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samples/bpf: convert to vmlinux.h with tracing programs
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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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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DanielTimLee authored and Alexei Starovoitov committed Aug 21, 2023
1 parent 34f6e38 commit e7e6c77
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Showing 10 changed files with 25 additions and 62 deletions.
2 changes: 2 additions & 0 deletions samples/bpf/net_shared.h
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Expand Up @@ -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)
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21 changes: 6 additions & 15 deletions samples/bpf/offwaketime_kern.c
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Expand Up @@ -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; \
Expand Down Expand Up @@ -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;
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10 changes: 6 additions & 4 deletions samples/bpf/spintest_kern.c
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Expand Up @@ -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);
Expand Down Expand Up @@ -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)
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29 changes: 2 additions & 27 deletions samples/bpf/test_overhead_tp.bpf.c
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Expand Up @@ -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;
}
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5 changes: 2 additions & 3 deletions samples/bpf/tracex1_kern.c
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Expand Up @@ -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>
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4 changes: 1 addition & 3 deletions samples/bpf/tracex3_kern.c
Original file line number Diff line number Diff line change
Expand Up @@ -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>

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3 changes: 1 addition & 2 deletions samples/bpf/tracex4_kern.c
Original file line number Diff line number Diff line change
Expand Up @@ -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>

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7 changes: 3 additions & 4 deletions samples/bpf/tracex5_kern.c
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Expand Up @@ -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 {
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3 changes: 1 addition & 2 deletions samples/bpf/tracex6_kern.c
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@@ -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 {
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3 changes: 1 addition & 2 deletions samples/bpf/tracex7_kern.c
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@@ -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>

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