| Message ID | 20240909125621.1994-1-ice_yangxiao@163.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] mm/vma: Return the exact errno in vms_gather_munmap_vmas() | expand |
* Xiao Yang <ice_yangxiao@163.com> [240909 08:56]: > __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. > > Fixes: 6898c9039bc8 ("mm/vma: extract the gathering of vmas from do_vmi_align_munmap()") > Signed-off-by: Xiao Yang <ice_yangxiao@163.com> > Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> > Reported-by: kernel test robot <oliver.sang@intel.com> > Closes: https://lore.kernel.org/oe-lkp/202409081536.d283a0fb-oliver.sang@intel.com > --- > mm/vma.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/mm/vma.c b/mm/vma.c > index 8d1686fc8d5a..dc5355d99a18 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 +1260,8 @@ 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); This line is too long. > + if (error) > goto userfaultfd_error; Good you saw this issue, I was going to point it out. > } > #ifdef CONFIG_DEBUG_VM_MAPLE_TREE > -- > 2.46.0 > > Besides the line over 80 characters, this looks good to me and should be squashed into my series. Thanks, Liam
diff --git a/mm/vma.c b/mm/vma.c index 8d1686fc8d5a..dc5355d99a18 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 +1260,8 @@ 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
__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. Fixes: 6898c9039bc8 ("mm/vma: extract the gathering of vmas from do_vmi_align_munmap()") Signed-off-by: Xiao Yang <ice_yangxiao@163.com> Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202409081536.d283a0fb-oliver.sang@intel.com --- mm/vma.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)