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AJvYcCXb3FbTV3qZyAyCui03WPZfnRFaSnleqwyGyW2q+ppN0Zk5sz5weBhMK5RyZjX4RTZ3lYV5P5C0RpSakA0=@vger.kernel.org X-Gm-Message-State: AOJu0Yy0oTnj7dpBBjOG0KUNP87AU8FXYjBpHdwsOAD3gF1mWxMoLgQ0 tKVdW2hXMXMTNPMNo0s3+jGahX+jqtWBZzpnf1mQiwsB/PZAGbbgUVtav9WJaW7xHCJJSgWrG0x 2ViLjGQ== X-Received: from dyx25.prod.google.com ([2002:a05:693c:8219:b0:2c0:c743:7f67]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:220f:b0:119:e56b:98b9 with SMTP id a92af1059eb24-12a726bb993mr3455319c88.32.1774158201439; Sat, 21 Mar 2026 22:43:21 -0700 (PDT) Date: Sat, 21 Mar 2026 22:43:08 -0700 In-Reply-To: <20260322054309.898214-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260322054309.898214-1-surenb@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: <20260322054309.898214-5-surenb@google.com> Subject: [PATCH v4 4/4] mm: use vma_start_write_killable() in process_vma_walk_lock() From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, david@kernel.org, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, lorenzo.stoakes@oracle.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@suse.cz, jannh@google.com, rppt@kernel.org, mhocko@suse.com, pfalcato@suse.de, kees@kernel.org, maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au, chleroy@kernel.org, borntraeger@linux.ibm.com, frankja@linux.ibm.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com, gerald.schaefer@linux.ibm.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, surenb@google.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Replace vma_start_write() with vma_start_write_killable() when process_vma_walk_lock() is used with PGWALK_WRLOCK option. Adjust its direct and indirect users to check for a possible error and handle it. Ensure users handle EINTR correctly and do not ignore it. Signed-off-by: Suren Baghdasaryan --- fs/proc/task_mmu.c | 5 ++++- mm/mempolicy.c | 1 + mm/pagewalk.c | 20 ++++++++++++++------ 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e091931d7ca1..2fe3d11aad03 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1797,6 +1797,7 @@ static ssize_t clear_refs_write(struct file *file, co= nst char __user *buf, struct clear_refs_private cp =3D { .type =3D type, }; + int err; =20 if (mmap_write_lock_killable(mm)) { count =3D -EINTR; @@ -1824,7 +1825,9 @@ static ssize_t clear_refs_write(struct file *file, co= nst char __user *buf, 0, mm, 0, -1UL); mmu_notifier_invalidate_range_start(&range); } - walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); + err =3D walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); + if (err) + count =3D err; if (type =3D=3D CLEAR_REFS_SOFT_DIRTY) { mmu_notifier_invalidate_range_end(&range); flush_tlb_mm(mm); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 929e843543cf..bb5b0e83ce0f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -969,6 +969,7 @@ static const struct mm_walk_ops queue_pages_lock_vma_wa= lk_ops =3D { * (a hugetlbfs page or a transparent huge page being counted as 1). * -EIO - a misplaced page found, when MPOL_MF_STRICT specified without MO= VEs. * -EFAULT - a hole in the memory range, when MPOL_MF_DISCONTIG_OK unspeci= fied. + * -EINTR - walk got terminated due to pending fatal signal. */ static long queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long= end, diff --git a/mm/pagewalk.c b/mm/pagewalk.c index eda74273c8ec..a42cd6a6d812 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -438,14 +438,13 @@ static inline void process_mm_walk_lock(struct mm_str= uct *mm, mmap_assert_write_locked(mm); } =20 -static inline void process_vma_walk_lock(struct vm_area_struct *vma, +static inline int process_vma_walk_lock(struct vm_area_struct *vma, enum page_walk_lock walk_lock) { #ifdef CONFIG_PER_VMA_LOCK switch (walk_lock) { case PGWALK_WRLOCK: - vma_start_write(vma); - break; + return vma_start_write_killable(vma); case PGWALK_WRLOCK_VERIFY: vma_assert_write_locked(vma); break; @@ -457,6 +456,7 @@ static inline void process_vma_walk_lock(struct vm_area= _struct *vma, break; } #endif + return 0; } =20 /* @@ -500,7 +500,9 @@ int walk_page_range_mm_unsafe(struct mm_struct *mm, uns= igned long start, if (ops->pte_hole) err =3D ops->pte_hole(start, next, -1, &walk); } else { /* inside vma */ - process_vma_walk_lock(vma, ops->walk_lock); + err =3D process_vma_walk_lock(vma, ops->walk_lock); + if (err) + break; walk.vma =3D vma; next =3D min(end, vma->vm_end); vma =3D find_vma(mm, vma->vm_end); @@ -717,6 +719,7 @@ int walk_page_range_vma_unsafe(struct vm_area_struct *v= ma, unsigned long start, .vma =3D vma, .private =3D private, }; + int err; =20 if (start >=3D end || !walk.mm) return -EINVAL; @@ -724,7 +727,9 @@ int walk_page_range_vma_unsafe(struct vm_area_struct *v= ma, unsigned long start, return -EINVAL; =20 process_mm_walk_lock(walk.mm, ops->walk_lock); - process_vma_walk_lock(vma, ops->walk_lock); + err =3D process_vma_walk_lock(vma, ops->walk_lock); + if (err) + return err; return __walk_page_range(start, end, &walk); } =20 @@ -747,6 +752,7 @@ int walk_page_vma(struct vm_area_struct *vma, const str= uct mm_walk_ops *ops, .vma =3D vma, .private =3D private, }; + int err; =20 if (!walk.mm) return -EINVAL; @@ -754,7 +760,9 @@ int walk_page_vma(struct vm_area_struct *vma, const str= uct mm_walk_ops *ops, return -EINVAL; =20 process_mm_walk_lock(walk.mm, ops->walk_lock); - process_vma_walk_lock(vma, ops->walk_lock); + err =3D process_vma_walk_lock(vma, ops->walk_lock); + if (err) + return err; return __walk_page_range(vma->vm_start, vma->vm_end, &walk); } =20 --=20 2.53.0.1018.g2bb0e51243-goog