diff options
| author | Alistair Popple <apopple@nvidia.com> | 2022-01-14 14:09:31 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-27 10:54:36 +0100 |
| commit | 62925037005243c57067a5b81764a0c0ca93d580 (patch) | |
| tree | addae0ac5e85eb0af96ffd3f4cb8f53f9cccbbbb /lib | |
| parent | 33bb7f027b069530110ec533829e65f22db8c8ff (diff) | |
| download | linux-stable-62925037005243c57067a5b81764a0c0ca93d580.tar.gz linux-stable-62925037005243c57067a5b81764a0c0ca93d580.tar.bz2 linux-stable-62925037005243c57067a5b81764a0c0ca93d580.zip | |
mm/hmm.c: allow VM_MIXEDMAP to work with hmm_range_fault
commit 87c01d57fa23de82fff593a7d070933d08755801 upstream.
hmm_range_fault() can be used instead of get_user_pages() for devices
which allow faulting however unlike get_user_pages() it will return an
error when used on a VM_MIXEDMAP range.
To make hmm_range_fault() more closely match get_user_pages() remove
this restriction. This requires dealing with the !ARCH_HAS_PTE_SPECIAL
case in hmm_vma_handle_pte(). Rather than replicating the logic of
vm_normal_page() call it directly and do a check for the zero pfn
similar to what get_user_pages() currently does.
Also add a test to hmm selftest to verify functionality.
Link: https://lkml.kernel.org/r/20211104012001.2555676-1-apopple@nvidia.com
Fixes: da4c3c735ea4 ("mm/hmm/mirror: helper to snapshot CPU page table")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_hmm.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 80a78877bd93..a85613068d60 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -965,9 +965,33 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp, return 0; } +static int dmirror_fops_mmap(struct file *file, struct vm_area_struct *vma) +{ + unsigned long addr; + + for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) { + struct page *page; + int ret; + + page = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!page) + return -ENOMEM; + + ret = vm_insert_page(vma, addr, page); + if (ret) { + __free_page(page); + return ret; + } + put_page(page); + } + + return 0; +} + static const struct file_operations dmirror_fops = { .open = dmirror_fops_open, .release = dmirror_fops_release, + .mmap = dmirror_fops_mmap, .unlocked_ioctl = dmirror_fops_unlocked_ioctl, .llseek = default_llseek, .owner = THIS_MODULE, |