kernel/linux.git/tools/lib/bpf/hashmap.c, branch v5.9.2

libbpf, hashmap: Fix signedness warnings

2020-05-15T23:06:05+00:00

Fixes the following warnings: hashmap.c: In function ‘hashmap__clear’: hashmap.h:150:20: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare] 150 | for (bkt = 0; bkt < map->cap; bkt++) \ hashmap.c: In function ‘hashmap_grow’: hashmap.h:150:20: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare] 150 | for (bkt = 0; bkt < map->cap; bkt++) \ Signed-off-by: Ian Rogers Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200515165007.217120-4-irogers@google.com

libbpf: Fix memory leak and possible double-free in hashmap__clear

2020-04-29T02:48:05+00:00

Fix memory leak in hashmap_clear() not freeing hashmap_entry structs for each of the remaining entries. Also NULL-out bucket list to prevent possible double-free between hashmap__clear() and hashmap__free(). Running test_progs-asan flavor clearly showed this problem. Reported-by: Alston Tang Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com

libbpf: Poison kernel-only integer types

2020-01-10T18:38:00+00:00

It's been a recurring issue with types like u32 slipping into libbpf source code accidentally. This is not detected during builds inside kernel source tree, but becomes a compilation error in libbpf's Github repo. Libbpf is supposed to use only __{s,u}{8,16,32,64} typedefs, so poison {s,u}{8,16,32,64} explicitly in every .c file. Doing that in a bit more centralized way, e.g., inside libbpf_internal.h breaks selftests, which are both using kernel u32 and libbpf_internal.h. This patch also fixes a new u32 occurence in libbpf.c, added recently. Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200110181916.271446-1-andriin@fb.com

libbpf: add resizable non-thread safe internal hashmap

2019-05-24T21:05:57+00:00

There is a need for fast point lookups inside libbpf for multiple use cases (e.g., name resolution for BTF-to-C conversion, by-name lookups in BTF for upcoming BPF CO-RE relocation support, etc). This patch implements simple resizable non-thread safe hashmap using single linked list chains. Four different insert strategies are supported: - HASHMAP_ADD - only add key/value if key doesn't exist yet; - HASHMAP_SET - add key/value pair if key doesn't exist yet; otherwise, update value; - HASHMAP_UPDATE - update value, if key already exists; otherwise, do nothing and return -ENOENT; - HASHMAP_APPEND - always add key/value pair, even if key already exists. This turns hashmap into a multimap by allowing multiple values to be associated with the same key. Most useful read API for such hashmap is hashmap__for_each_key_entry() iteration. If hashmap__find() is still used, it will return last inserted key/value entry (first in a bucket chain). For HASHMAP_SET and HASHMAP_UPDATE, old key/value pair is returned, so that calling code can handle proper memory management, if necessary. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov