search for: vm_read

Hi Andi, Here's a couple of patches to fix up COMPAT_VDSO: The first is a straightforward implementation of Jan's original idea of relocating the VDSO to match its mapped location. Unlike Jan and Zach's version, I changed it to relocate based on the phdrs rather than the sections; the result is pleasantly compact. The second patch takes advantage of the fact that all the

Hi Andi, Here's a couple of patches to fix up COMPAT_VDSO: The first is a straightforward implementation of Jan's original idea of relocating the VDSO to match its mapped location. Unlike Jan and Zach's version, I changed it to relocate based on the phdrs rather than the sections; the result is pleasantly compact. The second patch takes advantage of the fact that all the

....g.: static int hmm_pfns_fill(unsigned long addr, unsigned long end, struct hmm_range *range, enum hmm_pfn_value_e value) > +static int hmm_vma_walk_test(unsigned long start, > + unsigned long end, > + struct mm_walk *walk) Same here. > + if (!(vma->vm_flags & VM_READ)) { > + (void) hmm_pfns_fill(start, end, range, HMM_PFN_NONE); There should be no need for the void cast here.

...VAL; + } else { + if (range->page_shift != PAGE_SHIFT) + return -EINVAL; + } + + /* + * If vma does not allow read access, then assume that it does not + * allow write access, either. HMM does not support architectures + * that allow write without read. + */ + if (!(vma->vm_flags & VM_READ)) + return -EPERM; + + return 0; } /* @@ -965,82 +996,35 @@ EXPORT_SYMBOL(hmm_range_unregister); */ long hmm_range_fault(struct hmm_range *range, unsigned int flags) { - const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP; - unsigned long start = range->start, end; - struct...

...f (vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP)) + return -EFAULT; + + /* + * If the vma does not allow read access, then assume that it does not + * allow write access either. HMM does not support architectures + * that allow write without read. + */ + if (!(vma->vm_flags & VM_READ)) { + (void) hmm_pfns_fill(start, end, range, HMM_PFN_NONE); + return -EPERM; + } + + return 0; } /* @@ -857,6 +879,7 @@ static const struct mm_walk_ops hmm_walk_ops = { .pmd_entry = hmm_vma_walk_pmd, .pte_hole = hmm_vma_walk_hole, .hugetlb_entry = hmm_vma_walk_hugetlb_entry, + .test_wa...

I have been working on converting Jerome's hmm_dummy driver and self tests into a stand-alone set of tests to be included in tools/testing/selftests/vm and came across these two bug fixes in the process. The tests aren't quite ready to be posted as a patch. I'm posting the fixes now since I thought they shouldn't wait. They should probably have a fixes line but with all the HMM

...area notify; > + int index = vma->vm_pgoff; > + > + if (vma->vm_end - vma->vm_start != PAGE_SIZE) > + return -EINVAL; > + if ((vma->vm_flags & VM_SHARED) == 0) > + return -EINVAL; > + if (vma->vm_flags & VM_READ) > + return -EINVAL; > + if (index > 65535) > + return -EINVAL; > + if (!ops->get_vq_notification) > + return -ENOTSUPP; > + > + /* To be safe and easily modelled by userspace, We only > + * support the...

Normally, callers to handle_mm_fault() are supposed to check the vma->vm_flags first. hmm_range_fault() checks for VM_READ but doesn't check for VM_WRITE if the caller requests a page to be faulted in with write permission (via the hmm_range.pfns[] value). If the vma is write protected, this can result in an infinite loop: hmm_range_fault() walk_page_range() ... hmm_vma_walk_hole() hmm_vma...

...a; + const struct vdpa_config_ops *ops = vdpa->config; + struct vdpa_notification_area notify; + int index = vma->vm_pgoff; + + if (vma->vm_end - vma->vm_start != PAGE_SIZE) + return -EINVAL; + if ((vma->vm_flags & VM_SHARED) == 0) + return -EINVAL; + if (vma->vm_flags & VM_READ) + return -EINVAL; + if (index > 65535) + return -EINVAL; + if (!ops->get_vq_notification) + return -ENOTSUPP; + + /* To be safe and easily modelled by userspace, We only + * support the doorbell which sits on the page boundary and + * does not share the page with other registers. + */...

...ea notify; >> +??? int index = vma->vm_pgoff; >> + >> +??? if (vma->vm_end - vma->vm_start != PAGE_SIZE) >> +??????? return -EINVAL; >> +??? if ((vma->vm_flags & VM_SHARED) == 0) >> +??????? return -EINVAL; >> +??? if (vma->vm_flags & VM_READ) >> +??????? return -EINVAL; >> +??? if (index > 65535) >> +??????? return -EINVAL; >> +??? if (!ops->get_vq_notification) >> +??????? return -ENOTSUPP; >> + >> +??? /* To be safe and easily modelled by userspace, We only >> +???? * support the...

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

Hi Andi, Four patches: - clean up asm/bugs.h, by moving all the C code into its own C file - split identify_cpu() into boot and secondary variants, so that boot-time setup functions can be marked __init - repost of the COMPAT_VDSO patches with a bit more robustness from unknown DT_tags, and functions marked __init, since all this is boot-time only setup. Thanks, J --

Here are seven more patches for things I found to clean up. This was based on top of Christoph's seven patches: "hmm_range_fault related fixes and legacy API removal v3". I assume this will go into Jason's tree since there will likely be more HMM changes in this cycle. Changes from v1 to v2: Added AMD GPU to hmm_update removal. Added 2 patches from Christoph. Added 2 patches as

...- if (is_vm_hugetlb_page(vma)) { - if (huge_page_shift(hstate_vma(vma)) != - range->page_shift && - range->page_shift != PAGE_SHIFT) - return -EINVAL; - } else { - if (range->page_shift != PAGE_SHIFT) - return -EINVAL; - } - if (!(vma->vm_flags & VM_READ)) { /* * If vma do not allow read access, then assume that it -- 2.20.1

...- if (is_vm_hugetlb_page(vma)) { - if (huge_page_shift(hstate_vma(vma)) != - range->page_shift && - range->page_shift != PAGE_SHIFT) - return -EINVAL; - } else { - if (range->page_shift != PAGE_SHIFT) - return -EINVAL; - } - if (!(vma->vm_flags & VM_READ)) { /* * If vma do not allow read access, then assume that it -- 2.20.1

...m_area_cachep, SLAB_KERNEL); + if (!vma) + return -ENOMEM; + + memset(vma, 0, sizeof(struct vm_area_struct)); + /* Could randomize here */ + vma->vm_start = VSYSCALL_BASE; + vma->vm_end = VSYSCALL_BASE + PAGE_SIZE; + /* MAYWRITE to allow gdb to COW and set breakpoints */ + vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; + vma->vm_flags |= mm->def_flags; + vma->vm_page_prot = protection_map[vma->vm_flags & 7]; + vma->vm_ops = &syscall_vm_ops; + vma->vm_mm = mm; + + down_write(&mm->mmap_sem); + if ((ret = insert_vm_struct(mm, vma))) { + up_...

...m_area_cachep, SLAB_KERNEL); + if (!vma) + return -ENOMEM; + + memset(vma, 0, sizeof(struct vm_area_struct)); + /* Could randomize here */ + vma->vm_start = VSYSCALL_BASE; + vma->vm_end = VSYSCALL_BASE + PAGE_SIZE; + /* MAYWRITE to allow gdb to COW and set breakpoints */ + vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; + vma->vm_flags |= mm->def_flags; + vma->vm_page_prot = protection_map[vma->vm_flags & 7]; + vma->vm_ops = &syscall_vm_ops; + vma->vm_mm = mm; + + down_write(&mm->mmap_sem); + if ((ret = insert_vm_struct(mm, vma))) { + up_...

Hi all: This series introduce basic functionality of doorbell mapping support for vhost-vDPA. Userspace program may use mmap() to map a the doorbell of a specific virtqueue into its address space. This is help to reudce the syscall or vmexit overhead. A new vdpa_config_ops was introduced to report the location of the doorbell, vhost_vdpa may then choose to map the doorbell when: - The doorbell

Hi all: This series introduce basic functionality of doorbell mapping support for vhost-vDPA. Userspace program may use mmap() to map a the doorbell of a specific virtqueue into its address space. This is help to reudce the syscall or vmexit overhead. A new vdpa_config_ops was introduced to report the location of the doorbell, vhost_vdpa may then choose to map the doorbell when: - The doorbell

These changes are based on Jason's latest hmm branch. Patch 1 was previously posted here [1] but was dropped from the orginal series. Hopefully, the tests will reduce concerns about edge conditions. I'm sure more tests could be usefully added but I thought this was a good starting point. [1] https://lore.kernel.org/linux-mm/20190726005650.2566-6-rcampbell at nvidia.com/ Ralph Campbell