samples/bpf: convert to vmlinux.h with tracing programs

This commit replaces separate headers with a single vmlinux.h to
tracing programs. Thanks to that, we no longer need to define the
argument structure for tracing programs directly. For example, argument
for the sched_switch tracpepoint (sched_switch_args) can be replaced
with the vmlinux.h provided trace_event_raw_sched_switch.

Additional defines have been added to the BPF program either directly
or through the inclusion of net_shared.h. Defined values are
PERF_MAX_STACK_DEPTH, IFNAMSIZ constants and __stringify() macro. This
change enables the BPF program to access internal structures with BTF
generated "vmlinux.h" header.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: DanielTimLee

samples/bpf/net_shared.h

@@ -17,6 +17,8 @@
 #define TC_ACT_OK		0
 #define TC_ACT_SHOT		2
 
+#define IFNAMSIZ 16
+
 #if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
 	__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define bpf_ntohs(x)		__builtin_bswap16(x)

samples/bpf/offwaketime_kern.c

@@ -4,14 +4,15 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <uapi/linux/bpf.h>
-#include <uapi/linux/ptrace.h>
-#include <uapi/linux/perf_event.h>
+#include "vmlinux.h"
 #include <linux/version.h>
-#include <linux/sched.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH         127
+#endif
+
 #define _(P)                                                                   \
 	({                                                                     \
 		typeof(P) val;                                                 \
@@ -111,18 +112,8 @@ static inline int update_counts(void *ctx, u32 pid, u64 delta)
 
 #if 1
 /* taken from /sys/kernel/tracing/events/sched/sched_switch/format */
-struct sched_switch_args {
-	unsigned long long pad;
-	char prev_comm[TASK_COMM_LEN];
-	int prev_pid;
-	int prev_prio;
-	long long prev_state;
-	char next_comm[TASK_COMM_LEN];
-	int next_pid;
-	int next_prio;
-};
 SEC("tracepoint/sched/sched_switch")
-int oncpu(struct sched_switch_args *ctx)
+int oncpu(struct trace_event_raw_sched_switch *ctx)
 {
 	/* record previous thread sleep time */
 	u32 pid = ctx->prev_pid;

samples/bpf/spintest_kern.c

@@ -4,14 +4,15 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <linux/skbuff.h>
-#include <linux/netdevice.h>
+#include "vmlinux.h"
 #include <linux/version.h>
-#include <uapi/linux/bpf.h>
-#include <uapi/linux/perf_event.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH         127
+#endif
+
 struct {
 	__uint(type, BPF_MAP_TYPE_HASH);
 	__type(key, long);
@@ -60,6 +61,7 @@ SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
 SEC("kprobe/_raw_spin_trylock")PROG(p12)
 SEC("kprobe/_raw_spin_lock")PROG(p13)
 SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
+
 /* and to inner bpf helpers */
 SEC("kprobe/htab_map_update_elem")PROG(p15)
 SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)

samples/bpf/test_overhead_tp.bpf.c

@@ -8,40 +8,15 @@
 #include <bpf/bpf_helpers.h>
 
 /* from /sys/kernel/tracing/events/task/task_rename/format */
-struct task_rename {
-	__u64 pad;
-	__u32 pid;
-	char oldcomm[TASK_COMM_LEN];
-	char newcomm[TASK_COMM_LEN];
-	__u16 oom_score_adj;
-};
 SEC("tracepoint/task/task_rename")
-int prog(struct task_rename *ctx)
+int prog(struct trace_event_raw_task_rename *ctx)
 {
 	return 0;
 }
 
 /* from /sys/kernel/tracing/events/fib/fib_table_lookup/format */
-struct fib_table_lookup {
-	__u64 pad;
-	__u32 tb_id;
-	int err;
-	int oif;
-	int iif;
-	__u8 proto;
-	__u8 tos;
-	__u8 scope;
-	__u8 flags;
-	__u8 src[4];
-	__u8 dst[4];
-	__u8 gw4[4];
-	__u8 gw6[16];
-	__u16 sport;
-	__u16 dport;
-	char name[16];
-};
 SEC("tracepoint/fib/fib_table_lookup")
-int prog2(struct fib_table_lookup *ctx)
+int prog2(struct trace_event_raw_fib_table_lookup *ctx)
 {
 	return 0;
 }

samples/bpf/tracex1_kern.c

@@ -4,9 +4,8 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <linux/skbuff.h>
-#include <linux/netdevice.h>
-#include <uapi/linux/bpf.h>
+#include "vmlinux.h"
+#include "net_shared.h"
 #include <linux/version.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>

samples/bpf/tracex3_kern.c

@@ -4,10 +4,8 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <linux/skbuff.h>
-#include <linux/netdevice.h>
+#include "vmlinux.h"
 #include <linux/version.h>
-#include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 

samples/bpf/tracex4_kern.c

@@ -4,9 +4,8 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <linux/ptrace.h>
+#include "vmlinux.h"
 #include <linux/version.h>
-#include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 

samples/bpf/tracex5_kern.c

@@ -4,15 +4,14 @@
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  */
-#include <linux/ptrace.h>
+#include "vmlinux.h"
+#include "syscall_nrs.h"
 #include <linux/version.h>
-#include <uapi/linux/bpf.h>
-#include <uapi/linux/seccomp.h>
 #include <uapi/linux/unistd.h>
-#include "syscall_nrs.h"
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 
+#define __stringify(x) #x
 #define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
 
 struct {

samples/bpf/tracex6_kern.c

@@ -1,6 +1,5 @@
-#include <linux/ptrace.h>
+#include "vmlinux.h"
 #include <linux/version.h>
-#include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
 struct {

samples/bpf/tracex7_kern.c

@@ -1,5 +1,4 @@
-#include <uapi/linux/ptrace.h>
-#include <uapi/linux/bpf.h>
+#include "vmlinux.h"
 #include <linux/version.h>
 #include <bpf/bpf_helpers.h>