bpftool: Switch to libbpf's hashmap for PIDs/names references

In order to show PIDs and names for processes holding references to BPF
programs, maps, links, or BTF objects, bpftool creates hash maps to
store all relevant information. This commit is part of a set that
transitions from the kernel's hash map implementation to the one coming
with libbpf.

The motivation is to make bpftool less dependent of kernel headers, to
ease the path to a potential out-of-tree mirror, like libbpf has.

This is the third and final step of the transition, in which we convert
the hash maps used for storing the information about the processes
holding references to BPF objects (programs, maps, links, BTF), and at
last we drop the inclusion of tools/include/linux/hashtable.h.

Note: Checkpatch complains about the use of __weak declarations, and the
missing empty lines after the bunch of empty function declarations when
compiling without the BPF skeletons (none of these were introduced in
this patch). We want to keep things as they are, and the reports should
be safe to ignore.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211023205154.6710-6-quentin@isovalent.com

1 files changed, 3 insertions, 2 deletions

diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 7a33f0e6da28..28237d7cef67 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -10,8 +10,9 @@
 #include <string.h>
 
 #include <bpf/bpf.h>
-#include <bpf/libbpf.h>
 #include <bpf/btf.h>
+#include <bpf/hashmap.h>
+#include <bpf/libbpf.h>
 
 #include "main.h"
 
@@ -31,7 +32,7 @@ bool verifier_logs;
 bool relaxed_maps;
 bool use_loader;
 struct btf *base_btf;
-struct obj_refs_table refs_table;
+struct hashmap *refs_table;
 
 static void __noreturn clean_and_exit(int i)
 {