mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-02 16:44:10 +08:00
9c2136be08
Commitfa2c3254d7(sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20) added a new prev_state argument to the sched_switch tracepoint, before the prev task_struct pointer. This reordering of arguments broke BPF programs that use the raw tracepoint (e.g. tp_btf programs). The type of the second argument has changed and existing programs that assume a task_struct* argument (e.g. for bpf_task_storage access) will now fail to verify. If we instead append the new argument to the end, all existing programs would continue to work and can conditionally extract the prev_state argument on supported kernel versions. Fixes:fa2c3254d7(sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20) Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com
97 lines
2.4 KiB
C
97 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
/*
|
|
* Like the headers that use TRACE_EVENT(), the TRACE_CUSTOM_EVENT()
|
|
* needs a header that allows for multiple inclusions.
|
|
*
|
|
* Test for a unique name (here we have _TRACE_CUSTOM_SCHED_H),
|
|
* also allowing to continue if TRACE_CUSTOM_MULTI_READ is defined.
|
|
*/
|
|
#if !defined(_TRACE_CUSTOM_SCHED_H) || defined(TRACE_CUSTOM_MULTI_READ)
|
|
#define _TRACE_CUSTOM_SCHED_H
|
|
|
|
/* Include linux/trace_events.h for initial defines of TRACE_CUSTOM_EVENT() */
|
|
#include <linux/trace_events.h>
|
|
|
|
/*
|
|
* TRACE_CUSTOM_EVENT() is just like TRACE_EVENT(). The first parameter
|
|
* is the event name of an existing event where the TRACE_EVENT has been included
|
|
* in the C file before including this file.
|
|
*/
|
|
TRACE_CUSTOM_EVENT(sched_switch,
|
|
|
|
/*
|
|
* The TP_PROTO() and TP_ARGS must match the trace event
|
|
* that the custom event is using.
|
|
*/
|
|
TP_PROTO(bool preempt,
|
|
struct task_struct *prev,
|
|
struct task_struct *next,
|
|
unsigned int prev_state),
|
|
|
|
TP_ARGS(preempt, prev, next, prev_state),
|
|
|
|
/*
|
|
* The next fields are where the customization happens.
|
|
* The TP_STRUCT__entry() defines what will be recorded
|
|
* in the ring buffer when the custom event triggers.
|
|
*
|
|
* The rest is just like the TRACE_EVENT() macro except that
|
|
* it uses the custom entry.
|
|
*/
|
|
TP_STRUCT__entry(
|
|
__field( unsigned short, prev_prio )
|
|
__field( unsigned short, next_prio )
|
|
__field( pid_t, next_pid )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->prev_prio = prev->prio;
|
|
__entry->next_pid = next->pid;
|
|
__entry->next_prio = next->prio;
|
|
),
|
|
|
|
TP_printk("prev_prio=%d next_pid=%d next_prio=%d",
|
|
__entry->prev_prio, __entry->next_pid, __entry->next_prio)
|
|
)
|
|
|
|
|
|
TRACE_CUSTOM_EVENT(sched_waking,
|
|
|
|
TP_PROTO(struct task_struct *p),
|
|
|
|
TP_ARGS(p),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( pid_t, pid )
|
|
__field( unsigned short, prio )
|
|
),
|
|
|
|
TP_fast_assign(
|
|
__entry->pid = p->pid;
|
|
__entry->prio = p->prio;
|
|
),
|
|
|
|
TP_printk("pid=%d prio=%d", __entry->pid, __entry->prio)
|
|
)
|
|
#endif
|
|
/*
|
|
* Just like the headers that create TRACE_EVENTs, the below must
|
|
* be outside the protection of the above #if block.
|
|
*/
|
|
|
|
/*
|
|
* It is required that the Makefile includes:
|
|
* CFLAGS_<c_file>.o := -I$(src)
|
|
*/
|
|
#undef TRACE_INCLUDE_PATH
|
|
#undef TRACE_INCLUDE_FILE
|
|
#define TRACE_INCLUDE_PATH .
|
|
|
|
/*
|
|
* It is requred that the TRACE_INCLUDE_FILE be the same
|
|
* as this file without the ".h".
|
|
*/
|
|
#define TRACE_INCLUDE_FILE trace_custom_sched
|
|
#include <trace/define_custom_trace.h>
|