linux-stable/tools/testing/selftests/bpf/progs/test_vmlinux.c

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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <asm/unistd.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#define MY_TV_NSEC 1337
bool tp_called = false;
bool raw_tp_called = false;
bool tp_btf_called = false;
bool kprobe_called = false;
bool fentry_called = false;
SEC("tp/syscalls/sys_enter_nanosleep")
int handle__tp(struct trace_event_raw_sys_enter *args)
{
struct __kernel_timespec *ts;
long tv_nsec;
if (args->id != __NR_nanosleep)
return 0;
ts = (void *)args->args[0];
if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
tv_nsec != MY_TV_NSEC)
return 0;
tp_called = true;
return 0;
}
SEC("raw_tp/sys_enter")
int BPF_PROG(handle__raw_tp, struct pt_regs *regs, long id)
{
struct __kernel_timespec *ts;
long tv_nsec;
if (id != __NR_nanosleep)
return 0;
ts = (void *)PT_REGS_PARM1_CORE(regs);
if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
tv_nsec != MY_TV_NSEC)
return 0;
raw_tp_called = true;
return 0;
}
SEC("tp_btf/sys_enter")
int BPF_PROG(handle__tp_btf, struct pt_regs *regs, long id)
{
struct __kernel_timespec *ts;
long tv_nsec;
if (id != __NR_nanosleep)
return 0;
ts = (void *)PT_REGS_PARM1_CORE(regs);
if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
tv_nsec != MY_TV_NSEC)
return 0;
tp_btf_called = true;
return 0;
}
selftests/bpf: Switch test_vmlinux to use hrtimer_range_start_ns. The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But in a kernel built by clang, which performs more aggresive inlining, that function gets inlined into its caller SyS_nanosleep. Therefore, even though fentry and kprobe do hook on the function, they aren't triggered by the call to nanosleep in the test. A possible fix is switching to use a function that is less likely to be inlined, such as hrtimer_range_start_ns. The EXPORT_SYMBOL functions shouldn't be inlined based on the description of [1], therefore safe to use for this test. Also the arguments of this function include the duration of sleep, therefore suitable for test verification. [1] af3b56289be1 time: don't inline EXPORT_SYMBOL functions Tested: In a clang build kernel, before this change, the test fails: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After switching to hrtimer_range_start_ns, the test passes: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200701175315.1161242-1-haoluo@google.com
2020-07-01 17:53:15 +00:00
SEC("kprobe/hrtimer_start_range_ns")
int BPF_KPROBE(handle__kprobe, struct hrtimer *timer, ktime_t tim, u64 delta_ns,
const enum hrtimer_mode mode)
{
selftests/bpf: Switch test_vmlinux to use hrtimer_range_start_ns. The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But in a kernel built by clang, which performs more aggresive inlining, that function gets inlined into its caller SyS_nanosleep. Therefore, even though fentry and kprobe do hook on the function, they aren't triggered by the call to nanosleep in the test. A possible fix is switching to use a function that is less likely to be inlined, such as hrtimer_range_start_ns. The EXPORT_SYMBOL functions shouldn't be inlined based on the description of [1], therefore safe to use for this test. Also the arguments of this function include the duration of sleep, therefore suitable for test verification. [1] af3b56289be1 time: don't inline EXPORT_SYMBOL functions Tested: In a clang build kernel, before this change, the test fails: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After switching to hrtimer_range_start_ns, the test passes: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200701175315.1161242-1-haoluo@google.com
2020-07-01 17:53:15 +00:00
if (tim == MY_TV_NSEC)
kprobe_called = true;
return 0;
}
selftests/bpf: Switch test_vmlinux to use hrtimer_range_start_ns. The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But in a kernel built by clang, which performs more aggresive inlining, that function gets inlined into its caller SyS_nanosleep. Therefore, even though fentry and kprobe do hook on the function, they aren't triggered by the call to nanosleep in the test. A possible fix is switching to use a function that is less likely to be inlined, such as hrtimer_range_start_ns. The EXPORT_SYMBOL functions shouldn't be inlined based on the description of [1], therefore safe to use for this test. Also the arguments of this function include the duration of sleep, therefore suitable for test verification. [1] af3b56289be1 time: don't inline EXPORT_SYMBOL functions Tested: In a clang build kernel, before this change, the test fails: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After switching to hrtimer_range_start_ns, the test passes: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200701175315.1161242-1-haoluo@google.com
2020-07-01 17:53:15 +00:00
SEC("fentry/hrtimer_start_range_ns")
int BPF_PROG(handle__fentry, struct hrtimer *timer, ktime_t tim, u64 delta_ns,
const enum hrtimer_mode mode)
{
selftests/bpf: Switch test_vmlinux to use hrtimer_range_start_ns. The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But in a kernel built by clang, which performs more aggresive inlining, that function gets inlined into its caller SyS_nanosleep. Therefore, even though fentry and kprobe do hook on the function, they aren't triggered by the call to nanosleep in the test. A possible fix is switching to use a function that is less likely to be inlined, such as hrtimer_range_start_ns. The EXPORT_SYMBOL functions shouldn't be inlined based on the description of [1], therefore safe to use for this test. Also the arguments of this function include the duration of sleep, therefore suitable for test verification. [1] af3b56289be1 time: don't inline EXPORT_SYMBOL functions Tested: In a clang build kernel, before this change, the test fails: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After switching to hrtimer_range_start_ns, the test passes: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <haoluo@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200701175315.1161242-1-haoluo@google.com
2020-07-01 17:53:15 +00:00
if (tim == MY_TV_NSEC)
fentry_called = true;
return 0;
}
char _license[] SEC("license") = "GPL";