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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: E7C51180002 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: zdneks47y6t1q5x6s1nqrdrs74xana6i X-HE-Tag: 1729553811-508327 X-HE-Meta: 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 5wRzdgJM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Oct 17, 2024 at 1:06=E2=80=AFAM Namhyung Kim = wrote: > > The new subtest is attached to sleepable fentry of syncfs() syscall. > It iterates the kmem_cache using bpf_for_each loop and count the number > of entries. Finally it checks it with the number of entries from the > regular iterator. > > $ ./vmtest.sh -- ./test_progs -t kmem_cache_iter > ... > #130/1 kmem_cache_iter/check_task_struct:OK > #130/2 kmem_cache_iter/check_slabinfo:OK > #130/3 kmem_cache_iter/open_coded_iter:OK > #130 kmem_cache_iter:OK > Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED > > Also simplify the code by using attach routine of the skeleton. > > Signed-off-by: Namhyung Kim > --- > .../testing/selftests/bpf/bpf_experimental.h | 6 ++++ > .../bpf/prog_tests/kmem_cache_iter.c | 28 +++++++++++-------- > .../selftests/bpf/progs/kmem_cache_iter.c | 24 ++++++++++++++++ > 3 files changed, 46 insertions(+), 12 deletions(-) > > diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testi= ng/selftests/bpf/bpf_experimental.h > index b0668f29f7b394eb..cd8ecd39c3f3c68d 100644 > --- a/tools/testing/selftests/bpf/bpf_experimental.h > +++ b/tools/testing/selftests/bpf/bpf_experimental.h > @@ -582,4 +582,10 @@ extern int bpf_wq_set_callback_impl(struct bpf_wq *w= q, > unsigned int flags__k, void *aux__ign) __ksym; > #define bpf_wq_set_callback(timer, cb, flags) \ > bpf_wq_set_callback_impl(timer, cb, flags, NULL) > + > +struct bpf_iter_kmem_cache; > +extern int bpf_iter_kmem_cache_new(struct bpf_iter_kmem_cache *it) __wea= k __ksym; > +extern struct kmem_cache *bpf_iter_kmem_cache_next(struct bpf_iter_kmem_= cache *it) __weak __ksym; > +extern void bpf_iter_kmem_cache_destroy(struct bpf_iter_kmem_cache *it) = __weak __ksym; > + we should be getting this from vmlinux.h nowadays, so this is probably unnecessary > #endif > diff --git a/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c b/t= ools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c > index 848d8fc9171fae45..a1fd3bc57c0b21bb 100644 > --- a/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c > +++ b/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c > @@ -68,12 +68,18 @@ static void subtest_kmem_cache_iter_check_slabinfo(st= ruct kmem_cache_iter *skel) > fclose(fp); > } > > +static void subtest_kmem_cache_iter_open_coded(struct kmem_cache_iter *s= kel) > +{ > + /* To trigger the open coded iterator attached to the syscall */ > + syncfs(0); what Martin said, you still need to filter by PID > + > + /* It should be same as we've seen from the explicit iterator */ > + ASSERT_EQ(skel->bss->open_coded_seen, skel->bss->kmem_cache_seen,= "open_code_seen_eq"); > +} > + > void test_kmem_cache_iter(void) > { > - DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); > struct kmem_cache_iter *skel =3D NULL; > - union bpf_iter_link_info linfo =3D {}; > - struct bpf_link *link; > char buf[256]; > int iter_fd; > > @@ -81,16 +87,12 @@ void test_kmem_cache_iter(void) > if (!ASSERT_OK_PTR(skel, "kmem_cache_iter__open_and_load")) > return; > > - opts.link_info =3D &linfo; > - opts.link_info_len =3D sizeof(linfo); > - > - link =3D bpf_program__attach_iter(skel->progs.slab_info_collector= , &opts); > - if (!ASSERT_OK_PTR(link, "attach_iter")) > + if (!ASSERT_OK(kmem_cache_iter__attach(skel), "skel_attach")) > goto destroy; > > - iter_fd =3D bpf_iter_create(bpf_link__fd(link)); > + iter_fd =3D bpf_iter_create(bpf_link__fd(skel->links.slab_info_co= llector)); > if (!ASSERT_GE(iter_fd, 0, "iter_create")) > - goto free_link; > + goto detach; > > memset(buf, 0, sizeof(buf)); > while (read(iter_fd, buf, sizeof(buf) > 0)) { > @@ -105,11 +107,13 @@ void test_kmem_cache_iter(void) > subtest_kmem_cache_iter_check_task_struct(skel); > if (test__start_subtest("check_slabinfo")) > subtest_kmem_cache_iter_check_slabinfo(skel); > + if (test__start_subtest("open_coded_iter")) > + subtest_kmem_cache_iter_open_coded(skel); > > close(iter_fd); > > -free_link: > - bpf_link__destroy(link); > +detach: > + kmem_cache_iter__detach(skel); > destroy: > kmem_cache_iter__destroy(skel); > } > diff --git a/tools/testing/selftests/bpf/progs/kmem_cache_iter.c b/tools/= testing/selftests/bpf/progs/kmem_cache_iter.c > index 72c9dafecd98406b..4c44aa279a5328fe 100644 > --- a/tools/testing/selftests/bpf/progs/kmem_cache_iter.c > +++ b/tools/testing/selftests/bpf/progs/kmem_cache_iter.c > @@ -2,6 +2,8 @@ > /* Copyright (c) 2024 Google */ > > #include "bpf_iter.h" > +#include "bpf_experimental.h" > +#include "bpf_misc.h" > #include > #include > > @@ -33,6 +35,7 @@ extern struct kmem_cache *bpf_get_kmem_cache(u64 addr) = __ksym; > /* Result, will be checked by userspace */ > int task_struct_found; > int kmem_cache_seen; > +int open_coded_seen; > > SEC("iter/kmem_cache") > int slab_info_collector(struct bpf_iter__kmem_cache *ctx) > @@ -85,3 +88,24 @@ int BPF_PROG(check_task_struct) > task_struct_found =3D -2; > return 0; > } > + > +SEC("fentry.s/" SYS_PREFIX "sys_syncfs") > +int open_coded_iter(const void *ctx) > +{ > + struct kmem_cache *s; > + > + bpf_for_each(kmem_cache, s) { > + struct kmem_cache_result *r; > + int idx =3D open_coded_seen; > + > + r =3D bpf_map_lookup_elem(&slab_result, &idx); nit: you don't need idx, just `&open_coded_seen` should be fine, I think > + if (r =3D=3D NULL) nit: !r > + break; > + > + open_coded_seen++; > + > + if (r->obj_size !=3D s->size) > + break; > + } > + return 0; > +} > -- > 2.47.0.rc1.288.g06298d1525-goog >