hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ICA1GK -------------------------------- Add a special kfunc for concatenating buf content of seq_file. Signed-off-by: GONG Ruiqi <gongruiqi1@huawei.com> --- kernel/bpf-rvi/common_kfuncs.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/kernel/bpf-rvi/common_kfuncs.c b/kernel/bpf-rvi/common_kfuncs.c index c93b1fc08395..c8c47f72e7fd 100644 --- a/kernel/bpf-rvi/common_kfuncs.c +++ b/kernel/bpf-rvi/common_kfuncs.c @@ -5,6 +5,7 @@ #include <linux/swap.h> #include <linux/types.h> #include <linux/page_counter.h> +#include <linux/seq_file.h> #include <linux/btf_ids.h> #include <linux/bpf.h> @@ -43,9 +44,25 @@ __bpf_kfunc unsigned long bpf_page_counter_read(struct page_counter *counter) return page_counter_read(counter); } +/* Moving src's content to the end of dst. Reference: seq_vprintf. */ +__bpf_kfunc void bpf_seq_file_append(struct seq_file *dst, struct seq_file *src) +{ + /* + * ->count: length of content + * ->size: available buffer space + * i.e. seq_printf(dst, "%s", src->buf) + */ + if (dst->count < dst->size) + if (src->count < dst->size - dst->count) { + memmove(dst->buf + dst->count, src->buf, src->count); + dst->count += src->count; + } +} + BTF_SET8_START(bpf_common_kfuncs_ids) BTF_ID_FLAGS(func, bpf_si_memswinfo) BTF_ID_FLAGS(func, bpf_page_counter_read) +BTF_ID_FLAGS(func, bpf_seq_file_append) BTF_SET8_END(bpf_common_kfuncs_ids) static const struct btf_kfunc_id_set bpf_common_kfuncs_set = { -- 2.25.1