The following commit has been merged into the perf/core branch of tip:
Commit-ID: ebfe83832e392f25b4fe1fedf816eebb76f1f5b4
Gitweb: https://git.kernel.org/tip/ebfe83832e392f25b4fe1fedf816eebb76f1f5b4
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 04 Nov 2024 14:39:17 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sat, 01 Mar 2025 19:54:06 +01:00
perf/core: Simplify perf_event_alloc()
Using the previous simplifications, transition perf_event_alloc() to
the cleanup way of things -- reducing error path magic.
[ mingo: Ported it to recent kernels. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241104135518.410755241@xxxxxxxxxxxxx
---
kernel/events/core.c | 59 ++++++++++++++++---------------------------
1 file changed, 22 insertions(+), 37 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index fd35236..348a379 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5410,6 +5410,8 @@ static void __free_event(struct perf_event *event)
call_rcu(&event->rcu_head, free_event_rcu);
}
+DEFINE_FREE(__free_event, struct perf_event *, if (_T) __free_event(_T))
+
/* vs perf_event_alloc() success */
static void _free_event(struct perf_event *event)
{
@@ -12291,7 +12293,6 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
void *context, int cgroup_fd)
{
struct pmu *pmu;
- struct perf_event *event;
struct hw_perf_event *hwc;
long err = -EINVAL;
int node;
@@ -12306,8 +12307,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
}
node = (cpu >= 0) ? cpu_to_node(cpu) : -1;
- event = kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO,
- node);
+ struct perf_event *event __free(__free_event) =
+ kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO, node);
if (!event)
return ERR_PTR(-ENOMEM);
@@ -12414,65 +12415,53 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
* See perf_output_read().
*/
if (has_inherit_and_sample_read(attr) && !(attr->sample_type & PERF_SAMPLE_TID))
- goto err;
+ return ERR_PTR(-EINVAL);
if (!has_branch_stack(event))
event->attr.branch_sample_type = 0;
pmu = perf_init_event(event);
- if (IS_ERR(pmu)) {
- err = PTR_ERR(pmu);
- goto err;
- }
+ if (IS_ERR(pmu))
+ return (void*)pmu;
/*
* Disallow uncore-task events. Similarly, disallow uncore-cgroup
* events (they don't make sense as the cgroup will be different
* on other CPUs in the uncore mask).
*/
- if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1)) {
- err = -EINVAL;
- goto err;
- }
+ if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1))
+ return ERR_PTR(-EINVAL);
if (event->attr.aux_output &&
(!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) ||
- event->attr.aux_pause || event->attr.aux_resume)) {
- err = -EOPNOTSUPP;
- goto err;
- }
+ event->attr.aux_pause || event->attr.aux_resume))
+ return ERR_PTR(-EOPNOTSUPP);
- if (event->attr.aux_pause && event->attr.aux_resume) {
- err = -EINVAL;
- goto err;
- }
+ if (event->attr.aux_pause && event->attr.aux_resume)
+ return ERR_PTR(-EINVAL);
if (event->attr.aux_start_paused) {
- if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) {
- err = -EOPNOTSUPP;
- goto err;
- }
+ if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE))
+ return ERR_PTR(-EOPNOTSUPP);
event->hw.aux_paused = 1;
}
if (cgroup_fd != -1) {
err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
if (err)
- goto err;
+ return ERR_PTR(err);
}
err = exclusive_event_init(event);
if (err)
- goto err;
+ return ERR_PTR(err);
if (has_addr_filter(event)) {
event->addr_filter_ranges = kcalloc(pmu->nr_addr_filters,
sizeof(struct perf_addr_filter_range),
GFP_KERNEL);
- if (!event->addr_filter_ranges) {
- err = -ENOMEM;
- goto err;
- }
+ if (!event->addr_filter_ranges)
+ return ERR_PTR(-ENOMEM);
/*
* Clone the parent's vma offsets: they are valid until exec()
@@ -12496,23 +12485,19 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
err = get_callchain_buffers(attr->sample_max_stack);
if (err)
- goto err;
+ return ERR_PTR(err);
event->attach_state |= PERF_ATTACH_CALLCHAIN;
}
}
err = security_perf_event_alloc(event);
if (err)
- goto err;
+ return ERR_PTR(err);
/* symmetric to unaccount_event() in _free_event() */
account_event(event);
- return event;
-
-err:
- __free_event(event);
- return ERR_PTR(err);
+ return_ptr(event);
}
static int perf_copy_attr(struct perf_event_attr __user *uattr,
|