diff options
| -rw-r--r-- | include/linux/mm.h | 4 | ||||
| -rw-r--r-- | mm/huge_memory.c | 3 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 03cf5526e445..2b17d2fca429 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1123,6 +1123,10 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, * followed by taking the mmap_sem for writing before modifying the * vmas or anything the coredump pretends not to change from under it. * + * It also has to be called when mmgrab() is used in the context of + * the process, but then the mm_count refcount is transferred outside + * the context of the process to run down_write() on that pinned mm. + * * NOTE: find_extend_vma() called from GUP context is the only place * that can modify the "mm" (notably the vm_start/end) under mmap_sem * for reading and outside the context of the process, so it is also diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 465786cd6490..c5628ebc0fc2 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2587,6 +2587,9 @@ static void collapse_huge_page(struct mm_struct *mm, * handled by the anon_vma lock + PG_lock. */ down_write(&mm->mmap_sem); + result = SCAN_ANY_PROCESS; + if (!mmget_still_valid(mm)) + goto out; if (unlikely(khugepaged_test_exit(mm))) goto out; |