From: Andrii Nakryiko andrii@kernel.org
mainline inclusion from mainline-5.12-rc1 commit 9e80114b1a271803767d4c5baa11ea9e8678aac3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add selftests validating that newly added variations of BPF_CORE_READ(), for use with user-space addresses and for non-CO-RE reads, work as expected.
Signed-off-by: Andrii Nakryiko andrii@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/20201218235614.2284956-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org (cherry picked from commit 9e80114b1a271803767d4c5baa11ea9e8678aac3) Signed-off-by: Wang Yufen wangyufen@huawei.com --- .../bpf/prog_tests/core_read_macros.c | 64 +++++++++++++++++++ .../bpf/progs/test_core_read_macros.c | 50 +++++++++++++++ 2 files changed, 114 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/core_read_macros.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_read_macros.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_read_macros.c b/tools/testing/selftests/bpf/prog_tests/core_read_macros.c new file mode 100644 index 000000000000..96f5cf3c6fa2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/core_read_macros.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include <test_progs.h> + +struct callback_head { + struct callback_head *next; + void (*func)(struct callback_head *head); +}; + +/* ___shuffled flavor is just an illusion for BPF code, it doesn't really + * exist and user-space needs to provide data in the memory layout that + * matches callback_head. We just defined ___shuffled flavor to make it easier + * to work with the skeleton + */ +struct callback_head___shuffled { + struct callback_head___shuffled *next; + void (*func)(struct callback_head *head); +}; + +#include "test_core_read_macros.skel.h" + +void test_core_read_macros(void) +{ + int duration = 0, err; + struct test_core_read_macros* skel; + struct test_core_read_macros__bss *bss; + struct callback_head u_probe_in; + struct callback_head___shuffled u_core_in; + + skel = test_core_read_macros__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + bss = skel->bss; + bss->my_pid = getpid(); + + /* next pointers have to be set from the kernel side */ + bss->k_probe_in.func = (void *)(long)0x1234; + bss->k_core_in.func = (void *)(long)0xabcd; + + u_probe_in.next = &u_probe_in; + u_probe_in.func = (void *)(long)0x5678; + bss->u_probe_in = &u_probe_in; + + u_core_in.next = &u_core_in; + u_core_in.func = (void *)(long)0xdbca; + bss->u_core_in = &u_core_in; + + err = test_core_read_macros__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* trigger tracepoint */ + usleep(1); + + ASSERT_EQ(bss->k_probe_out, 0x1234, "k_probe_out"); + ASSERT_EQ(bss->k_core_out, 0xabcd, "k_core_out"); + + ASSERT_EQ(bss->u_probe_out, 0x5678, "u_probe_out"); + ASSERT_EQ(bss->u_core_out, 0xdbca, "u_core_out"); + +cleanup: + test_core_read_macros__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_core_read_macros.c b/tools/testing/selftests/bpf/progs/test_core_read_macros.c new file mode 100644 index 000000000000..fd54caa17319 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_core_read_macros.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_core_read.h> + +char _license[] SEC("license") = "GPL"; + +/* shuffled layout for relocatable (CO-RE) reads */ +struct callback_head___shuffled { + void (*func)(struct callback_head___shuffled *head); + struct callback_head___shuffled *next; +}; + +struct callback_head k_probe_in = {}; +struct callback_head___shuffled k_core_in = {}; + +struct callback_head *u_probe_in = 0; +struct callback_head___shuffled *u_core_in = 0; + +long k_probe_out = 0; +long u_probe_out = 0; + +long k_core_out = 0; +long u_core_out = 0; + +int my_pid = 0; + +SEC("raw_tracepoint/sys_enter") +int handler(void *ctx) +{ + int pid = bpf_get_current_pid_tgid() >> 32; + + if (my_pid != pid) + return 0; + + /* next pointers for kernel address space have to be initialized from + * BPF side, user-space mmaped addresses are stil user-space addresses + */ + k_probe_in.next = &k_probe_in; + __builtin_preserve_access_index(({k_core_in.next = &k_core_in;})); + + k_probe_out = (long)BPF_PROBE_READ(&k_probe_in, next, next, func); + k_core_out = (long)BPF_CORE_READ(&k_core_in, next, next, func); + u_probe_out = (long)BPF_PROBE_READ_USER(u_probe_in, next, next, func); + u_core_out = (long)BPF_CORE_READ_USER(u_core_in, next, next, func); + + return 0; +}