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olsajiriAlexei Starovoitov
olsajiri
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Alexei Starovoitov
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selftests/bpf: Add kprobe_multi attach test
Adding kprobe_multi attach test that uses new fprobe interface to attach kprobe program to multiple functions. The test is attaching programs to bpf_fentry_test* functions and uses single trampoline program bpf_prog_test_run to trigger bpf_fentry_test* functions. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
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‎tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c

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// SPDX-License-Identifier: GPL-2.0
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#include <test_progs.h>
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#include "kprobe_multi.skel.h"
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#include "trace_helpers.h"
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static void kprobe_multi_test_run(struct kprobe_multi *skel)
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{
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LIBBPF_OPTS(bpf_test_run_opts, topts);
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int err, prog_fd;
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prog_fd = bpf_program__fd(skel->progs.trigger);
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err = bpf_prog_test_run_opts(prog_fd, &topts);
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ASSERT_OK(err, "test_run");
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ASSERT_EQ(topts.retval, 0, "test_run");
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ASSERT_EQ(skel->bss->kprobe_test1_result, 1, "kprobe_test1_result");
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ASSERT_EQ(skel->bss->kprobe_test2_result, 1, "kprobe_test2_result");
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ASSERT_EQ(skel->bss->kprobe_test3_result, 1, "kprobe_test3_result");
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ASSERT_EQ(skel->bss->kprobe_test4_result, 1, "kprobe_test4_result");
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ASSERT_EQ(skel->bss->kprobe_test5_result, 1, "kprobe_test5_result");
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ASSERT_EQ(skel->bss->kprobe_test6_result, 1, "kprobe_test6_result");
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ASSERT_EQ(skel->bss->kprobe_test7_result, 1, "kprobe_test7_result");
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ASSERT_EQ(skel->bss->kprobe_test8_result, 1, "kprobe_test8_result");
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ASSERT_EQ(skel->bss->kretprobe_test1_result, 1, "kretprobe_test1_result");
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ASSERT_EQ(skel->bss->kretprobe_test2_result, 1, "kretprobe_test2_result");
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ASSERT_EQ(skel->bss->kretprobe_test3_result, 1, "kretprobe_test3_result");
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ASSERT_EQ(skel->bss->kretprobe_test4_result, 1, "kretprobe_test4_result");
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ASSERT_EQ(skel->bss->kretprobe_test5_result, 1, "kretprobe_test5_result");
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ASSERT_EQ(skel->bss->kretprobe_test6_result, 1, "kretprobe_test6_result");
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ASSERT_EQ(skel->bss->kretprobe_test7_result, 1, "kretprobe_test7_result");
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ASSERT_EQ(skel->bss->kretprobe_test8_result, 1, "kretprobe_test8_result");
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}
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static void test_skel_api(void)
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{
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struct kprobe_multi *skel = NULL;
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int err;
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skel = kprobe_multi__open_and_load();
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if (!ASSERT_OK_PTR(skel, "kprobe_multi__open_and_load"))
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goto cleanup;
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skel->bss->pid = getpid();
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err = kprobe_multi__attach(skel);
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if (!ASSERT_OK(err, "kprobe_multi__attach"))
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goto cleanup;
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kprobe_multi_test_run(skel);
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cleanup:
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kprobe_multi__destroy(skel);
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}
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static void test_link_api(struct bpf_link_create_opts *opts)
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{
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int prog_fd, link1_fd = -1, link2_fd = -1;
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struct kprobe_multi *skel = NULL;
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skel = kprobe_multi__open_and_load();
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if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load"))
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goto cleanup;
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skel->bss->pid = getpid();
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prog_fd = bpf_program__fd(skel->progs.test_kprobe);
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link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts);
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if (!ASSERT_GE(link1_fd, 0, "link_fd"))
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goto cleanup;
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opts->kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN;
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prog_fd = bpf_program__fd(skel->progs.test_kretprobe);
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link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, opts);
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if (!ASSERT_GE(link2_fd, 0, "link_fd"))
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goto cleanup;
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kprobe_multi_test_run(skel);
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cleanup:
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if (link1_fd != -1)
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close(link1_fd);
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if (link2_fd != -1)
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close(link2_fd);
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kprobe_multi__destroy(skel);
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}
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#define GET_ADDR(__sym, __addr) ({ \
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__addr = ksym_get_addr(__sym); \
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if (!ASSERT_NEQ(__addr, 0, "kallsyms load failed for " #__sym)) \
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return; \
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})
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static void test_link_api_addrs(void)
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{
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LIBBPF_OPTS(bpf_link_create_opts, opts);
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unsigned long long addrs[8];
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GET_ADDR("bpf_fentry_test1", addrs[0]);
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GET_ADDR("bpf_fentry_test2", addrs[1]);
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GET_ADDR("bpf_fentry_test3", addrs[2]);
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GET_ADDR("bpf_fentry_test4", addrs[3]);
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GET_ADDR("bpf_fentry_test5", addrs[4]);
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GET_ADDR("bpf_fentry_test6", addrs[5]);
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GET_ADDR("bpf_fentry_test7", addrs[6]);
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GET_ADDR("bpf_fentry_test8", addrs[7]);
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opts.kprobe_multi.addrs = (const unsigned long*) addrs;
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opts.kprobe_multi.cnt = ARRAY_SIZE(addrs);
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test_link_api(&opts);
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}
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static void test_link_api_syms(void)
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{
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LIBBPF_OPTS(bpf_link_create_opts, opts);
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const char *syms[8] = {
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"bpf_fentry_test1",
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"bpf_fentry_test2",
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"bpf_fentry_test3",
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"bpf_fentry_test4",
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"bpf_fentry_test5",
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"bpf_fentry_test6",
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"bpf_fentry_test7",
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"bpf_fentry_test8",
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};
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opts.kprobe_multi.syms = syms;
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opts.kprobe_multi.cnt = ARRAY_SIZE(syms);
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test_link_api(&opts);
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}
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void test_kprobe_multi_test(void)
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{
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if (!ASSERT_OK(load_kallsyms(), "load_kallsyms"))
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return;
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if (test__start_subtest("skel_api"))
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test_skel_api();
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if (test__start_subtest("link_api_addrs"))
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test_link_api_syms();
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if (test__start_subtest("link_api_syms"))
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test_link_api_addrs();
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}

‎tools/testing/selftests/bpf/progs/kprobe_multi.c

Lines changed: 95 additions & 0 deletions
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <stdbool.h>
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char _license[] SEC("license") = "GPL";
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extern const void bpf_fentry_test1 __ksym;
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extern const void bpf_fentry_test2 __ksym;
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extern const void bpf_fentry_test3 __ksym;
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extern const void bpf_fentry_test4 __ksym;
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extern const void bpf_fentry_test5 __ksym;
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extern const void bpf_fentry_test6 __ksym;
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extern const void bpf_fentry_test7 __ksym;
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extern const void bpf_fentry_test8 __ksym;
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int pid = 0;
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__u64 kprobe_test1_result = 0;
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__u64 kprobe_test2_result = 0;
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__u64 kprobe_test3_result = 0;
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__u64 kprobe_test4_result = 0;
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__u64 kprobe_test5_result = 0;
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__u64 kprobe_test6_result = 0;
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__u64 kprobe_test7_result = 0;
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__u64 kprobe_test8_result = 0;
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__u64 kretprobe_test1_result = 0;
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__u64 kretprobe_test2_result = 0;
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__u64 kretprobe_test3_result = 0;
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__u64 kretprobe_test4_result = 0;
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__u64 kretprobe_test5_result = 0;
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__u64 kretprobe_test6_result = 0;
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__u64 kretprobe_test7_result = 0;
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__u64 kretprobe_test8_result = 0;
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static void kprobe_multi_check(void *ctx, bool is_return)
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{
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if (bpf_get_current_pid_tgid() >> 32 != pid)
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return;
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__u64 addr = bpf_get_func_ip(ctx);
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#define SET(__var, __addr) ({ \
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if ((const void *) addr == __addr) \
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__var = 1; \
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})
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if (is_return) {
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SET(kretprobe_test1_result, &bpf_fentry_test1);
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SET(kretprobe_test2_result, &bpf_fentry_test2);
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SET(kretprobe_test3_result, &bpf_fentry_test3);
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SET(kretprobe_test4_result, &bpf_fentry_test4);
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SET(kretprobe_test5_result, &bpf_fentry_test5);
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SET(kretprobe_test6_result, &bpf_fentry_test6);
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SET(kretprobe_test7_result, &bpf_fentry_test7);
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SET(kretprobe_test8_result, &bpf_fentry_test8);
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} else {
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SET(kprobe_test1_result, &bpf_fentry_test1);
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SET(kprobe_test2_result, &bpf_fentry_test2);
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SET(kprobe_test3_result, &bpf_fentry_test3);
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SET(kprobe_test4_result, &bpf_fentry_test4);
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SET(kprobe_test5_result, &bpf_fentry_test5);
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SET(kprobe_test6_result, &bpf_fentry_test6);
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SET(kprobe_test7_result, &bpf_fentry_test7);
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SET(kprobe_test8_result, &bpf_fentry_test8);
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}
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#undef SET
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}
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/*
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* No tests in here, just to trigger 'bpf_fentry_test*'
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* through tracing test_run
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*/
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SEC("fentry/bpf_modify_return_test")
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int BPF_PROG(trigger)
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{
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return 0;
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}
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SEC("kprobe.multi/bpf_fentry_tes??")
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int test_kprobe(struct pt_regs *ctx)
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{
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kprobe_multi_check(ctx, false);
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return 0;
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}
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SEC("kretprobe.multi/bpf_fentry_test*")
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int test_kretprobe(struct pt_regs *ctx)
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{
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kprobe_multi_check(ctx, true);
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return 0;
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}

‎tools/testing/selftests/bpf/trace_helpers.c

Lines changed: 7 additions & 0 deletions
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@@ -34,6 +34,13 @@ int load_kallsyms(void)
3434
if (!f)
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return -ENOENT;
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/*
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* This is called/used from multiplace places,
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* load symbols just once.
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*/
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if (sym_cnt)
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return 0;
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3744
while (fgets(buf, sizeof(buf), f)) {
3845
if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
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break;

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