From c302378bc157f6a73b6cae4ca67f5f6aa931dcec Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Wed, 9 Nov 2022 16:26:09 +0200 Subject: libbpf: Hashmap interface update to allow both long and void* keys/values An update for libbpf's hashmap interface from void* -> void* to a polymorphic one, allowing both long and void* keys and values. This simplifies many use cases in libbpf as hashmaps there are mostly integer to integer. Perf copies hashmap implementation from libbpf and has to be updated as well. Changes to libbpf, selftests/bpf and perf are packed as a single commit to avoid compilation issues with any future bisect. Polymorphic interface is acheived by hiding hashmap interface functions behind auxiliary macros that take care of necessary type casts, for example: #define hashmap_cast_ptr(p) \ ({ \ _Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\ #p " pointee should be a long-sized integer or a pointer"); \ (long *)(p); \ }) bool hashmap_find(const struct hashmap *map, long key, long *value); #define hashmap__find(map, key, value) \ hashmap_find((map), (long)(key), hashmap_cast_ptr(value)) - hashmap__find macro casts key and value parameters to long and long* respectively - hashmap_cast_ptr ensures that value pointer points to a memory of appropriate size. This hack was suggested by Andrii Nakryiko in [1]. This is a follow up for [2]. [1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/ [2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com --- tools/bpf/bpftool/prog.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'tools/bpf/bpftool/prog.c') diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index a858b907da16..9d32ffb9f22e 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -486,9 +486,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd) jsonw_name(json_wtr, "pinned"); jsonw_start_array(json_wtr); - hashmap__for_each_key_entry(prog_table, entry, - u32_as_hash_field(info->id)) - jsonw_string(json_wtr, entry->value); + hashmap__for_each_key_entry(prog_table, entry, info->id) + jsonw_string(json_wtr, entry->pvalue); jsonw_end_array(json_wtr); } @@ -561,9 +560,8 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd) if (!hashmap__empty(prog_table)) { struct hashmap_entry *entry; - hashmap__for_each_key_entry(prog_table, entry, - u32_as_hash_field(info->id)) - printf("\n\tpinned %s", (char *)entry->value); + hashmap__for_each_key_entry(prog_table, entry, info->id) + printf("\n\tpinned %s", (char *)entry->pvalue); } if (info->btf_id) -- cgit v1.2.3