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| author | Andrii Nakryiko <andrii@kernel.org> | 2023-03-17 15:44:27 -0700 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2023-03-17 15:46:03 -0700 |
| commit | 6cae5a7106e272e7908a1facdf519a307f93872d (patch) | |
| tree | dd3fb68a821169c52d13421de0ba528db0ce70ba /tools/testing/selftests/bpf | |
| parent | 0f10f647f45545004ea50b73a7a7c5c3309ff286 (diff) | |
| parent | 95fdf6e313a981b0729886f86916190cb418b04c (diff) | |
Merge branch 'bpf: Add detection of kfuncs.'
Alexei Starovoitov says:
====================
From: Alexei Starovoitov <ast@kernel.org>
Allow BPF programs detect at load time whether particular kfunc exists.
Patch 1: Allow ld_imm64 to point to kfunc in the kernel.
Patch 2: Fix relocation of kfunc in ld_imm64 insn when kfunc is in kernel module.
Patch 3: Introduce bpf_ksym_exists() macro.
Patch 4: selftest.
NOTE: detection of kfuncs from light skeleton is not supported yet.
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/task_kfunc_success.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index 4f61596b0242..cfa7f12b84e8 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -17,6 +17,10 @@ int err, pid; * TP_PROTO(struct task_struct *p, u64 clone_flags) */ +struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak; +void invalid_kfunc(void) __ksym __weak; +void bpf_testmod_test_mod_kfunc(int i) __ksym __weak; + static bool is_test_kfunc_task(void) { int cur_pid = bpf_get_current_pid_tgid() >> 32; @@ -26,7 +30,21 @@ static bool is_test_kfunc_task(void) static int test_acquire_release(struct task_struct *task) { - struct task_struct *acquired; + struct task_struct *acquired = NULL; + + if (!bpf_ksym_exists(bpf_task_acquire)) { + err = 3; + return 0; + } + if (!bpf_ksym_exists(bpf_testmod_test_mod_kfunc)) { + err = 4; + return 0; + } + if (bpf_ksym_exists(invalid_kfunc)) { + /* the verifier's dead code elimination should remove this */ + err = 5; + asm volatile ("goto -1"); /* for (;;); */ + } acquired = bpf_task_acquire(task); bpf_task_release(acquired); |