diff options
| author | Jann Horn <jannh@google.com> | 2020-10-15 20:13:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 11:11:22 -0700 |
| commit | 4d45e75a9955ade5c2f49bd96fc4173b2cec9a72 (patch) | |
| tree | 71b16b0e22ee630e2956a3285990fb49df84685e /mm | |
| parent | 7f3bfab52cab96c510fd60dd757a32db7bc52d3c (diff) | |
| download | linux-4d45e75a9955ade5c2f49bd96fc4173b2cec9a72.tar.gz linux-4d45e75a9955ade5c2f49bd96fc4173b2cec9a72.tar.bz2 linux-4d45e75a9955ade5c2f49bd96fc4173b2cec9a72.zip | |
mm: remove the now-unnecessary mmget_still_valid() hack
The preceding patches have ensured that core dumping properly takes the
mmap_lock. Thanks to that, we can now remove mmget_still_valid() and all
its users.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/20200827114932.3572699-8-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/khugepaged.c | 2 | ||||
| -rw-r--r-- | mm/madvise.c | 17 | ||||
| -rw-r--r-- | mm/mmap.c | 5 |
3 files changed, 2 insertions, 22 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 58b0d9c502a1..4e3dff13eb70 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -434,7 +434,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, static inline int khugepaged_test_exit(struct mm_struct *mm) { - return atomic_read(&mm->mm_users) == 0 || !mmget_still_valid(mm); + return atomic_read(&mm->mm_users) == 0; } static bool hugepage_vma_check(struct vm_area_struct *vma, diff --git a/mm/madvise.c b/mm/madvise.c index 68b761c359d0..fd1f448b4e1d 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1085,23 +1085,6 @@ int do_madvise(unsigned long start, size_t len_in, int behavior) if (write) { if (mmap_write_lock_killable(current->mm)) return -EINTR; - - /* - * We may have stolen the mm from another process - * that is undergoing core dumping. - * - * Right now that's io_ring, in the future it may - * be remote process management and not "current" - * at all. - * - * We need to fix core dumping to not do this, - * but for now we have the mmget_still_valid() - * model. - */ - if (!mmget_still_valid(current->mm)) { - mmap_write_unlock(current->mm); - return -EINTR; - } } else { mmap_read_lock(current->mm); } diff --git a/mm/mmap.c b/mm/mmap.c index 9fb9f8a233c7..ebb92f5515a1 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2562,7 +2562,7 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr) if (vma && (vma->vm_start <= addr)) return vma; /* don't alter vm_end if the coredump is running */ - if (!prev || !mmget_still_valid(mm) || expand_stack(prev, addr)) + if (!prev || expand_stack(prev, addr)) return NULL; if (prev->vm_flags & VM_LOCKED) populate_vma_page_range(prev, addr, prev->vm_end, NULL); @@ -2588,9 +2588,6 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr) return vma; if (!(vma->vm_flags & VM_GROWSDOWN)) return NULL; - /* don't alter vm_start if the coredump is running */ - if (!mmget_still_valid(mm)) - return NULL; start = vma->vm_start; if (expand_stack(vma, addr)) return NULL; |