[PATCH v4 48/66] fork: Use VMA iterator
From: Liam Howlett <hidden>
Date: 2021-12-01 14:38:03
Also in:
lkml
Subsystem:
exec & binfmt api, elf, memory management - core, scheduler, the rest · Maintainers:
Kees Cook, Andrew Morton, David Hildenbrand, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
From: "Liam R. Howlett" <redacted> The VMA iterator is faster than the linked list and removing the linked list will shrink the vm_area_struct. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <redacted> --- kernel/fork.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index 3493117c8d35..6de302e93519 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c@@ -1228,13 +1228,16 @@ int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) /* Forbid mm->exe_file change if old file still mapped. */ old_exe_file = get_mm_exe_file(mm); if (old_exe_file) { + VMA_ITERATOR(vmi, mm, 0); mmap_read_lock(mm); - for (vma = mm->mmap; vma && !ret; vma = vma->vm_next) { + for_each_vma(vmi, vma) { if (!vma->vm_file) continue; if (path_equal(&vma->vm_file->f_path, - &old_exe_file->f_path)) + &old_exe_file->f_path)) { ret = -EBUSY; + break; + } } mmap_read_unlock(mm); fput(old_exe_file);
--
2.30.2