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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/perf_event.h>#include <linux/vmalloc.h>#include <linux/slab.h>#include <linux/circ_buf.h>#include <linux/poll.h>#include <linux/nospec.h>
#include "internal.h"
static void perf_output_wakeup(struct perf_output_handle *handle){ atomic_set(&handle->rb->poll, EPOLLIN | EPOLLRDNORM);
handle->event->pending_wakeup = 1;
if (*perf_event_fasync(handle->event) && !handle->event->pending_kill) handle->event->pending_kill = POLL_IN;
irq_work_queue(&handle->event->pending_irq);}
/* * We need to ensure a later event_id doesn't publish a head when a former * event isn't done writing. However since we need to deal with NMIs we * cannot fully serialize things. * * We only publish the head (and generate a wakeup) when the outer-most * event completes. */static void perf_output_get_handle(struct perf_output_handle *handle){ struct perf_buffer *rb = handle->rb;
preempt_disable();
/* * Avoid an explicit LOAD/STORE such that architectures with memops * can use them. */ (*(volatile unsigned int *)&rb->nest)++; handle->wakeup = local_read(&rb->wakeup);}
static void perf_output_put_handle(struct perf_output_handle *handle){ struct perf_buffer *rb = handle->rb; unsigned long head; unsigned int nest;
/* * If this isn't the outermost nesting, we don't have to update * @rb->user_page->data_head. */ nest = READ_ONCE(rb->nest); if (nest > 1) { WRITE_ONCE(rb->nest, nest - 1); goto out; }
again: /* * In order to avoid publishing a head value that goes backwards, * we must ensure the load of @rb->head happens after we've * incremented @rb->nest. * * Otherwise we can observe a @rb->head value before one published * by an IRQ/NMI happening between the load and the increment. */ barrier(); head = local_read(&rb->head);
/* * IRQ/NMI can happen here and advance @rb->head, causing our * load above to be stale. */
/* * Since the mmap() consumer (userspace) can run on a different CPU: * * kernel user * * if (LOAD ->data_tail) { LOAD ->data_head * (A) smp_rmb() (C) * STORE $data LOAD $data * smp_wmb() (B) smp_mb() (D) * STORE ->data_head STORE ->data_tail * } * * Where A pairs with D, and B pairs with C. * * In our case (A) is a control dependency that separates the load of * the ->data_tail and the stores of $data. In case ->data_tail * indicates there is no room in the buffer to store $data we do not. * * D needs to be a full barrier since it separates the data READ * from the tail WRITE. * * For B a WMB is sufficient since it separates two WRITEs, and for C * an RMB is sufficient since it separates two READs. * * See perf_output_begin(). */ smp_wmb(); /* B, matches C */ WRITE_ONCE(rb->user_page->data_head, head);
/* * We must publish the head before decrementing the nest count, * otherwise an IRQ/NMI can publish a more recent head value and our * write will (temporarily) publish a stale value. */ barrier(); WRITE_ONCE(rb->nest, 0);
/* * Ensure we decrement @rb->nest before we validate the @rb->head. * Otherwise we cannot be sure we caught the 'last' nested update. */ barrier(); if (unlikely(head != local_read(&rb->head))) { WRITE_ONCE(rb->nest, 1); goto again; }
if (handle->wakeup != local_read(&rb->wakeup)) perf_output_wakeup(handle);
out: preempt_enable();}
static __always_inline boolring_buffer_has_space(unsigned long head, unsigned long tail, unsigned long data_size, unsigned int size, bool backward){ if (!backward) return CIRC_SPACE(head, tail, data_size) >= size; else return CIRC_SPACE(tail, head, data_size) >= size;}
static __always_inline int__perf_output_begin(struct perf_output_handle *handle, struct perf_sample_data *data, struct perf_event *event, unsigned int size, bool backward){ struct perf_buffer *rb; unsigned long tail, offset, head; int have_lost, page_shift; struct { struct perf_event_header header; u64 id; u64 lost; } lost_event;
rcu_read_lock(); /* * For inherited events we send all the output towards the parent. */ if (event->parent) event = event->parent;
rb = rcu_dereference(event->rb); if (unlikely(!rb)) goto out;
if (unlikely(rb->paused)) { if (rb->nr_pages) { local_inc(&rb->lost); atomic64_inc(&event->lost_samples); } goto out; }
handle->rb = rb; handle->event = event; handle->flags = 0;
have_lost = local_read(&rb->lost); if (unlikely(have_lost)) { size += sizeof(lost_event); if (event->attr.sample_id_all) size += event->id_header_size; }
perf_output_get_handle(handle);
offset = local_read(&rb->head); do { head = offset; tail = READ_ONCE(rb->user_page->data_tail); if (!rb->overwrite) { if (unlikely(!ring_buffer_has_space(head, tail, perf_data_size(rb), size, backward))) goto fail; }
/* * The above forms a control dependency barrier separating the * @tail load above from the data stores below. Since the @tail * load is required to compute the branch to fail below. * * A, matches D; the full memory barrier userspace SHOULD issue * after reading the data and before storing the new tail * position. * * See perf_output_put_handle(). */
if (!backward) head += size; else head -= size; } while (!local_try_cmpxchg(&rb->head, &offset, head));
if (backward) { offset = head; head = (u64)(-head); }
/* * We rely on the implied barrier() by local_cmpxchg() to ensure * none of the data stores below can be lifted up by the compiler. */
if (unlikely(head - local_read(&rb->wakeup) > rb->watermark)) local_add(rb->watermark, &rb->wakeup);
page_shift = PAGE_SHIFT + page_order(rb);
handle->page = (offset >> page_shift) & (rb->nr_pages - 1); offset &= (1UL << page_shift) - 1; handle->addr = rb->data_pages[handle->page] + offset; handle->size = (1UL << page_shift) - offset;
if (unlikely(have_lost)) { lost_event.header.size = sizeof(lost_event); lost_event.header.type = PERF_RECORD_LOST; lost_event.header.misc = 0; lost_event.id = event->id; lost_event.lost = local_xchg(&rb->lost, 0);
/* XXX mostly redundant; @data is already fully initializes */ perf_event_header__init_id(&lost_event.header, data, event); perf_output_put(handle, lost_event); perf_event__output_id_sample(event, handle, data); }
return 0;
fail: local_inc(&rb->lost); atomic64_inc(&event->lost_samples); perf_output_put_handle(handle);out: rcu_read_unlock();
return -ENOSPC;}
int perf_output_begin_forward(struct perf_output_handle *handle, struct perf_sample_data *data, struct perf_event *event, unsigned int size){ return __perf_output_begin(handle, data, event, size, false);}
int perf_output_begin_backward(struct perf_output_handle *handle, struct perf_sample_data *data, struct perf_event *event, unsigned int size){ return __perf_output_begin(handle, data, event, size, true);}
int perf_output_begin(struct perf_output_handle *handle, struct perf_sample_data *data, struct perf_event *event, unsigned int size){
return __perf_output_begin(handle, data, event, size, unlikely(is_write_backward(event)));}
unsigned int perf_output_copy(struct perf_output_handle *handle, const void *buf, unsigned int len){ return __output_copy(handle, buf, len);}
unsigned int perf_output_skip(struct perf_output_handle *handle, unsigned int len){ return __output_skip(handle, NULL, len);}
void perf_output_end(struct perf_output_handle *handle){ perf_output_put_handle(handle); rcu_read_unlock();}
static voidring_buffer_init(struct perf_buffer *rb, long watermark, int flags){ long max_size = perf_data_size(rb);
if (watermark) rb->watermark = min(max_size, watermark);
if (!rb->watermark) rb->watermark = max_size / 2;
if (flags & RING_BUFFER_WRITABLE) rb->overwrite = 0; else rb->overwrite = 1;
refcount_set(&rb->refcount, 1);
INIT_LIST_HEAD(&rb->event_list); spin_lock_init(&rb->event_lock);
/* * perf_output_begin() only checks rb->paused, therefore * rb->paused must be true if we have no pages for output. */ if (!rb->nr_pages) rb->paused = 1;
mutex_init(&rb->aux_mutex); rb->mmap_user = get_current_user(); refcount_set(&rb->mmap_count, 1);}
void perf_aux_output_flag(struct perf_output_handle *handle, u64 flags){ /* * OVERWRITE is determined by perf_aux_output_end() and can't * be passed in directly. */ if (WARN_ON_ONCE(flags & PERF_AUX_FLAG_OVERWRITE)) return;
handle->aux_flags |= flags;}EXPORT_SYMBOL_GPL(perf_aux_output_flag);
/* * This is called before hardware starts writing to the AUX area to * obtain an output handle and make sure there's room in the buffer. * When the capture completes, call perf_aux_output_end() to commit * the recorded data to the buffer. * * The ordering is similar to that of perf_output_{begin,end}, with * the exception of (B), which should be taken care of by the pmu * driver, since ordering rules will differ depending on hardware. * * Call this from pmu::start(); see the comment in perf_aux_output_end() * about its use in pmu callbacks. Both can also be called from the PMI * handler if needed. */void *perf_aux_output_begin(struct perf_output_handle *handle, struct perf_event *event){ struct perf_event *output_event = event; unsigned long aux_head, aux_tail; struct perf_buffer *rb; unsigned int nest;
if (output_event->parent) output_event = output_event->parent;
/* * Since this will typically be open across pmu::add/pmu::del, we * grab ring_buffer's refcount instead of holding rcu read lock * to make sure it doesn't disappear under us. */ rb = ring_buffer_get(output_event); if (!rb) return NULL;
if (!rb_has_aux(rb)) goto err;
/* * If aux_mmap_count is zero, the aux buffer is in perf_mmap_close(), * about to get freed, so we leave immediately. * * Checking rb::aux_mmap_count and rb::refcount has to be done in * the same order, see perf_mmap_close. Otherwise we end up freeing * aux pages in this path, which is a bug, because in_atomic(). */ if (!refcount_read(&rb->aux_mmap_count)) goto err;
if (!refcount_inc_not_zero(&rb->aux_refcount)) goto err;
nest = READ_ONCE(rb->aux_nest); /* * Nesting is not supported for AUX area, make sure nested * writers are caught early */ if (WARN_ON_ONCE(nest)) goto err_put;
WRITE_ONCE(rb->aux_nest, nest + 1);
aux_head = rb->aux_head;
handle->rb = rb; handle->event = event; handle->head = aux_head; handle->size = 0; handle->aux_flags = 0;
/* * In overwrite mode, AUX data stores do not depend on aux_tail, * therefore (A) control dependency barrier does not exist. The * (B) <-> (C) ordering is still observed by the pmu driver. */ if (!rb->aux_overwrite) { aux_tail = READ_ONCE(rb->user_page->aux_tail); handle->wakeup = rb->aux_wakeup + rb->aux_watermark; if (aux_head - aux_tail < perf_aux_size(rb)) handle->size = CIRC_SPACE(aux_head, aux_tail, perf_aux_size(rb));
/* * handle->size computation depends on aux_tail load; this forms a * control dependency barrier separating aux_tail load from aux data * store that will be enabled on successful return */ if (!handle->size) { /* A, matches D */ perf_event_disable_inatomic(handle->event); perf_output_wakeup(handle); WRITE_ONCE(rb->aux_nest, 0); goto err_put; } }
return handle->rb->aux_priv;
err_put: /* can't be last */ rb_free_aux(rb);
err: ring_buffer_put(rb); handle->event = NULL;
return NULL;}EXPORT_SYMBOL_GPL(perf_aux_output_begin);
static __always_inline bool rb_need_aux_wakeup(struct perf_buffer *rb){ if (rb->aux_overwrite) return false;
if (rb->aux_head - rb->aux_wakeup >= rb->aux_watermark) { rb->aux_wakeup = rounddown(rb->aux_head, rb->aux_watermark); return true; }
return false;}
/* * Commit the data written by hardware into the ring buffer by adjusting * aux_head and posting a PERF_RECORD_AUX into the perf buffer. It is the * pmu driver's responsibility to observe ordering rules of the hardware, * so that all the data is externally visible before this is called. * * Note: this has to be called from pmu::stop() callback, as the assumption * of the AUX buffer management code is that after pmu::stop(), the AUX * transaction must be stopped and therefore drop the AUX reference count. */void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size){ bool wakeup = !!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED); struct perf_buffer *rb = handle->rb; unsigned long aux_head;
/* in overwrite mode, driver provides aux_head via handle */ if (rb->aux_overwrite) { handle->aux_flags |= PERF_AUX_FLAG_OVERWRITE;
aux_head = handle->head; rb->aux_head = aux_head; } else { handle->aux_flags &= ~PERF_AUX_FLAG_OVERWRITE;
aux_head = rb->aux_head; rb->aux_head += size; }
/* * Only send RECORD_AUX if we have something useful to communicate * * Note: the OVERWRITE records by themselves are not considered * useful, as they don't communicate any *new* information, * aside from the short-lived offset, that becomes history at * the next event sched-in and therefore isn't useful. * The userspace that needs to copy out AUX data in overwrite * mode should know to use user_page::aux_head for the actual * offset. So, from now on we don't output AUX records that * have *only* OVERWRITE flag set. */ if (size || (handle->aux_flags & ~(u64)PERF_AUX_FLAG_OVERWRITE)) perf_event_aux_event(handle->event, aux_head, size, handle->aux_flags);
WRITE_ONCE(rb->user_page->aux_head, rb->aux_head); if (rb_need_aux_wakeup(rb)) wakeup = true;
if (wakeup) { if (handle->aux_flags & PERF_AUX_FLAG_TRUNCATED) perf_event_disable_inatomic(handle->event); perf_output_wakeup(handle); }
handle->event = NULL;
WRITE_ONCE(rb->aux_nest, 0); /* can't be last */ rb_free_aux(rb); ring_buffer_put(rb);}EXPORT_SYMBOL_GPL(perf_aux_output_end);
/* * Skip over a given number of bytes in the AUX buffer, due to, for example, * hardware's alignment constraints. */int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size){ struct perf_buffer *rb = handle->rb;
if (size > handle->size) return -ENOSPC;
rb->aux_head += size;
WRITE_ONCE(rb->user_page->aux_head, rb->aux_head); if (rb_need_aux_wakeup(rb)) { perf_output_wakeup(handle); handle->wakeup = rb->aux_wakeup + rb->aux_watermark; }
handle->head = rb->aux_head; handle->size -= size;
return 0;}EXPORT_SYMBOL_GPL(perf_aux_output_skip);
void *perf_get_aux(struct perf_output_handle *handle){ /* this is only valid between perf_aux_output_begin and *_end */ if (!handle->event) return NULL;
return handle->rb->aux_priv;}EXPORT_SYMBOL_GPL(perf_get_aux);
/* * Copy out AUX data from an AUX handle. */long perf_output_copy_aux(struct perf_output_handle *aux_handle, struct perf_output_handle *handle, unsigned long from, unsigned long to){ struct perf_buffer *rb = aux_handle->rb; unsigned long tocopy, remainder, len = 0; void *addr;
from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1; to &= (rb->aux_nr_pages << PAGE_SHIFT) - 1;
do { tocopy = PAGE_SIZE - offset_in_page(from); if (to > from) tocopy = min(tocopy, to - from); if (!tocopy) break;
addr = rb->aux_pages[from >> PAGE_SHIFT]; addr += offset_in_page(from);
remainder = perf_output_copy(handle, addr, tocopy); if (remainder) return -EFAULT;
len += tocopy; from += tocopy; from &= (rb->aux_nr_pages << PAGE_SHIFT) - 1; } while (to != from);
return len;}
#define PERF_AUX_GFP (GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY)
static struct page *rb_alloc_aux_page(int node, int order){ struct page *page;
if (order > MAX_PAGE_ORDER) order = MAX_PAGE_ORDER;
do { page = alloc_pages_node(node, PERF_AUX_GFP, order); } while (!page && order--);
if (page && order) { /* * Communicate the allocation size to the driver: * if we managed to secure a high-order allocation, * set its first page's private to this order; * !PagePrivate(page) means it's just a normal page. */ split_page(page, order); SetPagePrivate(page); set_page_private(page, order); }
return page;}
static void rb_free_aux_page(struct perf_buffer *rb, int idx){ struct page *page = virt_to_page(rb->aux_pages[idx]);
ClearPagePrivate(page); __free_page(page);}
static void __rb_free_aux(struct perf_buffer *rb){ int pg;
/* * Should never happen, the last reference should be dropped from * perf_mmap_close() path, which first stops aux transactions (which * in turn are the atomic holders of aux_refcount) and then does the * last rb_free_aux(). */ WARN_ON_ONCE(in_atomic());
if (rb->aux_priv) { rb->free_aux(rb->aux_priv); rb->free_aux = NULL; rb->aux_priv = NULL; }
if (rb->aux_nr_pages) { for (pg = 0; pg < rb->aux_nr_pages; pg++) rb_free_aux_page(rb, pg);
kfree(rb->aux_pages); rb->aux_nr_pages = 0; }}
int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event, pgoff_t pgoff, int nr_pages, long watermark, int flags){ bool overwrite = !(flags & RING_BUFFER_WRITABLE); int node = (event->cpu == -1) ? -1 : cpu_to_node(event->cpu); bool use_contiguous_pages = event->pmu->capabilities & ( PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_PREFER_LARGE); /* * Initialize max_order to 0 for page allocation. This allocates single * pages to minimize memory fragmentation. This is overridden if the * PMU needs or prefers contiguous pages (use_contiguous_pages = true). */ int max_order = 0; int ret = -ENOMEM;
if (!has_aux(event)) return -EOPNOTSUPP;
if (nr_pages <= 0) return -EINVAL;
if (!overwrite) { /* * Watermark defaults to half the buffer, to aid PMU drivers * in double buffering. */ if (!watermark) watermark = min_t(unsigned long, U32_MAX, (unsigned long)nr_pages << (PAGE_SHIFT - 1));
/* * If using contiguous pages, use aux_watermark as the basis * for chunking to help PMU drivers honor the watermark. */ if (use_contiguous_pages) max_order = get_order(watermark); } else { /* * If using contiguous pages, we need to start with the * max_order that fits in nr_pages, not the other way around, * hence ilog2() and not get_order. */ if (use_contiguous_pages) max_order = ilog2(nr_pages); watermark = 0; }
/* * kcalloc_node() is unable to allocate buffer if the size is larger * than: PAGE_SIZE << MAX_PAGE_ORDER; directly bail out in this case. */ if (get_order((unsigned long)nr_pages * sizeof(void *)) > MAX_PAGE_ORDER) return -ENOMEM; rb->aux_pages = kcalloc_node(nr_pages, sizeof(void *), GFP_KERNEL, node); if (!rb->aux_pages) return -ENOMEM;
rb->free_aux = event->pmu->free_aux; for (rb->aux_nr_pages = 0; rb->aux_nr_pages < nr_pages;) { struct page *page; int last, order;
order = min(max_order, ilog2(nr_pages - rb->aux_nr_pages)); page = rb_alloc_aux_page(node, order); if (!page) goto out;
for (last = rb->aux_nr_pages + (1 << page_private(page)); last > rb->aux_nr_pages; rb->aux_nr_pages++) rb->aux_pages[rb->aux_nr_pages] = page_address(page++); }
/* * In overwrite mode, PMUs that don't support SG may not handle more * than one contiguous allocation, since they rely on PMI to do double * buffering. In this case, the entire buffer has to be one contiguous * chunk. */ if ((event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) && overwrite) { struct page *page = virt_to_page(rb->aux_pages[0]);
if (page_private(page) != max_order) goto out; }
rb->aux_priv = event->pmu->setup_aux(event, rb->aux_pages, nr_pages, overwrite); if (!rb->aux_priv) goto out;
ret = 0;
/* * aux_pages (and pmu driver's private data, aux_priv) will be * referenced in both producer's and consumer's contexts, thus * we keep a refcount here to make sure either of the two can * reference them safely. */ refcount_set(&rb->aux_refcount, 1);
rb->aux_overwrite = overwrite; rb->aux_watermark = watermark;
out: if (!ret) rb->aux_pgoff = pgoff; else __rb_free_aux(rb);
return ret;}
void rb_free_aux(struct perf_buffer *rb){ if (refcount_dec_and_test(&rb->aux_refcount)) __rb_free_aux(rb);}
#ifndef CONFIG_PERF_USE_VMALLOC
/* * Back perf_mmap() with regular GFP_KERNEL-0 pages. */
static struct page *__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff){ if (pgoff > rb->nr_pages) return NULL;
if (pgoff == 0) return virt_to_page(rb->user_page);
return virt_to_page(rb->data_pages[pgoff - 1]);}
static void *perf_mmap_alloc_page(int cpu){ struct page *page; int node;
node = (cpu == -1) ? cpu : cpu_to_node(cpu); page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); if (!page) return NULL;
return page_address(page);}
static void perf_mmap_free_page(void *addr){ struct page *page = virt_to_page(addr);
__free_page(page);}
struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags){ struct perf_buffer *rb; unsigned long size; int i, node;
size = sizeof(struct perf_buffer); size += nr_pages * sizeof(void *);
if (order_base_2(size) > PAGE_SHIFT+MAX_PAGE_ORDER) goto fail;
node = (cpu == -1) ? cpu : cpu_to_node(cpu); rb = kzalloc_node(size, GFP_KERNEL, node); if (!rb) goto fail;
rb->user_page = perf_mmap_alloc_page(cpu); if (!rb->user_page) goto fail_user_page;
for (i = 0; i < nr_pages; i++) { rb->data_pages[i] = perf_mmap_alloc_page(cpu); if (!rb->data_pages[i]) goto fail_data_pages; }
rb->nr_pages = nr_pages;
ring_buffer_init(rb, watermark, flags);
return rb;
fail_data_pages: for (i--; i >= 0; i--) perf_mmap_free_page(rb->data_pages[i]);
perf_mmap_free_page(rb->user_page);
fail_user_page: kfree(rb);
fail: return NULL;}
void rb_free(struct perf_buffer *rb){ int i;
perf_mmap_free_page(rb->user_page); for (i = 0; i < rb->nr_pages; i++) perf_mmap_free_page(rb->data_pages[i]); kfree(rb);}
#elsestatic struct page *__perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff){ /* The '>' counts in the user page. */ if (pgoff > data_page_nr(rb)) return NULL;
return vmalloc_to_page((void *)rb->user_page + pgoff * PAGE_SIZE);}
static void rb_free_work(struct work_struct *work){ struct perf_buffer *rb;
rb = container_of(work, struct perf_buffer, work);
vfree(rb->user_page); kfree(rb);}
void rb_free(struct perf_buffer *rb){ schedule_work(&rb->work);}
struct perf_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags){ struct perf_buffer *rb; unsigned long size; void *all_buf; int node;
size = sizeof(struct perf_buffer); size += sizeof(void *);
node = (cpu == -1) ? cpu : cpu_to_node(cpu); rb = kzalloc_node(size, GFP_KERNEL, node); if (!rb) goto fail;
INIT_WORK(&rb->work, rb_free_work);
all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE); if (!all_buf) goto fail_all_buf;
rb->user_page = all_buf; rb->data_pages[0] = all_buf + PAGE_SIZE; if (nr_pages) { rb->nr_pages = 1; rb->page_order = ilog2(nr_pages); }
ring_buffer_init(rb, watermark, flags);
return rb;
fail_all_buf: kfree(rb);
fail: return NULL;}
#endif
struct page *perf_mmap_to_page(struct perf_buffer *rb, unsigned long pgoff){ if (rb->aux_nr_pages) { /* above AUX space */ if (pgoff > rb->aux_pgoff + rb->aux_nr_pages) return NULL;
/* AUX space */ if (pgoff >= rb->aux_pgoff) { int aux_pgoff = array_index_nospec(pgoff - rb->aux_pgoff, rb->aux_nr_pages); return virt_to_page(rb->aux_pages[aux_pgoff]); } }
return __perf_mmap_to_page(rb, pgoff);}