Commit acbd0620 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann

selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls

Add vmlinux.h generation to selftest/bpf's Makefile. Use it from newly added
test_vmlinux to trace nanosleep syscall using 5 different types of programs:
  - tracepoint;
  - raw tracepoint;
  - raw tracepoint w/ direct memory reads (tp_btf);
  - kprobe;
  - fentry.

These programs are realistic variants of real-life tracing programs,
excercising vmlinux.h's usage with tracing applications.
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200313172336.1879637-5-andriin@fb.com
parent b8ebce86
......@@ -136,7 +136,7 @@ VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux) \
../../../../vmlinux \
/sys/kernel/btf/vmlinux \
/boot/vmlinux-$(shell uname -r)
VMLINUX_BTF:= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
VMLINUX_BTF := $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
$(OUTPUT)/runqslower: $(BPFOBJ)
$(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \
......@@ -177,6 +177,10 @@ $(BUILD_DIR)/libbpf $(BUILD_DIR)/bpftool $(INCLUDE_DIR):
$(call msg,MKDIR,,$@)
mkdir -p $@
$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) | $(BPFTOOL) $(INCLUDE_DIR)
$(call msg,GEN,,$@)
$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
# Get Clang's default includes on this system, as opposed to those seen by
# '-target bpf'. This fixes "missing" files on some architectures/distros,
# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
......@@ -285,6 +289,7 @@ $(TRUNNER_BPF_PROGS_DIR)$(if $2,-)$2-bpfobjs := y
$(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \
$(TRUNNER_BPF_PROGS_DIR)/%.c \
$(TRUNNER_BPF_PROGS_DIR)/*.h \
$$(INCLUDE_DIR)/vmlinux.h \
$$(BPFOBJ) | $(TRUNNER_OUTPUT)
$$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@, \
$(TRUNNER_BPF_CFLAGS), \
......
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include <test_progs.h>
#include <time.h>
#include "test_vmlinux.skel.h"
#define MY_TV_NSEC 1337
static void nsleep()
{
struct timespec ts = { .tv_nsec = MY_TV_NSEC };
(void)nanosleep(&ts, NULL);
}
void test_vmlinux(void)
{
int duration = 0, err;
struct test_vmlinux* skel;
struct test_vmlinux__bss *bss;
skel = test_vmlinux__open_and_load();
if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
return;
bss = skel->bss;
err = test_vmlinux__attach(skel);
if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
goto cleanup;
/* trigger everything */
nsleep();
CHECK(!bss->tp_called, "tp", "not called\n");
CHECK(!bss->raw_tp_called, "raw_tp", "not called\n");
CHECK(!bss->tp_btf_called, "tp_btf", "not called\n");
CHECK(!bss->kprobe_called, "kprobe", "not called\n");
CHECK(!bss->fentry_called, "fentry", "not called\n");
cleanup:
test_vmlinux__destroy(skel);
}
// 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;
if (args->id != __NR_nanosleep)
return 0;
ts = (void *)args->args[0];
if (BPF_CORE_READ(ts, 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;
if (id != __NR_nanosleep)
return 0;
ts = (void *)PT_REGS_PARM1_CORE(regs);
if (BPF_CORE_READ(ts, 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;
if (id != __NR_nanosleep)
return 0;
ts = (void *)PT_REGS_PARM1_CORE(regs);
if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
return 0;
tp_btf_called = true;
return 0;
}
SEC("kprobe/hrtimer_nanosleep")
int BPF_KPROBE(handle__kprobe,
ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
{
if (rqtp == MY_TV_NSEC)
kprobe_called = true;
return 0;
}
SEC("fentry/hrtimer_nanosleep")
int BPF_PROG(handle__fentry,
ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
{
if (rqtp == MY_TV_NSEC)
fentry_called = true;
return 0;
}
char _license[] SEC("license") = "GPL";
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