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Revert "perf/core: Add aux_pause, aux_resume, aux_start_paused"

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This reverts commit c61feda373 which is
commit 18d92bb57c39504d9da11c6ef604f58eb1d5a117 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I29205f8d540692f5415a1cd3e7fcf74076b2b3b8
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman
2025-05-07 06:40:20 +00:00
parent 1f8271add4
commit 5b889365dc
4 changed files with 5 additions and 110 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
include/linux/perf_event.h
View File

@@ -170,12 +170,6 @@ struct hw_perf_event {
};
struct { /* aux / Intel-PT */
u64 aux_config;
/*
* For AUX area events, aux_paused cannot be a state
* flag because it can be updated asynchronously to
* state.
*/
unsigned int aux_paused;
};
struct { /* software */
struct hrtimer hrtimer;
@@ -300,7 +294,6 @@ struct perf_event_pmu_context;
#define PERF_PMU_CAP_NO_EXCLUDE 0x0040
#define PERF_PMU_CAP_AUX_OUTPUT 0x0080
#define PERF_PMU_CAP_EXTENDED_HW_TYPE 0x0100
#define PERF_PMU_CAP_AUX_PAUSE 0x0200
/**
* pmu::scope
@@ -391,8 +384,6 @@ struct pmu {
#define PERF_EF_START 0x01 /* start the counter when adding */
#define PERF_EF_RELOAD 0x02 /* reload the counter when starting */
#define PERF_EF_UPDATE 0x04 /* update the counter when stopping */
#define PERF_EF_PAUSE 0x08 /* AUX area event, pause tracing */
#define PERF_EF_RESUME 0x10 /* AUX area event, resume tracing */
/*
* Adds/Removes a counter to/from the PMU, can be done inside a
@@ -432,18 +423,6 @@ struct pmu {
*
* ->start() with PERF_EF_RELOAD will reprogram the counter
* value, must be preceded by a ->stop() with PERF_EF_UPDATE.
*
* ->stop() with PERF_EF_PAUSE will stop as simply as possible. Will not
* overlap another ->stop() with PERF_EF_PAUSE nor ->start() with
* PERF_EF_RESUME.
*
* ->start() with PERF_EF_RESUME will start as simply as possible but
* only if the counter is not otherwise stopped. Will not overlap
* another ->start() with PERF_EF_RESUME nor ->stop() with
* PERF_EF_PAUSE.
*
* Notably, PERF_EF_PAUSE/PERF_EF_RESUME *can* be concurrent with other
* ->stop()/->start() invocations, just not itself.
*/
void (*start) (struct perf_event *event, int flags);
void (*stop) (struct perf_event *event, int flags);
@@ -1724,13 +1703,6 @@ static inline bool has_aux(struct perf_event *event)
return event->pmu->setup_aux;
}
static inline bool has_aux_action(struct perf_event *event)
{
return event->attr.aux_sample_size ||
event->attr.aux_pause ||
event->attr.aux_resume;
}
static inline bool is_write_backward(struct perf_event *event)
{
return !!event->attr.write_backward;

11
include/uapi/linux/perf_event.h
View File

@@ -511,16 +511,7 @@ struct perf_event_attr {
__u16 sample_max_stack;
__u16 __reserved_2;
__u32 aux_sample_size;
union {
__u32 aux_action;
struct {
__u32 aux_start_paused : 1, /* start AUX area tracing paused */
aux_pause : 1, /* on overflow, pause AUX area tracing */
aux_resume : 1, /* on overflow, resume AUX area tracing */
__reserved_3 : 29;
};
};
__u32 __reserved_3;
/*
* User provided data if sigtrap=1, passed back to user via

75
kernel/events/core.c
View File

@@ -2146,7 +2146,7 @@ static void perf_put_aux_event(struct perf_event *event)
static bool perf_need_aux_event(struct perf_event *event)
{
return event->attr.aux_output || has_aux_action(event);
return !!event->attr.aux_output || !!event->attr.aux_sample_size;
}
static int perf_get_aux_event(struct perf_event *event,
@@ -2171,10 +2171,6 @@ static int perf_get_aux_event(struct perf_event *event,
!perf_aux_output_match(event, group_leader))
return 0;
if ((event->attr.aux_pause || event->attr.aux_resume) &&
!(group_leader->pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE))
return 0;
if (event->attr.aux_sample_size && !group_leader->pmu->snapshot_aux)
return 0;
@@ -8019,49 +8015,6 @@ void perf_prepare_header(struct perf_event_header *header,
WARN_ON_ONCE(header->size & 7);
}
static void __perf_event_aux_pause(struct perf_event *event, bool pause)
{
if (pause) {
if (!event->hw.aux_paused) {
event->hw.aux_paused = 1;
event->pmu->stop(event, PERF_EF_PAUSE);
}
} else {
if (event->hw.aux_paused) {
event->hw.aux_paused = 0;
event->pmu->start(event, PERF_EF_RESUME);
}
}
}
static void perf_event_aux_pause(struct perf_event *event, bool pause)
{
struct perf_buffer *rb;
if (WARN_ON_ONCE(!event))
return;
rb = ring_buffer_get(event);
if (!rb)
return;
scoped_guard (irqsave) {
/*
* Guard against self-recursion here. Another event could trip
* this same from NMI context.
*/
if (READ_ONCE(rb->aux_in_pause_resume))
break;
WRITE_ONCE(rb->aux_in_pause_resume, 1);
barrier();
__perf_event_aux_pause(event, pause);
barrier();
WRITE_ONCE(rb->aux_in_pause_resume, 0);
}
ring_buffer_put(rb);
}
static __always_inline int
__perf_event_output(struct perf_event *event,
struct perf_sample_data *data,
@@ -9865,12 +9818,9 @@ static int __perf_event_overflow(struct perf_event *event,
ret = __perf_event_account_interrupt(event, throttle);
if (event->attr.aux_pause)
perf_event_aux_pause(event->aux_event, true);
if (event->prog && event->prog->type == BPF_PROG_TYPE_PERF_EVENT &&
!bpf_overflow_handler(event, data, regs))
goto out;
return ret;
/*
* XXX event_limit might not quite work as expected on inherited
@@ -9932,9 +9882,6 @@ static int __perf_event_overflow(struct perf_event *event,
event->pending_wakeup = 1;
irq_work_queue(&event->pending_irq);
}
out:
if (event->attr.aux_resume)
perf_event_aux_pause(event->aux_event, false);
return ret;
}
@@ -12351,25 +12298,11 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
}
if (event->attr.aux_output &&
(!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) ||
event->attr.aux_pause || event->attr.aux_resume)) {
!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT)) {
err = -EOPNOTSUPP;
goto err_pmu;
}
if (event->attr.aux_pause && event->attr.aux_resume) {
err = -EINVAL;
goto err_pmu;
}
if (event->attr.aux_start_paused) {
if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) {
err = -EOPNOTSUPP;
goto err_pmu;
}
event->hw.aux_paused = 1;
}
if (cgroup_fd != -1) {
err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
if (err)
@@ -13165,7 +13098,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
* Grouping is not supported for kernel events, neither is 'AUX',
* make sure the caller's intentions are adjusted.
*/
if (attr->aux_output || attr->aux_action)
if (attr->aux_output)
return ERR_PTR(-EINVAL);
event = perf_event_alloc(attr, cpu, task, NULL, NULL,

1
kernel/events/internal.h
View File

@@ -52,7 +52,6 @@ struct perf_buffer {
void (*free_aux)(void *);
refcount_t aux_refcount;
int aux_in_sampling;
int aux_in_pause_resume;
void **aux_pages;
void *aux_priv;