This is a note to let you know that I've just added the patch titled selftests/bpf: Add test_verifier support to fixup kfunc call insns to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-bpf-add-test_verifier-support-to-fixup-kfunc-call-insns.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0201b80772ac2b712bbbfe783cdb731fdfb4247e Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> Date: Fri, 14 Jan 2022 22:09:51 +0530 Subject: selftests/bpf: Add test_verifier support to fixup kfunc call insns From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> commit 0201b80772ac2b712bbbfe783cdb731fdfb4247e upstream. This allows us to add tests (esp. negative tests) where we only want to ensure the program doesn't pass through the verifier, and also verify the error. The next commit will add the tests making use of this. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> Link: https://lore.kernel.org/r/20220114163953.1455836-9-memxor@xxxxxxxxx Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> [PHLin: backport due to lack of fixup_map_timer] Signed-off-by: Po-Hsu Lin <po-hsu.lin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/bpf/test_verifier.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -31,6 +31,7 @@ #include <linux/if_ether.h> #include <linux/btf.h> +#include <bpf/btf.h> #include <bpf/bpf.h> #include <bpf/libbpf.h> @@ -63,6 +64,11 @@ static bool unpriv_disabled = false; static int skips; static bool verbose = false; +struct kfunc_btf_id_pair { + const char *kfunc; + int insn_idx; +}; + struct bpf_test { const char *descr; struct bpf_insn insns[MAX_INSNS]; @@ -88,6 +94,7 @@ struct bpf_test { int fixup_map_event_output[MAX_FIXUPS]; int fixup_map_reuseport_array[MAX_FIXUPS]; int fixup_map_ringbuf[MAX_FIXUPS]; + struct kfunc_btf_id_pair fixup_kfunc_btf_id[MAX_FIXUPS]; /* Expected verifier log output for result REJECT or VERBOSE_ACCEPT. * Can be a tab-separated sequence of expected strings. An empty string * means no log verification. @@ -718,6 +725,7 @@ static void do_test_fixup(struct bpf_tes int *fixup_map_event_output = test->fixup_map_event_output; int *fixup_map_reuseport_array = test->fixup_map_reuseport_array; int *fixup_map_ringbuf = test->fixup_map_ringbuf; + struct kfunc_btf_id_pair *fixup_kfunc_btf_id = test->fixup_kfunc_btf_id; if (test->fill_helper) { test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn)); @@ -903,6 +911,26 @@ static void do_test_fixup(struct bpf_tes fixup_map_ringbuf++; } while (*fixup_map_ringbuf); } + + /* Patch in kfunc BTF IDs */ + if (fixup_kfunc_btf_id->kfunc) { + struct btf *btf; + int btf_id; + + do { + btf_id = 0; + btf = btf__load_vmlinux_btf(); + if (btf) { + btf_id = btf__find_by_name_kind(btf, + fixup_kfunc_btf_id->kfunc, + BTF_KIND_FUNC); + btf_id = btf_id < 0 ? 0 : btf_id; + } + btf__free(btf); + prog[fixup_kfunc_btf_id->insn_idx].imm = btf_id; + fixup_kfunc_btf_id++; + } while (fixup_kfunc_btf_id->kfunc); + } } struct libcap { Patches currently in stable-queue which might be from memxor@xxxxxxxxx are queue-5.15/selftests-bpf-add-test_verifier-support-to-fixup-kfunc-call-insns.patch