The following commit has been merged into the perf/core branch of tip: Commit-ID: 8f2221f52eced88e74c7ae22b4b2d67dc7a96bd2 Gitweb: https://git.kernel.org/tip/8f2221f52eced88e74c7ae22b4b2d67dc7a96bd2 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Mon, 04 Nov 2024 14:39:17 +01:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Tue, 04 Mar 2025 09:42:40 +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> Reviewed-by: Ravi Bangoria <ravi.bangoria@xxxxxxx> 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,
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