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authorMarco Elver <elver@google.com>2021-04-08 12:35:58 +0200
committerPeter Zijlstra <peterz@infradead.org>2021-04-16 16:32:40 +0200
commit2b26f0aa004995f49f7b6f4100dd0e4c39a9ed5f (patch)
tree27077a92806b93fffb58a3eaf0fad81cbf2e42c9 /kernel/events
parent47f661eca0700928012e11c57ea0328f5ccfc3b9 (diff)
perf: Support only inheriting events if cloned with CLONE_THREAD
Adds bit perf_event_attr::inherit_thread, to restricting inheriting events only if the child was cloned with CLONE_THREAD. This option supports the case where an event is supposed to be process-wide only (including subthreads), but should not propagate beyond the current process's shared environment. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/lkml/YBvj6eJR%2FDY2TsEB@hirez.programming.kicks-ass.net/
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 10ed2cd434dc..3e3c00fd0b2e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11653,6 +11653,9 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
(attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT))
return -EINVAL;
+ if (!attr->inherit && attr->inherit_thread)
+ return -EINVAL;
+
out:
return ret;
@@ -12873,12 +12876,13 @@ static int
inherit_task_group(struct perf_event *event, struct task_struct *parent,
struct perf_event_context *parent_ctx,
struct task_struct *child, int ctxn,
- int *inherited_all)
+ u64 clone_flags, int *inherited_all)
{
int ret;
struct perf_event_context *child_ctx;
- if (!event->attr.inherit) {
+ if (!event->attr.inherit ||
+ (event->attr.inherit_thread && !(clone_flags & CLONE_THREAD))) {
*inherited_all = 0;
return 0;
}
@@ -12910,7 +12914,8 @@ inherit_task_group(struct perf_event *event, struct task_struct *parent,
/*
* Initialize the perf_event context in task_struct
*/
-static int perf_event_init_context(struct task_struct *child, int ctxn)
+static int perf_event_init_context(struct task_struct *child, int ctxn,
+ u64 clone_flags)
{
struct perf_event_context *child_ctx, *parent_ctx;
struct perf_event_context *cloned_ctx;
@@ -12950,7 +12955,8 @@ static int perf_event_init_context(struct task_struct *child, int ctxn)
*/
perf_event_groups_for_each(event, &parent_ctx->pinned_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, &inherited_all);
+ child, ctxn, clone_flags,
+ &inherited_all);
if (ret)
goto out_unlock;
}
@@ -12966,7 +12972,8 @@ static int perf_event_init_context(struct task_struct *child, int ctxn)
perf_event_groups_for_each(event, &parent_ctx->flexible_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, &inherited_all);
+ child, ctxn, clone_flags,
+ &inherited_all);
if (ret)
goto out_unlock;
}
@@ -13008,7 +13015,7 @@ out_unlock:
/*
* Initialize the perf_event context in task_struct
*/
-int perf_event_init_task(struct task_struct *child)
+int perf_event_init_task(struct task_struct *child, u64 clone_flags)
{
int ctxn, ret;
@@ -13017,7 +13024,7 @@ int perf_event_init_task(struct task_struct *child)
INIT_LIST_HEAD(&child->perf_event_list);
for_each_task_context_nr(ctxn) {
- ret = perf_event_init_context(child, ctxn);
+ ret = perf_event_init_context(child, ctxn, clone_flags);
if (ret) {
perf_event_free_task(child);
return ret;