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charset="utf-8" vma_expand() error handling is a bit confusing with "if (ret) return ret;" mixed with "if (!ret && ...) ret =3D ...;". Simplify the code to check for errors and return immediately after an operation that might fail. This also makes later changes to this function more readable. No functional change intended. Suggested-by: Jann Horn Signed-off-by: Suren Baghdasaryan Reviewed-by: Liam R. Howlett Reviewed-by: Lorenzo Stoakes --- mm/vma.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index be64f781a3aa..bb4d0326fecb 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -1186,12 +1186,16 @@ int vma_expand(struct vma_merge_struct *vmg) * Note that, by convention, callers ignore OOM for this case, so * we don't need to account for vmg->give_up_on_mm here. */ - if (remove_next) + if (remove_next) { ret =3D dup_anon_vma(target, next, &anon_dup); - if (!ret && vmg->copied_from) + if (ret) + return ret; + } + if (vmg->copied_from) { ret =3D dup_anon_vma(target, vmg->copied_from, &anon_dup); - if (ret) - return ret; + if (ret) + return ret; + } =20 if (remove_next) { vma_start_write(next); --=20 2.53.0.414.gf7e9f6c205-goog From nobody Thu Apr 16 19:11:13 2026 Received: from mail-dl1-f73.google.com (mail-dl1-f73.google.com [74.125.82.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66E3838E5D7 for ; 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Wed, 25 Feb 2026 23:06:17 -0800 (PST) Date: Wed, 25 Feb 2026 23:06:08 -0800 In-Reply-To: <20260226070609.3072570-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260226070609.3072570-1-surenb@google.com> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog Message-ID: <20260226070609.3072570-3-surenb@google.com> Subject: [PATCH v3 2/3] mm: replace vma_start_write() with vma_start_write_killable() 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, "Ritesh Harjani (IBM)" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that we have vma_start_write_killable() we can replace most of the vma_start_write() calls with it, improving reaction time to the kill signal. There are several places which are left untouched by this patch: 1. free_pgtables() because function should free page tables even if a fatal signal is pending. 2. process_vma_walk_lock(), which requires changes in its callers and will be handled in the next patch. 3. userfaultd code, where some paths calling vma_start_write() can handle EINTR and some can't without a deeper code refactoring. 4. mpol_rebind_mm() which is used by cpusset controller for migrations and operates on a remote mm. Incomplete operations here would result in an inconsistent cgroup state. 5. vm_flags_{set|mod|clear} require refactoring that involves moving vma_start_write() out of these functions and replacing it with vma_assert_write_locked(), then callers of these functions should lock the vma themselves using vma_start_write_killable() whenever possible. Suggested-by: Matthew Wilcox Signed-off-by: Suren Baghdasaryan Reviewed-by: Ritesh Harjani (IBM) # powerpc Reviewed-by: Liam R. Howlett --- arch/powerpc/kvm/book3s_hv_uvmem.c | 5 +- mm/khugepaged.c | 5 +- mm/madvise.c | 4 +- mm/memory.c | 2 + mm/mempolicy.c | 8 ++- mm/mlock.c | 21 +++++-- mm/mprotect.c | 4 +- mm/mremap.c | 4 +- mm/vma.c | 93 +++++++++++++++++++++--------- mm/vma_exec.c | 6 +- 10 files changed, 109 insertions(+), 43 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_h= v_uvmem.c index 5fbb95d90e99..0a28b48a46b8 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -410,7 +410,10 @@ static int kvmppc_memslot_page_merge(struct kvm *kvm, ret =3D H_STATE; break; } - vma_start_write(vma); + if (vma_start_write_killable(vma)) { + ret =3D H_STATE; + break; + } /* Copy vm_flags to avoid partial modifications in ksm_madvise */ vm_flags =3D vma->vm_flags; ret =3D ksm_madvise(vma, vma->vm_start, vma->vm_end, diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 1dd3cfca610d..6c92e31ee5fb 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1141,7 +1141,10 @@ static enum scan_result collapse_huge_page(struct mm= _struct *mm, unsigned long a if (result !=3D SCAN_SUCCEED) goto out_up_write; /* check if the pmd is still valid */ - vma_start_write(vma); + if (vma_start_write_killable(vma)) { + result =3D SCAN_FAIL; + goto out_up_write; + } result =3D check_pmd_still_valid(mm, address, pmd); if (result !=3D SCAN_SUCCEED) goto out_up_write; diff --git a/mm/madvise.c b/mm/madvise.c index c0370d9b4e23..ccdaea6b3b15 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -173,7 +173,9 @@ static int madvise_update_vma(vm_flags_t new_flags, madv_behavior->vma =3D vma; =20 /* vm_flags is protected by the mmap_lock held in write mode. */ - vma_start_write(vma); + if (vma_start_write_killable(vma)) + return -EINTR; + vm_flags_reset(vma, new_flags); if (set_new_anon_name) return replace_anon_vma_name(vma, anon_name); diff --git a/mm/memory.c b/mm/memory.c index 07778814b4a8..691062154cf5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -379,6 +379,8 @@ void free_pgd_range(struct mmu_gather *tlb, * page tables that should be removed. This can differ from the vma mappi= ngs on * some archs that may have mappings that need to be removed outside the v= mas. * Note that the prev->vm_end and next->vm_start are often used. + * We don't use vma_start_write_killable() because page tables should be f= reed + * even if the task is being killed. * * The vma_end differs from the pg_end when a dup_mmap() failed and the tr= ee has * unrelated data to the mm_struct being torn down. diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 0e5175f1c767..90939f5bde02 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1784,7 +1784,8 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned lon= g, start, unsigned long, le return -EINVAL; if (end =3D=3D start) return 0; - mmap_write_lock(mm); + if (mmap_write_lock_killable(mm)) + return -EINTR; prev =3D vma_prev(&vmi); for_each_vma_range(vmi, vma, end) { /* @@ -1801,13 +1802,16 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned l= ong, start, unsigned long, le err =3D -EOPNOTSUPP; break; } + if (vma_start_write_killable(vma)) { + err =3D -EINTR; + break; + } new =3D mpol_dup(old); if (IS_ERR(new)) { err =3D PTR_ERR(new); break; } =20 - vma_start_write(vma); new->home_node =3D home_node; err =3D mbind_range(&vmi, vma, &prev, start, end, new); mpol_put(new); diff --git a/mm/mlock.c b/mm/mlock.c index 2f699c3497a5..c562c77c3ee0 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -420,7 +420,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long ad= dr, * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED; * called for munlock() and munlockall(), to clear VM_LOCKED from @vma. */ -static void mlock_vma_pages_range(struct vm_area_struct *vma, +static int mlock_vma_pages_range(struct vm_area_struct *vma, unsigned long start, unsigned long end, vm_flags_t newflags) { static const struct mm_walk_ops mlock_walk_ops =3D { @@ -441,7 +441,9 @@ static void mlock_vma_pages_range(struct vm_area_struct= *vma, */ if (newflags & VM_LOCKED) newflags |=3D VM_IO; - vma_start_write(vma); + if (vma_start_write_killable(vma)) + return -EINTR; + vm_flags_reset_once(vma, newflags); =20 lru_add_drain(); @@ -452,6 +454,7 @@ static void mlock_vma_pages_range(struct vm_area_struct= *vma, newflags &=3D ~VM_IO; vm_flags_reset_once(vma, newflags); } + return 0; } =20 /* @@ -501,10 +504,12 @@ static int mlock_fixup(struct vma_iterator *vmi, stru= ct vm_area_struct *vma, */ if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) { /* No work to do, and mlocking twice would be wrong */ - vma_start_write(vma); + ret =3D vma_start_write_killable(vma); + if (ret) + goto out; vm_flags_reset(vma, newflags); } else { - mlock_vma_pages_range(vma, start, end, newflags); + ret =3D mlock_vma_pages_range(vma, start, end, newflags); } out: *prev =3D vma; @@ -733,9 +738,13 @@ static int apply_mlockall_flags(int flags) =20 error =3D mlock_fixup(&vmi, vma, &prev, vma->vm_start, vma->vm_end, newflags); - /* Ignore errors, but prev needs fixing up. */ - if (error) + /* Ignore errors except EINTR, but prev needs fixing up. */ + if (error) { + if (error =3D=3D -EINTR) + return error; + prev =3D vma; + } cond_resched(); } out: diff --git a/mm/mprotect.c b/mm/mprotect.c index c0571445bef7..49dbb7156936 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -765,7 +765,9 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gat= her *tlb, * vm_flags and vm_page_prot are protected by the mmap_lock * held in write mode. */ - vma_start_write(vma); + error =3D vma_start_write_killable(vma); + if (error < 0) + goto fail; vm_flags_reset_once(vma, newflags); if (vma_wants_manual_pte_write_upgrade(vma)) mm_cp_flags |=3D MM_CP_TRY_CHANGE_WRITABLE; diff --git a/mm/mremap.c b/mm/mremap.c index 2be876a70cc0..aef1e5f373c7 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -1286,7 +1286,9 @@ static unsigned long move_vma(struct vma_remap_struct= *vrm) return -ENOMEM; =20 /* We don't want racing faults. */ - vma_start_write(vrm->vma); + err =3D vma_start_write_killable(vrm->vma); + if (err) + return err; =20 /* Perform copy step. */ err =3D copy_vma_and_data(vrm, &new_vma); diff --git a/mm/vma.c b/mm/vma.c index bb4d0326fecb..9f2664f1d078 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -530,6 +530,13 @@ __split_vma(struct vma_iterator *vmi, struct vm_area_s= truct *vma, if (err) goto out_free_vmi; =20 + err =3D vma_start_write_killable(vma); + if (err) + goto out_free_mpol; + err =3D vma_start_write_killable(new); + if (err) + goto out_free_mpol; + err =3D anon_vma_clone(new, vma, VMA_OP_SPLIT); if (err) goto out_free_mpol; @@ -540,9 +547,6 @@ __split_vma(struct vma_iterator *vmi, struct vm_area_st= ruct *vma, if (new->vm_ops && new->vm_ops->open) new->vm_ops->open(new); =20 - vma_start_write(vma); - vma_start_write(new); - init_vma_prep(&vp, vma); vp.insert =3D new; vma_prepare(&vp); @@ -895,16 +899,22 @@ static __must_check struct vm_area_struct *vma_merge_= existing_range( } =20 /* No matter what happens, we will be adjusting middle. */ - vma_start_write(middle); + err =3D vma_start_write_killable(middle); + if (err) + goto abort; =20 if (merge_right) { - vma_start_write(next); + err =3D vma_start_write_killable(next); + if (err) + goto abort; vmg->target =3D next; sticky_flags |=3D (next->vm_flags & VM_STICKY); } =20 if (merge_left) { - vma_start_write(prev); + err =3D vma_start_write_killable(prev); + if (err) + goto abort; vmg->target =3D prev; sticky_flags |=3D (prev->vm_flags & VM_STICKY); } @@ -1155,10 +1165,12 @@ int vma_expand(struct vma_merge_struct *vmg) struct vm_area_struct *next =3D vmg->next; bool remove_next =3D false; vm_flags_t sticky_flags; - int ret =3D 0; + int ret; =20 mmap_assert_write_locked(vmg->mm); - vma_start_write(target); + ret =3D vma_start_write_killable(target); + if (ret) + return ret; =20 if (next && target !=3D next && vmg->end =3D=3D next->vm_end) remove_next =3D true; @@ -1187,6 +1199,9 @@ int vma_expand(struct vma_merge_struct *vmg) * we don't need to account for vmg->give_up_on_mm here. */ if (remove_next) { + ret =3D vma_start_write_killable(next); + if (ret) + return ret; ret =3D dup_anon_vma(target, next, &anon_dup); if (ret) return ret; @@ -1197,10 +1212,8 @@ int vma_expand(struct vma_merge_struct *vmg) return ret; } =20 - if (remove_next) { - vma_start_write(next); + if (remove_next) vmg->__remove_next =3D true; - } if (commit_merge(vmg)) goto nomem; =20 @@ -1233,6 +1246,7 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_ar= ea_struct *vma, unsigned long start, unsigned long end, pgoff_t pgoff) { struct vma_prepare vp; + int err; =20 WARN_ON((vma->vm_start !=3D start) && (vma->vm_end !=3D end)); =20 @@ -1244,7 +1258,11 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_a= rea_struct *vma, if (vma_iter_prealloc(vmi, NULL)) return -ENOMEM; =20 - vma_start_write(vma); + err =3D vma_start_write_killable(vma); + if (err) { + vma_iter_free(vmi); + return err; + } =20 init_vma_prep(&vp, vma); vma_prepare(&vp); @@ -1434,7 +1452,9 @@ static int vms_gather_munmap_vmas(struct vma_munmap_s= truct *vms, if (error) goto end_split_failed; } - vma_start_write(next); + error =3D vma_start_write_killable(next); + if (error) + goto munmap_gather_failed; mas_set(mas_detach, vms->vma_count++); error =3D mas_store_gfp(mas_detach, next, GFP_KERNEL); if (error) @@ -1828,12 +1848,17 @@ static void vma_link_file(struct vm_area_struct *vm= a, bool hold_rmap_lock) static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma) { VMA_ITERATOR(vmi, mm, 0); + int err; =20 vma_iter_config(&vmi, vma->vm_start, vma->vm_end); if (vma_iter_prealloc(&vmi, vma)) return -ENOMEM; =20 - vma_start_write(vma); + err =3D vma_start_write_killable(vma); + if (err) { + vma_iter_free(&vmi); + return err; + } vma_iter_store_new(&vmi, vma); vma_link_file(vma, /* hold_rmap_lock=3D */false); mm->map_count++; @@ -2215,9 +2240,8 @@ int mm_take_all_locks(struct mm_struct *mm) * is reached. */ for_each_vma(vmi, vma) { - if (signal_pending(current)) + if (signal_pending(current) || vma_start_write_killable(vma)) goto out_unlock; - vma_start_write(vma); } =20 vma_iter_init(&vmi, mm, 0); @@ -2522,6 +2546,11 @@ static int __mmap_new_vma(struct mmap_state *map, st= ruct vm_area_struct **vmap) if (!vma) return -ENOMEM; =20 + /* Lock the VMA since it is modified after insertion into VMA tree */ + error =3D vma_start_write_killable(vma); + if (error) + goto free_vma; + vma_iter_config(vmi, map->addr, map->end); vma_set_range(vma, map->addr, map->end, map->pgoff); vm_flags_init(vma, map->vm_flags); @@ -2552,8 +2581,6 @@ static int __mmap_new_vma(struct mmap_state *map, str= uct vm_area_struct **vmap) WARN_ON_ONCE(!arch_validate_flags(map->vm_flags)); #endif =20 - /* Lock the VMA since it is modified after insertion into VMA tree */ - vma_start_write(vma); vma_iter_store_new(vmi, vma); map->mm->map_count++; vma_link_file(vma, map->hold_file_rmap_lock); @@ -2864,6 +2891,7 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_= area_struct *vma, unsigned long addr, unsigned long len, vm_flags_t vm_flags) { struct mm_struct *mm =3D current->mm; + int err =3D -ENOMEM; =20 /* * Check against address space limits by the changed size @@ -2908,7 +2936,10 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm= _area_struct *vma, vma_set_range(vma, addr, addr + len, addr >> PAGE_SHIFT); vm_flags_init(vma, vm_flags); vma->vm_page_prot =3D vm_get_page_prot(vm_flags); - vma_start_write(vma); + if (vma_start_write_killable(vma)) { + err =3D -EINTR; + goto mas_store_fail; + } if (vma_iter_store_gfp(vmi, vma, GFP_KERNEL)) goto mas_store_fail; =20 @@ -2928,7 +2959,7 @@ int do_brk_flags(struct vma_iterator *vmi, struct vm_= area_struct *vma, vm_area_free(vma); unacct_fail: vm_unacct_memory(len >> PAGE_SHIFT); - return -ENOMEM; + return err; } =20 /** @@ -3089,7 +3120,7 @@ int expand_upwards(struct vm_area_struct *vma, unsign= ed long address) struct mm_struct *mm =3D vma->vm_mm; struct vm_area_struct *next; unsigned long gap_addr; - int error =3D 0; + int error; VMA_ITERATOR(vmi, mm, vma->vm_start); =20 if (!(vma->vm_flags & VM_GROWSUP)) @@ -3126,12 +3157,14 @@ int expand_upwards(struct vm_area_struct *vma, unsi= gned long address) =20 /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) { - vma_iter_free(&vmi); - return -ENOMEM; + error =3D -ENOMEM; + goto free; } =20 /* Lock the VMA before expanding to prevent concurrent page faults */ - vma_start_write(vma); + error =3D vma_start_write_killable(vma); + if (error) + goto free; /* We update the anon VMA tree. */ anon_vma_lock_write(vma->anon_vma); =20 @@ -3160,6 +3193,7 @@ int expand_upwards(struct vm_area_struct *vma, unsign= ed long address) } } anon_vma_unlock_write(vma->anon_vma); +free: vma_iter_free(&vmi); validate_mm(mm); return error; @@ -3174,7 +3208,7 @@ int expand_downwards(struct vm_area_struct *vma, unsi= gned long address) { struct mm_struct *mm =3D vma->vm_mm; struct vm_area_struct *prev; - int error =3D 0; + int error; VMA_ITERATOR(vmi, mm, vma->vm_start); =20 if (!(vma->vm_flags & VM_GROWSDOWN)) @@ -3205,12 +3239,14 @@ int expand_downwards(struct vm_area_struct *vma, un= signed long address) =20 /* We must make sure the anon_vma is allocated. */ if (unlikely(anon_vma_prepare(vma))) { - vma_iter_free(&vmi); - return -ENOMEM; + error =3D -ENOMEM; + goto free; } =20 /* Lock the VMA before expanding to prevent concurrent page faults */ - vma_start_write(vma); + error =3D vma_start_write_killable(vma); + if (error) + goto free; /* We update the anon VMA tree. */ anon_vma_lock_write(vma->anon_vma); =20 @@ -3240,6 +3276,7 @@ int expand_downwards(struct vm_area_struct *vma, unsi= gned long address) } } anon_vma_unlock_write(vma->anon_vma); 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Wed, 25 Feb 2026 23:06:19 -0800 (PST) Date: Wed, 25 Feb 2026 23:06:09 -0800 In-Reply-To: <20260226070609.3072570-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260226070609.3072570-1-surenb@google.com> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog Message-ID: <20260226070609.3072570-4-surenb@google.com> Subject: [PATCH v3 3/3] 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 Acked-by: Claudio Imbrenda --- arch/s390/kvm/kvm-s390.c | 2 +- fs/proc/task_mmu.c | 5 ++++- mm/mempolicy.c | 14 +++++++++++--- mm/pagewalk.c | 20 ++++++++++++++------ mm/vma.c | 22 ++++++++++++++-------- mm/vma.h | 6 ++++++ 6 files changed, 50 insertions(+), 19 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 7a175d86cef0..337e4f7db63a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2948,7 +2948,7 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int= ioctl, unsigned long arg) } /* must be called without kvm->lock */ r =3D kvm_s390_handle_pv(kvm, &args); - if (copy_to_user(argp, &args, sizeof(args))) { + if (r !=3D -EINTR && copy_to_user(argp, &args, sizeof(args))) { r =3D -EFAULT; break; } diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e091931d7ca1..1238a2988eb6 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 < 0) + 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 90939f5bde02..3c8b3dfc9c56 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -988,6 +988,8 @@ queue_pages_range(struct mm_struct *mm, unsigned long s= tart, unsigned long end, &queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops; =20 err =3D walk_page_range(mm, start, end, ops, &qp); + if (err =3D=3D -EINTR) + return err; =20 if (!qp.first) /* whole range in hole */ @@ -1309,9 +1311,14 @@ static long migrate_to_node(struct mm_struct *mm, in= t source, int dest, flags | MPOL_MF_DISCONTIG_OK, &pagelist); mmap_read_unlock(mm); =20 + if (nr_failed =3D=3D -EINTR) + err =3D nr_failed; + if (!list_empty(&pagelist)) { - err =3D migrate_pages(&pagelist, alloc_migration_target, NULL, - (unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL); + if (!err) + err =3D migrate_pages(&pagelist, alloc_migration_target, + NULL, (unsigned long)&mtc, + MIGRATE_SYNC, MR_SYSCALL, NULL); if (err) putback_movable_pages(&pagelist); } @@ -1611,7 +1618,8 @@ static long do_mbind(unsigned long start, unsigned lo= ng len, MR_MEMPOLICY_MBIND, NULL); } =20 - if (nr_failed && (flags & MPOL_MF_STRICT)) + /* Do not mask EINTR */ + if ((err !=3D -EINTR) && (nr_failed && (flags & MPOL_MF_STRICT))) err =3D -EIO; if (!list_empty(&pagelist)) putback_movable_pages(&pagelist); diff --git a/mm/pagewalk.c b/mm/pagewalk.c index a94c401ab2cf..dc9f7a7709c6 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -425,14 +425,13 @@ 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; @@ -444,6 +443,7 @@ static inline void process_vma_walk_lock(struct vm_area= _struct *vma, break; } #endif + return 0; } =20 /* @@ -487,7 +487,9 @@ 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); @@ -704,6 +706,7 @@ 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; @@ -711,7 +714,9 @@ 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 @@ -734,6 +739,7 @@ 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; @@ -741,7 +747,9 @@ 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 diff --git a/mm/vma.c b/mm/vma.c index 9f2664f1d078..46bbad6e64a4 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -998,14 +998,18 @@ static __must_check struct vm_area_struct *vma_merge_= existing_range( if (anon_dup) unlink_anon_vmas(anon_dup); =20 - /* - * This means we have failed to clone anon_vma's correctly, but no - * actual changes to VMAs have occurred, so no harm no foul - if the - * user doesn't want this reported and instead just wants to give up on - * the merge, allow it. - */ - if (!vmg->give_up_on_oom) - vmg->state =3D VMA_MERGE_ERROR_NOMEM; + if (err =3D=3D -EINTR) { + vmg->state =3D VMA_MERGE_ERROR_INTR; + } else { + /* + * This means we have failed to clone anon_vma's correctly, + * but no actual changes to VMAs have occurred, so no harm no + * foul - if the user doesn't want this reported and instead + * just wants to give up on the merge, allow it. + */ + if (!vmg->give_up_on_oom) + vmg->state =3D VMA_MERGE_ERROR_NOMEM; + } return NULL; } =20 @@ -1681,6 +1685,8 @@ static struct vm_area_struct *vma_modify(struct vma_m= erge_struct *vmg) merged =3D vma_merge_existing_range(vmg); if (merged) return merged; + if (vmg_intr(vmg)) + return ERR_PTR(-EINTR); if (vmg_nomem(vmg)) return ERR_PTR(-ENOMEM); =20 diff --git a/mm/vma.h b/mm/vma.h index eba388c61ef4..fe4560f81f4f 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -56,6 +56,7 @@ struct vma_munmap_struct { enum vma_merge_state { VMA_MERGE_START, VMA_MERGE_ERROR_NOMEM, + VMA_MERGE_ERROR_INTR, VMA_MERGE_NOMERGE, VMA_MERGE_SUCCESS, }; @@ -226,6 +227,11 @@ static inline bool vmg_nomem(struct vma_merge_struct *= vmg) return vmg->state =3D=3D VMA_MERGE_ERROR_NOMEM; } =20 +static inline bool vmg_intr(struct vma_merge_struct *vmg) +{ + return vmg->state =3D=3D VMA_MERGE_ERROR_INTR; +} + /* Assumes addr >=3D vma->vm_start. */ static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma, unsigned long addr) --=20 2.53.0.414.gf7e9f6c205-goog