From 932c60558109a9131e54dacfda6070147fd1cdfb Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 4 Dec 2020 15:20:01 -0800 Subject: tools/bpftool: Fix PID fetching with a lot of results In case of having so many PID results that they don't fit into a singe page (4096) bytes, bpftool will erroneously conclude that it got corrupted data due to 4096 not being a multiple of struct pid_iter_entry, so the last entry will be partially truncated. Fix this by sizing the buffer to fit exactly N entries with no truncation in the middle of record. Fixes: d53dee3fe013 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20201204232002.3589803-1-andrii@kernel.org --- tools/bpf/bpftool/pids.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c index df7d8ec76036..477e55d59c34 100644 --- a/tools/bpf/bpftool/pids.c +++ b/tools/bpf/bpftool/pids.c @@ -89,9 +89,9 @@ libbpf_print_none(__maybe_unused enum libbpf_print_level level, int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type) { - char buf[4096]; - struct pid_iter_bpf *skel; struct pid_iter_entry *e; + char buf[4096 / sizeof(*e) * sizeof(*e)]; + struct pid_iter_bpf *skel; int err, ret, fd = -1, i; libbpf_print_fn_t default_print; -- cgit v1.2.3