From 47f661eca0700928012e11c57ea0328f5ccfc3b9 Mon Sep 17 00:00:00 2001
From: Marco Elver <elver@google.com>
Date: Thu, 8 Apr 2021 12:35:57 +0200
Subject: [PATCH] perf: Apply PERF_EVENT_IOC_MODIFY_ATTRIBUTES to children
As with other ioctls (such as PERF_EVENT_IOC_{ENABLE,DISABLE}), fix up
handling of PERF_EVENT_IOC_MODIFY_ATTRIBUTES to also apply to children.
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lkml.kernel.org/r/20210408103605.1676875-3-elver@google.com
---
kernel/events/core.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 318ff7b021b4f1..10ed2cd434dc0b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3200,16 +3200,36 @@ static int perf_event_modify_breakpoint(struct perf_event *bp,
static int perf_event_modify_attr(struct perf_event *event,
struct perf_event_attr *attr)
{
+ int (*func)(struct perf_event *, struct perf_event_attr *);
+ struct perf_event *child;
+ int err;
+
if (event->attr.type != attr->type)
return -EINVAL;
switch (event->attr.type) {
case PERF_TYPE_BREAKPOINT:
- return perf_event_modify_breakpoint(event, attr);
+ func = perf_event_modify_breakpoint;
+ break;
default:
/* Place holder for future additions. */
return -EOPNOTSUPP;
}
+
+ WARN_ON_ONCE(event->ctx->parent_ctx);
+
+ mutex_lock(&event->child_mutex);
+ err = func(event, attr);
+ if (err)
+ goto out;
+ list_for_each_entry(child, &event->child_list, child_list) {
+ err = func(child, attr);
+ if (err)
+ goto out;
+ }
+out:
+ mutex_unlock(&event->child_mutex);
+ return err;
}
static void ctx_sched_out(struct perf_event_context *ctx,
--
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