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author | 2018-12-05 13:16:24 -0500 | |
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committer | 2018-12-05 13:23:38 -0500 | |
commit | 14a4467a0a5eacb2ebbe3aab1b4e25af3519c76a (patch) | |
tree | 541647056606d3e0aa1e06e62d2b40417623f8cb /mm/hugetlb.c | |
parent | media: pixfmt-meta-d4xx.rst: Add a license to it (diff) | |
parent | Merge tag 'media/v4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mc... (diff) | |
download | linux-14a4467a0a5eacb2ebbe3aab1b4e25af3519c76a.tar.gz linux-14a4467a0a5eacb2ebbe3aab1b4e25af3519c76a.tar.bz2 linux-14a4467a0a5eacb2ebbe3aab1b4e25af3519c76a.zip |
Merge commit '0072a0c14d5b7cb72c611d396f143f5dcd73ebe2' into patchwork
Merge from Upstream after the latest media fixes branch, because we
need one patch that it is there.
* commit '0072a0c14d5b7cb72c611d396f143f5dcd73ebe2': (1108 commits)
ide: Change to use DEFINE_SHOW_ATTRIBUTE macro
ide: pmac: add of_node_put()
drivers/tty: add missing of_node_put()
drivers/sbus/char: add of_node_put()
sbus: char: add of_node_put()
Linux 4.20-rc5
PCI: Fix incorrect value returned from pcie_get_speed_cap()
MAINTAINERS: Update linux-mips mailing list address
ocfs2: fix potential use after free
mm/khugepaged: fix the xas_create_range() error path
mm/khugepaged: collapse_shmem() do not crash on Compound
mm/khugepaged: collapse_shmem() without freezing new_page
mm/khugepaged: minor reorderings in collapse_shmem()
mm/khugepaged: collapse_shmem() remember to clear holes
mm/khugepaged: fix crashes due to misaccounted holes
mm/khugepaged: collapse_shmem() stop if punched or truncated
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
mm/huge_memory: splitting set mapping+index before unfreeze
mm/huge_memory: rename freeze_page() to unmap_page()
initramfs: clean old path before creating a hardlink
...
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r-- | mm/hugetlb.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index c007fb5fb8d5..705a3e9cc910 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3233,7 +3233,7 @@ static int is_hugetlb_entry_hwpoisoned(pte_t pte) int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma) { - pte_t *src_pte, *dst_pte, entry; + pte_t *src_pte, *dst_pte, entry, dst_entry; struct page *ptepage; unsigned long addr; int cow; @@ -3261,15 +3261,30 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, break; } - /* If the pagetables are shared don't copy or take references */ - if (dst_pte == src_pte) + /* + * If the pagetables are shared don't copy or take references. + * dst_pte == src_pte is the common case of src/dest sharing. + * + * However, src could have 'unshared' and dst shares with + * another vma. If dst_pte !none, this implies sharing. + * Check here before taking page table lock, and once again + * after taking the lock below. + */ + dst_entry = huge_ptep_get(dst_pte); + if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) continue; dst_ptl = huge_pte_lock(h, dst, dst_pte); src_ptl = huge_pte_lockptr(h, src, src_pte); spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); entry = huge_ptep_get(src_pte); - if (huge_pte_none(entry)) { /* skip none entry */ + dst_entry = huge_ptep_get(dst_pte); + if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { + /* + * Skip if src entry none. Also, skip in the + * unlikely case dst entry !none as this implies + * sharing with another vma. + */ ; } else if (unlikely(is_hugetlb_entry_migration(entry) || is_hugetlb_entry_hwpoisoned(entry))) { @@ -4065,7 +4080,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, /* fallback to copy_from_user outside mmap_sem */ if (unlikely(ret)) { - ret = -EFAULT; + ret = -ENOENT; *pagep = page; /* don't free the page */ goto out; |