The patch titled
Subject: mm/vma: return the exact errno in vms_gather_munmap_vmas()
has been added to the -mm mm-unstable branch. Its filename is
mm-vma-return-the-exact-errno-in-vms_gather_munmap_vmas.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vma-return-the-exact-errno-in-vms_gather_munmap_vmas.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Xiao Yang <ice_yangxiao@xxxxxxx>
Subject: mm/vma: return the exact errno in vms_gather_munmap_vmas()
Date: Mon, 9 Sep 2024 21:56:21 +0900
__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.
Link: https://lkml.kernel.org/r/20240909125621.1994-1-ice_yangxiao@xxxxxxx
Fixes: 6898c9039bc8 ("mm/vma: extract the gathering of vmas from do_vmi_align_munmap()")
Signed-off-by: Xiao Yang <ice_yangxiao@xxxxxxx>
Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-lkp/202409081536.d283a0fb-oliver.sang@xxxxxxxxx
Cc: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vma.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
--- a/mm/vma.c~mm-vma-return-the-exact-errno-in-vms_gather_munmap_vmas
+++ a/mm/vma.c
@@ -1171,13 +1171,13 @@ void vms_complete_munmap_vmas(struct vma
* @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_mu
* 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_mu
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_mu
}
/* 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_mu
* 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
_
Patches currently in -mm which might be from ice_yangxiao@xxxxxxx are
mm-vma-return-the-exact-errno-in-vms_gather_munmap_vmas.patch
