March 2024 - Linux-stable-mirror

RE: [PATCH 3/5] virtio_blk: Fix device surprise removal

by Parav Pandit

> From: Parav Pandit <parav(a)nvidia.com> > Sent: Tuesday, March 5, 2024 12:06 PM > > When the PCI device is surprise removed, requests won't complete from the > device. These IOs are never completed and disk deletion hangs indefinitely. > > Fix it by aborting the IOs which the device will never complete when the VQ is > broken. > > With this fix now fio completes swiftly. > An alternative of IO timeout has been considered, however timeout can take > very long time. For unresponsive device, quickly completing the request with > error enables users and upper layer to react quickly. > > Verified with multiple device unplug cycles with pending IOs in virtio used ring > and some pending with device. > > Also verified without surprise removal. > > Fixes: 43bb40c5b926 ("virtio_pci: Support surprise removal of virtio pci > device") > Cc: stable(a)vger.kernel.org > Reported-by: lirongqing(a)baidu.com > Closes: > https://lore.kernel.org/virtualization/c45dd68698cd47238c55fb73ca9b4741 > @baidu.com/ > Co-developed-by: Chaitanya Kulkarni <kch(a)nvidia.com> > Signed-off-by: Chaitanya Kulkarni <kch(a)nvidia.com> > Signed-off-by: Parav Pandit <parav(a)nvidia.com> > --- Please ignore this patch, I am still debugging and verifying it. Incorrectly it got CCed to stable. I am sorry for the noise. > changelog: > v0->v1: > - addressed comments from Ming and Michael > - changed the flow to not depend on broken vq anymore to avoid > the race of missing the detection > - flow updated to quiesce request queue and device, followed by > syncing with any ongoing interrupt handler or callbacks, > finally finishing the requests which are not completed by device > with error. > --- > drivers/block/virtio_blk.c | 46 +++++++++++++++++++++++++++++++++++- > -- > 1 file changed, 43 insertions(+), 3 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index > 2bf14a0e2815..1956172b4b1a 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -1562,9 +1562,52 @@ static int virtblk_probe(struct virtio_device *vdev) > return err; > } > > +static bool virtblk_cancel_request(struct request *rq, void *data) { > + struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); > + > + vbr->in_hdr.status = VIRTIO_BLK_S_IOERR; > + if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) > + blk_mq_complete_request(rq); > + > + return true; > +} > + > static void virtblk_remove(struct virtio_device *vdev) { > struct virtio_blk *vblk = vdev->priv; > + int i; > + > + /* Block upper layer to not get any new requests */ > + blk_mq_quiesce_queue(vblk->disk->queue); > + > + mutex_lock(&vblk->vdev_mutex); > + > + /* Stop all the virtqueues and configuration change notification and > also > + * synchronize with pending interrupt handlers. > + */ > + virtio_reset_device(vdev); > + > + mutex_unlock(&vblk->vdev_mutex); > + > + /* Syncronize with any callback handlers for request completion */ > + for (i = 0; i < vblk->num_vqs; i++) > + virtblk_done(vblk->vqs[i].vq); > + > + blk_sync_queue(vblk->disk->queue); > + > + /* At this point block layer and device/transport are quiet; > + * hence, safely complete all the pending requests with error. > + */ > + blk_mq_tagset_busy_iter(&vblk->tag_set, virtblk_cancel_request, > vblk); > + blk_mq_tagset_wait_completed_request(&vblk->tag_set); > + > + /* > + * Unblock any pending dispatch I/Os before we destroy device. From > + * del_gendisk() -> __blk_mark_disk_dead(disk) will set GD_DEAD flag, > + * that will make sure any new I/O from bio_queue_enter() to fail. > + */ > + blk_mq_unquiesce_queue(vblk->disk->queue); > > /* Make sure no work handler is accessing the device. */ > flush_work(&vblk->config_work); > @@ -1574,9 +1617,6 @@ static void virtblk_remove(struct virtio_device > *vdev) > > mutex_lock(&vblk->vdev_mutex); > > - /* Stop all the virtqueues. */ > - virtio_reset_device(vdev); > - > /* Virtqueues are stopped, nothing can use vblk->vdev anymore. */ > vblk->vdev = NULL; > > -- > 2.34.1

9 months, 3 weeks

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[PATCH] tee: optee: Fix kernel panic caused by incorrect error handling

by Sumit Garg

The error path while failing to register devices on the TEE bus has a bug leading to kernel panic as follows: [ 15.398930] Unable to handle kernel paging request at virtual address ffff07ed00626d7c [ 15.406913] Mem abort info: [ 15.409722] ESR = 0x0000000096000005 [ 15.413490] EC = 0x25: DABT (current EL), IL = 32 bits [ 15.418814] SET = 0, FnV = 0 [ 15.421878] EA = 0, S1PTW = 0 [ 15.425031] FSC = 0x05: level 1 translation fault [ 15.429922] Data abort info: [ 15.432813] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 15.438310] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 15.443372] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 15.448697] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000d9e3e000 [ 15.455413] [ffff07ed00626d7c] pgd=1800000bffdf9003, p4d=1800000bffdf9003, pud=0000000000000000 [ 15.464146] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Commit 7269cba53d90 ("tee: optee: Fix supplicant based device enumeration") lead to the introduction of this bug. So fix it appropriately. Reported-by: Mikko Rapeli <mikko.rapeli(a)linaro.org> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218542 Fixes: 7269cba53d90 ("tee: optee: Fix supplicant based device enumeration") Cc: stable(a)vger.kernel.org Signed-off-by: Sumit Garg <sumit.garg(a)linaro.org> --- drivers/tee/optee/device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c index 9d2afac96acc..d296c70ddfdc 100644 --- a/drivers/tee/optee/device.c +++ b/drivers/tee/optee/device.c @@ -90,13 +90,14 @@ static int optee_register_device(const uuid_t *device_uuid, u32 func) if (rc) { pr_err("device registration failed, err: %d\n", rc); put_device(&optee_device->dev); + return rc; } if (func == PTA_CMD_GET_DEVICES_SUPP) device_create_file(&optee_device->dev, &dev_attr_need_supplicant); - return rc; + return 0; } static int __optee_enumerate_devices(u32 func) -- 2.34.1

9 months, 3 weeks

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Re: [PATCH 6.7 000/162] 6.7.9-rc1 review

by Ronald Warsow

Hi Greg *no* regressions here on x86_64 (RKL, Intel 11th Gen. CPU) Thanks Tested-by: Ronald Warsow <rwarsow(a)gmx.de>

9 months, 3 weeks

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[merged mm-hotfixes-stable] init-kconfig-lower-gcc-version-check-for-warray-bounds.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: init/Kconfig: lower GCC version check for -Warray-bounds has been removed from the -mm tree. Its filename was init-kconfig-lower-gcc-version-check-for-warray-bounds.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Kees Cook <keescook(a)chromium.org> Subject: init/Kconfig: lower GCC version check for -Warray-bounds Date: Fri, 23 Feb 2024 09:08:27 -0800 We continue to see false positives from -Warray-bounds even in GCC 10, which is getting reported in a few places[1] still: security/security.c:811:2: warning: `memcpy' offset 32 is out of the bounds [0, 0] [-Warray-bounds] Lower the GCC version check from 11 to 10. Link: https://lkml.kernel.org/r/20240223170824.work.768-kees@kernel.org Reported-by: Lu Yao <yaolu(a)kylinos.cn> Closes: https://lore.kernel.org/lkml/20240117014541.8887-1-yaolu@kylinos.cn/ Link: https://lore.kernel.org/linux-next/65d84438.620a0220.7d171.81a7@mx.google.c… [1] Signed-off-by: Kees Cook <keescook(a)chromium.org> Reviewed-by: Paul Moore <paul(a)paul-moore.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: "Gustavo A. R. Silva" <gustavoars(a)kernel.org> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Marc Aur��le La France <tsi(a)tuyoix.net> Cc: Masahiro Yamada <masahiroy(a)kernel.org> Cc: Nathan Chancellor <nathan(a)kernel.org> Cc: Nhat Pham <nphamcs(a)gmail.com> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Randy Dunlap <rdunlap(a)infradead.org> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- init/Kconfig | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/init/Kconfig~init-kconfig-lower-gcc-version-check-for-warray-bounds +++ a/init/Kconfig @@ -876,14 +876,14 @@ config CC_IMPLICIT_FALLTHROUGH default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5) default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough) -# Currently, disable gcc-11+ array-bounds globally. +# Currently, disable gcc-10+ array-bounds globally. # It's still broken in gcc-13, so no upper bound yet. -config GCC11_NO_ARRAY_BOUNDS +config GCC10_NO_ARRAY_BOUNDS def_bool y config CC_NO_ARRAY_BOUNDS bool - default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC11_NO_ARRAY_BOUNDS + default y if CC_IS_GCC && GCC_VERSION >= 100000 && GCC10_NO_ARRAY_BOUNDS # Currently, disable -Wstringop-overflow for GCC globally. config GCC_NO_STRINGOP_OVERFLOW _ Patches currently in -mm which might be from keescook(a)chromium.org are

9 months, 3 weeks

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[merged mm-hotfixes-stable] mm-mmap-fix-vma_merge-case-7-with-vma_ops-close.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm, mmap: fix vma_merge() case 7 with vma_ops->close has been removed from the -mm tree. Its filename was mm-mmap-fix-vma_merge-case-7-with-vma_ops-close.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Vlastimil Babka <vbabka(a)suse.cz> Subject: mm, mmap: fix vma_merge() case 7 with vma_ops->close Date: Thu, 22 Feb 2024 22:59:31 +0100 When debugging issues with a workload using SysV shmem, Michal Hocko has come up with a reproducer that shows how a series of mprotect() operations can result in an elevated shm_nattch and thus leak of the resource. The problem is caused by wrong assumptions in vma_merge() commit 714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in mergeability test"). The shmem vmas have a vma_ops->close callback that decrements shm_nattch, and we remove the vma without calling it. vma_merge() has thus historically avoided merging vma's with vma_ops->close and commit 714965ca8252 was supposed to keep it that way. It relaxed the checks for vma_ops->close in can_vma_merge_after() assuming that it is never called on a vma that would be a candidate for removal. However, the vma_merge() code does also use the result of this check in the decision to remove a different vma in the merge case 7. A robust solution would be to refactor vma_merge() code in a way that the vma_ops->close check is only done for vma's that are actually going to be removed, and not as part of the preliminary checks. That would both solve the existing bug, and also allow additional merges that the checks currently prevent unnecessarily in some cases. However to fix the existing bug first with a minimized risk, and for easier stable backports, this patch only adds a vma_ops->close check to the buggy case 7 specifically. All other cases of vma removal are covered by the can_vma_merge_before() check that includes the test for vma_ops->close. The reproducer code, adapted from Michal Hocko's code: int main(int argc, char *argv[]) { int segment_id; size_t segment_size = 20 * PAGE_SIZE; char * sh_mem; struct shmid_ds shmid_ds; key_t key = 0x1234; segment_id = shmget(key, segment_size, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR); sh_mem = (char *)shmat(segment_id, NULL, 0); mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_NONE); mprotect(sh_mem + PAGE_SIZE, PAGE_SIZE, PROT_WRITE); mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_WRITE); shmdt(sh_mem); shmctl(segment_id, IPC_STAT, &shmid_ds); printf("nattch after shmdt(): %lu (expected: 0)\n", shmid_ds.shm_nattch); if (shmctl(segment_id, IPC_RMID, 0)) printf("IPCRM failed %d\n", errno); return (shmid_ds.shm_nattch) ? 1 : 0; } Link: https://lkml.kernel.org/r/20240222215930.14637-2-vbabka@suse.cz Fixes: 714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in mergeability test") Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Reported-by: Michal Hocko <mhocko(a)suse.com> Reviewed-by: Lorenzo Stoakes <lstoakes(a)gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/mmap.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/mm/mmap.c~mm-mmap-fix-vma_merge-case-7-with-vma_ops-close +++ a/mm/mmap.c @@ -954,13 +954,21 @@ static struct vm_area_struct } else if (merge_prev) { /* case 2 */ if (curr) { vma_start_write(curr); - err = dup_anon_vma(prev, curr, &anon_dup); if (end == curr->vm_end) { /* case 7 */ + /* + * can_vma_merge_after() assumed we would not be + * removing prev vma, so it skipped the check + * for vm_ops->close, but we are removing curr + */ + if (curr->vm_ops && curr->vm_ops->close) + err = -EINVAL; remove = curr; } else { /* case 5 */ adjust = curr; adj_start = (end - curr->vm_start); } + if (!err) + err = dup_anon_vma(prev, curr, &anon_dup); } } else { /* merge_next */ vma_start_write(next); _ Patches currently in -mm which might be from vbabka(a)suse.cz are

9 months, 3 weeks

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[merged mm-hotfixes-stable] mm-userfaultfd-fix-unexpected-change-to-src_folio-when-uffdio_move-fails.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails has been removed from the -mm tree. Its filename was mm-userfaultfd-fix-unexpected-change-to-src_folio-when-uffdio_move-fails.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Qi Zheng <zhengqi.arch(a)bytedance.com> Subject: mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails Date: Thu, 22 Feb 2024 16:08:15 +0800 After ptep_clear_flush(), if we find that src_folio is pinned we will fail UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to src_folio->{mapping,index} is not restored in this process. This is not what we expected, so fix it. This can cause the rmap for that page to be invalid, possibly resulting in memory corruption. At least swapout+migration would no longer work, because we might fail to locate the mappings of that folio. Link: https://lkml.kernel.org/r/20240222080815.46291-1-zhengqi.arch@bytedance.com Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Qi Zheng <zhengqi.arch(a)bytedance.com> Reviewed-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Suren Baghdasaryan <surenb(a)google.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/userfaultfd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/userfaultfd.c~mm-userfaultfd-fix-unexpected-change-to-src_folio-when-uffdio_move-fails +++ a/mm/userfaultfd.c @@ -914,9 +914,6 @@ static int move_present_pte(struct mm_st goto out; } - folio_move_anon_rmap(src_folio, dst_vma); - WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); - orig_src_pte = ptep_clear_flush(src_vma, src_addr, src_pte); /* Folio got pinned from under us. Put it back and fail the move. */ if (folio_maybe_dma_pinned(src_folio)) { @@ -925,6 +922,9 @@ static int move_present_pte(struct mm_st goto out; } + folio_move_anon_rmap(src_folio, dst_vma); + WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); + orig_dst_pte = mk_pte(&src_folio->page, dst_vma->vm_page_prot); /* Follow mremap() behavior and treat the entry dirty after the move */ orig_dst_pte = pte_mkwrite(pte_mkdirty(orig_dst_pte), dst_vma); _ Patches currently in -mm which might be from zhengqi.arch(a)bytedance.com are mm-pgtable-correct-the-wrong-comment-about-ptdesc-__page_flags.patch mm-pgtable-add-missing-pt_index-to-struct-ptdesc.patch s390-supplement-for-ptdesc-conversion.patch

9 months, 3 weeks

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[merged mm-hotfixes-stable] mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations has been removed from the -mm tree. Its filename was mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Vlastimil Babka <vbabka(a)suse.cz> Subject: mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations Date: Wed, 21 Feb 2024 12:43:58 +0100 Sven reports an infinite loop in __alloc_pages_slowpath() for costly order __GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO. Such combination can happen in a suspend/resume context where a GFP_KERNEL allocation can have __GFP_IO masked out via gfp_allowed_mask. Quoting Sven: 1. try to do a "costly" allocation (order > PAGE_ALLOC_COSTLY_ORDER) with __GFP_RETRY_MAYFAIL set. 2. page alloc's __alloc_pages_slowpath tries to get a page from the freelist. This fails because there is nothing free of that costly order. 3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim, which bails out because a zone is ready to be compacted; it pretends to have made a single page of progress. 4. page alloc tries to compact, but this always bails out early because __GFP_IO is not set (it's not passed by the snd allocator, and even if it were, we are suspending so the __GFP_IO flag would be cleared anyway). 5. page alloc believes reclaim progress was made (because of the pretense in item 3) and so it checks whether it should retry compaction. The compaction retry logic thinks it should try again, because: a) reclaim is needed because of the early bail-out in item 4 b) a zonelist is suitable for compaction 6. goto 2. indefinite stall. (end quote) The immediate root cause is confusing the COMPACT_SKIPPED returned from __alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be indicating a lack of order-0 pages, and in step 5 evaluating that in should_compact_retry() as a reason to retry, before incrementing and limiting the number of retries. There are however other places that wrongly assume that compaction can happen while we lack __GFP_IO. To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO evaluation and switch the open-coded test in try_to_compact_pages() to use it. Also use the new helper in: - compaction_ready(), which will make reclaim not bail out in step 3, so there's at least one attempt to actually reclaim, even if chances are small for a costly order - in_reclaim_compaction() which will make should_continue_reclaim() return false and we don't over-reclaim unnecessarily - in __alloc_pages_slowpath() to set a local variable can_compact, which is then used to avoid retrying reclaim/compaction for costly allocations (step 5) if we can't compact and also to skip the early compaction attempt that we do in some cases Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"") Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Reported-by: Sven van Ashbrook <svenva(a)chromium.org> Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBz… Tested-by: Karthikeyan Ramasubramanian <kramasub(a)chromium.org> Cc: Brian Geffon <bgeffon(a)google.com> Cc: Curtis Malainey <cujomalainey(a)chromium.org> Cc: Jaroslav Kysela <perex(a)perex.cz> Cc: Mel Gorman <mgorman(a)techsingularity.net> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: Takashi Iwai <tiwai(a)suse.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/gfp.h | 9 +++++++++ mm/compaction.c | 7 +------ mm/page_alloc.c | 10 ++++++---- mm/vmscan.c | 5 ++++- 4 files changed, 20 insertions(+), 11 deletions(-) --- a/include/linux/gfp.h~mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations +++ a/include/linux/gfp.h @@ -353,6 +353,15 @@ static inline bool gfp_has_io_fs(gfp_t g return (gfp & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS); } +/* + * Check if the gfp flags allow compaction - GFP_NOIO is a really + * tricky context because the migration might require IO. + */ +static inline bool gfp_compaction_allowed(gfp_t gfp_mask) +{ + return IS_ENABLED(CONFIG_COMPACTION) && (gfp_mask & __GFP_IO); +} + extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma); #ifdef CONFIG_CONTIG_ALLOC --- a/mm/compaction.c~mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations +++ a/mm/compaction.c @@ -2723,16 +2723,11 @@ enum compact_result try_to_compact_pages unsigned int alloc_flags, const struct alloc_context *ac, enum compact_priority prio, struct page **capture) { - int may_perform_io = (__force int)(gfp_mask & __GFP_IO); struct zoneref *z; struct zone *zone; enum compact_result rc = COMPACT_SKIPPED; - /* - * Check if the GFP flags allow compaction - GFP_NOIO is really - * tricky context because the migration might require IO - */ - if (!may_perform_io) + if (!gfp_compaction_allowed(gfp_mask)) return COMPACT_SKIPPED; trace_mm_compaction_try_to_compact_pages(order, gfp_mask, prio); --- a/mm/page_alloc.c~mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations +++ a/mm/page_alloc.c @@ -4041,6 +4041,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u struct alloc_context *ac) { bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM; + bool can_compact = gfp_compaction_allowed(gfp_mask); const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER; struct page *page = NULL; unsigned int alloc_flags; @@ -4111,7 +4112,7 @@ restart: * Don't try this for allocations that are allowed to ignore * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen. */ - if (can_direct_reclaim && + if (can_direct_reclaim && can_compact && (costly_order || (order > 0 && ac->migratetype != MIGRATE_MOVABLE)) && !gfp_pfmemalloc_allowed(gfp_mask)) { @@ -4209,9 +4210,10 @@ retry: /* * Do not retry costly high order allocations unless they are - * __GFP_RETRY_MAYFAIL + * __GFP_RETRY_MAYFAIL and we can compact */ - if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL)) + if (costly_order && (!can_compact || + !(gfp_mask & __GFP_RETRY_MAYFAIL))) goto nopage; if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, @@ -4224,7 +4226,7 @@ retry: * implementation of the compaction depends on the sufficient amount * of free memory (see __compaction_suitable) */ - if (did_some_progress > 0 && + if (did_some_progress > 0 && can_compact && should_compact_retry(ac, order, alloc_flags, compact_result, &compact_priority, &compaction_retries)) --- a/mm/vmscan.c~mm-vmscan-prevent-infinite-loop-for-costly-gfp_noio-__gfp_retry_mayfail-allocations +++ a/mm/vmscan.c @@ -5753,7 +5753,7 @@ static void shrink_lruvec(struct lruvec /* Use reclaim/compaction for costly allocs or under memory pressure */ static bool in_reclaim_compaction(struct scan_control *sc) { - if (IS_ENABLED(CONFIG_COMPACTION) && sc->order && + if (gfp_compaction_allowed(sc->gfp_mask) && sc->order && (sc->order > PAGE_ALLOC_COSTLY_ORDER || sc->priority < DEF_PRIORITY - 2)) return true; @@ -5998,6 +5998,9 @@ static inline bool compaction_ready(stru { unsigned long watermark; + if (!gfp_compaction_allowed(sc->gfp_mask)) + return false; + /* Allocation can already succeed, nothing to do */ if (zone_watermark_ok(zone, sc->order, min_wmark_pages(zone), sc->reclaim_idx, 0)) _ Patches currently in -mm which might be from vbabka(a)suse.cz are

9 months, 3 weeks

1
0
0 0

[PATCH 5.10] xen/events: close evtchn after mapping cleanup

by Andrew Panyakin

From: Maximilian Heyne <mheyne(a)amazon.de> Commit fa765c4b4aed2d64266b694520ecb025c862c5a9 upstream shutdown_pirq and startup_pirq are not taking the irq_mapping_update_lock because they can't due to lock inversion. Both are called with the irq_desc->lock being taking. The lock order, however, is first irq_mapping_update_lock and then irq_desc->lock. This opens multiple races: - shutdown_pirq can be interrupted by a function that allocates an event channel: CPU0 CPU1 shutdown_pirq { xen_evtchn_close(e) __startup_pirq { EVTCHNOP_bind_pirq -> returns just freed evtchn e set_evtchn_to_irq(e, irq) } xen_irq_info_cleanup() { set_evtchn_to_irq(e, -1) } } Assume here event channel e refers here to the same event channel number. After this race the evtchn_to_irq mapping for e is invalid (-1). - __startup_pirq races with __unbind_from_irq in a similar way. Because __startup_pirq doesn't take irq_mapping_update_lock it can grab the evtchn that __unbind_from_irq is currently freeing and cleaning up. In this case even though the event channel is allocated, its mapping can be unset in evtchn_to_irq. The fix is to first cleanup the mappings and then close the event channel. In this way, when an event channel gets allocated it's potential previous evtchn_to_irq mappings are guaranteed to be unset already. This is also the reverse order of the allocation where first the event channel is allocated and then the mappings are setup. On a 5.10 kernel prior to commit 3fcdaf3d7634 ("xen/events: modify internal [un]bind interfaces"), we hit a BUG like the following during probing of NVMe devices. The issue is that during nvme_setup_io_queues, pci_free_irq is called for every device which results in a call to shutdown_pirq. With many nvme devices it's therefore likely to hit this race during boot because there will be multiple calls to shutdown_pirq and startup_pirq are running potentially in parallel. ------------[ cut here ]------------ blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled kernel BUG at drivers/xen/events/events_base.c:499! invalid opcode: 0000 [#1] SMP PTI CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1 Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006 Workqueue: nvme-reset-wq nvme_reset_work RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0 Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00 RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006 RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? show_trace_log_lvl+0x1c1/0x2d9 ? show_trace_log_lvl+0x1c1/0x2d9 ? set_affinity_irq+0xdc/0x1c0 ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0x90/0x110 ? bind_evtchn_to_cpu+0xdf/0xf0 ? do_error_trap+0x65/0x80 ? bind_evtchn_to_cpu+0xdf/0xf0 ? exc_invalid_op+0x4e/0x70 ? bind_evtchn_to_cpu+0xdf/0xf0 ? asm_exc_invalid_op+0x12/0x20 ? bind_evtchn_to_cpu+0xdf/0xf0 ? bind_evtchn_to_cpu+0xc5/0xf0 set_affinity_irq+0xdc/0x1c0 irq_do_set_affinity+0x1d7/0x1f0 irq_setup_affinity+0xd6/0x1a0 irq_startup+0x8a/0xf0 __setup_irq+0x639/0x6d0 ? nvme_suspend+0x150/0x150 request_threaded_irq+0x10c/0x180 ? nvme_suspend+0x150/0x150 pci_request_irq+0xa8/0xf0 ? __blk_mq_free_request+0x74/0xa0 queue_request_irq+0x6f/0x80 nvme_create_queue+0x1af/0x200 nvme_create_io_queues+0xbd/0xf0 nvme_setup_io_queues+0x246/0x320 ? nvme_irq_check+0x30/0x30 nvme_reset_work+0x1c8/0x400 process_one_work+0x1b0/0x350 worker_thread+0x49/0x310 ? process_one_work+0x350/0x350 kthread+0x11b/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x22/0x30 Modules linked in: ---[ end trace a11715de1eee1873 ]--- Fixes: d46a78b05c0e ("xen: implement pirq type event channels") Cc: stable(a)vger.kernel.org Co-debugged-by: Andrew Panyakin <apanyaki(a)amazon.com> Signed-off-by: Maximilian Heyne <mheyne(a)amazon.de> [apanyaki: backport to v5.10-stable] Signed-off-by: Andrew Paniakin <apanyaki(a)amazon.com> --- Compare to upstream patch this one does not have close_evtchn flag because there is no need to handle static event channels. This feature was added only in 58f6259b7a08f ("xen/evtchn: Introduce new IOCTL to bind static evtchn") drivers/xen/events/events_base.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 24e39984914f..f608663bdfd5 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -885,8 +885,8 @@ static void shutdown_pirq(struct irq_data *data) return; do_mask(info, EVT_MASK_REASON_EXPLICIT); - xen_evtchn_close(evtchn); xen_irq_info_cleanup(info); + xen_evtchn_close(evtchn); } static void enable_pirq(struct irq_data *data) @@ -929,8 +929,6 @@ static void __unbind_from_irq(unsigned int irq) if (VALID_EVTCHN(evtchn)) { unsigned int cpu = cpu_from_irq(irq); - xen_evtchn_close(evtchn); - switch (type_from_irq(irq)) { case IRQT_VIRQ: per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1; @@ -943,6 +941,7 @@ static void __unbind_from_irq(unsigned int irq) } xen_irq_info_cleanup(info); + xen_evtchn_close(evtchn); } xen_free_irq(irq); -- 2.40.1

9 months, 3 weeks

3
3
0 0

[PATCH v2] serial: Lock console when calling into driver before registration

by Peter Collingbourne

During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc(a)google.com> Reviewed-by: John Ogness <john.ogness(a)linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b2553… Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org --- drivers/tty/serial/8250/8250_port.c | 6 ------ drivers/tty/serial/serial_core.c | 12 ++++++++++++ kernel/printk/printk.c | 21 ++++++++++++++++++--- 3 files changed, 30 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 8ca061d3bbb9..1d65055dde27 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1329,9 +1329,6 @@ static void autoconfig_irq(struct uart_8250_port *up) inb_p(ICP); } - if (uart_console(port)) - console_lock(); - /* forget possible initially masked and pending IRQ */ probe_irq_off(probe_irq_on()); save_mcr = serial8250_in_MCR(up); @@ -1371,9 +1368,6 @@ static void autoconfig_irq(struct uart_8250_port *up) if (port->flags & UPF_FOURPORT) outb_p(save_ICP, ICP); - if (uart_console(port)) - console_unlock(); - port->irq = (irq > 0) ? irq : 0; } diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index d6a58a9e072a..ff85ebd3a007 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2608,7 +2608,12 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, port->type = PORT_UNKNOWN; flags |= UART_CONFIG_TYPE; } + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); port->ops->config_port(port, flags); + if (uart_console(port)) + console_unlock(); } if (port->type != PORT_UNKNOWN) { @@ -2616,6 +2621,10 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, uart_report_port(drv, port); + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); + /* Power up port for set_mctrl() */ uart_change_pm(state, UART_PM_STATE_ON); @@ -2632,6 +2641,9 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, uart_rs485_config(port); + if (uart_console(port)) + console_unlock(); + /* * If this driver supports console, and it hasn't been * successfully registered yet, try to re-register it. diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index f2444b581e16..f51e4e5a869d 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3263,6 +3263,21 @@ static int __init keep_bootcon_setup(char *str) early_param("keep_bootcon", keep_bootcon_setup); +static int console_call_setup(struct console *newcon, char *options) +{ + int err; + + if (!newcon->setup) + return 0; + + /* Synchronize with possible boot console. */ + console_lock(); + err = newcon->setup(newcon, options); + console_unlock(); + + return err; +} + /* * This is called by register_console() to try to match * the newly registered console with any of the ones selected @@ -3298,8 +3313,8 @@ static int try_enable_preferred_console(struct console *newcon, if (_braille_register_console(newcon, c)) return 0; - if (newcon->setup && - (err = newcon->setup(newcon, c->options)) != 0) + err = console_call_setup(newcon, c->options); + if (err != 0) return err; } newcon->flags |= CON_ENABLED; @@ -3325,7 +3340,7 @@ static void try_enable_default_console(struct console *newcon) if (newcon->index < 0) newcon->index = 0; - if (newcon->setup && newcon->setup(newcon, NULL) != 0) + if (console_call_setup(newcon, NULL) != 0) return; newcon->flags |= CON_ENABLED; -- 2.44.0.rc1.240.g4c46232300-goog

9 months, 3 weeks

2
2
0 0

[PATCH v3] serial: Lock console when calling into driver before registration

by Peter Collingbourne

During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc(a)google.com> Reviewed-by: John Ogness <john.ogness(a)linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b2553… Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org --- v3: - switch to if (err) v2: - add some comments drivers/tty/serial/8250/8250_port.c | 6 ------ drivers/tty/serial/serial_core.c | 12 ++++++++++++ kernel/printk/printk.c | 21 ++++++++++++++++++--- 3 files changed, 30 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 8ca061d3bbb9..1d65055dde27 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1329,9 +1329,6 @@ static void autoconfig_irq(struct uart_8250_port *up) inb_p(ICP); } - if (uart_console(port)) - console_lock(); - /* forget possible initially masked and pending IRQ */ probe_irq_off(probe_irq_on()); save_mcr = serial8250_in_MCR(up); @@ -1371,9 +1368,6 @@ static void autoconfig_irq(struct uart_8250_port *up) if (port->flags & UPF_FOURPORT) outb_p(save_ICP, ICP); - if (uart_console(port)) - console_unlock(); - port->irq = (irq > 0) ? irq : 0; } diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index d6a58a9e072a..ff85ebd3a007 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2608,7 +2608,12 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, port->type = PORT_UNKNOWN; flags |= UART_CONFIG_TYPE; } + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); port->ops->config_port(port, flags); + if (uart_console(port)) + console_unlock(); } if (port->type != PORT_UNKNOWN) { @@ -2616,6 +2621,10 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, uart_report_port(drv, port); + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); + /* Power up port for set_mctrl() */ uart_change_pm(state, UART_PM_STATE_ON); @@ -2632,6 +2641,9 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, uart_rs485_config(port); + if (uart_console(port)) + console_unlock(); + /* * If this driver supports console, and it hasn't been * successfully registered yet, try to re-register it. diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index f2444b581e16..89f2aa2e1172 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3263,6 +3263,21 @@ static int __init keep_bootcon_setup(char *str) early_param("keep_bootcon", keep_bootcon_setup); +static int console_call_setup(struct console *newcon, char *options) +{ + int err; + + if (!newcon->setup) + return 0; + + /* Synchronize with possible boot console. */ + console_lock(); + err = newcon->setup(newcon, options); + console_unlock(); + + return err; +} + /* * This is called by register_console() to try to match * the newly registered console with any of the ones selected @@ -3298,8 +3313,8 @@ static int try_enable_preferred_console(struct console *newcon, if (_braille_register_console(newcon, c)) return 0; - if (newcon->setup && - (err = newcon->setup(newcon, c->options)) != 0) + err = console_call_setup(newcon, c->options); + if (err) return err; } newcon->flags |= CON_ENABLED; @@ -3325,7 +3340,7 @@ static void try_enable_default_console(struct console *newcon) if (newcon->index < 0) newcon->index = 0; - if (newcon->setup && newcon->setup(newcon, NULL) != 0) + if (console_call_setup(newcon, NULL) != 0) return; newcon->flags |= CON_ENABLED; -- 2.44.0.278.ge034bb2e1d-goog

9 months, 3 weeks

1
0
0 0

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