free_local_storage = bpf_selem_unlink_storage_nolock( local_storage, selem, true); - raw_spin_unlock_bh(&local_storage->lock); + raw_spin_unlock_irqrestore(&local_storage->lock, flags); if (free_local_storage) kfree_rcu(local_storage, rcu); @@ -167,6 +168,7 @@ void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map *smap; struct bpf_local_storage_map_bucket *b; + unsigned long flags; if (unlikely(!selem_linked_to_map(selem))) /* selem has already be unlinked from smap */ @@ -174,21 +176,22 @@ void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem) smap = rcu_dereference(SDATA(selem)->smap); b = select_bucket(smap, selem); - raw_spin_lock_bh(&b->lock); + raw_spin_lock_irqsave(&b->lock, flags); if (likely(selem_linked_to_map(selem))) hlist_del_init_rcu(&selem->map_node); - raw_spin_unlock_bh(&b->lock); + raw_spin_unlock_irqrestore(&b->lock, flags); } void bpf_selem_link_map(struct bpf_local_storage_map *smap, struct bpf_local_storage_elem *selem) { struct bpf_local_storage_map_bucket *b = select_bucket(smap, selem); + unsigned long flags; - raw_spin_lock_bh(&b->lock); + raw_spin_lock_irqsave(&b->lock, flags); RCU_INIT_POINTER(SDATA(selem)->smap, smap); hlist_add_head_rcu(&selem->map_node, &b->list); - raw_spin_unlock_bh(&b->lock); + raw_spin_unlock_irqrestore(&b->lock, flags); } void bpf_selem_unlink(struct bpf_local_storage_elem *selem) @@ -224,16 +227,18 @@ bpf_local_storage_lookup(struct bpf_local_storage *local_storage, sdata = SDATA(selem); if (cacheit_lockit) { + unsigned long flags; + /* spinlock is needed to avoid racing with the * parallel delete. Otherwise, publishing an already * deleted sdata to the cache will become a use-after-free * problem in the next bpf_local_storage_lookup(). */ - raw_spin_lock_bh(&local_storage->lock); + raw_spin_lock_irqsave(&local_storage->lock, flags); if (selem_linked_to_storage(selem)) rcu_assign_pointer(local_storage->cache[smap->cache_idx], sdata); - raw_spin_unlock_bh(&local_storage->lock); + raw_spin_unlock_irqrestore(&local_storage->lock, flags); } return sdata; @@ -327,6 +332,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, struct bpf_local_storage_data *old_sdata = NULL; struct bpf_local_storage_elem *selem; struct bpf_local_storage *local_storage; + unsigned long flags; int err; /* BPF_EXIST and BPF_NOEXIST cannot be both set */ @@ -374,7 +380,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, } } - raw_spin_lock_bh(&local_storage->lock); + raw_spin_lock_irqsave(&local_storage->lock, flags); /* Recheck local_storage->list under local_storage->lock */ if (unlikely(hlist_empty(&local_storage->list))) { @@ -428,11 +434,11 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, } unlock: - raw_spin_unlock_bh(&local_storage->lock); + raw_spin_unlock_irqrestore(&local_storage->lock, flags); return SDATA(selem); unlock_err: - raw_spin_unlock_bh(&local_storage->lock); + raw_spin_unlock_irqrestore(&local_storage->lock, flags); return ERR_PTR(err); } diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c index 1622a44d1617..9829f381b51c 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -115,10 +115,6 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_spin_lock_proto; case BPF_FUNC_spin_unlock: return &bpf_spin_unlock_proto; - case BPF_FUNC_task_storage_get: - return &bpf_task_storage_get_proto; - case BPF_FUNC_task_storage_delete: - return &bpf_task_storage_delete_proto; case BPF_FUNC_bprm_opts_set: return &bpf_bprm_opts_set_proto; case BPF_FUNC_ima_inode_hash: diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c index e0da0258b732..baf3566e2323 100644 --- a/kernel/bpf/bpf_task_storage.c +++ b/kernel/bpf/bpf_task_storage.c @@ -15,7 +15,6 @@ #include <linux/bpf_local_storage.h> #include <linux/filter.h> #include <uapi/linux/btf.h> -#include <linux/bpf_lsm.h> #include <linux/btf_ids.h> #include <linux/fdtable.h> @@ -24,12 +23,8 @@ DEFINE_BPF_STORAGE_CACHE(task_cache); static struct bpf_local_storage __rcu **task_storage_ptr(void *owner) { struct task_struct *task = owner; - struct bpf_storage_blob *bsb; - bsb = bpf_task(task); - if (!bsb) - return NULL; - return &bsb->storage; + return &task->bpf_storage; } static struct bpf_local_storage_data * @@ -38,13 +33,8 @@ task_storage_lookup(struct task_struct *task, struct bpf_map *map, { struct bpf_local_storage *task_storage; struct bpf_local_storage_map *smap; - struct bpf_storage_blob *bsb; - - bsb = bpf_task(task); - if (!bsb) - return NULL; - task_storage = rcu_dereference(bsb->storage); + task_storage = rcu_dereference(task->bpf_storage); if (!task_storage) return NULL; @@ -57,16 +47,12 @@ void bpf_task_storage_free(struct task_struct *task) struct bpf_local_storage_elem *selem; struct bpf_local_storage *local_storage; bool free_task_storage = false; - struct bpf_storage_blob *bsb; struct hlist_node *n; - - bsb = bpf_task(task); - if (!bsb) - return; + unsigned long flags; rcu_read_lock(); - local_storage = rcu_dereference(bsb->storage); + local_storage = rcu_dereference(task->bpf_storage); if (!local_storage) { rcu_read_unlock(); return; @@ -81,7 +67,7 @@ void bpf_task_storage_free(struct task_struct *task) * when unlinking elem from the local_storage->list and * the map's bucket->list. */ - raw_spin_lock_bh(&local_storage->lock); + raw_spin_lock_irqsave(&local_storage->lock, flags); hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) { /* Always unlink from map before unlinking from * local_storage. @@ -90,7 +76,7 @@ void bpf_task_storage_free(struct task_struct *task) free_task_storage = bpf_selem_unlink_storage_nolock( local_storage, selem, false); } - raw_spin_unlock_bh(&local_storage->lock); + raw_spin_unlock_irqrestore(&local_storage->lock, flags); rcu_read_unlock(); /* free_task_storage should always be true as long as @@ -150,7 +136,7 @@ static int bpf_pid_task_storage_update_elem(struct bpf_map *map, void *key, */ WARN_ON_ONCE(!rcu_read_lock_held()); task = pid_task(pid, PIDTYPE_PID); - if (!task || !task_storage_ptr(task)) { + if (!task) { err = -ENOENT; goto out; } @@ -213,23 +199,16 @@ BPF_CALL_4(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *, if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE)) return (unsigned long)NULL; - /* explicitly check that the task_storage_ptr is not - * NULL as task_storage_lookup returns NULL in this case and - * bpf_local_storage_update expects the owner to have a - * valid storage pointer. - */ - if (!task || !task_storage_ptr(task)) + if (!task) return (unsigned long)NULL; sdata = task_storage_lookup(task, map, true); if (sdata) return (unsigned long)sdata->data; - /* This helper must only be called from places where the lifetime of the task - * is guaranteed. Either by being refcounted or by being protected - * by an RCU read-side critical section. - */ - if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) { + /* only allocate new storage, when the task is refcounted */ + if (refcount_read(&task->usage) && + (flags & BPF_LOCAL_STORAGE_GET_F_CREATE)) { sdata = bpf_local_storage_update( task, (struct bpf_local_storage_map *)map, value, BPF_NOEXIST); diff --git a/kernel/fork.c b/kernel/fork.c index d66cd1014211..181604db2d65 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -96,6 +96,7 @@ #include <linux/kasan.h> #include <linux/scs.h> #include <linux/io_uring.h> +#include <linux/bpf.h> #include <asm/pgalloc.h> #include <linux/uaccess.h> @@ -734,6 +735,7 @@ void __put_task_struct(struct task_struct *tsk) cgroup_free(tsk); task_numa_free(tsk, true); security_task_free(tsk); + bpf_task_storage_free(tsk); exit_creds(tsk); delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); @@ -2062,6 +2064,9 @@ static __latent_entropy struct task_struct *copy_process( p->sequential_io = 0; p->sequential_io_avg = 0; #endif +#ifdef CONFIG_BPF_SYSCALL + RCU_INIT_POINTER(p->bpf_storage, NULL); +#endif /* Perform scheduler related setup. Assign this task to a CPU. */ retval = sched_fork(clone_flags, p); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index b0c45d923f0f..e9701744d8e4 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1367,6 +1367,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_per_cpu_ptr_proto; case BPF_FUNC_this_cpu_ptr: return &bpf_this_cpu_ptr_proto; + case BPF_FUNC_task_storage_get: + return &bpf_task_storage_get_proto; + case BPF_FUNC_task_storage_delete: + return &bpf_task_storage_delete_proto; default: return NULL; } |