From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> The do_vma_munmap() wrapper existed for callers that didn't have a vma iterator and needed to check the vma mseal status prior to calling the underlying munmap(). All callers now use a vma iterator and since the mseal check of can_modify_mm() has been moved to do_vmi_align_munmap() and the vmas are aligned, this function can just be called instead. do_vmi_align_munmap() can no longer be static as ipc/shm is using it and it is exported via the mm.h header. Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> --- include/linux/mm.h | 6 +++--- ipc/shm.c | 8 ++++---- mm/mmap.c | 33 +++++---------------------------- 3 files changed, 12 insertions(+), 35 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index e2140ea6ae98..40f1db1fb233 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3400,14 +3400,14 @@ extern unsigned long do_mmap(struct file *file, unsigned long addr, extern int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf, bool unlock); +extern int do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, + struct mm_struct *mm, unsigned long start, + unsigned long end, struct list_head *uf, bool unlock); extern int do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf); extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior); #ifdef CONFIG_MMU -extern int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, - unsigned long start, unsigned long end, - struct list_head *uf, bool unlock); extern int __mm_populate(unsigned long addr, unsigned long len, int ignore_errors); static inline void mm_populate(unsigned long addr, unsigned long len) diff --git a/ipc/shm.c b/ipc/shm.c index 3e3071252dac..99564c870084 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1778,8 +1778,8 @@ long ksys_shmdt(char __user *shmaddr) */ file = vma->vm_file; size = i_size_read(file_inode(vma->vm_file)); - do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, - NULL, false); + do_vmi_align_munmap(&vmi, vma, mm, vma->vm_start, + vma->vm_end, NULL, false); /* * We discovered the size of the shm segment, so * break out of here and fall through to the next @@ -1803,8 +1803,8 @@ long ksys_shmdt(char __user *shmaddr) if ((vma->vm_ops == &shm_vm_ops) && ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) && (vma->vm_file == file)) { - do_vma_munmap(&vmi, vma, vma->vm_start, vma->vm_end, - NULL, false); + do_vmi_align_munmap(&vmi, vma, mm, vma->vm_start, + vma->vm_end, NULL, false); } vma = vma_next(&vmi); diff --git a/mm/mmap.c b/mm/mmap.c index c343366b3ad2..18c269bf8703 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -268,11 +268,12 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) goto out; /* mapping intersects with an existing non-brk vma. */ /* * mm->brk must be protected by write mmap_lock. - * do_vma_munmap() will drop the lock on success, so update it - * before calling do_vma_munmap(). + * do_vmi_align_munmap() will drop the lock on success, so + * update it before calling do_vma_munmap(). */ mm->brk = brk; - if (do_vma_munmap(&vmi, brkvma, newbrk, oldbrk, &uf, true)) + if (do_vmi_align_munmap(&vmi, brkvma, mm, newbrk, oldbrk, &uf, + /* unlock = */ true)) goto out; goto success_unlocked; @@ -2837,7 +2838,7 @@ static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, * Return: 0 on success and drops the lock if so directed, error and leaves the * lock held otherwise. */ -static int +int do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, struct mm_struct *mm, unsigned long start, unsigned long end, struct list_head *uf, bool unlock) @@ -3319,30 +3320,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, return ret; } -/* - * do_vma_munmap() - Unmap a full or partial vma. - * @vmi: The vma iterator pointing at the vma - * @vma: The first vma to be munmapped - * @start: the start of the address to unmap - * @end: The end of the address to unmap - * @uf: The userfaultfd list_head - * @unlock: Drop the lock on success - * - * unmaps a VMA mapping when the vma iterator is already in position. - * Does not handle alignment. - * - * Return: 0 on success drops the lock of so directed, error on failure and will - * still hold the lock. - */ -int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma, - unsigned long start, unsigned long end, struct list_head *uf, - bool unlock) -{ - struct mm_struct *mm = vma->vm_mm; - - return do_vmi_align_munmap(vmi, vma, mm, start, end, uf, unlock); -} - /* * do_brk_flags() - Increase the brk vma if the flags match. * @vmi: The vma iterator -- 2.43.0