Commit e7e6c774 authored by Daniel T. Lee's avatar Daniel T. Lee Committed by Alexei Starovoitov
Browse files

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: default avatarDaniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-3-danieltimlee@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 34f6e38f

samples/bpf/net_shared.h

+2 −0
Original line number Diff line number Diff line
@@ -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

+6 −15
Original line number Diff line number Diff line
@@ -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

+6 −4
Original line number Diff line number Diff line
@@ -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

+2 −27
Original line number Diff line number Diff line
@@ -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

+2 −3
Original line number Diff line number Diff line
@@ -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>