cregit-Linux how code gets into the kernel

Release 4.11 drivers/infiniband/core/umem.c

/*
 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Cisco Systems.  All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/export.h>
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <rdma/ib_umem_odp.h>

#include "uverbs.h"



static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty) { struct scatterlist *sg; struct page *page; int i; if (umem->nmap > 0) ib_dma_unmap_sg(dev, umem->sg_head.sgl, umem->npages, DMA_BIDIRECTIONAL); for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) { page = sg_page(sg); if (umem->writable && dirty) set_page_dirty_lock(page); put_page(page); } sg_free_table(&umem->sg_head); return; }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier5957.28%120.00%
Yishai Hadas3836.89%120.00%
Jens Axboe43.88%120.00%
Ralph Campbell10.97%120.00%
Sebastian Ott10.97%120.00%
Total103100.00%5100.00%

/** * ib_umem_get - Pin and DMA map userspace memory. * * If access flags indicate ODP memory, avoid pinning. Instead, stores * the mm for future page fault handling in conjunction with MMU notifiers. * * @context: userspace context to pin memory for * @addr: userspace virtual address to start at * @size: length of region to pin * @access: IB_ACCESS_xxx flags for memory being pinned * @dmasync: flush in-flight DMA when the memory region is written */
struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, size_t size, int access, int dmasync) { struct ib_umem *umem; struct page **page_list; struct vm_area_struct **vma_list; unsigned long locked; unsigned long lock_limit; unsigned long cur_base; unsigned long npages; int ret; int i; unsigned long dma_attrs = 0; struct scatterlist *sg, *sg_list_start; int need_release = 0; unsigned int gup_flags = FOLL_WRITE; if (dmasync) dma_attrs |= DMA_ATTR_WRITE_BARRIER; /* * If the combination of the addr and size requested for this memory * region causes an integer overflow, return error. */ if (((addr + size) < addr) || PAGE_ALIGN(addr + size) < (addr + size)) return ERR_PTR(-EINVAL); if (!can_do_mlock()) return ERR_PTR(-EPERM); umem = kzalloc(sizeof *umem, GFP_KERNEL); if (!umem) return ERR_PTR(-ENOMEM); umem->context = context; umem->length = size; umem->address = addr; umem->page_size = PAGE_SIZE; umem->pid = get_task_pid(current, PIDTYPE_PID); /* * We ask for writable memory if any of the following * access flags are set. "Local write" and "remote write" * obviously require write access. "Remote atomic" can do * things like fetch and add, which will modify memory, and * "MW bind" can change permissions by binding a window. */ umem->writable = !!(access & (IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND)); if (access & IB_ACCESS_ON_DEMAND) { put_pid(umem->pid); ret = ib_umem_odp_get(context, umem); if (ret) { kfree(umem); return ERR_PTR(ret); } return umem; } umem->odp_data = NULL; /* We assume the memory is from hugetlb until proved otherwise */ umem->hugetlb = 1; page_list = (struct page **) __get_free_page(GFP_KERNEL); if (!page_list) { put_pid(umem->pid); kfree(umem); return ERR_PTR(-ENOMEM); } /* * if we can't alloc the vma_list, it's not so bad; * just assume the memory is not hugetlb memory */ vma_list = (struct vm_area_struct **) __get_free_page(GFP_KERNEL); if (!vma_list) umem->hugetlb = 0; npages = ib_umem_num_pages(umem); down_write(&current->mm->mmap_sem); locked = npages + current->mm->pinned_vm; lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { ret = -ENOMEM; goto out; } cur_base = addr & PAGE_MASK; if (npages == 0 || npages > UINT_MAX) { ret = -EINVAL; goto out; } ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); if (ret) goto out; if (!umem->writable) gup_flags |= FOLL_FORCE; need_release = 1; sg_list_start = umem->sg_head.sgl; while (npages) { ret = get_user_pages(cur_base, min_t(unsigned long, npages, PAGE_SIZE / sizeof (struct page *)), gup_flags, page_list, vma_list); if (ret < 0) goto out; umem->npages += ret; cur_base += ret * PAGE_SIZE; npages -= ret; for_each_sg(sg_list_start, sg, ret, i) { if (vma_list && !is_vm_hugetlb_page(vma_list[i])) umem->hugetlb = 0; sg_set_page(sg, page_list[i], PAGE_SIZE, 0); } /* preparing for next loop */ sg_list_start = sg; } umem->nmap = ib_dma_map_sg_attrs(context->device, umem->sg_head.sgl, umem->npages, DMA_BIDIRECTIONAL, dma_attrs); if (umem->nmap <= 0) { ret = -ENOMEM; goto out; } ret = 0; out: if (ret < 0) { if (need_release) __ib_umem_release(context->device, umem, 0); put_pid(umem->pid); kfree(umem); } else current->mm->pinned_vm = locked; up_write(&current->mm->mmap_sem); if (vma_list) free_page((unsigned long) vma_list); free_page((unsigned long) page_list); return ret < 0 ? ERR_PTR(ret) : umem; }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier37452.45%314.29%
Yishai Hadas9012.62%14.76%
Joachim Fenkes709.82%14.76%
Shachar Raindel689.54%29.52%
Lorenzo Stoakes182.52%14.76%
Shawn Bohrer182.52%14.76%
Kenneth Lee141.96%14.76%
Arthur Kepner111.54%14.76%
Sagi Grimberg101.40%14.76%
Jens Axboe91.26%29.52%
Krzysztof Kozlowski91.26%14.76%
Yann Droneaud81.12%14.76%
Mark Bloch40.56%14.76%
Andrew Morton30.42%14.76%
Jiri Slaby30.42%14.76%
Christoph Lameter20.28%14.76%
Haggai Eran20.28%14.76%
Total713100.00%21100.00%

EXPORT_SYMBOL(ib_umem_get);
static void ib_umem_account(struct work_struct *work) { struct ib_umem *umem = container_of(work, struct ib_umem, work); down_write(&umem->mm->mmap_sem); umem->mm->pinned_vm -= umem->diff; up_write(&umem->mm->mmap_sem); mmput(umem->mm); kfree(umem); }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier5885.29%250.00%
David Howells913.24%125.00%
Christoph Lameter11.47%125.00%
Total68100.00%4100.00%

/** * ib_umem_release - release memory pinned with ib_umem_get * @umem: umem struct to release */
void ib_umem_release(struct ib_umem *umem) { struct ib_ucontext *context = umem->context; struct mm_struct *mm; struct task_struct *task; unsigned long diff; if (umem->odp_data) { ib_umem_odp_release(umem); return; } __ib_umem_release(umem->context->device, umem, 1); task = get_pid_task(umem->pid, PIDTYPE_PID); put_pid(umem->pid); if (!task) goto out; mm = get_task_mm(task); put_task_struct(task); if (!mm) goto out; diff = ib_umem_num_pages(umem); /* * We may be called with the mm's mmap_sem already held. This * can happen when a userspace munmap() is the call that drops * the last reference to our file and calls our release * method. If there are memory regions to destroy, we'll end * up here and not be able to take the mmap_sem. In that case * we defer the vm_locked accounting to the system workqueue. */ if (context->closing) { if (!down_write_trylock(&mm->mmap_sem)) { INIT_WORK(&umem->work, ib_umem_account); umem->mm = mm; umem->diff = diff; queue_work(ib_wq, &umem->work); return; } } else down_write(&mm->mmap_sem); mm->pinned_vm -= diff; up_write(&mm->mmap_sem); mmput(mm); out: kfree(umem); }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier13968.47%440.00%
Shawn Bohrer4220.69%110.00%
Shachar Raindel146.90%110.00%
Eli Cohen31.48%110.00%
Tejun Heo31.48%110.00%
Yishai Hadas10.49%110.00%
Haggai Eran10.49%110.00%
Total203100.00%10100.00%

EXPORT_SYMBOL(ib_umem_release);
int ib_umem_page_count(struct ib_umem *umem) { int shift; int i; int n; struct scatterlist *sg; if (umem->odp_data) return ib_umem_num_pages(umem); shift = ilog2(umem->page_size); n = 0; for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) n += sg_dma_len(sg) >> shift; return n; }

Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier4766.20%250.00%
Yishai Hadas1216.90%125.00%
Shachar Raindel1216.90%125.00%
Total71100.00%4100.00%

EXPORT_SYMBOL(ib_umem_page_count); /* * Copy from the given ib_umem's pages to the given buffer. * * umem - the umem to copy from * offset - offset to start copying from * dst - destination buffer * length - buffer length * * Returns 0 on success, or an error code. */
int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, size_t length) { size_t end = offset + length; int ret; if (offset > umem->length || length > umem->length - offset) { pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", offset, umem->length, end); return -EINVAL; } ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->nmap, dst, length, offset + ib_umem_offset(umem)); if (ret < 0) return ret; else if (ret != length) return -EINVAL; else return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Haggai Eran115100.00%1100.00%
Total115100.00%1100.00%

EXPORT_SYMBOL(ib_umem_copy_from);

Overall Contributors

PersonTokensPropCommitsCommitProp
Roland Dreier70353.10%616.22%
Yishai Hadas14110.65%25.41%
Haggai Eran1259.44%38.11%
Shachar Raindel977.33%25.41%
Joachim Fenkes735.51%12.70%
Shawn Bohrer604.53%12.70%
Lorenzo Stoakes181.36%12.70%
Kenneth Lee141.06%12.70%
Jens Axboe130.98%25.41%
Arthur Kepner110.83%12.70%
Sagi Grimberg100.76%12.70%
David Howells90.68%12.70%
Krzysztof Kozlowski90.68%12.70%
Yann Droneaud80.60%12.70%
Tejun Heo60.45%25.41%
Mark Bloch40.30%12.70%
Ingo Molnar40.30%25.41%
Eli Cohen30.23%12.70%
Christoph Lameter30.23%12.70%
Jiri Slaby30.23%12.70%
Andrew Morton30.23%12.70%
Paul Gortmaker30.23%12.70%
Alexey Dobriyan20.15%12.70%
Sebastian Ott10.08%12.70%
Ralph Campbell10.08%12.70%
Total1324100.00%37100.00%
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