diff options
Diffstat (limited to 'kernel/bpf/bpf_iter.c')
| -rw-r--r-- | kernel/bpf/bpf_iter.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index d5d96ceca105..24b755eca0b3 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -68,23 +68,27 @@ static void bpf_iter_done_stop(struct seq_file *seq) iter_priv->done_stop = true; } +static inline bool bpf_iter_target_support_resched(const struct bpf_iter_target_info *tinfo) +{ + return tinfo->reg_info->feature & BPF_ITER_RESCHED; +} + static bool bpf_iter_support_resched(struct seq_file *seq) { struct bpf_iter_priv_data *iter_priv; iter_priv = container_of(seq->private, struct bpf_iter_priv_data, target_private); - return iter_priv->tinfo->reg_info->feature & BPF_ITER_RESCHED; + return bpf_iter_target_support_resched(iter_priv->tinfo); } /* maximum visited objects before bailing out */ #define MAX_ITER_OBJECTS 1000000 /* bpf_seq_read, a customized and simpler version for bpf iterator. - * no_llseek is assumed for this file. * The following are differences from seq_read(): * . fixed buffer size (PAGE_SIZE) - * . assuming no_llseek + * . assuming NULL ->llseek() * . stop() may call bpf program, handling potential overflow there */ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size, @@ -538,6 +542,10 @@ int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, if (!tinfo) return -ENOENT; + /* Only allow sleepable program for resched-able iterator */ + if (prog->aux->sleepable && !bpf_iter_target_support_resched(tinfo)) + return -EINVAL; + link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN); if (!link) return -ENOMEM; @@ -723,9 +731,6 @@ const struct bpf_func_proto bpf_for_each_map_elem_proto = { .arg4_type = ARG_ANYTHING, }; -/* maximum number of loops */ -#define MAX_LOOPS BIT(23) - BPF_CALL_4(bpf_loop, u32, nr_loops, void *, callback_fn, void *, callback_ctx, u64, flags) { @@ -733,9 +738,13 @@ BPF_CALL_4(bpf_loop, u32, nr_loops, void *, callback_fn, void *, callback_ctx, u64 ret; u32 i; + /* Note: these safety checks are also verified when bpf_loop + * is inlined, be careful to modify this code in sync. See + * function verifier.c:inline_bpf_loop. + */ if (flags) return -EINVAL; - if (nr_loops > MAX_LOOPS) + if (nr_loops > BPF_MAX_LOOPS) return -E2BIG; for (i = 0; i < nr_loops; i++) { |