From 63ae8eb2c5b1388eeda39bc95e89e4ad906fa336 Mon Sep 17 00:00:00 2001 From: Dave Marchevsky Date: Thu, 17 Aug 2023 15:53:53 -0700 Subject: [PATCH] selftests/bpf: Add CO-RE relocs kfunc flavors tests This patch adds selftests that exercise kfunc flavor relocation functionality added in the previous patch. The actual kfunc defined in kernel/bpf/helpers.c is: struct task_struct *bpf_task_acquire(struct task_struct *p) The following relocation behaviors are checked: struct task_struct *bpf_task_acquire___one(struct task_struct *name) * Should succeed despite differing param name struct task_struct *bpf_task_acquire___two(struct task_struct *p, void *ctx) * Should fail because there is no two-param bpf_task_acquire struct task_struct *bpf_task_acquire___three(void *ctx) * Should fail because, despite vmlinux's bpf_task_acquire having one param, the types don't match Signed-off-by: Dave Marchevsky Signed-off-by: Daniel Borkmann Acked-by: David Vernet Link: https://lore.kernel.org/bpf/20230817225353.2570845-2-davemarchevsky@fb.com --- .../testing/selftests/bpf/prog_tests/task_kfunc.c | 2 + .../selftests/bpf/progs/task_kfunc_success.c | 51 ++++++++++++++++++++++ 2 files changed, 53 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c index 740d5f644b40..d4579f735398 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c +++ b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c @@ -79,6 +79,8 @@ static const char * const success_tests[] = { "test_task_from_pid_current", "test_task_from_pid_invalid", "task_kfunc_acquire_trusted_walked", + "test_task_kfunc_flavor_relo", + "test_task_kfunc_flavor_relo_not_found", }; void test_task_kfunc(void) diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index b09371bba204..70df695312dc 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -18,6 +18,13 @@ int err, pid; */ struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; + +struct task_struct *bpf_task_acquire___one(struct task_struct *task) __ksym __weak; +/* The two-param bpf_task_acquire doesn't exist */ +struct task_struct *bpf_task_acquire___two(struct task_struct *p, void *ctx) __ksym __weak; +/* Incorrect type for first param */ +struct task_struct *bpf_task_acquire___three(void *ctx) __ksym __weak; + void invalid_kfunc(void) __ksym __weak; void bpf_testmod_test_mod_kfunc(int i) __ksym __weak; @@ -56,6 +63,50 @@ static int test_acquire_release(struct task_struct *task) } SEC("tp_btf/task_newtask") +int BPF_PROG(test_task_kfunc_flavor_relo, struct task_struct *task, u64 clone_flags) +{ + struct task_struct *acquired = NULL; + int fake_ctx = 42; + + if (bpf_ksym_exists(bpf_task_acquire___one)) { + acquired = bpf_task_acquire___one(task); + } else if (bpf_ksym_exists(bpf_task_acquire___two)) { + /* Here, bpf_object__resolve_ksym_func_btf_id's find_ksym_btf_id + * call will find vmlinux's bpf_task_acquire, but subsequent + * bpf_core_types_are_compat will fail + */ + acquired = bpf_task_acquire___two(task, &fake_ctx); + err = 3; + return 0; + } else if (bpf_ksym_exists(bpf_task_acquire___three)) { + /* bpf_core_types_are_compat will fail similarly to above case */ + acquired = bpf_task_acquire___three(&fake_ctx); + err = 4; + return 0; + } + + if (acquired) + bpf_task_release(acquired); + else + err = 5; + return 0; +} + +SEC("tp_btf/task_newtask") +int BPF_PROG(test_task_kfunc_flavor_relo_not_found, struct task_struct *task, u64 clone_flags) +{ + /* Neither symbol should successfully resolve. + * Success or failure of one ___flavor should not affect others + */ + if (bpf_ksym_exists(bpf_task_acquire___two)) + err = 1; + else if (bpf_ksym_exists(bpf_task_acquire___three)) + err = 2; + + return 0; +} + +SEC("tp_btf/task_newtask") int BPF_PROG(test_task_acquire_release_argument, struct task_struct *task, u64 clone_flags) { if (!is_test_kfunc_task()) -- 2.11.0