diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2024-11-04 16:39:25 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-04 11:43:10 +0300 |
| commit | 0c8a4e4139adf09b27fb910edbc596ea2d31a5db (patch) | |
| tree | 7125055b8b0dcc83f6a2ab77e8248c0036f7180b | |
| parent | 954878377bc81459b95937a05f01e8ebf6a05083 (diff) | |
| download | linux-0c8a4e4139adf09b27fb910edbc596ea2d31a5db.tar.xz | |
perf/core: Further simplify perf_mmap()
Perform CSE and such.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20241104135519.354909594@infradead.org
| -rw-r--r-- | kernel/events/core.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index d1b04c850881..4cd3494c65e2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6698,9 +6698,18 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) return ret; vma_size = vma->vm_end - vma->vm_start; + nr_pages = vma_size / PAGE_SIZE; + + if (nr_pages > INT_MAX) + return -ENOMEM; + + if (vma_size != PAGE_SIZE * nr_pages) + return -EINVAL; + + user_extra = nr_pages; if (vma->vm_pgoff == 0) { - nr_pages = (vma_size / PAGE_SIZE) - 1; + nr_pages -= 1; /* * If we have rb pages ensure they're a power-of-two number, so we @@ -6709,9 +6718,6 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) if (nr_pages != 0 && !is_power_of_2(nr_pages)) return -EINVAL; - if (vma_size != PAGE_SIZE * (1 + nr_pages)) - return -EINVAL; - WARN_ON_ONCE(event->ctx->parent_ctx); again: mutex_lock(&event->mmap_mutex); @@ -6735,8 +6741,6 @@ again: rb = event->rb; goto unlock; } - - user_extra = nr_pages + 1; } else { /* * AUX area mapping: if rb->aux_nr_pages != 0, it's already @@ -6748,10 +6752,6 @@ again: if (!event->rb) return -EINVAL; - nr_pages = vma_size / PAGE_SIZE; - if (nr_pages > INT_MAX) - return -ENOMEM; - mutex_lock(&event->mmap_mutex); ret = -EINVAL; @@ -6795,7 +6795,6 @@ again: } atomic_set(&rb->aux_mmap_count, 1); - user_extra = nr_pages; } user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); |