From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EDA05478D for ; Fri, 27 Mar 2026 23:04:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774652697; cv=none; b=mla4JjsBEtjpFBrHM4k/6Dqk0Yt0E5vvQZ88z55dCOiO7PUZqwq1RSP3w2mG1jCY5hu9LwRMuML0dg8h8hrgnUsETIdoaiGPu+eGTuhmCZNPlfajglG40jvoX/DMWg1x0fHVgmbVTNcVtmRfD4nnt6rj7JSd0U23QuWIZ/VogYM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774652697; c=relaxed/simple; bh=EVeLCeFYjq7aBUzoPgWCPu//1N4kzWzTSYVqzUn8sFU=; h=Date:To:From:Subject:Message-Id; b=Nsg1vTT92sHW1cp/2aTik6zRkefGo8B0Zh2CXV9lB8b1LzKTJ6IFpnCejus0UGTpBzvaJGMvPhlDoVnA8eQOZC+TnijHIrTiagxx3gTql1VhvaUuuipSIwXoOJtDMscOTQj1Nm6f3Zj05GWnVw2hiTY1HHuXt/p7+b2tJKqiQHw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=SNMco5+H; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="SNMco5+H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0611BC19423; Fri, 27 Mar 2026 23:04:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774652697; bh=EVeLCeFYjq7aBUzoPgWCPu//1N4kzWzTSYVqzUn8sFU=; h=Date:To:From:Subject:From; b=SNMco5+HX6ncnej9FgG81G+dTR6C+zf3qMRduZuCdsP/BAp0elcM+ePhy+oRFRRUp ZI1gaulmjhQ16MQ1UvzsXVqmeV8lUMSK6BG8ralbtByek0SDntROm6wmADJ86NFRp8 F1Ay1KUmf3MWbYh14bJKyNcjlxDeLukqIHPjRx3I= Date: Fri, 27 Mar 2026 16:04:56 -0700 To: mm-commits@vger.kernel.org,surenb@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-use-vma_start_write_killable-in-mm-syscalls.patch removed from -mm tree Message-Id: <20260327230457.0611BC19423@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: use vma_start_write_killable() in mm syscalls has been removed from the -mm tree. Its filename was mm-use-vma_start_write_killable-in-mm-syscalls.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Suren Baghdasaryan Subject: mm: use vma_start_write_killable() in mm syscalls Date: Thu, 26 Mar 2026 01:08:32 -0700 Replace vma_start_write() with vma_start_write_killable() in syscalls, improving reaction time to the kill signal. In a number of places we now lock VMA earlier than before to avoid doing work and undoing it later if a fatal signal is pending. This is safe because the moves are happening within sections where we already hold the mmap_write_lock, so the moves do not change the locking order relative to other kernel locks. Link: https://lkml.kernel.org/r/20260326080836.695207-3-surenb@google.com Signed-off-by: Suren Baghdasaryan Suggested-by: Matthew Wilcox Reviewed-by: Lorenzo Stoakes (Oracle) Cc: Alexander Gordeev Cc: Alistair Popple Cc: Baolin Wang Cc: Barry Song Cc: Byungchul Park Cc: Christian Borntraeger Cc: "Christophe Leroy (CS GROUP)" Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Dev Jain Cc: Gerald Schaefer Cc: Gregory Price Cc: Heiko Carstens Cc: "Huang, Ying" Cc: Jann Horn Cc: Janosch Frank Cc: Joshua Hahn Cc: Kees Cook Cc: Lance Yang Cc: Liam R. Howlett Cc: Madhavan Srinivasan Cc: Matthew Brost Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Nico Pache Cc: Pedro Falcato Cc: Rakie Kim Cc: Ritesh Harjani (IBM) Cc: Ryan Roberts Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/madvise.c | 4 +++- mm/memory.c | 2 ++ mm/mempolicy.c | 11 +++++++++-- mm/mlock.c | 28 ++++++++++++++++++++++------ mm/mprotect.c | 5 ++++- mm/mremap.c | 8 +++++--- mm/mseal.c | 5 ++++- 7 files changed, 49 insertions(+), 14 deletions(-) --- a/mm/madvise.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/madvise.c @@ -175,7 +175,9 @@ static int madvise_update_vma(vm_flags_t madv_behavior->vma = vma; /* vm_flags is protected by the mmap_lock held in write mode. */ - vma_start_write(vma); + if (vma_start_write_killable(vma)) + return -EINTR; + vma->flags = new_vma_flags; if (set_new_anon_name) return replace_anon_vma_name(vma, anon_name); --- a/mm/memory.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/memory.c @@ -366,6 +366,8 @@ void free_pgd_range(struct mmu_gather *t * page tables that should be removed. This can differ from the vma mappings on * some archs that may have mappings that need to be removed outside the vmas. * 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 freed + * even if the task is being killed. * * The vma_end differs from the pg_end when a dup_mmap() failed and the tree has * unrelated data to the mm_struct being torn down. --- a/mm/mempolicy.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/mempolicy.c @@ -1784,7 +1784,8 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, return -EINVAL; if (end == start) return 0; - mmap_write_lock(mm); + if (mmap_write_lock_killable(mm)) + return -EINTR; prev = vma_prev(&vmi); for_each_vma_range(vmi, vma, end) { /* @@ -1801,13 +1802,19 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, err = -EOPNOTSUPP; break; } + /* + * Lock the VMA early to avoid extra work if fatal signal + * is pending. + */ + err = vma_start_write_killable(vma); + if (err) + break; new = mpol_dup(old); if (IS_ERR(new)) { err = PTR_ERR(new); break; } - vma_start_write(vma); new->home_node = home_node; err = mbind_range(&vmi, vma, &prev, start, end, new); mpol_put(new); --- a/mm/mlock.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/mlock.c @@ -419,8 +419,10 @@ out: * * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED; * called for munlock() and munlockall(), to clear VM_LOCKED from @vma. + * + * Return: 0 on success, -EINTR if fatal signal is pending. */ -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, vma_flags_t *new_vma_flags) { @@ -442,7 +444,9 @@ static void mlock_vma_pages_range(struct */ if (vma_flags_test(new_vma_flags, VMA_LOCKED_BIT)) vma_flags_set(new_vma_flags, VMA_IO_BIT); - vma_start_write(vma); + if (vma_start_write_killable(vma)) + return -EINTR; + vma_flags_reset_once(vma, new_vma_flags); lru_add_drain(); @@ -453,6 +457,7 @@ static void mlock_vma_pages_range(struct vma_flags_clear(new_vma_flags, VMA_IO_BIT); vma_flags_reset_once(vma, new_vma_flags); } + return 0; } /* @@ -506,11 +511,13 @@ static int mlock_fixup(struct vma_iterat */ if (vma_flags_test(&new_vma_flags, VMA_LOCKED_BIT) && vma_flags_test(&old_vma_flags, VMA_LOCKED_BIT)) { + ret = vma_start_write_killable(vma); + if (ret) + goto out; /* mm->locked_vm is fine as nr_pages == 0 */ /* No work to do, and mlocking twice would be wrong */ - vma_start_write(vma); vma->flags = new_vma_flags; } else { - mlock_vma_pages_range(vma, start, end, &new_vma_flags); + ret = mlock_vma_pages_range(vma, start, end, &new_vma_flags); } out: *prev = vma; @@ -739,9 +746,18 @@ static int apply_mlockall_flags(int flag error = mlock_fixup(&vmi, vma, &prev, vma->vm_start, vma->vm_end, newflags); - /* Ignore errors, but prev needs fixing up. */ - if (error) + if (error) { + /* + * If we failed due to a pending fatal signal, return + * now. If we locked the vma before signal arrived, it + * will be unlocked when we drop mmap_write_lock. + */ + if (fatal_signal_pending(current)) + return -EINTR; + + /* Ignore errors, but prev needs fixing up. */ prev = vma; + } cond_resched(); } out: --- a/mm/mprotect.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/mprotect.c @@ -784,7 +784,10 @@ mprotect_fixup(struct vma_iterator *vmi, * vm_flags and vm_page_prot are protected by the mmap_lock * held in write mode. */ - vma_start_write(vma); + error = vma_start_write_killable(vma); + if (error) + goto fail; + vma_flags_reset_once(vma, &new_vma_flags); if (vma_wants_manual_pte_write_upgrade(vma)) mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; --- a/mm/mremap.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/mremap.c @@ -1348,6 +1348,11 @@ static unsigned long move_vma(struct vma if (err) return err; + /* We don't want racing faults. */ + err = vma_start_write_killable(vrm->vma); + if (err) + return err; + /* * If accounted, determine the number of bytes the operation will * charge. @@ -1355,9 +1360,6 @@ static unsigned long move_vma(struct vma if (!vrm_calc_charge(vrm)) return -ENOMEM; - /* We don't want racing faults. */ - vma_start_write(vrm->vma); - /* Perform copy step. */ err = copy_vma_and_data(vrm, &new_vma); /* --- a/mm/mseal.c~mm-use-vma_start_write_killable-in-mm-syscalls +++ a/mm/mseal.c @@ -70,6 +70,7 @@ static int mseal_apply(struct mm_struct if (!vma_test(vma, VMA_SEALED_BIT)) { vma_flags_t vma_flags = vma->flags; + int err; vma_flags_set(&vma_flags, VMA_SEALED_BIT); @@ -77,7 +78,9 @@ static int mseal_apply(struct mm_struct curr_end, &vma_flags); if (IS_ERR(vma)) return PTR_ERR(vma); - vma_start_write(vma); + err = vma_start_write_killable(vma); + if (err) + return err; vma_set_flags(vma, VMA_SEALED_BIT); } _ Patches currently in -mm which might be from surenb@google.com are a.patch mm-khugepaged-use-vma_start_write_killable-in-collapse_huge_page.patch mm-vma-use-vma_start_write_killable-in-vma-operations.patch mm-use-vma_start_write_killable-in-process_vma_walk_lock.patch kvm-ppc-use-vma_start_write_killable-in-kvmppc_memslot_page_merge.patch mm-vmscan-prevent-mglru-reclaim-from-pinning-address-space.patch