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authorYonghong Song <yhs@fb.com>2020-05-13 11:02:19 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-05-13 12:30:50 -0700
commit15172a46fa2796c1a1358a36babd31274716ed41 (patch)
treec03b6ee05a943f83193860af50c6a9b364b13d4f /kernel/bpf/bpf_iter.c
parent2e3ed68bfcd9c5ca2cf8b88ba23a34992ccd0b1f (diff)
bpf: net: Refactor bpf_iter target registration
Currently bpf_iter_reg_target takes parameters from target and allocates memory to save them. This is really not necessary, esp. in the future we may grow information passed from targets to bpf_iter manager. The patch refactors the code so target reg_info becomes static and bpf_iter manager can just take a reference to it. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200513180219.2949605-1-yhs@fb.com
Diffstat (limited to 'kernel/bpf/bpf_iter.c')
-rw-r--r--kernel/bpf/bpf_iter.c36
1 files changed, 17 insertions, 19 deletions
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 0a45a6cdfabd..051fb8cab62a 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -8,11 +8,7 @@
struct bpf_iter_target_info {
struct list_head list;
- const char *target;
- const struct seq_operations *seq_ops;
- bpf_iter_init_seq_priv_t init_seq_private;
- bpf_iter_fini_seq_priv_t fini_seq_private;
- u32 seq_priv_size;
+ const struct bpf_iter_reg *reg_info;
u32 btf_id; /* cached value */
};
@@ -222,8 +218,8 @@ static int iter_release(struct inode *inode, struct file *file)
iter_priv = container_of(seq->private, struct bpf_iter_priv_data,
target_private);
- if (iter_priv->tinfo->fini_seq_private)
- iter_priv->tinfo->fini_seq_private(seq->private);
+ if (iter_priv->tinfo->reg_info->fini_seq_private)
+ iter_priv->tinfo->reg_info->fini_seq_private(seq->private);
bpf_prog_put(iter_priv->prog);
seq->private = iter_priv;
@@ -238,7 +234,12 @@ const struct file_operations bpf_iter_fops = {
.release = iter_release,
};
-int bpf_iter_reg_target(struct bpf_iter_reg *reg_info)
+/* The argument reg_info will be cached in bpf_iter_target_info.
+ * The common practice is to declare target reg_info as
+ * a const static variable and passed as an argument to
+ * bpf_iter_reg_target().
+ */
+int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info)
{
struct bpf_iter_target_info *tinfo;
@@ -246,11 +247,7 @@ int bpf_iter_reg_target(struct bpf_iter_reg *reg_info)
if (!tinfo)
return -ENOMEM;
- tinfo->target = reg_info->target;
- tinfo->seq_ops = reg_info->seq_ops;
- tinfo->init_seq_private = reg_info->init_seq_private;
- tinfo->fini_seq_private = reg_info->fini_seq_private;
- tinfo->seq_priv_size = reg_info->seq_priv_size;
+ tinfo->reg_info = reg_info;
INIT_LIST_HEAD(&tinfo->list);
mutex_lock(&targets_mutex);
@@ -267,7 +264,7 @@ void bpf_iter_unreg_target(const char *target)
mutex_lock(&targets_mutex);
list_for_each_entry(tinfo, &targets, list) {
- if (!strcmp(target, tinfo->target)) {
+ if (!strcmp(target, tinfo->reg_info->target)) {
list_del(&tinfo->list);
kfree(tinfo);
found = true;
@@ -303,7 +300,7 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog)
supported = true;
break;
}
- if (!strcmp(attach_fname + prefix_len, tinfo->target)) {
+ if (!strcmp(attach_fname + prefix_len, tinfo->reg_info->target)) {
cache_btf_id(tinfo, prog);
supported = true;
break;
@@ -431,15 +428,16 @@ static int prepare_seq_file(struct file *file, struct bpf_iter_link *link)
tinfo = link->tinfo;
total_priv_dsize = offsetof(struct bpf_iter_priv_data, target_private) +
- tinfo->seq_priv_size;
- priv_data = __seq_open_private(file, tinfo->seq_ops, total_priv_dsize);
+ tinfo->reg_info->seq_priv_size;
+ priv_data = __seq_open_private(file, tinfo->reg_info->seq_ops,
+ total_priv_dsize);
if (!priv_data) {
err = -ENOMEM;
goto release_prog;
}
- if (tinfo->init_seq_private) {
- err = tinfo->init_seq_private(priv_data->target_private);
+ if (tinfo->reg_info->init_seq_private) {
+ err = tinfo->reg_info->init_seq_private(priv_data->target_private);
if (err)
goto release_seq_file;
}