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tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN

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As the sched:sched_switch tracepoint args are derived from the kernel,
we'd better make it same with the kernel.  So the macro TASK_COMM_LEN is
converted to type enum, then all the BPF programs can get it through
BTF.

The BPF program which wants to use TASK_COMM_LEN should include the
header vmlinux.h.  Regarding the test_stacktrace_map and
test_tracepoint, as the type defined in linux/bpf.h are also defined in
vmlinux.h, so we don't need to include linux/bpf.h again.

Link: https://lkml.kernel.org/r/20211120112738.45980-8-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yafang Shao 2022-01-19 18:08:40 -08:00 committed by Linus Torvalds
parent 4cfb943537
commit 3087c61ed2
3 changed files with 13 additions and 8 deletions
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9
include/linux/sched.h
View File

@ -274,8 +274,13 @@ struct task_group;
#define get_current_state() READ_ONCE(current->__state)
/* Task command name length: */
#define TASK_COMM_LEN 16
/*
* Define the task command name length as enum, then it can be visible to
* BPF programs.
*/
enum {
TASK_COMM_LEN = 16,
};
extern void scheduler_tick(void);

6
tools/testing/selftests/bpf/progs/test_stacktrace_map.c
View File

@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook
#include <linux/bpf.h>
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#ifndef PERF_MAX_STACK_DEPTH
@ -41,11 +41,11 @@ struct {
/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
struct sched_switch_args {
unsigned long long pad;
char prev_comm[16];
char prev_comm[TASK_COMM_LEN];
int prev_pid;
int prev_prio;
long long prev_state;
char next_comm[16];
char next_comm[TASK_COMM_LEN];
int next_pid;
int next_prio;
};

6
tools/testing/selftests/bpf/progs/test_tracepoint.c
View File

@ -1,17 +1,17 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Facebook
#include <linux/bpf.h>
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
struct sched_switch_args {
unsigned long long pad;
char prev_comm[16];
char prev_comm[TASK_COMM_LEN];
int prev_pid;
int prev_prio;
long long prev_state;
char next_comm[16];
char next_comm[TASK_COMM_LEN];
int next_pid;
int next_prio;
};