selftests/bpf: Add tests for u[ret]probe attach by name
add tests that verify attaching by name for 1. local functions in a program 2. library functions in a shared object ...succeed for uprobe and uretprobes using new "func_name" option for bpf_program__attach_uprobe_opts(). Also verify auto-attach works where uprobe, path to binary and function name are specified, but fails with -EOPNOTSUPP with a SEC name that does not specify binary path/function. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1648654000-21758-5-git-send-email-alan.maguire@oracle.com
This commit is contained in:
Alan Maguire
Andrii Nakryiko
parent
39f8dc43b7
commit
ba7499bc9d
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@ -11,15 +11,22 @@ static void trigger_func(void)
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asm volatile ("");
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}
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/* attach point for byname uprobe */
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static void trigger_func2(void)
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{
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asm volatile ("");
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}
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void test_attach_probe(void)
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{
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DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
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int duration = 0;
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struct bpf_link *kprobe_link, *kretprobe_link;
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struct bpf_link *uprobe_link, *uretprobe_link;
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struct test_attach_probe* skel;
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ssize_t uprobe_offset, ref_ctr_offset;
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struct bpf_link *uprobe_err_link;
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bool legacy;
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char *mem;
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/* Check if new-style kprobe/uprobe API is supported.
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* Kernels that support new FD-based kprobe and uprobe BPF attachment
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@ -43,9 +50,9 @@ void test_attach_probe(void)
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return;
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skel = test_attach_probe__open_and_load();
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if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
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if (!ASSERT_OK_PTR(skel, "skel_open"))
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return;
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if (CHECK(!skel->bss, "check_bss", ".bss wasn't mmap()-ed\n"))
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if (!ASSERT_OK_PTR(skel->bss, "check_bss"))
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goto cleanup;
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kprobe_link = bpf_program__attach_kprobe(skel->progs.handle_kprobe,
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@ -90,25 +97,73 @@ void test_attach_probe(void)
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goto cleanup;
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skel->links.handle_uretprobe = uretprobe_link;
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/* verify auto-attach fails for old-style uprobe definition */
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uprobe_err_link = bpf_program__attach(skel->progs.handle_uprobe_byname);
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if (!ASSERT_EQ(libbpf_get_error(uprobe_err_link), -EOPNOTSUPP,
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"auto-attach should fail for old-style name"))
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goto cleanup;
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uprobe_opts.func_name = "trigger_func2";
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uprobe_opts.retprobe = false;
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uprobe_opts.ref_ctr_offset = 0;
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skel->links.handle_uprobe_byname =
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bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
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0 /* this pid */,
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"/proc/self/exe",
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0, &uprobe_opts);
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if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname, "attach_uprobe_byname"))
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goto cleanup;
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/* verify auto-attach works */
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skel->links.handle_uretprobe_byname =
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bpf_program__attach(skel->progs.handle_uretprobe_byname);
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if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname, "attach_uretprobe_byname"))
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goto cleanup;
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/* test attach by name for a library function, using the library
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* as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo().
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*/
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uprobe_opts.func_name = "malloc";
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uprobe_opts.retprobe = false;
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skel->links.handle_uprobe_byname2 =
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bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2,
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0 /* this pid */,
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"libc.so.6",
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0, &uprobe_opts);
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if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2"))
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goto cleanup;
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uprobe_opts.func_name = "free";
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uprobe_opts.retprobe = true;
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skel->links.handle_uretprobe_byname2 =
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bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2,
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-1 /* any pid */,
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"libc.so.6",
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0, &uprobe_opts);
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if (!ASSERT_OK_PTR(skel->links.handle_uretprobe_byname2, "attach_uretprobe_byname2"))
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goto cleanup;
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/* trigger & validate kprobe && kretprobe */
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usleep(1);
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if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res",
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"wrong kprobe res: %d\n", skel->bss->kprobe_res))
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goto cleanup;
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if (CHECK(skel->bss->kretprobe_res != 2, "check_kretprobe_res",
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"wrong kretprobe res: %d\n", skel->bss->kretprobe_res))
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goto cleanup;
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/* trigger & validate shared library u[ret]probes attached by name */
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mem = malloc(1);
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free(mem);
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/* trigger & validate uprobe & uretprobe */
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trigger_func();
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if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
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"wrong uprobe res: %d\n", skel->bss->uprobe_res))
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goto cleanup;
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if (CHECK(skel->bss->uretprobe_res != 4, "check_uretprobe_res",
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"wrong uretprobe res: %d\n", skel->bss->uretprobe_res))
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goto cleanup;
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/* trigger & validate uprobe attached by name */
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trigger_func2();
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ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
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ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
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ASSERT_EQ(skel->bss->uprobe_res, 3, "check_uprobe_res");
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ASSERT_EQ(skel->bss->uretprobe_res, 4, "check_uretprobe_res");
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ASSERT_EQ(skel->bss->uprobe_byname_res, 5, "check_uprobe_byname_res");
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ASSERT_EQ(skel->bss->uretprobe_byname_res, 6, "check_uretprobe_byname_res");
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ASSERT_EQ(skel->bss->uprobe_byname2_res, 7, "check_uprobe_byname2_res");
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ASSERT_EQ(skel->bss->uretprobe_byname2_res, 8, "check_uretprobe_byname2_res");
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cleanup:
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test_attach_probe__destroy(skel);
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@ -10,6 +10,10 @@ int kprobe_res = 0;
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int kretprobe_res = 0;
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int uprobe_res = 0;
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int uretprobe_res = 0;
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int uprobe_byname_res = 0;
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int uretprobe_byname_res = 0;
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int uprobe_byname2_res = 0;
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int uretprobe_byname2_res = 0;
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SEC("kprobe/sys_nanosleep")
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int handle_kprobe(struct pt_regs *ctx)
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@ -25,18 +29,51 @@ int BPF_KRETPROBE(handle_kretprobe)
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return 0;
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}
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SEC("uprobe/trigger_func")
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SEC("uprobe")
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int handle_uprobe(struct pt_regs *ctx)
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{
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uprobe_res = 3;
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return 0;
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}
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SEC("uretprobe/trigger_func")
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SEC("uretprobe")
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int handle_uretprobe(struct pt_regs *ctx)
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{
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uretprobe_res = 4;
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return 0;
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}
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SEC("uprobe")
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int handle_uprobe_byname(struct pt_regs *ctx)
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{
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uprobe_byname_res = 5;
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return 0;
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}
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/* use auto-attach format for section definition. */
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SEC("uretprobe//proc/self/exe:trigger_func2")
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int handle_uretprobe_byname(struct pt_regs *ctx)
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{
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uretprobe_byname_res = 6;
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return 0;
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}
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SEC("uprobe")
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int handle_uprobe_byname2(struct pt_regs *ctx)
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{
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unsigned int size = PT_REGS_PARM1(ctx);
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/* verify malloc size */
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if (size == 1)
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uprobe_byname2_res = 7;
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return 0;
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}
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SEC("uretprobe")
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int handle_uretprobe_byname2(struct pt_regs *ctx)
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{
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uretprobe_byname2_res = 8;
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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