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	mm: introduce vma_merge_struct and abstract vma_merge(),vma_modify()
Rather than passing around huge numbers of parameters to numerous helper
functions, abstract them into a single struct that we thread through the
operation, the vma_merge_struct ('vmg').
Adjust vma_merge() and vma_modify() to accept this parameter, as well as
predicate functions can_vma_merge_before(), can_vma_merge_after(), and the
vma_modify_...() helper functions.
Also introduce VMG_STATE() and VMG_VMA_STATE() helper macros to allow for
easy vmg declaration.
We additionally remove the requirement that vma_merge() is passed a VMA
object representing the candidate new VMA.  Previously it used this to
obtain the mm_struct, file and anon_vma properties of the proposed range
(a rather confusing state of affairs), which are now provided by the vmg
directly.
We also remove the pgoff calculation previously performed vma_modify(),
and instead calculate this in VMG_VMA_STATE() via the vma_pgoff_offset()
helper.
Link: https://lkml.kernel.org/r/a955aad09d81329f6fbeb636b2dd10cde7b73dab.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
			
			
This commit is contained in:
		
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						commit
						2f1c6611b0
					
				
					 4 changed files with 242 additions and 203 deletions
				
			
		
							
								
								
									
										42
									
								
								mm/mmap.c
									
									
									
									
									
								
							
							
						
						
									
										42
									
								
								mm/mmap.c
									
									
									
									
									
								
							| 
						 | 
				
			
			@ -1373,10 +1373,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
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	unsigned long end = addr + len;
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	unsigned long merge_start = addr, merge_end = end;
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	bool writable_file_mapping = false;
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	pgoff_t vm_pgoff;
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	int error = -ENOMEM;
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	VMA_ITERATOR(vmi, mm, addr);
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	VMG_STATE(vmg, mm, &vmi, addr, end, vm_flags, pgoff);
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	vmg.file = file;
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	/* Find the first overlapping VMA */
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	vma = vma_find(&vmi, end);
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	init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
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| 
						 | 
				
			
			@ -1389,12 +1390,12 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
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		if (error)
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			goto gather_failed;
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		next = vms.next;
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		prev = vms.prev;
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		next = vmg.next = vms.next;
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		prev = vmg.prev = vms.prev;
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		vma = NULL;
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	} else {
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		next = vma_next(&vmi);
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		prev = vma_prev(&vmi);
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		next = vmg.next = vma_next(&vmi);
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		prev = vmg.prev = vma_prev(&vmi);
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		if (prev)
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			vma_iter_next_range(&vmi);
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	}
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| 
						 | 
				
			
			@ -1414,6 +1415,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
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		vms.nr_accounted = 0;
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		vm_flags |= VM_ACCOUNT;
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		vmg.flags = vm_flags;
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	}
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	if (vm_flags & VM_SPECIAL)
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| 
						 | 
				
			
			@ -1422,28 +1424,31 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
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	/* Attempt to expand an old mapping */
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	/* Check next */
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	if (next && next->vm_start == end && !vma_policy(next) &&
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	    can_vma_merge_before(next, vm_flags, NULL, file, pgoff+pglen,
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				 NULL_VM_UFFD_CTX, NULL)) {
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	    can_vma_merge_before(&vmg)) {
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		merge_end = next->vm_end;
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		vma = next;
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		vm_pgoff = next->vm_pgoff - pglen;
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		vmg.pgoff = next->vm_pgoff - pglen;
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		/*
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		 * We set this here so if we will merge with the previous VMA in
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		 * the code below, can_vma_merge_after() ensures anon_vma
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		 * compatibility between prev and next.
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		 */
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		vmg.anon_vma = vma->anon_vma;
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		vmg.uffd_ctx = vma->vm_userfaultfd_ctx;
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	}
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	/* Check prev */
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	if (prev && prev->vm_end == addr && !vma_policy(prev) &&
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	    (vma ? can_vma_merge_after(prev, vm_flags, vma->anon_vma, file,
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				       pgoff, vma->vm_userfaultfd_ctx, NULL) :
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		   can_vma_merge_after(prev, vm_flags, NULL, file, pgoff,
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				       NULL_VM_UFFD_CTX, NULL))) {
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	    can_vma_merge_after(&vmg)) {
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		merge_start = prev->vm_start;
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		vma = prev;
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		vm_pgoff = prev->vm_pgoff;
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		vmg.pgoff = prev->vm_pgoff;
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		vma_prev(&vmi); /* Equivalent to going to the previous range */
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	}
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	if (vma) {
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		/* Actually expand, if possible */
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		if (!vma_expand(&vmi, vma, merge_start, merge_end, vm_pgoff, next)) {
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		if (!vma_expand(&vmi, vma, merge_start, merge_end, vmg.pgoff, next)) {
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			khugepaged_enter_vma(vma, vm_flags);
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			goto expanded;
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		}
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						 | 
				
			
			@ -1774,9 +1779,11 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
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	 * Expand the existing vma if possible; Note that singular lists do not
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	 * occur after forking, so the expand will only happen on new VMAs.
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	 */
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	if (vma && vma->vm_end == addr && !vma_policy(vma) &&
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	    can_vma_merge_after(vma, flags, NULL, NULL,
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				addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL)) {
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	if (vma && vma->vm_end == addr && !vma_policy(vma)) {
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		VMG_STATE(vmg, mm, vmi, addr, addr + len, flags, PHYS_PFN(addr));
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		vmg.prev = vma;
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		if (can_vma_merge_after(&vmg)) {
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			vma_iter_config(vmi, vma->vm_start, addr + len);
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			if (vma_iter_prealloc(vmi, vma))
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				goto unacct_fail;
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						 | 
				
			
			@ -1795,6 +1802,7 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
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			khugepaged_enter_vma(vma, flags);
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			goto out;
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		}
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	}
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	if (vma)
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		vma_iter_next_range(vmi);
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						 | 
				
			
			
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		|||
							
								
								
									
										207
									
								
								mm/vma.c
									
									
									
									
									
								
							
							
						
						
									
										207
									
								
								mm/vma.c
									
									
									
									
									
								
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			@ -7,16 +7,18 @@
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#include "vma_internal.h"
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#include "vma.h"
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/*
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 * If the vma has a ->close operation then the driver probably needs to release
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 * per-vma resources, so we don't attempt to merge those if the caller indicates
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 * the current vma may be removed as part of the merge.
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 */
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static inline bool is_mergeable_vma(struct vm_area_struct *vma,
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		struct file *file, unsigned long vm_flags,
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		struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
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		struct anon_vma_name *anon_name, bool may_remove_vma)
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static inline bool is_mergeable_vma(struct vma_merge_struct *vmg, bool merge_next)
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{
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	struct vm_area_struct *vma = merge_next ? vmg->next : vmg->prev;
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	/*
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	 * If the vma has a ->close operation then the driver probably needs to
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	 * release per-vma resources, so we don't attempt to merge those if the
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	 * caller indicates the current vma may be removed as part of the merge,
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	 * which is the case if we are attempting to merge the next VMA into
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	 * this one.
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	 */
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	bool may_remove_vma = merge_next;
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	/*
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	 * VM_SOFTDIRTY should not prevent from VMA merging, if we
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	 * match the flags but dirty bit -- the caller should mark
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						 | 
				
			
			@ -25,15 +27,15 @@ static inline bool is_mergeable_vma(struct vm_area_struct *vma,
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	 * the kernel to generate new VMAs when old one could be
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	 * extended instead.
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	 */
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	if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY)
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	if ((vma->vm_flags ^ vmg->flags) & ~VM_SOFTDIRTY)
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		return false;
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	if (vma->vm_file != file)
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	if (vma->vm_file != vmg->file)
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		return false;
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	if (may_remove_vma && vma->vm_ops && vma->vm_ops->close)
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		return false;
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	if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
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	if (!is_mergeable_vm_userfaultfd_ctx(vma, vmg->uffd_ctx))
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		return false;
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	if (!anon_vma_name_eq(anon_vma_name(vma), anon_name))
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	if (!anon_vma_name_eq(anon_vma_name(vma), vmg->anon_name))
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		return false;
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	return true;
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}
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			@ -94,16 +96,16 @@ static void init_multi_vma_prep(struct vma_prepare *vp,
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 * We assume the vma may be removed as part of the merge.
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 */
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bool
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can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
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		struct anon_vma *anon_vma, struct file *file,
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		pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
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		struct anon_vma_name *anon_name)
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can_vma_merge_before(struct vma_merge_struct *vmg)
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{
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	if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name, true) &&
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	    is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
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		if (vma->vm_pgoff == vm_pgoff)
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	pgoff_t pglen = PHYS_PFN(vmg->end - vmg->start);
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	if (is_mergeable_vma(vmg, /* merge_next = */ true) &&
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	    is_mergeable_anon_vma(vmg->anon_vma, vmg->next->anon_vma, vmg->next)) {
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		if (vmg->next->vm_pgoff == vmg->pgoff + pglen)
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			return true;
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	}
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	return false;
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}
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			@ -116,18 +118,11 @@ can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
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 *
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 * We assume that vma is not removed as part of the merge.
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 */
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bool
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can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
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		struct anon_vma *anon_vma, struct file *file,
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		pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
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		struct anon_vma_name *anon_name)
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bool can_vma_merge_after(struct vma_merge_struct *vmg)
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{
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	if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name, false) &&
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	    is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
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		pgoff_t vm_pglen;
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		vm_pglen = vma_pages(vma);
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		if (vma->vm_pgoff + vm_pglen == vm_pgoff)
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	if (is_mergeable_vma(vmg, /* merge_next = */ false) &&
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	    is_mergeable_anon_vma(vmg->anon_vma, vmg->prev->anon_vma, vmg->prev)) {
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		if (vmg->prev->vm_pgoff + vma_pages(vmg->prev) == vmg->pgoff)
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			return true;
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	}
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	return false;
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| 
						 | 
				
			
			@ -1017,16 +1012,10 @@ int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
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 * **** is not represented - it will be merged and the vma containing the
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 *      area is returned, or the function will return NULL
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 */
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static struct vm_area_struct
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*vma_merge(struct vma_iterator *vmi, struct vm_area_struct *prev,
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	   struct vm_area_struct *src, unsigned long addr, unsigned long end,
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	   unsigned long vm_flags, pgoff_t pgoff, struct mempolicy *policy,
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	   struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
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	   struct anon_vma_name *anon_name)
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static struct vm_area_struct *vma_merge(struct vma_merge_struct *vmg)
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{
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	struct mm_struct *mm = src->vm_mm;
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	struct anon_vma *anon_vma = src->anon_vma;
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	struct file *file = src->vm_file;
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	struct mm_struct *mm = vmg->mm;
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	struct vm_area_struct *prev = vmg->prev;
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	struct vm_area_struct *curr, *next, *res;
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	struct vm_area_struct *vma, *adjust, *remove, *remove2;
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	struct vm_area_struct *anon_dup = NULL;
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| 
						 | 
				
			
			@ -1036,16 +1025,18 @@ static struct vm_area_struct
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	bool merge_prev = false;
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	bool merge_next = false;
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	bool vma_expanded = false;
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	unsigned long addr = vmg->start;
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	unsigned long end = vmg->end;
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	unsigned long vma_start = addr;
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	unsigned long vma_end = end;
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	pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
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	pgoff_t pglen = PHYS_PFN(end - addr);
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	long adj_start = 0;
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	/*
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	 * We later require that vma->vm_flags == vm_flags,
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	 * so this tests vma->vm_flags & VM_SPECIAL, too.
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	 */
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	if (vm_flags & VM_SPECIAL)
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	if (vmg->flags & VM_SPECIAL)
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		return NULL;
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	/* Does the input range span an existing VMA? (cases 5 - 8) */
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| 
						 | 
				
			
			@ -1053,27 +1044,26 @@ static struct vm_area_struct
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	if (!curr ||			/* cases 1 - 4 */
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	    end == curr->vm_end)	/* cases 6 - 8, adjacent VMA */
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		next = vma_lookup(mm, end);
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		next = vmg->next = vma_lookup(mm, end);
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	else
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		next = NULL;		/* case 5 */
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		next = vmg->next = NULL;	/* case 5 */
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	if (prev) {
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		vma_start = prev->vm_start;
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		vma_pgoff = prev->vm_pgoff;
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		/* Can we merge the predecessor? */
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		if (addr == prev->vm_end && mpol_equal(vma_policy(prev), policy)
 | 
			
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		    && can_vma_merge_after(prev, vm_flags, anon_vma, file,
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		||||
					   pgoff, vm_userfaultfd_ctx, anon_name)) {
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		if (addr == prev->vm_end && mpol_equal(vma_policy(prev), vmg->policy)
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		    && can_vma_merge_after(vmg)) {
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 | 
			
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			merge_prev = true;
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			vma_prev(vmi);
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			vma_prev(vmg->vmi);
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		}
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	}
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	/* Can we merge the successor? */
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	if (next && mpol_equal(policy, vma_policy(next)) &&
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	    can_vma_merge_before(next, vm_flags, anon_vma, file, pgoff+pglen,
 | 
			
		||||
				 vm_userfaultfd_ctx, anon_name)) {
 | 
			
		||||
	if (next && mpol_equal(vmg->policy, vma_policy(next)) &&
 | 
			
		||||
	    can_vma_merge_before(vmg)) {
 | 
			
		||||
		merge_next = true;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -1164,13 +1154,13 @@ static struct vm_area_struct
 | 
			
		|||
		vma_expanded = true;
 | 
			
		||||
 | 
			
		||||
	if (vma_expanded) {
 | 
			
		||||
		vma_iter_config(vmi, vma_start, vma_end);
 | 
			
		||||
		vma_iter_config(vmg->vmi, vma_start, vma_end);
 | 
			
		||||
	} else {
 | 
			
		||||
		vma_iter_config(vmi, adjust->vm_start + adj_start,
 | 
			
		||||
		vma_iter_config(vmg->vmi, adjust->vm_start + adj_start,
 | 
			
		||||
				adjust->vm_end);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (vma_iter_prealloc(vmi, vma))
 | 
			
		||||
	if (vma_iter_prealloc(vmg->vmi, vma))
 | 
			
		||||
		goto prealloc_fail;
 | 
			
		||||
 | 
			
		||||
	init_multi_vma_prep(&vp, vma, adjust, remove, remove2);
 | 
			
		||||
| 
						 | 
				
			
			@ -1182,20 +1172,20 @@ static struct vm_area_struct
 | 
			
		|||
	vma_set_range(vma, vma_start, vma_end, vma_pgoff);
 | 
			
		||||
 | 
			
		||||
	if (vma_expanded)
 | 
			
		||||
		vma_iter_store(vmi, vma);
 | 
			
		||||
		vma_iter_store(vmg->vmi, vma);
 | 
			
		||||
 | 
			
		||||
	if (adj_start) {
 | 
			
		||||
		adjust->vm_start += adj_start;
 | 
			
		||||
		adjust->vm_pgoff += adj_start >> PAGE_SHIFT;
 | 
			
		||||
		if (adj_start < 0) {
 | 
			
		||||
			WARN_ON(vma_expanded);
 | 
			
		||||
			vma_iter_store(vmi, next);
 | 
			
		||||
			vma_iter_store(vmg->vmi, next);
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	vma_complete(&vp, vmi, mm);
 | 
			
		||||
	vma_complete(&vp, vmg->vmi, mm);
 | 
			
		||||
	validate_mm(mm);
 | 
			
		||||
	khugepaged_enter_vma(res, vm_flags);
 | 
			
		||||
	khugepaged_enter_vma(res, vmg->flags);
 | 
			
		||||
	return res;
 | 
			
		||||
 | 
			
		||||
prealloc_fail:
 | 
			
		||||
| 
						 | 
				
			
			@ -1203,8 +1193,8 @@ static struct vm_area_struct
 | 
			
		|||
		unlink_anon_vmas(anon_dup);
 | 
			
		||||
 | 
			
		||||
anon_vma_fail:
 | 
			
		||||
	vma_iter_set(vmi, addr);
 | 
			
		||||
	vma_iter_load(vmi);
 | 
			
		||||
	vma_iter_set(vmg->vmi, addr);
 | 
			
		||||
	vma_iter_load(vmg->vmi);
 | 
			
		||||
	return NULL;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -1221,32 +1211,27 @@ static struct vm_area_struct
 | 
			
		|||
 * The function returns either the merged VMA, the original VMA if a split was
 | 
			
		||||
 * required instead, or an error if the split failed.
 | 
			
		||||
 */
 | 
			
		||||
struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
 | 
			
		||||
				  struct vm_area_struct *prev,
 | 
			
		||||
				  struct vm_area_struct *vma,
 | 
			
		||||
				  unsigned long start, unsigned long end,
 | 
			
		||||
				  unsigned long vm_flags,
 | 
			
		||||
				  struct mempolicy *policy,
 | 
			
		||||
				  struct vm_userfaultfd_ctx uffd_ctx,
 | 
			
		||||
				  struct anon_vma_name *anon_name)
 | 
			
		||||
static struct vm_area_struct *vma_modify(struct vma_merge_struct *vmg)
 | 
			
		||||
{
 | 
			
		||||
	pgoff_t pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
 | 
			
		||||
	struct vm_area_struct *vma = vmg->vma;
 | 
			
		||||
	struct vm_area_struct *merged;
 | 
			
		||||
 | 
			
		||||
	merged = vma_merge(vmi, prev, vma, start, end, vm_flags,
 | 
			
		||||
			   pgoff, policy, uffd_ctx, anon_name);
 | 
			
		||||
	/* First, try to merge. */
 | 
			
		||||
	merged = vma_merge(vmg);
 | 
			
		||||
	if (merged)
 | 
			
		||||
		return merged;
 | 
			
		||||
 | 
			
		||||
	if (vma->vm_start < start) {
 | 
			
		||||
		int err = split_vma(vmi, vma, start, 1);
 | 
			
		||||
	/* Split any preceding portion of the VMA. */
 | 
			
		||||
	if (vma->vm_start < vmg->start) {
 | 
			
		||||
		int err = split_vma(vmg->vmi, vma, vmg->start, 1);
 | 
			
		||||
 | 
			
		||||
		if (err)
 | 
			
		||||
			return ERR_PTR(err);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	if (vma->vm_end > end) {
 | 
			
		||||
		int err = split_vma(vmi, vma, end, 0);
 | 
			
		||||
	/* Split any trailing portion of the VMA. */
 | 
			
		||||
	if (vma->vm_end > vmg->end) {
 | 
			
		||||
		int err = split_vma(vmg->vmi, vma, vmg->end, 0);
 | 
			
		||||
 | 
			
		||||
		if (err)
 | 
			
		||||
			return ERR_PTR(err);
 | 
			
		||||
| 
						 | 
				
			
			@ -1255,6 +1240,65 @@ struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
 | 
			
		|||
	return vma;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct *vma_modify_flags(
 | 
			
		||||
	struct vma_iterator *vmi, struct vm_area_struct *prev,
 | 
			
		||||
	struct vm_area_struct *vma, unsigned long start, unsigned long end,
 | 
			
		||||
	unsigned long new_flags)
 | 
			
		||||
{
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
 | 
			
		||||
 | 
			
		||||
	vmg.flags = new_flags;
 | 
			
		||||
 | 
			
		||||
	return vma_modify(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_flags_name(struct vma_iterator *vmi,
 | 
			
		||||
		       struct vm_area_struct *prev,
 | 
			
		||||
		       struct vm_area_struct *vma,
 | 
			
		||||
		       unsigned long start,
 | 
			
		||||
		       unsigned long end,
 | 
			
		||||
		       unsigned long new_flags,
 | 
			
		||||
		       struct anon_vma_name *new_name)
 | 
			
		||||
{
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
 | 
			
		||||
 | 
			
		||||
	vmg.flags = new_flags;
 | 
			
		||||
	vmg.anon_name = new_name;
 | 
			
		||||
 | 
			
		||||
	return vma_modify(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_policy(struct vma_iterator *vmi,
 | 
			
		||||
		   struct vm_area_struct *prev,
 | 
			
		||||
		   struct vm_area_struct *vma,
 | 
			
		||||
		   unsigned long start, unsigned long end,
 | 
			
		||||
		   struct mempolicy *new_pol)
 | 
			
		||||
{
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
 | 
			
		||||
 | 
			
		||||
	vmg.policy = new_pol;
 | 
			
		||||
 | 
			
		||||
	return vma_modify(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_flags_uffd(struct vma_iterator *vmi,
 | 
			
		||||
		       struct vm_area_struct *prev,
 | 
			
		||||
		       struct vm_area_struct *vma,
 | 
			
		||||
		       unsigned long start, unsigned long end,
 | 
			
		||||
		       unsigned long new_flags,
 | 
			
		||||
		       struct vm_userfaultfd_ctx new_ctx)
 | 
			
		||||
{
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
 | 
			
		||||
 | 
			
		||||
	vmg.flags = new_flags;
 | 
			
		||||
	vmg.uffd_ctx = new_ctx;
 | 
			
		||||
 | 
			
		||||
	return vma_modify(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Attempt to merge a newly mapped VMA with those adjacent to it. The caller
 | 
			
		||||
 * must ensure that [start, end) does not overlap any existing VMA.
 | 
			
		||||
| 
						 | 
				
			
			@ -1264,8 +1308,11 @@ struct vm_area_struct
 | 
			
		|||
		   struct vm_area_struct *vma, unsigned long start,
 | 
			
		||||
		   unsigned long end, pgoff_t pgoff)
 | 
			
		||||
{
 | 
			
		||||
	return vma_merge(vmi, prev, vma, start, end, vma->vm_flags, pgoff,
 | 
			
		||||
			 vma_policy(vma), vma->vm_userfaultfd_ctx, anon_vma_name(vma));
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
 | 
			
		||||
 | 
			
		||||
	vmg.pgoff = pgoff;
 | 
			
		||||
 | 
			
		||||
	return vma_merge(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
| 
						 | 
				
			
			@ -1276,12 +1323,10 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
 | 
			
		|||
					struct vm_area_struct *vma,
 | 
			
		||||
					unsigned long delta)
 | 
			
		||||
{
 | 
			
		||||
	pgoff_t pgoff = vma->vm_pgoff + vma_pages(vma);
 | 
			
		||||
	VMG_VMA_STATE(vmg, vmi, vma, vma, vma->vm_end, vma->vm_end + delta);
 | 
			
		||||
 | 
			
		||||
	/* vma is specified as prev, so case 1 or 2 will apply. */
 | 
			
		||||
	return vma_merge(vmi, vma, vma, vma->vm_end, vma->vm_end + delta,
 | 
			
		||||
			 vma->vm_flags, pgoff, vma_policy(vma),
 | 
			
		||||
			 vma->vm_userfaultfd_ctx, anon_vma_name(vma));
 | 
			
		||||
	return vma_merge(&vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
void unlink_file_vma_batch_init(struct unlink_vma_file_batch *vb)
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
							
								
								
									
										123
									
								
								mm/vma.h
									
									
									
									
									
								
							
							
						
						
									
										123
									
								
								mm/vma.h
									
									
									
									
									
								
							| 
						 | 
				
			
			@ -52,6 +52,59 @@ struct vma_munmap_struct {
 | 
			
		|||
	unsigned long data_vm;
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
/* Represents a VMA merge operation. */
 | 
			
		||||
struct vma_merge_struct {
 | 
			
		||||
	struct mm_struct *mm;
 | 
			
		||||
	struct vma_iterator *vmi;
 | 
			
		||||
	pgoff_t pgoff;
 | 
			
		||||
	struct vm_area_struct *prev;
 | 
			
		||||
	struct vm_area_struct *next; /* Modified by vma_merge(). */
 | 
			
		||||
	struct vm_area_struct *vma; /* Either a new VMA or the one being modified. */
 | 
			
		||||
	unsigned long start;
 | 
			
		||||
	unsigned long end;
 | 
			
		||||
	unsigned long flags;
 | 
			
		||||
	struct file *file;
 | 
			
		||||
	struct anon_vma *anon_vma;
 | 
			
		||||
	struct mempolicy *policy;
 | 
			
		||||
	struct vm_userfaultfd_ctx uffd_ctx;
 | 
			
		||||
	struct anon_vma_name *anon_name;
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
/* Assumes addr >= vma->vm_start. */
 | 
			
		||||
static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma,
 | 
			
		||||
				       unsigned long addr)
 | 
			
		||||
{
 | 
			
		||||
	return vma->vm_pgoff + PHYS_PFN(addr - vma->vm_start);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
#define VMG_STATE(name, mm_, vmi_, start_, end_, flags_, pgoff_)	\
 | 
			
		||||
	struct vma_merge_struct name = {				\
 | 
			
		||||
		.mm = mm_,						\
 | 
			
		||||
		.vmi = vmi_,						\
 | 
			
		||||
		.start = start_,					\
 | 
			
		||||
		.end = end_,						\
 | 
			
		||||
		.flags = flags_,					\
 | 
			
		||||
		.pgoff = pgoff_,					\
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
#define VMG_VMA_STATE(name, vmi_, prev_, vma_, start_, end_)	\
 | 
			
		||||
	struct vma_merge_struct name = {			\
 | 
			
		||||
		.mm = vma_->vm_mm,				\
 | 
			
		||||
		.vmi = vmi_,					\
 | 
			
		||||
		.prev = prev_,					\
 | 
			
		||||
		.next = NULL,					\
 | 
			
		||||
		.vma = vma_,					\
 | 
			
		||||
		.start = start_,				\
 | 
			
		||||
		.end = end_,					\
 | 
			
		||||
		.flags = vma_->vm_flags,			\
 | 
			
		||||
		.pgoff = vma_pgoff_offset(vma_, start_),	\
 | 
			
		||||
		.file = vma_->vm_file,				\
 | 
			
		||||
		.anon_vma = vma_->anon_vma,			\
 | 
			
		||||
		.policy = vma_policy(vma_),			\
 | 
			
		||||
		.uffd_ctx = vma_->vm_userfaultfd_ctx,		\
 | 
			
		||||
		.anon_name = anon_vma_name(vma_),		\
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
 | 
			
		||||
void validate_mm(struct mm_struct *mm);
 | 
			
		||||
#else
 | 
			
		||||
| 
						 | 
				
			
			@ -212,80 +265,52 @@ void remove_vma(struct vm_area_struct *vma, bool unreachable, bool closed);
 | 
			
		|||
void unmap_region(struct ma_state *mas, struct vm_area_struct *vma,
 | 
			
		||||
		struct vm_area_struct *prev, struct vm_area_struct *next);
 | 
			
		||||
 | 
			
		||||
/* Required by mmap_region(). */
 | 
			
		||||
bool
 | 
			
		||||
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
 | 
			
		||||
		struct anon_vma *anon_vma, struct file *file,
 | 
			
		||||
		pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
 | 
			
		||||
		struct anon_vma_name *anon_name);
 | 
			
		||||
/*
 | 
			
		||||
 * Can we merge the VMA described by vmg into the following VMA vmg->next?
 | 
			
		||||
 *
 | 
			
		||||
 * Required by mmap_region().
 | 
			
		||||
 */
 | 
			
		||||
bool can_vma_merge_before(struct vma_merge_struct *vmg);
 | 
			
		||||
 | 
			
		||||
/* Required by mmap_region() and do_brk_flags(). */
 | 
			
		||||
bool
 | 
			
		||||
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
 | 
			
		||||
		struct anon_vma *anon_vma, struct file *file,
 | 
			
		||||
		pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
 | 
			
		||||
		struct anon_vma_name *anon_name);
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
 | 
			
		||||
				  struct vm_area_struct *prev,
 | 
			
		||||
				  struct vm_area_struct *vma,
 | 
			
		||||
				  unsigned long start, unsigned long end,
 | 
			
		||||
				  unsigned long vm_flags,
 | 
			
		||||
				  struct mempolicy *policy,
 | 
			
		||||
				  struct vm_userfaultfd_ctx uffd_ctx,
 | 
			
		||||
				  struct anon_vma_name *anon_name);
 | 
			
		||||
/*
 | 
			
		||||
 * Can we merge the VMA described by vmg into the preceding VMA vmg->prev?
 | 
			
		||||
 *
 | 
			
		||||
 * Required by mmap_region() and do_brk_flags().
 | 
			
		||||
 */
 | 
			
		||||
bool can_vma_merge_after(struct vma_merge_struct *vmg);
 | 
			
		||||
 | 
			
		||||
/* We are about to modify the VMA's flags. */
 | 
			
		||||
static inline struct vm_area_struct
 | 
			
		||||
*vma_modify_flags(struct vma_iterator *vmi,
 | 
			
		||||
		  struct vm_area_struct *prev,
 | 
			
		||||
		  struct vm_area_struct *vma,
 | 
			
		||||
struct vm_area_struct *vma_modify_flags(struct vma_iterator *vmi,
 | 
			
		||||
		struct vm_area_struct *prev, struct vm_area_struct *vma,
 | 
			
		||||
		unsigned long start, unsigned long end,
 | 
			
		||||
		  unsigned long new_flags)
 | 
			
		||||
{
 | 
			
		||||
	return vma_modify(vmi, prev, vma, start, end, new_flags,
 | 
			
		||||
			  vma_policy(vma), vma->vm_userfaultfd_ctx,
 | 
			
		||||
			  anon_vma_name(vma));
 | 
			
		||||
}
 | 
			
		||||
		unsigned long new_flags);
 | 
			
		||||
 | 
			
		||||
/* We are about to modify the VMA's flags and/or anon_name. */
 | 
			
		||||
static inline struct vm_area_struct
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_flags_name(struct vma_iterator *vmi,
 | 
			
		||||
		       struct vm_area_struct *prev,
 | 
			
		||||
		       struct vm_area_struct *vma,
 | 
			
		||||
		       unsigned long start,
 | 
			
		||||
		       unsigned long end,
 | 
			
		||||
		       unsigned long new_flags,
 | 
			
		||||
		       struct anon_vma_name *new_name)
 | 
			
		||||
{
 | 
			
		||||
	return vma_modify(vmi, prev, vma, start, end, new_flags,
 | 
			
		||||
			  vma_policy(vma), vma->vm_userfaultfd_ctx, new_name);
 | 
			
		||||
}
 | 
			
		||||
		       struct anon_vma_name *new_name);
 | 
			
		||||
 | 
			
		||||
/* We are about to modify the VMA's memory policy. */
 | 
			
		||||
static inline struct vm_area_struct
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_policy(struct vma_iterator *vmi,
 | 
			
		||||
		   struct vm_area_struct *prev,
 | 
			
		||||
		   struct vm_area_struct *vma,
 | 
			
		||||
		   unsigned long start, unsigned long end,
 | 
			
		||||
		   struct mempolicy *new_pol)
 | 
			
		||||
{
 | 
			
		||||
	return vma_modify(vmi, prev, vma, start, end, vma->vm_flags,
 | 
			
		||||
			  new_pol, vma->vm_userfaultfd_ctx, anon_vma_name(vma));
 | 
			
		||||
}
 | 
			
		||||
		   struct mempolicy *new_pol);
 | 
			
		||||
 | 
			
		||||
/* We are about to modify the VMA's flags and/or uffd context. */
 | 
			
		||||
static inline struct vm_area_struct
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_modify_flags_uffd(struct vma_iterator *vmi,
 | 
			
		||||
		       struct vm_area_struct *prev,
 | 
			
		||||
		       struct vm_area_struct *vma,
 | 
			
		||||
		       unsigned long start, unsigned long end,
 | 
			
		||||
		       unsigned long new_flags,
 | 
			
		||||
		       struct vm_userfaultfd_ctx new_ctx)
 | 
			
		||||
{
 | 
			
		||||
	return vma_modify(vmi, prev, vma, start, end, new_flags,
 | 
			
		||||
			  vma_policy(vma), new_ctx, anon_vma_name(vma));
 | 
			
		||||
}
 | 
			
		||||
		       struct vm_userfaultfd_ctx new_ctx);
 | 
			
		||||
 | 
			
		||||
struct vm_area_struct
 | 
			
		||||
*vma_merge_new_vma(struct vma_iterator *vmi, struct vm_area_struct *prev,
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -22,26 +22,6 @@ static bool fail_prealloc;
 | 
			
		|||
 */
 | 
			
		||||
#include "../../../mm/vma.c"
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * Temporarily forward-ported from a future in which vmg's are used for merging.
 | 
			
		||||
 */
 | 
			
		||||
struct vma_merge_struct {
 | 
			
		||||
	struct mm_struct *mm;
 | 
			
		||||
	struct vma_iterator *vmi;
 | 
			
		||||
	pgoff_t pgoff;
 | 
			
		||||
	struct vm_area_struct *prev;
 | 
			
		||||
	struct vm_area_struct *next; /* Modified by vma_merge(). */
 | 
			
		||||
	struct vm_area_struct *vma; /* Either a new VMA or the one being modified. */
 | 
			
		||||
	unsigned long start;
 | 
			
		||||
	unsigned long end;
 | 
			
		||||
	unsigned long flags;
 | 
			
		||||
	struct file *file;
 | 
			
		||||
	struct anon_vma *anon_vma;
 | 
			
		||||
	struct mempolicy *policy;
 | 
			
		||||
	struct vm_userfaultfd_ctx uffd_ctx;
 | 
			
		||||
	struct anon_vma_name *anon_name;
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
const struct vm_operations_struct vma_dummy_vm_ops;
 | 
			
		||||
static struct anon_vma dummy_anon_vma;
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -115,14 +95,6 @@ static struct vm_area_struct *alloc_and_link_vma(struct mm_struct *mm,
 | 
			
		|||
/* Helper function which provides a wrapper around a merge new VMA operation. */
 | 
			
		||||
static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
 | 
			
		||||
{
 | 
			
		||||
	/* vma_merge() needs a VMA to determine mm, anon_vma, and file. */
 | 
			
		||||
	struct vm_area_struct dummy = {
 | 
			
		||||
		.vm_mm = vmg->mm,
 | 
			
		||||
		.vm_flags = vmg->flags,
 | 
			
		||||
		.anon_vma = vmg->anon_vma,
 | 
			
		||||
		.vm_file = vmg->file,
 | 
			
		||||
	};
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * For convenience, get prev and next VMAs. Which the new VMA operation
 | 
			
		||||
	 * requires.
 | 
			
		||||
| 
						 | 
				
			
			@ -131,8 +103,7 @@ static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
 | 
			
		|||
	vmg->prev = vma_prev(vmg->vmi);
 | 
			
		||||
 | 
			
		||||
	vma_iter_set(vmg->vmi, vmg->start);
 | 
			
		||||
	return vma_merge_new_vma(vmg->vmi, vmg->prev, &dummy, vmg->start,
 | 
			
		||||
				 vmg->end, vmg->pgoff);
 | 
			
		||||
	return vma_merge(vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
| 
						 | 
				
			
			@ -141,17 +112,7 @@ static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
 | 
			
		|||
 */
 | 
			
		||||
static struct vm_area_struct *merge_existing(struct vma_merge_struct *vmg)
 | 
			
		||||
{
 | 
			
		||||
	/* vma_merge() needs a VMA to determine mm, anon_vma, and file. */
 | 
			
		||||
	struct vm_area_struct dummy = {
 | 
			
		||||
		.vm_mm = vmg->mm,
 | 
			
		||||
		.vm_flags = vmg->flags,
 | 
			
		||||
		.anon_vma = vmg->anon_vma,
 | 
			
		||||
		.vm_file = vmg->file,
 | 
			
		||||
	};
 | 
			
		||||
 | 
			
		||||
	return vma_merge(vmg->vmi, vmg->prev, &dummy, vmg->start, vmg->end,
 | 
			
		||||
			 vmg->flags, vmg->pgoff, vmg->policy, vmg->uffd_ctx,
 | 
			
		||||
			 vmg->anon_name);
 | 
			
		||||
	return vma_merge(vmg);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
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		Reference in a new issue