From: Lorenzo Stoakes Date: Fri, 3 Jan 2025 19:35:36 +0000 (+0000) Subject: mm/debug: prefer VM_WARN_ON_VMG() to report VMG debug warnings X-Git-Tag: v6.14-rc1~77^2~158 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fe1679ed02bc24d88918c555dd9e5d95ddb03ab1;p=thirdparty%2Fkernel%2Flinux.git mm/debug: prefer VM_WARN_ON_VMG() to report VMG debug warnings Now we have VM_WARN_ON_VMG() to provide us with considerably more debug output when a debug assert fails, utilise it everywhere we can. This allows us to have considerably more information to go on when things go wrong, especially when a non-repro issue occurs as reported by syzkaller or the like. Link: https://lkml.kernel.org/r/986e45e9549e71284ac7a7fa878688568a94d58b.1735932169.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Cc: David Hildenbrand Cc: Jann Horn Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- diff --git a/mm/vma.c b/mm/vma.c index 0caaeea899a96..5ef2ea843a8a5 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -729,19 +729,20 @@ static __must_check struct vm_area_struct *vma_merge_existing_range( bool expanded; mmap_assert_write_locked(vmg->mm); - VM_WARN_ON(!vma); /* We are modifying a VMA, so caller must specify. */ - VM_WARN_ON(vmg->next); /* We set this. */ - VM_WARN_ON(prev && start <= prev->vm_start); - VM_WARN_ON(start >= end); + VM_WARN_ON_VMG(!vma, vmg); /* We are modifying a VMA, so caller must specify. */ + VM_WARN_ON_VMG(vmg->next, vmg); /* We set this. */ + VM_WARN_ON_VMG(prev && start <= prev->vm_start, vmg); + VM_WARN_ON_VMG(start >= end, vmg); + /* * If vma == prev, then we are offset into a VMA. Otherwise, if we are * not, we must span a portion of the VMA. */ - VM_WARN_ON(vma && ((vma != prev && vmg->start != vma->vm_start) || - vmg->end > vma->vm_end)); + VM_WARN_ON_VMG(vma && ((vma != prev && vmg->start != vma->vm_start) || + vmg->end > vma->vm_end), vmg); /* The vmi must be positioned within vmg->vma. */ - VM_WARN_ON(vma && !(vma_iter_addr(vmg->vmi) >= vma->vm_start && - vma_iter_addr(vmg->vmi) < vma->vm_end)); + VM_WARN_ON_VMG(vma && !(vma_iter_addr(vmg->vmi) >= vma->vm_start && + vma_iter_addr(vmg->vmi) < vma->vm_end), vmg); vmg->state = VMA_MERGE_NOMERGE; @@ -858,9 +859,9 @@ static __must_check struct vm_area_struct *vma_merge_existing_range( pgoff_t pglen = PHYS_PFN(vmg->end - vmg->start); - VM_WARN_ON(!merge_right); + VM_WARN_ON_VMG(!merge_right, vmg); /* If we are offset into a VMA, then prev must be vma. */ - VM_WARN_ON(vmg->start > vma->vm_start && prev && vma != prev); + VM_WARN_ON_VMG(vmg->start > vma->vm_start && prev && vma != prev, vmg); if (merge_will_delete_vma) { vmg->vma = next; @@ -972,9 +973,9 @@ struct vm_area_struct *vma_merge_new_range(struct vma_merge_struct *vmg) bool just_expand = vmg->merge_flags & VMG_FLAG_JUST_EXPAND; mmap_assert_write_locked(vmg->mm); - VM_WARN_ON(vmg->vma); + VM_WARN_ON_VMG(vmg->vma, vmg); /* vmi must point at or before the gap. */ - VM_WARN_ON(vma_iter_addr(vmg->vmi) > end); + VM_WARN_ON_VMG(vma_iter_addr(vmg->vmi) > end, vmg); vmg->state = VMA_MERGE_NOMERGE; @@ -1056,7 +1057,7 @@ int vma_expand(struct vma_merge_struct *vmg) remove_next = true; /* This should already have been checked by this point. */ - VM_WARN_ON(!can_merge_remove_vma(next)); + VM_WARN_ON_VMG(!can_merge_remove_vma(next), vmg); vma_start_write(next); ret = dup_anon_vma(vma, next, &anon_dup); if (ret) @@ -1064,10 +1065,10 @@ int vma_expand(struct vma_merge_struct *vmg) } /* Not merging but overwriting any part of next is not handled. */ - VM_WARN_ON(next && !remove_next && - next != vma && vmg->end > next->vm_start); + VM_WARN_ON_VMG(next && !remove_next && + next != vma && vmg->end > next->vm_start, vmg); /* Only handles expanding */ - VM_WARN_ON(vma->vm_start < vmg->start || vma->vm_end > vmg->end); + VM_WARN_ON_VMG(vma->vm_start < vmg->start || vma->vm_end > vmg->end, vmg); if (commit_merge(vmg, NULL, remove_next ? next : NULL, NULL, 0, true)) goto nomem;