From: Hugh Dickins hughd@google.com
mainline inclusion from mainline-v6.7-rc1 commit 4b981bc1aa73c204c2aa7f99b5f4f74d03b0e381 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9OHHN CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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It seems strange that kernfs should be an outlier with a set_policy and get_policy in its kernfs_vm_ops. Ah, it dates back to v2.6.30's commit 095160aee954 ("sysfs: fix some bin_vm_ops errors"), when I had crashed on powerpc's pci_mmap_legacy_page_range() fallback to shmem_zero_setup().
Well, that was commendably thorough, to give sysfs-bin a set_policy and get_policy, just to avoid the way it was coded resulting in EINVAL from mmap when CONFIG_NUMA; but somehow feels a bit over-the-top to me now.
It's easier to say that nobody should expect to manage a shmem object's shared NUMA mempolicy via some kernfs backdoor to that object: delete that code (and there's no longer an EINVAL from mmap in the NUMA case).
This then leaves set_policy/get_policy as implemented only by shmem - though importantly also by SysV SHM, which has to interface with shmem which implements them, and with SHM_HUGETLB which does not.
Link: https://lkml.kernel.org/r/302164-a760-4a9e-879b-6870c9b4013@google.com Signed-off-by: Hugh Dickins hughd@google.com Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Cc: Andi Kleen ak@linux.intel.com Cc: Christoph Lameter cl@linux.com Cc: David Hildenbrand david@redhat.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Huang, Ying" ying.huang@intel.com Cc: Kefeng Wang wangkefeng.wang@huawei.com Cc: Mel Gorman mgorman@techsingularity.net Cc: Michal Hocko mhocko@suse.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Nhat Pham nphamcs@gmail.com Cc: Sidhartha Kumar sidhartha.kumar@oracle.com Cc: Suren Baghdasaryan surenb@google.com Cc: Tejun heo tj@kernel.org Cc: Vishal Moola (Oracle) vishal.moola@gmail.com Cc: Yang Shi shy828301@gmail.com Cc: Yosry Ahmed yosryahmed@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Ze Zuo zuoze1@huawei.com --- fs/kernfs/file.c | 49 ------------------------------------------------ 1 file changed, 49 deletions(-)
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 1cbf9a44422e..b1511c228852 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -433,60 +433,11 @@ static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr, return ret; }
-#ifdef CONFIG_NUMA -static int kernfs_vma_set_policy(struct vm_area_struct *vma, - struct mempolicy *new) -{ - struct file *file = vma->vm_file; - struct kernfs_open_file *of = kernfs_of(file); - int ret; - - if (!of->vm_ops) - return 0; - - if (!kernfs_get_active(of->kn)) - return -EINVAL; - - ret = 0; - if (of->vm_ops->set_policy) - ret = of->vm_ops->set_policy(vma, new); - - kernfs_put_active(of->kn); - return ret; -} - -static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, - unsigned long addr) -{ - struct file *file = vma->vm_file; - struct kernfs_open_file *of = kernfs_of(file); - struct mempolicy *pol; - - if (!of->vm_ops) - return vma->vm_policy; - - if (!kernfs_get_active(of->kn)) - return vma->vm_policy; - - pol = vma->vm_policy; - if (of->vm_ops->get_policy) - pol = of->vm_ops->get_policy(vma, addr); - - kernfs_put_active(of->kn); - return pol; -} - -#endif - static const struct vm_operations_struct kernfs_vm_ops = { .open = kernfs_vma_open, .fault = kernfs_vma_fault, .page_mkwrite = kernfs_vma_page_mkwrite, .access = kernfs_vma_access, -#ifdef CONFIG_NUMA - .set_policy = kernfs_vma_set_policy, - .get_policy = kernfs_vma_get_policy, -#endif };
static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)