linux/tools/testing/selftests/bpf/progs/test_module_attach.c
Steven Rostedt ac01fa73f5 tracepoint: Have tracepoints created with DECLARE_TRACE() have _tp suffix
Most tracepoints in the kernel are created with TRACE_EVENT(). The
TRACE_EVENT() macro (and DECLARE_EVENT_CLASS() and DEFINE_EVENT() where in
reality, TRACE_EVENT() is just a helper macro that calls those other two
macros), will create not only a tracepoint (the function trace_<event>()
used in the kernel), it also exposes the tracepoint to user space along
with defining what fields will be saved by that tracepoint.

There are a few places that tracepoints are created in the kernel that are
not exposed to userspace via tracefs. They can only be accessed from code
within the kernel. These tracepoints are created with DEFINE_TRACE()

Most of these tracepoints end with "_tp". This is useful as when the
developer sees that, they know that the tracepoint is for in-kernel only
(meaning it can only be accessed inside the kernel, either directly by the
kernel or indirectly via modules and BPF programs) and is not exposed to
user space.

Instead of making this only a process to add "_tp", enforce it by making
the DECLARE_TRACE() append the "_tp" suffix to the tracepoint. This
requires adding DECLARE_TRACE_EVENT() macros for the TRACE_EVENT() macro
to use that keeps the original name.

Link: https://lore.kernel.org/all/20250418083351.20a60e64@gandalf.local.home/

Cc: netdev <netdev@vger.kernel.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250510163730.092fad5b@gandalf.local.home
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-05-14 11:19:32 -04:00

142 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#include "../test_kmods/bpf_testmod.h"
__u32 raw_tp_read_sz = 0;
SEC("raw_tp/bpf_testmod_test_read")
int BPF_PROG(handle_raw_tp,
struct task_struct *task, struct bpf_testmod_test_read_ctx *read_ctx)
{
raw_tp_read_sz = BPF_CORE_READ(read_ctx, len);
return 0;
}
__u32 raw_tp_bare_write_sz = 0;
SEC("raw_tp/bpf_testmod_test_write_bare_tp")
int BPF_PROG(handle_raw_tp_bare,
struct task_struct *task, struct bpf_testmod_test_write_ctx *write_ctx)
{
raw_tp_bare_write_sz = BPF_CORE_READ(write_ctx, len);
return 0;
}
int raw_tp_writable_bare_in_val = 0;
int raw_tp_writable_bare_early_ret = 0;
int raw_tp_writable_bare_out_val = 0;
SEC("raw_tp.w/bpf_testmod_test_writable_bare_tp")
int BPF_PROG(handle_raw_tp_writable_bare,
struct bpf_testmod_test_writable_ctx *writable)
{
raw_tp_writable_bare_in_val = writable->val;
writable->early_ret = raw_tp_writable_bare_early_ret;
writable->val = raw_tp_writable_bare_out_val;
return 0;
}
__u32 tp_btf_read_sz = 0;
SEC("tp_btf/bpf_testmod_test_read")
int BPF_PROG(handle_tp_btf,
struct task_struct *task, struct bpf_testmod_test_read_ctx *read_ctx)
{
tp_btf_read_sz = read_ctx->len;
return 0;
}
__u32 fentry_read_sz = 0;
SEC("fentry/bpf_testmod_test_read")
int BPF_PROG(handle_fentry,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
{
fentry_read_sz = len;
return 0;
}
__u32 fentry_manual_read_sz = 0;
SEC("fentry")
int BPF_PROG(handle_fentry_manual,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
{
fentry_manual_read_sz = len;
return 0;
}
__u32 fentry_explicit_read_sz = 0;
SEC("fentry/bpf_testmod:bpf_testmod_test_read")
int BPF_PROG(handle_fentry_explicit,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
{
fentry_explicit_read_sz = len;
return 0;
}
__u32 fentry_explicit_manual_read_sz = 0;
SEC("fentry")
int BPF_PROG(handle_fentry_explicit_manual,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
{
fentry_explicit_manual_read_sz = len;
return 0;
}
__u32 fexit_read_sz = 0;
int fexit_ret = 0;
SEC("fexit/bpf_testmod_test_read")
int BPF_PROG(handle_fexit,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len,
int ret)
{
fexit_read_sz = len;
fexit_ret = ret;
return 0;
}
SEC("fexit/bpf_testmod_return_ptr")
int BPF_PROG(handle_fexit_ret, int arg, struct file *ret)
{
long buf = 0;
bpf_probe_read_kernel(&buf, 8, ret);
bpf_probe_read_kernel(&buf, 8, (char *)ret + 256);
*(volatile int *)ret;
*(volatile int *)&ret->f_mode;
return 0;
}
__u32 fmod_ret_read_sz = 0;
SEC("fmod_ret/bpf_testmod_test_read")
int BPF_PROG(handle_fmod_ret,
struct file *file, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf, loff_t off, size_t len)
{
fmod_ret_read_sz = len;
return 0; /* don't override the exit code */
}
SEC("kprobe.multi/bpf_testmod_test_read")
int BPF_PROG(kprobe_multi)
{
return 0;
}
char _license[] SEC("license") = "GPL";