From 659c55ef981bb63355a65ffc3b3b5cad562b806a Mon Sep 17 00:00:00 2001 From: Xiao Yang Date: Mon, 9 Sep 2024 21:56:21 +0900 Subject: [PATCH] mm/vma: return the exact errno in vms_gather_munmap_vmas() __split_vma() and mas_store_gfp() returns several types of errno on failure so don't ignore them in vms_gather_munmap_vmas(). For example, __split_vma() returns -EINVAL when an unaligned huge page is unmapped. This issue is reproduced by ltp memfd_create03 test. Don't initialise the error variable and assign it when a failure actually occurs. [akpm@linux-foundation.org: fix whitespace, per Liam] Link: https://lkml.kernel.org/r/20240909125621.1994-1-ice_yangxiao@163.com Fixes: 6898c9039bc8 ("mm/vma: extract the gathering of vmas from do_vmi_align_munmap()") Signed-off-by: Xiao Yang Suggested-by: Lorenzo Stoakes Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409081536.d283a0fb-oliver.sang@intel.com Cc: "Liam R. Howlett" Signed-off-by: Andrew Morton --- mm/vma.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index 8d1686fc8d5a..4737afcb064c 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -1171,13 +1171,13 @@ void vms_complete_munmap_vmas(struct vma_munmap_struct *vms, * @vms: The vma munmap struct * @mas_detach: The maple state tracking the detached tree * - * Return: 0 on success, -EPERM on mseal vmas, -ENOMEM otherwise + * Return: 0 on success, error otherwise */ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, struct ma_state *mas_detach) { struct vm_area_struct *next = NULL; - int error = -ENOMEM; + int error; /* * If we need to split any vma, do it now to save pain later. @@ -1191,8 +1191,10 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, * its limit temporarily, to help free resources as expected. */ if (vms->end < vms->vma->vm_end && - vms->vma->vm_mm->map_count >= sysctl_max_map_count) + vms->vma->vm_mm->map_count >= sysctl_max_map_count) { + error = -ENOMEM; goto map_count_exceeded; + } /* Don't bother splitting the VMA if we can't unmap it anyway */ if (!can_modify_vma(vms->vma)) { @@ -1200,7 +1202,8 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, goto start_split_failed; } - if (__split_vma(vms->vmi, vms->vma, vms->start, 1)) + error = __split_vma(vms->vmi, vms->vma, vms->start, 1); + if (error) goto start_split_failed; } vms->prev = vma_prev(vms->vmi); @@ -1220,12 +1223,14 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, } /* Does it split the end? */ if (next->vm_end > vms->end) { - if (__split_vma(vms->vmi, next, vms->end, 0)) + error = __split_vma(vms->vmi, next, vms->end, 0); + if (error) goto end_split_failed; } vma_start_write(next); mas_set(mas_detach, vms->vma_count++); - if (mas_store_gfp(mas_detach, next, GFP_KERNEL)) + error = mas_store_gfp(mas_detach, next, GFP_KERNEL); + if (error) goto munmap_gather_failed; vma_mark_detached(next, true); @@ -1255,8 +1260,9 @@ int vms_gather_munmap_vmas(struct vma_munmap_struct *vms, * split, despite we could. This is unlikely enough * failure that it's not worth optimizing it for. */ - if (userfaultfd_unmap_prep(next, vms->start, vms->end, - vms->uf)) + error = userfaultfd_unmap_prep(next, vms->start, + vms->end, vms->uf); + if (error) goto userfaultfd_error; } #ifdef CONFIG_DEBUG_VM_MAPLE_TREE -- 2.20.1