commit: e6e998f862f051598cd9b9c6cdcb7ad1f9f16d65 Author: Mike Pagano <mpagano <AT> gentoo <DOT> org> AuthorDate: Sat Sep 7 14:26:05 2024 +0000 Commit: Mike Pagano <mpagano <AT> gentoo <DOT> org> CommitDate: Sat Sep 7 14:26:05 2024 +0000 URL: https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=e6e998f8
libbpf: workaround (another) -Wmaybe-uninitialized false positive Thanks to Sam Signed-off-by: Mike Pagano <mpagano <AT> gentoo.org> 0000_README | 4 ++ ...workaround-Wmaybe-uninitialized-false-pos.patch | 64 ++++++++++++++++++++++ 2 files changed, 68 insertions(+) diff --git a/0000_README b/0000_README index ad96829d..9948b161 100644 --- a/0000_README +++ b/0000_README @@ -111,6 +111,10 @@ Patch: 2910_bfp-mark-get-entry-ip-as--maybe-unused.patch From: https://www.spinics.net/lists/stable/msg604665.html Desc: bpf: mark get_entry_ip as __maybe_unused +Patch: 2911_libbpf-second-workaround-Wmaybe-uninitialized-false-pos.patch +From: https://lore.kernel.org/bpf/f6962729197ae7cdf4f6d1512625bd92f2322d31.1725630494.git....@gentoo.org/ +Desc: libbpf: workaround (another) -Wmaybe-uninitialized false positive + Patch: 2920_sign-file-patch-for-libressl.patch From: https://bugs.gentoo.org/717166 Desc: sign-file: full functionality with modern LibreSSL diff --git a/2911_libbpf-second-workaround-Wmaybe-uninitialized-false-pos.patch b/2911_libbpf-second-workaround-Wmaybe-uninitialized-false-pos.patch new file mode 100644 index 00000000..f01221c7 --- /dev/null +++ b/2911_libbpf-second-workaround-Wmaybe-uninitialized-false-pos.patch @@ -0,0 +1,64 @@ +From git@z Thu Jan 1 00:00:00 1970 +Subject: [PATCH] libbpf: workaround (another) -Wmaybe-uninitialized false + positive +From: Sam James <s...@gentoo.org> +Date: Fri, 06 Sep 2024 14:48:14 +0100 +Message-Id: <f6962729197ae7cdf4f6d1512625bd92f2322d31.1725630494.git....@gentoo.org> +MIME-Version: 1.0 +Content-Type: text/plain; charset="utf-8" +Content-Transfer-Encoding: 8bit + +We get this with GCC 15 -O3 (at least): +``` +libbpf.c: In function ‘bpf_map__init_kern_struct_ops’: +libbpf.c:1109:18: error: ‘mod_btf’ may be used uninitialized [-Werror=maybe-uninitialized] + 1109 | kern_btf = mod_btf ? mod_btf->btf : obj->btf_vmlinux; + | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +libbpf.c:1094:28: note: ‘mod_btf’ was declared here + 1094 | struct module_btf *mod_btf; + | ^~~~~~~ +In function ‘find_struct_ops_kern_types’, + inlined from ‘bpf_map__init_kern_struct_ops’ at libbpf.c:1102:8: +libbpf.c:982:21: error: ‘btf’ may be used uninitialized [-Werror=maybe-uninitialized] + 982 | kern_type = btf__type_by_id(btf, kern_type_id); + | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +libbpf.c: In function ‘bpf_map__init_kern_struct_ops’: +libbpf.c:967:21: note: ‘btf’ was declared here + 967 | struct btf *btf; + | ^~~ +``` + +This is similar to the other libbpf fix from a few weeks ago for +the same modelling-errno issue (fab45b962749184e1a1a57c7c583782b78fad539). + +Link: https://bugs.gentoo.org/939106 +Signed-off-by: Sam James <s...@gentoo.org> +--- + tools/lib/bpf/libbpf.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c +index a3be6f8fac09e..7315120574c29 100644 +--- a/tools/lib/bpf/libbpf.c ++++ b/tools/lib/bpf/libbpf.c +@@ -988,7 +988,7 @@ find_struct_ops_kern_types(struct bpf_object *obj, const char *tname_raw, + { + const struct btf_type *kern_type, *kern_vtype; + const struct btf_member *kern_data_member; +- struct btf *btf; ++ struct btf *btf = NULL; + __s32 kern_vtype_id, kern_type_id; + char tname[256]; + __u32 i; +@@ -1115,7 +1115,7 @@ static int bpf_map__init_kern_struct_ops(struct bpf_map *map) + const struct btf *btf = obj->btf; + struct bpf_struct_ops *st_ops; + const struct btf *kern_btf; +- struct module_btf *mod_btf; ++ struct module_btf *mod_btf = NULL; + void *data, *kern_data; + const char *tname; + int err; +-- +2.46.0 +
