From: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> Subject: mm: add account_locked_vm utility function locked_vm accounting is done roughly the same way in five places, so unify them in a helper. Include the helper's caller in the debug print to distinguish between callsites. Error codes stay the same, so user-visible behavior does too. The one exception is that the -EPERM case in tce_account_locked_vm is removed because Alexey has never seen it triggered. [daniel.m.jordan@xxxxxxxxxx: v3] Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@xxxxxxxxxx [sfr@xxxxxxxxxxxxxxxx: fix mm/util.c] Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@xxxxxxxxxx Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Tested-by: Alexey Kardashevskiy <aik@xxxxxxxxx> Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx> Cc: Alan Tull <atull@xxxxxxxxxx> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Moritz Fischer <mdf@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxxx> Cc: Steve Sistare <steven.sistare@xxxxxxxxxx> Cc: Wu Hao <hao.wu@xxxxxxxxx> Cc: Ira Weiny <ira.weiny@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/powerpc/kvm/book3s_64_vio.c | 44 +------------- arch/powerpc/mm/book3s64/iommu_api.c | 41 +------------ drivers/fpga/dfl-afu-dma-region.c | 53 +---------------- drivers/vfio/vfio_iommu_spapr_tce.c | 54 +----------------- drivers/vfio/vfio_iommu_type1.c | 17 ----- include/linux/mm.h | 4 + mm/util.c | 75 +++++++++++++++++++++++++ 7 files changed, 98 insertions(+), 190 deletions(-) --- a/arch/powerpc/kvm/book3s_64_vio.c~mm-add-account_locked_vm-utility-function +++ a/arch/powerpc/kvm/book3s_64_vio.c @@ -19,6 +19,7 @@ #include <linux/anon_inodes.h> #include <linux/iommu.h> #include <linux/file.h> +#include <linux/mm.h> #include <asm/kvm_ppc.h> #include <asm/kvm_book3s.h> @@ -45,43 +46,6 @@ static unsigned long kvmppc_stt_pages(un return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; } -static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) -{ - long ret = 0; - - if (!current || !current->mm) - return ret; /* process exited */ - - down_write(¤t->mm->mmap_sem); - - if (inc) { - unsigned long locked, lock_limit; - - locked = current->mm->locked_vm + stt_pages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) - ret = -ENOMEM; - else - current->mm->locked_vm += stt_pages; - } else { - if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm)) - stt_pages = current->mm->locked_vm; - - current->mm->locked_vm -= stt_pages; - } - - pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid, - inc ? '+' : '-', - stt_pages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK), - ret ? " - exceeded" : ""); - - up_write(¤t->mm->mmap_sem); - - return ret; -} - static void kvm_spapr_tce_iommu_table_free(struct rcu_head *head) { struct kvmppc_spapr_tce_iommu_table *stit = container_of(head, @@ -291,7 +255,7 @@ static int kvm_spapr_tce_release(struct kvm_put_kvm(stt->kvm); - kvmppc_account_memlimit( + account_locked_vm(current->mm, kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false); call_rcu(&stt->rcu, release_spapr_tce_table); @@ -316,7 +280,7 @@ long kvm_vm_ioctl_create_spapr_tce(struc return -EINVAL; npages = kvmppc_tce_pages(size); - ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true); + ret = account_locked_vm(current->mm, kvmppc_stt_pages(npages), true); if (ret) return ret; @@ -362,7 +326,7 @@ long kvm_vm_ioctl_create_spapr_tce(struc kfree(stt); fail_acct: - kvmppc_account_memlimit(kvmppc_stt_pages(npages), false); + account_locked_vm(current->mm, kvmppc_stt_pages(npages), false); return ret; } --- a/arch/powerpc/mm/book3s64/iommu_api.c~mm-add-account_locked_vm-utility-function +++ a/arch/powerpc/mm/book3s64/iommu_api.c @@ -14,6 +14,7 @@ #include <linux/hugetlb.h> #include <linux/swap.h> #include <linux/sizes.h> +#include <linux/mm.h> #include <asm/mmu_context.h> #include <asm/pte-walk.h> #include <linux/mm_inline.h> @@ -46,40 +47,6 @@ struct mm_iommu_table_group_mem_t { u64 dev_hpa; /* Device memory base address */ }; -static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, - unsigned long npages, bool incr) -{ - long ret = 0, locked, lock_limit; - - if (!npages) - return 0; - - down_write(&mm->mmap_sem); - - if (incr) { - locked = mm->locked_vm + npages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) - ret = -ENOMEM; - else - mm->locked_vm += npages; - } else { - if (WARN_ON_ONCE(npages > mm->locked_vm)) - npages = mm->locked_vm; - mm->locked_vm -= npages; - } - - pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n", - current ? current->pid : 0, - incr ? '+' : '-', - npages << PAGE_SHIFT, - mm->locked_vm << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK)); - up_write(&mm->mmap_sem); - - return ret; -} - bool mm_iommu_preregistered(struct mm_struct *mm) { return !list_empty(&mm->context.iommu_group_mem_list); @@ -96,7 +63,7 @@ static long mm_iommu_do_alloc(struct mm_ unsigned long entry, chunk; if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) { - ret = mm_iommu_adjust_locked_vm(mm, entries, true); + ret = account_locked_vm(mm, entries, true); if (ret) return ret; @@ -211,7 +178,7 @@ free_exit: kfree(mem); unlock_exit: - mm_iommu_adjust_locked_vm(mm, locked_entries, false); + account_locked_vm(mm, locked_entries, false); return ret; } @@ -311,7 +278,7 @@ long mm_iommu_put(struct mm_struct *mm, unlock_exit: mutex_unlock(&mem_list_mutex); - mm_iommu_adjust_locked_vm(mm, unlock_entries, false); + account_locked_vm(mm, unlock_entries, false); return ret; } --- a/drivers/fpga/dfl-afu-dma-region.c~mm-add-account_locked_vm-utility-function +++ a/drivers/fpga/dfl-afu-dma-region.c @@ -12,6 +12,7 @@ #include <linux/dma-mapping.h> #include <linux/sched/signal.h> #include <linux/uaccess.h> +#include <linux/mm.h> #include "dfl-afu.h" @@ -32,52 +33,6 @@ void afu_dma_region_init(struct dfl_feat } /** - * afu_dma_adjust_locked_vm - adjust locked memory - * @dev: port device - * @npages: number of pages - * @incr: increase or decrease locked memory - * - * Increase or decrease the locked memory size with npages input. - * - * Return 0 on success. - * Return -ENOMEM if locked memory size is over the limit and no CAP_IPC_LOCK. - */ -static int afu_dma_adjust_locked_vm(struct device *dev, long npages, bool incr) -{ - unsigned long locked, lock_limit; - int ret = 0; - - /* the task is exiting. */ - if (!current->mm) - return 0; - - down_write(¤t->mm->mmap_sem); - - if (incr) { - locked = current->mm->locked_vm + npages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) - ret = -ENOMEM; - else - current->mm->locked_vm += npages; - } else { - if (WARN_ON_ONCE(npages > current->mm->locked_vm)) - npages = current->mm->locked_vm; - current->mm->locked_vm -= npages; - } - - dev_dbg(dev, "[%d] RLIMIT_MEMLOCK %c%ld %ld/%ld%s\n", current->pid, - incr ? '+' : '-', npages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, rlimit(RLIMIT_MEMLOCK), - ret ? "- exceeded" : ""); - - up_write(¤t->mm->mmap_sem); - - return ret; -} - -/** * afu_dma_pin_pages - pin pages of given dma memory region * @pdata: feature device platform data * @region: dma memory region to be pinned @@ -92,7 +47,7 @@ static int afu_dma_pin_pages(struct dfl_ struct device *dev = &pdata->dev->dev; int ret, pinned; - ret = afu_dma_adjust_locked_vm(dev, npages, true); + ret = account_locked_vm(current->mm, npages, true); if (ret) return ret; @@ -121,7 +76,7 @@ put_pages: free_pages: kfree(region->pages); unlock_vm: - afu_dma_adjust_locked_vm(dev, npages, false); + account_locked_vm(current->mm, npages, false); return ret; } @@ -141,7 +96,7 @@ static void afu_dma_unpin_pages(struct d put_all_pages(region->pages, npages); kfree(region->pages); - afu_dma_adjust_locked_vm(dev, npages, false); + account_locked_vm(current->mm, npages, false); dev_dbg(dev, "%ld pages unpinned\n", npages); } --- a/drivers/vfio/vfio_iommu_spapr_tce.c~mm-add-account_locked_vm-utility-function +++ a/drivers/vfio/vfio_iommu_spapr_tce.c @@ -19,6 +19,7 @@ #include <linux/vmalloc.h> #include <linux/sched/mm.h> #include <linux/sched/signal.h> +#include <linux/mm.h> #include <asm/iommu.h> #include <asm/tce.h> @@ -31,51 +32,6 @@ static void tce_iommu_detach_group(void *iommu_data, struct iommu_group *iommu_group); -static long try_increment_locked_vm(struct mm_struct *mm, long npages) -{ - long ret = 0, locked, lock_limit; - - if (WARN_ON_ONCE(!mm)) - return -EPERM; - - if (!npages) - return 0; - - down_write(&mm->mmap_sem); - locked = mm->locked_vm + npages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) - ret = -ENOMEM; - else - mm->locked_vm += npages; - - pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid, - npages << PAGE_SHIFT, - mm->locked_vm << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK), - ret ? " - exceeded" : ""); - - up_write(&mm->mmap_sem); - - return ret; -} - -static void decrement_locked_vm(struct mm_struct *mm, long npages) -{ - if (!mm || !npages) - return; - - down_write(&mm->mmap_sem); - if (WARN_ON_ONCE(npages > mm->locked_vm)) - npages = mm->locked_vm; - mm->locked_vm -= npages; - pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid, - npages << PAGE_SHIFT, - mm->locked_vm << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK)); - up_write(&mm->mmap_sem); -} - /* * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation * @@ -333,7 +289,7 @@ static int tce_iommu_enable(struct tce_c return ret; locked = table_group->tce32_size >> PAGE_SHIFT; - ret = try_increment_locked_vm(container->mm, locked); + ret = account_locked_vm(container->mm, locked, true); if (ret) return ret; @@ -352,7 +308,7 @@ static void tce_iommu_disable(struct tce container->enabled = false; BUG_ON(!container->mm); - decrement_locked_vm(container->mm, container->locked_pages); + account_locked_vm(container->mm, container->locked_pages, false); } static void *tce_iommu_open(unsigned long arg) @@ -656,7 +612,7 @@ static long tce_iommu_create_table(struc if (!table_size) return -EINVAL; - ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT); + ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true); if (ret) return ret; @@ -675,7 +631,7 @@ static void tce_iommu_free_table(struct unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT; iommu_tce_table_put(tbl); - decrement_locked_vm(container->mm, pages); + account_locked_vm(container->mm, pages, false); } static long tce_iommu_create_window(struct tce_container *container, --- a/drivers/vfio/vfio_iommu_type1.c~mm-add-account_locked_vm-utility-function +++ a/drivers/vfio/vfio_iommu_type1.c @@ -272,21 +272,8 @@ static int vfio_lock_acct(struct vfio_dm ret = down_write_killable(&mm->mmap_sem); if (!ret) { - if (npage > 0) { - if (!dma->lock_cap) { - unsigned long limit; - - limit = task_rlimit(dma->task, - RLIMIT_MEMLOCK) >> PAGE_SHIFT; - - if (mm->locked_vm + npage > limit) - ret = -ENOMEM; - } - } - - if (!ret) - mm->locked_vm += npage; - + ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task, + dma->lock_cap); up_write(&mm->mmap_sem); } --- a/include/linux/mm.h~mm-add-account_locked_vm-utility-function +++ a/include/linux/mm.h @@ -1543,6 +1543,10 @@ long get_user_pages_unlocked(unsigned lo int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); +int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc); +int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, + struct task_struct *task, bool bypass_rlim); + /* Container for pinned pfns / pages */ struct frame_vector { unsigned int nr_allocated; /* Number of frames we have space for */ --- a/mm/util.c~mm-add-account_locked_vm-utility-function +++ a/mm/util.c @@ -7,6 +7,7 @@ #include <linux/err.h> #include <linux/sched.h> #include <linux/sched/mm.h> +#include <linux/sched/signal.h> #include <linux/sched/task_stack.h> #include <linux/security.h> #include <linux/swap.h> @@ -300,6 +301,80 @@ void arch_pick_mmap_layout(struct mm_str } #endif +/** + * __account_locked_vm - account locked pages to an mm's locked_vm + * @mm: mm to account against + * @pages: number of pages to account + * @inc: %true if @pages should be considered positive, %false if not + * @task: task used to check RLIMIT_MEMLOCK + * @bypass_rlim: %true if checking RLIMIT_MEMLOCK should be skipped + * + * Assumes @task and @mm are valid (i.e. at least one reference on each), and + * that mmap_sem is held as writer. + * + * Return: + * * 0 on success + * * -ENOMEM if RLIMIT_MEMLOCK would be exceeded. + */ +int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, + struct task_struct *task, bool bypass_rlim) +{ + unsigned long locked_vm, limit; + int ret = 0; + + lockdep_assert_held_write(&mm->mmap_sem); + + locked_vm = mm->locked_vm; + if (inc) { + if (!bypass_rlim) { + limit = task_rlimit(task, RLIMIT_MEMLOCK) >> PAGE_SHIFT; + if (locked_vm + pages > limit) + ret = -ENOMEM; + } + if (!ret) + mm->locked_vm = locked_vm + pages; + } else { + WARN_ON_ONCE(pages > locked_vm); + mm->locked_vm = locked_vm - pages; + } + + pr_debug("%s: [%d] caller %ps %c%lu %lu/%lu%s\n", __func__, task->pid, + (void *)_RET_IP_, (inc) ? '+' : '-', pages << PAGE_SHIFT, + locked_vm << PAGE_SHIFT, task_rlimit(task, RLIMIT_MEMLOCK), + ret ? " - exceeded" : ""); + + return ret; +} +EXPORT_SYMBOL_GPL(__account_locked_vm); + +/** + * account_locked_vm - account locked pages to an mm's locked_vm + * @mm: mm to account against, may be NULL + * @pages: number of pages to account + * @inc: %true if @pages should be considered positive, %false if not + * + * Assumes a non-NULL @mm is valid (i.e. at least one reference on it). + * + * Return: + * * 0 on success, or if mm is NULL + * * -ENOMEM if RLIMIT_MEMLOCK would be exceeded. + */ +int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc) +{ + int ret; + + if (pages == 0 || !mm) + return 0; + + down_write(&mm->mmap_sem); + ret = __account_locked_vm(mm, pages, inc, current, + capable(CAP_IPC_LOCK)); + up_write(&mm->mmap_sem); + + return ret; +} +EXPORT_SYMBOL_GPL(account_locked_vm); + unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flag, unsigned long pgoff) _
