On Thu 13-10-16 01:20:16, Lorenzo Stoakes wrote: > This patch removes the write and force parameters from get_user_pages() and > replaces them with a gup_flags parameter to make the use of FOLL_FORCE explicit > in callers as use of this flag can result in surprising behaviour (and hence > bugs) within the mm subsystem. > > Signed-off-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx> The patch looks good. You can add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > arch/cris/arch-v32/drivers/cryptocop.c | 4 +--- > arch/ia64/kernel/err_inject.c | 2 +- > arch/x86/mm/mpx.c | 5 ++--- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 7 +++++-- > drivers/gpu/drm/radeon/radeon_ttm.c | 3 ++- > drivers/gpu/drm/via/via_dmablit.c | 4 ++-- > drivers/infiniband/core/umem.c | 6 +++++- > drivers/infiniband/hw/mthca/mthca_memfree.c | 2 +- > drivers/infiniband/hw/qib/qib_user_pages.c | 3 ++- > drivers/infiniband/hw/usnic/usnic_uiom.c | 5 ++++- > drivers/media/v4l2-core/videobuf-dma-sg.c | 7 +++++-- > drivers/misc/mic/scif/scif_rma.c | 3 +-- > drivers/misc/sgi-gru/grufault.c | 2 +- > drivers/platform/goldfish/goldfish_pipe.c | 3 ++- > drivers/rapidio/devices/rio_mport_cdev.c | 3 ++- > .../vc04_services/interface/vchiq_arm/vchiq_2835_arm.c | 3 +-- > .../vc04_services/interface/vchiq_arm/vchiq_arm.c | 3 +-- > drivers/virt/fsl_hypervisor.c | 4 ++-- > include/linux/mm.h | 2 +- > mm/gup.c | 12 +++--------- > mm/mempolicy.c | 2 +- > mm/nommu.c | 18 ++++-------------- > 22 files changed, 49 insertions(+), 54 deletions(-) > > diff --git a/arch/cris/arch-v32/drivers/cryptocop.c b/arch/cris/arch-v32/drivers/cryptocop.c > index b5698c8..099e170 100644 > --- a/arch/cris/arch-v32/drivers/cryptocop.c > +++ b/arch/cris/arch-v32/drivers/cryptocop.c > @@ -2722,7 +2722,6 @@ static int cryptocop_ioctl_process(struct inode *inode, struct file *filp, unsig > err = get_user_pages((unsigned long int)(oper.indata + prev_ix), > noinpages, > 0, /* read access only for in data */ > - 0, /* no force */ > inpages, > NULL); > > @@ -2736,8 +2735,7 @@ static int cryptocop_ioctl_process(struct inode *inode, struct file *filp, unsig > if (oper.do_cipher){ > err = get_user_pages((unsigned long int)oper.cipher_outdata, > nooutpages, > - 1, /* write access for out data */ > - 0, /* no force */ > + FOLL_WRITE, /* write access for out data */ > outpages, > NULL); > up_read(¤t->mm->mmap_sem); > diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c > index 09f8457..5ed0ea9 100644 > --- a/arch/ia64/kernel/err_inject.c > +++ b/arch/ia64/kernel/err_inject.c > @@ -142,7 +142,7 @@ store_virtual_to_phys(struct device *dev, struct device_attribute *attr, > u64 virt_addr=simple_strtoull(buf, NULL, 16); > int ret; > > - ret = get_user_pages(virt_addr, 1, VM_READ, 0, NULL, NULL); > + ret = get_user_pages(virt_addr, 1, FOLL_WRITE, NULL, NULL); > if (ret<=0) { > #ifdef ERR_INJ_DEBUG > printk("Virtual address %lx is not existing.\n",virt_addr); > diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c > index 8047687..e4f8009 100644 > --- a/arch/x86/mm/mpx.c > +++ b/arch/x86/mm/mpx.c > @@ -544,10 +544,9 @@ static int mpx_resolve_fault(long __user *addr, int write) > { > long gup_ret; > int nr_pages = 1; > - int force = 0; > > - gup_ret = get_user_pages((unsigned long)addr, nr_pages, write, > - force, NULL, NULL); > + gup_ret = get_user_pages((unsigned long)addr, nr_pages, > + write ? FOLL_WRITE : 0, NULL, NULL); > /* > * get_user_pages() returns number of pages gotten. > * 0 means we failed to fault in and get anything, > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > index 887483b..dcaf691 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > @@ -555,10 +555,13 @@ struct amdgpu_ttm_tt { > int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) > { > struct amdgpu_ttm_tt *gtt = (void *)ttm; > - int write = !(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY); > + unsigned int flags = 0; > unsigned pinned = 0; > int r; > > + if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY)) > + flags |= FOLL_WRITE; > + > if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) { > /* check that we only use anonymous memory > to prevent problems with writeback */ > @@ -581,7 +584,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages) > list_add(&guptask.list, >t->guptasks); > spin_unlock(>t->guptasklock); > > - r = get_user_pages(userptr, num_pages, write, 0, p, NULL); > + r = get_user_pages(userptr, num_pages, flags, p, NULL); > > spin_lock(>t->guptasklock); > list_del(&guptask.list); > diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c > index 4552682..3de5e6e 100644 > --- a/drivers/gpu/drm/radeon/radeon_ttm.c > +++ b/drivers/gpu/drm/radeon/radeon_ttm.c > @@ -566,7 +566,8 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm) > uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE; > struct page **pages = ttm->pages + pinned; > > - r = get_user_pages(userptr, num_pages, write, 0, pages, NULL); > + r = get_user_pages(userptr, num_pages, write ? FOLL_WRITE : 0, > + pages, NULL); > if (r < 0) > goto release_pages; > > diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c > index 7e2a12c..1a3ad76 100644 > --- a/drivers/gpu/drm/via/via_dmablit.c > +++ b/drivers/gpu/drm/via/via_dmablit.c > @@ -241,8 +241,8 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer) > down_read(¤t->mm->mmap_sem); > ret = get_user_pages((unsigned long)xfer->mem_addr, > vsg->num_pages, > - (vsg->direction == DMA_FROM_DEVICE), > - 0, vsg->pages, NULL); > + (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0, > + vsg->pages, NULL); > > up_read(¤t->mm->mmap_sem); > if (ret != vsg->num_pages) { > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c > index c68746c..224ad27 100644 > --- a/drivers/infiniband/core/umem.c > +++ b/drivers/infiniband/core/umem.c > @@ -94,6 +94,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, > 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; > @@ -183,6 +184,9 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, > if (ret) > goto out; > > + if (!umem->writable) > + gup_flags |= FOLL_FORCE; > + > need_release = 1; > sg_list_start = umem->sg_head.sgl; > > @@ -190,7 +194,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, > ret = get_user_pages(cur_base, > min_t(unsigned long, npages, > PAGE_SIZE / sizeof (struct page *)), > - 1, !umem->writable, page_list, vma_list); > + gup_flags, page_list, vma_list); > > if (ret < 0) > goto out; > diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c > index 6c00d04..c6fe89d 100644 > --- a/drivers/infiniband/hw/mthca/mthca_memfree.c > +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c > @@ -472,7 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, > goto out; > } > > - ret = get_user_pages(uaddr & PAGE_MASK, 1, 1, 0, pages, NULL); > + ret = get_user_pages(uaddr & PAGE_MASK, 1, FOLL_WRITE, pages, NULL); > if (ret < 0) > goto out; > > diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c > index 2d2b94f..75f0862 100644 > --- a/drivers/infiniband/hw/qib/qib_user_pages.c > +++ b/drivers/infiniband/hw/qib/qib_user_pages.c > @@ -67,7 +67,8 @@ static int __qib_get_user_pages(unsigned long start_page, size_t num_pages, > > for (got = 0; got < num_pages; got += ret) { > ret = get_user_pages(start_page + got * PAGE_SIZE, > - num_pages - got, 1, 1, > + num_pages - got, > + FOLL_WRITE | FOLL_FORCE, > p + got, NULL); > if (ret < 0) > goto bail_release; > diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c > index a0b6ebe..1ccee6e 100644 > --- a/drivers/infiniband/hw/usnic/usnic_uiom.c > +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c > @@ -111,6 +111,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, > int i; > int flags; > dma_addr_t pa; > + unsigned int gup_flags; > > if (!can_do_mlock()) > return -EPERM; > @@ -135,6 +136,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, > > flags = IOMMU_READ | IOMMU_CACHE; > flags |= (writable) ? IOMMU_WRITE : 0; > + gup_flags = FOLL_WRITE; > + gup_flags |= (writable) ? 0 : FOLL_FORCE; > cur_base = addr & PAGE_MASK; > ret = 0; > > @@ -142,7 +145,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, > ret = get_user_pages(cur_base, > min_t(unsigned long, npages, > PAGE_SIZE / sizeof(struct page *)), > - 1, !writable, page_list, NULL); > + gup_flags, page_list, NULL); > > if (ret < 0) > goto out; > diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c > index f300f06..1db0af6 100644 > --- a/drivers/media/v4l2-core/videobuf-dma-sg.c > +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c > @@ -156,6 +156,7 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, > { > unsigned long first, last; > int err, rw = 0; > + unsigned int flags = FOLL_FORCE; > > dma->direction = direction; > switch (dma->direction) { > @@ -178,12 +179,14 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, > if (NULL == dma->pages) > return -ENOMEM; > > + if (rw == READ) > + flags |= FOLL_WRITE; > + > dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n", > data, size, dma->nr_pages); > > err = get_user_pages(data & PAGE_MASK, dma->nr_pages, > - rw == READ, 1, /* force */ > - dma->pages, NULL); > + flags, dma->pages, NULL); > > if (err != dma->nr_pages) { > dma->nr_pages = (err >= 0) ? err : 0; > diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c > index e0203b1..f806a44 100644 > --- a/drivers/misc/mic/scif/scif_rma.c > +++ b/drivers/misc/mic/scif/scif_rma.c > @@ -1396,8 +1396,7 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, > pinned_pages->nr_pages = get_user_pages( > (u64)addr, > nr_pages, > - !!(prot & SCIF_PROT_WRITE), > - 0, > + (prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0, > pinned_pages->pages, > NULL); > up_write(&mm->mmap_sem); > diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c > index a2d97b9..6fb773d 100644 > --- a/drivers/misc/sgi-gru/grufault.c > +++ b/drivers/misc/sgi-gru/grufault.c > @@ -198,7 +198,7 @@ static int non_atomic_pte_lookup(struct vm_area_struct *vma, > #else > *pageshift = PAGE_SHIFT; > #endif > - if (get_user_pages(vaddr, 1, write, 0, &page, NULL) <= 0) > + if (get_user_pages(vaddr, 1, write ? FOLL_WRITE : 0, &page, NULL) <= 0) > return -EFAULT; > *paddr = page_to_phys(page); > put_page(page); > diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c > index 07462d7..1aba2c7 100644 > --- a/drivers/platform/goldfish/goldfish_pipe.c > +++ b/drivers/platform/goldfish/goldfish_pipe.c > @@ -309,7 +309,8 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, > * much memory to the process. > */ > down_read(¤t->mm->mmap_sem); > - ret = get_user_pages(address, 1, !is_write, 0, &page, NULL); > + ret = get_user_pages(address, 1, is_write ? 0 : FOLL_WRITE, > + &page, NULL); > up_read(¤t->mm->mmap_sem); > if (ret < 0) > break; > diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c > index 436dfe8..9013a58 100644 > --- a/drivers/rapidio/devices/rio_mport_cdev.c > +++ b/drivers/rapidio/devices/rio_mport_cdev.c > @@ -892,7 +892,8 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode, > down_read(¤t->mm->mmap_sem); > pinned = get_user_pages( > (unsigned long)xfer->loc_addr & PAGE_MASK, > - nr_pages, dir == DMA_FROM_DEVICE, 0, > + nr_pages, > + dir == DMA_FROM_DEVICE ? FOLL_WRITE : 0, > page_list, NULL); > up_read(¤t->mm->mmap_sem); > > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c > index c29040f..1091b9f 100644 > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c > @@ -423,8 +423,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type, > actual_pages = get_user_pages(task, task->mm, > (unsigned long)buf & ~(PAGE_SIZE - 1), > num_pages, > - (type == PAGELIST_READ) /*Write */ , > - 0 /*Force */ , > + (type == PAGELIST_READ) ? FOLL_WRITE : 0, > pages, > NULL /*vmas */); > up_read(&task->mm->mmap_sem); > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > index e11c0e0..7b6cd4d 100644 > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > @@ -1477,8 +1477,7 @@ dump_phys_mem(void *virt_addr, uint32_t num_bytes) > current->mm, /* mm */ > (unsigned long)virt_addr, /* start */ > num_pages, /* len */ > - 0, /* write */ > - 0, /* force */ > + 0, /* gup_flags */ > pages, /* pages (array of page pointers) */ > NULL); /* vmas */ > up_read(¤t->mm->mmap_sem); > diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c > index 60bdad3..150ce2a 100644 > --- a/drivers/virt/fsl_hypervisor.c > +++ b/drivers/virt/fsl_hypervisor.c > @@ -245,8 +245,8 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) > /* Get the physical addresses of the source buffer */ > down_read(¤t->mm->mmap_sem); > num_pinned = get_user_pages(param.local_vaddr - lb_offset, > - num_pages, (param.source == -1) ? READ : WRITE, > - 0, pages, NULL); > + num_pages, (param.source == -1) ? 0 : FOLL_WRITE, > + pages, NULL); > up_read(¤t->mm->mmap_sem); > > if (num_pinned != num_pages) { > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 5ff084f6..686a477 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1279,7 +1279,7 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, > int write, int force, struct page **pages, > struct vm_area_struct **vmas); > long get_user_pages(unsigned long start, unsigned long nr_pages, > - int write, int force, struct page **pages, > + unsigned int gup_flags, struct page **pages, > struct vm_area_struct **vmas); > long get_user_pages_locked(unsigned long start, unsigned long nr_pages, > unsigned int gup_flags, struct page **pages, int *locked); > diff --git a/mm/gup.c b/mm/gup.c > index 7a0d033..dc91303 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -977,18 +977,12 @@ EXPORT_SYMBOL(get_user_pages_remote); > * obviously don't pass FOLL_REMOTE in here. > */ > long get_user_pages(unsigned long start, unsigned long nr_pages, > - int write, int force, struct page **pages, > + unsigned int gup_flags, struct page **pages, > struct vm_area_struct **vmas) > { > - unsigned int flags = FOLL_TOUCH; > - > - if (write) > - flags |= FOLL_WRITE; > - if (force) > - flags |= FOLL_FORCE; > - > return __get_user_pages_locked(current, current->mm, start, nr_pages, > - pages, vmas, NULL, false, flags); > + pages, vmas, NULL, false, > + gup_flags | FOLL_TOUCH); > } > EXPORT_SYMBOL(get_user_pages); > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index ad1c96a..0b859af 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -850,7 +850,7 @@ static int lookup_node(unsigned long addr) > struct page *p; > int err; > > - err = get_user_pages(addr & PAGE_MASK, 1, 0, 0, &p, NULL); > + err = get_user_pages(addr & PAGE_MASK, 1, 0, &p, NULL); > if (err >= 0) { > err = page_to_nid(p); > put_page(p); > diff --git a/mm/nommu.c b/mm/nommu.c > index 842cfdd..70cb844 100644 > --- a/mm/nommu.c > +++ b/mm/nommu.c > @@ -160,18 +160,11 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > * - don't permit access to VMAs that don't support it, such as I/O mappings > */ > long get_user_pages(unsigned long start, unsigned long nr_pages, > - int write, int force, struct page **pages, > + unsigned int gup_flags, struct page **pages, > struct vm_area_struct **vmas) > { > - int flags = 0; > - > - if (write) > - flags |= FOLL_WRITE; > - if (force) > - flags |= FOLL_FORCE; > - > - return __get_user_pages(current, current->mm, start, nr_pages, flags, > - pages, vmas, NULL); > + return __get_user_pages(current, current->mm, start, nr_pages, > + gup_flags, pages, vmas, NULL); > } > EXPORT_SYMBOL(get_user_pages); > > @@ -179,10 +172,7 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, > unsigned int gup_flags, struct page **pages, > int *locked) > { > - int write = gup_flags & FOLL_WRITE; > - int force = gup_flags & FOLL_FORCE; > - > - return get_user_pages(start, nr_pages, write, force, pages, NULL); > + return get_user_pages(start, nr_pages, gup_flags, pages, NULL); > } > EXPORT_SYMBOL(get_user_pages_locked); > > -- > 2.10.0 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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