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FAILED: patch "[PATCH] ALSA: wavefront: Fix integer overflow in sample size" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0c4a13ba88594fd4a27292853e736c6b4349823d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025121615-subplot-parachute-73bb@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0c4a13ba88594fd4a27292853e736c6b4349823d Mon Sep 17 00:00:00 2001 From: Junrui Luo <moonafterrain(a)outlook.com> Date: Thu, 6 Nov 2025 10:49:46 +0800 Subject: [PATCH] ALSA: wavefront: Fix integer overflow in sample size validation The wavefront_send_sample() function has an integer overflow issue when validating sample size. The header->size field is u32 but gets cast to int for comparison with dev->freemem Fix by using unsigned comparison to avoid integer overflow. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org Signed-off-by: Junrui Luo <moonafterrain(a)outlook.com> Link: https://patch.msgid.link/SYBPR01MB7881B47789D1B060CE8BF4C3AFC2A@SYBPR01MB78… Signed-off-by: Takashi Iwai <tiwai(a)suse.de> diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c index cd5c177943aa..0d78533e1cfd 100644 --- a/sound/isa/wavefront/wavefront_synth.c +++ b/sound/isa/wavefront/wavefront_synth.c @@ -950,9 +950,9 @@ wavefront_send_sample (snd_wavefront_t *dev, if (header->size) { dev->freemem = wavefront_freemem (dev); - if (dev->freemem < (int)header->size) { + if (dev->freemem < 0 || dev->freemem < header->size) { dev_err(dev->card->dev, - "insufficient memory to load %d byte sample.\n", + "insufficient memory to load %u byte sample.\n", header->size); return -ENOMEM; }

1 day, 8 hours

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FAILED: patch "[PATCH] ALSA: wavefront: Clear substream pointers on close" failed to apply to 6.17-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.17.y git checkout FETCH_HEAD git cherry-pick -x e11c5c13ce0ab2325d38fe63500be1dd88b81e38 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025121659-feline-king-9be3@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From e11c5c13ce0ab2325d38fe63500be1dd88b81e38 Mon Sep 17 00:00:00 2001 From: Junrui Luo <moonafterrain(a)outlook.com> Date: Thu, 6 Nov 2025 10:24:57 +0800 Subject: [PATCH] ALSA: wavefront: Clear substream pointers on close Clear substream pointers in close functions to avoid leaving dangling pointers, helping to improve code safety and prevents potential issues. Reported-by: Yuhao Jiang <danisjiang(a)gmail.com> Reported-by: Junrui Luo <moonafterrain(a)outlook.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable(a)vger.kernel.org Signed-off-by: Junrui Luo <moonafterrain(a)outlook.com> Link: https://patch.msgid.link/SYBPR01MB7881DF762CAB45EE42F6D812AFC2A@SYBPR01MB78… Signed-off-by: Takashi Iwai <tiwai(a)suse.de> diff --git a/sound/isa/wavefront/wavefront_midi.c b/sound/isa/wavefront/wavefront_midi.c index 1250ecba659a..69d87c4cafae 100644 --- a/sound/isa/wavefront/wavefront_midi.c +++ b/sound/isa/wavefront/wavefront_midi.c @@ -278,6 +278,7 @@ static int snd_wavefront_midi_input_close(struct snd_rawmidi_substream *substrea return -EIO; guard(spinlock_irqsave)(&midi->open); + midi->substream_input[mpu] = NULL; midi->mode[mpu] &= ~MPU401_MODE_INPUT; return 0; @@ -300,6 +301,7 @@ static int snd_wavefront_midi_output_close(struct snd_rawmidi_substream *substre return -EIO; guard(spinlock_irqsave)(&midi->open); + midi->substream_output[mpu] = NULL; midi->mode[mpu] &= ~MPU401_MODE_OUTPUT; return 0; }

1 day, 8 hours

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[PATCH] wifi: mac80211: restore non-chanctx injection behaviour

by Johannes Berg

From: Johannes Berg <johannes.berg(a)intel.com> During the transition to use channel contexts throughout, the ability to do injection while in monitor mode concurrent with another interface was lost, since the (virtual) monitor won't have a chanctx assigned in this scenario. It's harder to fix drivers that actually transitioned to using channel contexts themselves, such as mt76, but it's easy to do those that are (still) just using the emulation. Do that. Cc: stable(a)vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=218763 Reported-and-tested-by: Oscar Alfonso Diaz <oscar.alfonso.diaz(a)gmail.com> Fixes: 0a44dfc07074 ("wifi: mac80211: simplify non-chanctx drivers") Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> --- net/mac80211/tx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 9d8b0a25f73c..1b55e8340413 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2397,6 +2397,8 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb, if (chanctx_conf) chandef = &chanctx_conf->def; + else if (local->emulate_chanctx) + chandef = &local->hw.conf.chandef; else goto fail_rcu; -- 2.52.0

1 day, 8 hours

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[PATCH v2 4/4] mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather

by David Hildenbrand (Red Hat)

As reported, ever since commit 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") we can end up in some situations where we perform so many IPI broadcasts when unsharing hugetlb PMD page tables that it severely regresses some workloads. In particular, when we fork()+exit(), or when we munmap() a large area backed by many shared PMD tables, we perform one IPI broadcast per unshared PMD table. There are two optimizations to be had: (1) When we process (unshare) multiple such PMD tables, such as during exit(), it is sufficient to send a single IPI broadcast (as long as we respect locking rules) instead of one per PMD table. Locking prevents that any of these PMD tables could get reuse before we drop the lock. (2) When we are not the last sharer (> 2 users including us), there is no need to send the IPI broadcast. The shared PMD tables cannot become exclusive (fully unshared) before an IPI will be broadcasted by the last sharer. Concurrent GUP-fast could walk into a PMD table just before we unshared it. It could then succeed in grabbing a page from the shared page table even after munmap() etc succeeded (and supressed an IPI). But there is not difference compared to GUP-fast just sleeping for a while after grabbing the page and re-enabling IRQs. Most importantly, GUP-fast will never walk into page tables that are no-longer shared, because the last sharer will issue an IPI broadcast. (if ever required, checking whether the PUD changed in GUP-fast after grabbing the page like we do in the PTE case could handle this) So let's rework PMD sharing TLB flushing + IPI sync to use the mmu_gather infrastructure so we can implement these optimizations and demystify the code at least a bit. Extend the mmu_gather infrastructure to be able to deal with our special hugetlb PMD table sharing implementation. We'll consolidate the handling for (full) unsharing of PMD tables in tlb_unshare_pmd_ptdesc() and tlb_flush_unshared_tables(), and track in "struct mmu_gather" whether we had (full) unsharing of PMD tables. Because locking is very special (concurrent unsharing+reuse must be prevented), we disallow deferring flushing to tlb_finish_mmu() and instead require an explicit earlier call to tlb_flush_unshared_tables(). From hugetlb code, we call huge_pmd_unshare_flush() where we make sure that the expected lock protecting us from concurrent unsharing+reuse is still held. Check with a VM_WARN_ON_ONCE() in tlb_finish_mmu() that tlb_flush_unshared_tables() was properly called earlier. Document it all properly. Notes about tlb_remove_table_sync_one() interaction with unsharing: There are two fairly tricky things: (1) tlb_remove_table_sync_one() is a NOP on architectures without CONFIG_MMU_GATHER_RCU_TABLE_FREE. Here, the assumption is that the previous TLB flush would send an IPI to all relevant CPUs. Careful: some architectures like x86 only send IPIs to all relevant CPUs when tlb->freed_tables is set. The relevant architectures should be selecting MMU_GATHER_RCU_TABLE_FREE, but x86 might not do that in stable kernels and it might have been problematic before this patch. Also, the arch flushing behavior (independent of IPIs) is different when tlb->freed_tables is set. Do we have to enlighten them to also take care of tlb->unshared_tables? So far we didn't care, so hopefully we are fine. Of course, we could be setting tlb->freed_tables as well, but that might then unnecessarily flush too much, because the semantics of tlb->freed_tables are a bit fuzzy. This patch changes nothing in this regard. (2) tlb_remove_table_sync_one() is not a NOP on architectures with CONFIG_MMU_GATHER_RCU_TABLE_FREE that actually don't need a sync. Take x86 as an example: in the common case (!pv, !X86_FEATURE_INVLPGB) we still issue IPIs during TLB flushes and don't actually need the second tlb_remove_table_sync_one(). This optimized can be implemented on top of this, by checking e.g., in tlb_remove_table_sync_one() whether we really need IPIs. But as described in (1), it really must honor tlb->freed_tables then to send IPIs to all relevant CPUs. Further note that the ptdesc_pmd_pts_dec() in huge_pmd_share() is not a concern, as we are holding the i_mmap_lock the whole time, preventing concurrent unsharing. That ptdesc_pmd_pts_dec() usage will be removed separately as a cleanup later. There are plenty more cleanups to be had, but they have to wait until this is fixed. Fixes: 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") Reported-by: Uschakow, Stanislav" <suschako(a)amazon.de> Closes: https://lore.kernel.org/all/4d3878531c76479d9f8ca9789dc6485d@amazon.de/ Tested-by: Laurence Oberman <loberman(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org> --- include/asm-generic/tlb.h | 74 ++++++++++++++++++++++- include/linux/hugetlb.h | 19 +++--- mm/hugetlb.c | 121 ++++++++++++++++++++++---------------- mm/mmu_gather.c | 7 +++ mm/mprotect.c | 2 +- mm/rmap.c | 25 +++++--- 6 files changed, 179 insertions(+), 69 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 1fff717cae510..706416babb3d6 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -364,6 +364,20 @@ struct mmu_gather { unsigned int vma_huge : 1; unsigned int vma_pfn : 1; + /* + * Did we unshare (unmap) any shared page tables? For now only + * used for hugetlb PMD table sharing. + */ + unsigned int unshared_tables : 1; + + /* + * Did we unshare any page tables such that they are now exclusive + * and could get reused+modified by the new owner? When setting this + * flag, "unshared_tables" will be set as well. For now only used + * for hugetlb PMD table sharing. + */ + unsigned int fully_unshared_tables : 1; + unsigned int batch_count; #ifndef CONFIG_MMU_GATHER_NO_GATHER @@ -400,6 +414,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->cleared_pmds = 0; tlb->cleared_puds = 0; tlb->cleared_p4ds = 0; + tlb->unshared_tables = 0; /* * Do not reset mmu_gather::vma_* fields here, we do not * call into tlb_start_vma() again to set them if there is an @@ -484,7 +499,7 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) * these bits. */ if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds || - tlb->cleared_puds || tlb->cleared_p4ds)) + tlb->cleared_puds || tlb->cleared_p4ds || tlb->unshared_tables)) return; tlb_flush(tlb); @@ -773,6 +788,63 @@ static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) } #endif +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING +static inline void tlb_unshare_pmd_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt, + unsigned long addr) +{ + /* + * The caller must make sure that concurrent unsharing + exclusive + * reuse is impossible until tlb_flush_unshared_tables() was called. + */ + VM_WARN_ON_ONCE(!ptdesc_pmd_is_shared(pt)); + ptdesc_pmd_pts_dec(pt); + + /* Clearing a PUD pointing at a PMD table with PMD leaves. */ + tlb_flush_pmd_range(tlb, addr & PUD_MASK, PUD_SIZE); + + /* + * If the page table is now exclusively owned, we fully unshared + * a page table. + */ + if (!ptdesc_pmd_is_shared(pt)) + tlb->fully_unshared_tables = true; + tlb->unshared_tables = true; +} + +static inline void tlb_flush_unshared_tables(struct mmu_gather *tlb) +{ + /* + * As soon as the caller drops locks to allow for reuse of + * previously-shared tables, these tables could get modified and + * even reused outside of hugetlb context, so we have to make sure that + * any page table walkers (incl. TLB, GUP-fast) are aware of that + * change. + * + * Even if we are not fully unsharing a PMD table, we must + * flush the TLB for the unsharer now. + */ + if (tlb->unshared_tables) + tlb_flush_mmu_tlbonly(tlb); + + /* + * Similarly, we must make sure that concurrent GUP-fast will not + * walk previously-shared page tables that are getting modified+reused + * elsewhere. So broadcast an IPI to wait for any concurrent GUP-fast. + * + * We only perform this when we are the last sharer of a page table, + * as the IPI will reach all CPUs: any GUP-fast. + * + * Note that on configs where tlb_remove_table_sync_one() is a NOP, + * the expectation is that the tlb_flush_mmu_tlbonly() would have issued + * required IPIs already for us. + */ + if (tlb->fully_unshared_tables) { + tlb_remove_table_sync_one(); + tlb->fully_unshared_tables = false; + } +} +#endif /* CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ + #endif /* CONFIG_MMU */ #endif /* _ASM_GENERIC__TLB_H */ diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 03c8725efa289..63b248c6bfd47 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -240,8 +240,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz); unsigned long hugetlb_mask_last_page(struct hstate *h); -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep); +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma); void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end); @@ -271,7 +272,7 @@ void hugetlb_vma_unlock_write(struct vm_area_struct *vma); int hugetlb_vma_trylock_write(struct vm_area_struct *vma); void hugetlb_vma_assert_locked(struct vm_area_struct *vma); void hugetlb_vma_lock_release(struct kref *kref); -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags); void hugetlb_unshare_all_pmds(struct vm_area_struct *vma); @@ -300,13 +301,17 @@ static inline struct address_space *hugetlb_folio_mapping_lock_write( return NULL; } -static inline int huge_pmd_unshare(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +static inline int huge_pmd_unshare(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { return 0; } +static inline void huge_pmd_unshare_flush(struct mmu_gather *tlb, + struct vm_area_struct *vma) +{ +} + static inline void adjust_range_if_pmd_sharing_possible( struct vm_area_struct *vma, unsigned long *start, unsigned long *end) @@ -432,7 +437,7 @@ static inline void move_hugetlb_state(struct folio *old_folio, { } -static inline long hugetlb_change_protection( +static inline long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3c77cdef12a32..7fef0b94b5d1e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5096,8 +5096,9 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, unsigned long last_addr_mask; pte_t *src_pte, *dst_pte; struct mmu_notifier_range range; - bool shared_pmd = false; + struct mmu_gather tlb; + tlb_gather_mmu(&tlb, vma->vm_mm); mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, old_addr, old_end); adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); @@ -5122,12 +5123,12 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte))) continue; - if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { - shared_pmd = true; + if (huge_pmd_unshare(&tlb, vma, old_addr, src_pte)) { old_addr |= last_addr_mask; new_addr |= last_addr_mask; continue; } + tlb_remove_huge_tlb_entry(h, &tlb, src_pte, old_addr); dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); if (!dst_pte) @@ -5136,13 +5137,13 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz); } - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, old_end - len, old_end); + tlb_flush_mmu_tlbonly(&tlb); + huge_pmd_unshare_flush(&tlb, vma); + mmu_notifier_invalidate_range_end(&range); i_mmap_unlock_write(mapping); hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); return len + old_addr - old_end; } @@ -5161,7 +5162,6 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); bool adjust_reservation; unsigned long last_addr_mask; - bool force_flush = false; WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~huge_page_mask(h)); @@ -5184,10 +5184,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { spin_unlock(ptl); - tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); - force_flush = true; address |= last_addr_mask; continue; } @@ -5303,14 +5301,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } tlb_end_vma(tlb, vma); - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (force_flush) - tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); } void __hugetlb_zap_begin(struct vm_area_struct *vma, @@ -6399,7 +6390,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, } #endif /* CONFIG_USERFAULTFD */ -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) { @@ -6409,7 +6400,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte_t pte; struct hstate *h = hstate_vma(vma); long pages = 0, psize = huge_page_size(h); - bool shared_pmd = false; struct mmu_notifier_range range; unsigned long last_addr_mask; bool uffd_wp = cp_flags & MM_CP_UFFD_WP; @@ -6452,7 +6442,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, } } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { /* * When uffd-wp is enabled on the vma, unshare * shouldn't happen at all. Warn about it if it @@ -6461,7 +6451,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); pages++; spin_unlock(ptl); - shared_pmd = true; address |= last_addr_mask; continue; } @@ -6522,22 +6511,16 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte = huge_pte_clear_uffd_wp(pte); huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); pages++; + tlb_remove_huge_tlb_entry(h, tlb, ptep, address); } next: spin_unlock(ptl); cond_resched(); } - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, start, end); + + tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); /* * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() we are * downgrading page table protection not changing it to point to a new @@ -6904,18 +6887,27 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return pte; } -/* - * unmap huge page backed by shared pte. +/** + * huge_pmd_unshare - Unmap a pmd table if it is shared by multiple users + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * @addr: the address we are trying to unshare. + * @ptep: pointer into the (pmd) page table. + * + * Called with the page table lock held, the i_mmap_rwsem held in write mode + * and the hugetlb vma lock held in write mode. * - * Called with page table lock held. + * Note: The caller must call huge_pmd_unshare_flush() before dropping the + * i_mmap_rwsem. * - * returns: 1 successfully unmapped a shared pte page - * 0 the underlying pte page is not shared, or it is the last user + * Returns: 1 if it was a shared PMD table and it got unmapped, or 0 if it + * was not a shared PMD table. */ -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { unsigned long sz = huge_page_size(hstate_vma(vma)); + struct mm_struct *mm = vma->vm_mm; pgd_t *pgd = pgd_offset(mm, addr); p4d_t *p4d = p4d_offset(pgd, addr); pud_t *pud = pud_offset(p4d, addr); @@ -6927,18 +6919,36 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, i_mmap_assert_write_locked(vma->vm_file->f_mapping); hugetlb_vma_assert_locked(vma); pud_clear(pud); - /* - * Once our caller drops the rmap lock, some other process might be - * using this page table as a normal, non-hugetlb page table. - * Wait for pending gup_fast() in other threads to finish before letting - * that happen. - */ - tlb_remove_table_sync_one(); - ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); + + tlb_unshare_pmd_ptdesc(tlb, virt_to_ptdesc(ptep), addr); + mm_dec_nr_pmds(mm); return 1; } +/* + * huge_pmd_unshare_flush - Complete a sequence of huge_pmd_unshare() calls + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * + * Perform necessary TLB flushes or IPI broadcasts to synchronize PMD table + * unsharing with concurrent page table walkers. + * + * This function must be called after a sequence of huge_pmd_unshare() + * calls while still holding the i_mmap_rwsem. + */ +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + /* + * We must synchronize page table unsharing such that nobody will + * try reusing a previously-shared page table while it might still + * be in use by previous sharers (TLB, GUP_fast). + */ + i_mmap_assert_write_locked(vma->vm_file->f_mapping); + + tlb_flush_unshared_tables(tlb); +} + #else /* !CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, @@ -6947,12 +6957,16 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return NULL; } -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { return 0; } +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ +} + void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end) { @@ -7219,6 +7233,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); struct mm_struct *mm = vma->vm_mm; struct mmu_notifier_range range; + struct mmu_gather tlb; unsigned long address; spinlock_t *ptl; pte_t *ptep; @@ -7229,6 +7244,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (start >= end) return; + tlb_gather_mmu(&tlb, mm); flush_cache_range(vma, start, end); /* * No need to call adjust_range_if_pmd_sharing_possible(), because @@ -7248,10 +7264,10 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (!ptep) continue; ptl = huge_pte_lock(h, mm, ptep); - huge_pmd_unshare(mm, vma, address, ptep); + huge_pmd_unshare(&tlb, vma, address, ptep); spin_unlock(ptl); } - flush_hugetlb_tlb_range(vma, start, end); + huge_pmd_unshare_flush(&tlb, vma); if (take_locks) { i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); @@ -7261,6 +7277,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, * Documentation/mm/mmu_notifier.rst. */ mmu_notifier_invalidate_range_end(&range); + tlb_finish_mmu(&tlb); } /* diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index 247e3f9db6c7a..030a162a263ba 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -426,6 +426,7 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, #endif tlb->vma_pfn = 0; + tlb->fully_unshared_tables = 0; __tlb_reset_range(tlb); inc_tlb_flush_pending(tlb->mm); } @@ -468,6 +469,12 @@ void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) */ void tlb_finish_mmu(struct mmu_gather *tlb) { + /* + * We expect an earlier huge_pmd_unshare_flush() call to sort this out, + * due to complicated locking requirements with page table unsharing. + */ + VM_WARN_ON_ONCE(tlb->fully_unshared_tables); + /* * If there are parallel threads are doing PTE changes on same range * under non-exclusive lock (e.g., mmap_lock read-side) but defer TLB diff --git a/mm/mprotect.c b/mm/mprotect.c index 283889e4f1cec..5c330e817129e 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -652,7 +652,7 @@ long change_protection(struct mmu_gather *tlb, #endif if (is_vm_hugetlb_page(vma)) - pages = hugetlb_change_protection(vma, start, end, newprot, + pages = hugetlb_change_protection(tlb, vma, start, end, newprot, cp_flags); else pages = change_protection_range(tlb, vma, start, end, newprot, diff --git a/mm/rmap.c b/mm/rmap.c index 748f48727a162..d6799afe11147 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -76,7 +76,7 @@ #include <linux/mm_inline.h> #include <linux/oom.h> -#include <asm/tlbflush.h> +#include <asm/tlb.h> #define CREATE_TRACE_POINTS #include <trace/events/migrate.h> @@ -2008,13 +2008,17 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, * if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) goto walk_abort; - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { + + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2022,6 +2026,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, goto walk_done; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); if (pte_dirty(pteval)) @@ -2398,17 +2403,20 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, * fail if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) { page_vma_mapped_walk_done(&pvmw); ret = false; break; } - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { - hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { + hugetlb_vma_unlock_write(vma); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2417,6 +2425,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, break; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } /* Nuke the hugetlb page table entry */ pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); -- 2.52.0

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[PATCH v1 4/4] mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather

by David Hildenbrand (Red Hat)

As reported, ever since commit 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") we can end up in some situations where we perform so many IPI broadcasts when unsharing hugetlb PMD page tables that it severely regresses some workloads. In particular, when we fork()+exit(), or when we munmap() a large area backed by many shared PMD tables, we perform one IPI broadcast per unshared PMD table. There are two optimizations to be had: (1) When we process (unshare) multiple such PMD tables, such as during exit(), it is sufficient to send a single IPI broadcast (as long as we respect locking rules) instead of one per PMD table. Locking prevents that any of these PMD tables could get reuse before we drop the lock. (2) When we are not the last sharer (> 2 users including us), there is no need to send the IPI broadcast. The shared PMD tables cannot become exclusive (fully unshared) before an IPI will be broadcasted by the last sharer. Concurrent GUP-fast could walk into a PMD table just before we unshared it. It could then succeed in grabbing a page from the shared page table even after munmap() etc succeeded (and supressed an IPI). But there is not difference compared to GUP-fast just sleeping for a while after grabbing the page and re-enabling IRQs. Most importantly, GUP-fast will never walk into page tables that are no-longer shared, because the last sharer will issue an IPI broadcast. (if ever required, checking whether the PUD changed in GUP-fast after grabbing the page like we do in the PTE case could handle this) So let's rework PMD sharing TLB flushing + IPI sync to use the mmu_gather infrastructure so we can implement these optimizations and demystify the code at least a bit. Extend the mmu_gather infrastructure to be able to deal with our special hugetlb PMD table sharing implementation. We'll consolidate the handling for (full) unsharing of PMD tables in tlb_unshare_pmd_ptdesc() and tlb_flush_unshared_tables(), and track in "struct mmu_gather" whether we had (full) unsharing of PMD tables. Because locking is very special (concurrent unsharing+reuse must be prevented), we disallow deferring flushing to tlb_finish_mmu() and instead require an explicit earlier call to tlb_flush_unshared_tables(). From hugetlb code, we call huge_pmd_unshare_flush() where we make sure that the expected lock protecting us from concurrent unsharing+reuse is still held. Check with a VM_WARN_ON_ONCE() in tlb_finish_mmu() that tlb_flush_unshared_tables() was properly called earlier. Document it all properly. Notes about tlb_remove_table_sync_one() interaction with unsharing: There are two fairly tricky things: (1) tlb_remove_table_sync_one() is a NOP on architectures without CONFIG_MMU_GATHER_RCU_TABLE_FREE. Here, the assumption is that the previous TLB flush would send an IPI to all relevant CPUs. Careful: some architectures like x86 only send IPIs to all relevant CPUs when tlb->freed_tables is set. The relevant architectures should be selecting MMU_GATHER_RCU_TABLE_FREE, but x86 might not do that in stable kernels and it might have been problematic before this patch. Also, the arch flushing behavior (independent of IPIs) is different when tlb->freed_tables is set. Do we have to enlighten them to also take care of tlb->unshared_tables? So far we didn't care, so hopefully we are fine. Of course, we could be setting tlb->freed_tables as well, but that might then unnecessarily flush too much, because the semantics of tlb->freed_tables are a bit fuzzy. This patch changes nothing in this regard. (2) tlb_remove_table_sync_one() is not a NOP on architectures with CONFIG_MMU_GATHER_RCU_TABLE_FREE that actually don't need a sync. Take x86 as an example: in the common case (!pv, !X86_FEATURE_INVLPGB) we still issue IPIs during TLB flushes and don't actually need the second tlb_remove_table_sync_one(). This optimized can be implemented on top of this, by checking e.g., in tlb_remove_table_sync_one() whether we really need IPIs. But as described in (1), it really must honor tlb->freed_tables then to send IPIs to all relevant CPUs. Further note that the ptdesc_pmd_pts_dec() in huge_pmd_share() is not a concern, as we are holding the i_mmap_lock the whole time, preventing concurrent unsharing. That ptdesc_pmd_pts_dec() usage will be removed separately as a cleanup later. There are plenty more cleanups to be had, but they have to wait until this is fixed. Fixes: 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") Reported-by: Uschakow, Stanislav" <suschako(a)amazon.de> Closes: https://lore.kernel.org/all/4d3878531c76479d9f8ca9789dc6485d@amazon.de/ Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org> --- include/asm-generic/tlb.h | 69 +++++++++++++++++++++- include/linux/hugetlb.h | 19 +++--- mm/hugetlb.c | 121 ++++++++++++++++++++++---------------- mm/mmu_gather.c | 6 ++ mm/mprotect.c | 2 +- mm/rmap.c | 25 +++++--- 6 files changed, 173 insertions(+), 69 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 1fff717cae510..324a21f53b644 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -364,6 +364,17 @@ struct mmu_gather { unsigned int vma_huge : 1; unsigned int vma_pfn : 1; + /* + * Did we unshare (unmap) any shared page tables? + */ + unsigned int unshared_tables : 1; + + /* + * Did we unshare any page tables such that they are now exclusive + * and could get reused+modified by the new owner? + */ + unsigned int fully_unshared_tables : 1; + unsigned int batch_count; #ifndef CONFIG_MMU_GATHER_NO_GATHER @@ -400,6 +411,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->cleared_pmds = 0; tlb->cleared_puds = 0; tlb->cleared_p4ds = 0; + tlb->unshared_tables = 0; /* * Do not reset mmu_gather::vma_* fields here, we do not * call into tlb_start_vma() again to set them if there is an @@ -484,7 +496,7 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) * these bits. */ if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds || - tlb->cleared_puds || tlb->cleared_p4ds)) + tlb->cleared_puds || tlb->cleared_p4ds || tlb->unshared_tables)) return; tlb_flush(tlb); @@ -773,6 +785,61 @@ static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) } #endif +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING +static inline void tlb_unshare_pmd_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt, + unsigned long addr) +{ + /* + * The caller must make sure that concurrent unsharing + exclusive + * reuse is impossible until tlb_flush_unshared_tables() was called. + */ + VM_WARN_ON_ONCE(!ptdesc_pmd_is_shared(pt)); + ptdesc_pmd_pts_dec(pt); + + /* Clearing a PUD pointing at a PMD table with PMD leaves. */ + tlb_flush_pmd_range(tlb, addr & PUD_MASK, PUD_SIZE); + + /* + * If the page table is now exclusively owned, we fully unshared + * a page table. + */ + if (!ptdesc_pmd_is_shared(pt)) + tlb->fully_unshared_tables = true; + tlb->unshared_tables = true; +} + +static inline void tlb_flush_unshared_tables(struct mmu_gather *tlb) +{ + /* + * As soon as the caller drops locks to allow for reuse of + * previously-shared tables, these tables could get modified and + * even reused outside of hugetlb context. So flush the TLB now. + * + * Note that we cannot defer the flush to a later point even if we are + * not the last sharer of the page table. + */ + if (tlb->unshared_tables) + tlb_flush_mmu_tlbonly(tlb); + + /* + * Similarly, we must make sure that concurrent GUP-fast will not + * walk previously-shared page tables that are getting modified+reused + * elsewhere. So broadcast an IPI to wait for any concurrent GUP-fast. + * + * We only perform this when we are the last sharer of a page table, + * as the IPI will reach all CPUs: any GUP-fast. + * + * Note that on configs where tlb_remove_table_sync_one() is a NOP, + * the expectation is that the tlb_flush_mmu_tlbonly() would have issued + * required IPIs already for us. + */ + if (tlb->fully_unshared_tables) { + tlb_remove_table_sync_one(); + tlb->fully_unshared_tables = false; + } +} +#endif /* CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ + #endif /* CONFIG_MMU */ #endif /* _ASM_GENERIC__TLB_H */ diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 03c8725efa289..63b248c6bfd47 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -240,8 +240,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz); unsigned long hugetlb_mask_last_page(struct hstate *h); -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep); +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma); void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end); @@ -271,7 +272,7 @@ void hugetlb_vma_unlock_write(struct vm_area_struct *vma); int hugetlb_vma_trylock_write(struct vm_area_struct *vma); void hugetlb_vma_assert_locked(struct vm_area_struct *vma); void hugetlb_vma_lock_release(struct kref *kref); -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags); void hugetlb_unshare_all_pmds(struct vm_area_struct *vma); @@ -300,13 +301,17 @@ static inline struct address_space *hugetlb_folio_mapping_lock_write( return NULL; } -static inline int huge_pmd_unshare(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +static inline int huge_pmd_unshare(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { return 0; } +static inline void huge_pmd_unshare_flush(struct mmu_gather *tlb, + struct vm_area_struct *vma) +{ +} + static inline void adjust_range_if_pmd_sharing_possible( struct vm_area_struct *vma, unsigned long *start, unsigned long *end) @@ -432,7 +437,7 @@ static inline void move_hugetlb_state(struct folio *old_folio, { } -static inline long hugetlb_change_protection( +static inline long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3c77cdef12a32..3db94693a06fc 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5096,8 +5096,9 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, unsigned long last_addr_mask; pte_t *src_pte, *dst_pte; struct mmu_notifier_range range; - bool shared_pmd = false; + struct mmu_gather tlb; + tlb_gather_mmu(&tlb, vma->vm_mm); mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, old_addr, old_end); adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); @@ -5122,12 +5123,12 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte))) continue; - if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { - shared_pmd = true; + if (huge_pmd_unshare(&tlb, vma, old_addr, src_pte)) { old_addr |= last_addr_mask; new_addr |= last_addr_mask; continue; } + tlb_remove_huge_tlb_entry(h, &tlb, src_pte, old_addr); dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); if (!dst_pte) @@ -5136,13 +5137,13 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz); } - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, old_end - len, old_end); + tlb_flush_mmu_tlbonly(&tlb); + huge_pmd_unshare_flush(&tlb, vma); + mmu_notifier_invalidate_range_end(&range); i_mmap_unlock_write(mapping); hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); return len + old_addr - old_end; } @@ -5161,7 +5162,6 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); bool adjust_reservation; unsigned long last_addr_mask; - bool force_flush = false; WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~huge_page_mask(h)); @@ -5184,10 +5184,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { spin_unlock(ptl); - tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); - force_flush = true; address |= last_addr_mask; continue; } @@ -5303,14 +5301,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } tlb_end_vma(tlb, vma); - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (force_flush) - tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); } void __hugetlb_zap_begin(struct vm_area_struct *vma, @@ -6399,7 +6390,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte, } #endif /* CONFIG_USERFAULTFD */ -long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot, unsigned long cp_flags) { @@ -6409,7 +6400,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte_t pte; struct hstate *h = hstate_vma(vma); long pages = 0, psize = huge_page_size(h); - bool shared_pmd = false; struct mmu_notifier_range range; unsigned long last_addr_mask; bool uffd_wp = cp_flags & MM_CP_UFFD_WP; @@ -6452,7 +6442,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, } } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { /* * When uffd-wp is enabled on the vma, unshare * shouldn't happen at all. Warn about it if it @@ -6461,7 +6451,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); pages++; spin_unlock(ptl); - shared_pmd = true; address |= last_addr_mask; continue; } @@ -6522,22 +6511,16 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte = huge_pte_clear_uffd_wp(pte); huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); pages++; + tlb_remove_huge_tlb_entry(h, tlb, ptep, address); } next: spin_unlock(ptl); cond_resched(); } - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, start, end); + + tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); /* * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() we are * downgrading page table protection not changing it to point to a new @@ -6904,18 +6887,27 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return pte; } -/* - * unmap huge page backed by shared pte. +/** + * huge_pmd_unshare - Unmap a pmd table if it is shared by multiple users + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * @addr: the address we are trying to unshare. + * @ptep: pointer into the (pmd) page table. + * + * Called with the page table lock held, the i_mmap_rwsem held in write mode + * and the hugetlb vma lock held in write mode. * - * Called with page table lock held. + * Note: The caller must call huge_pmd_unshare_flush() before dropping the + * i_mmap_rwsem. * - * returns: 1 successfully unmapped a shared pte page - * 0 the underlying pte page is not shared, or it is the last user + * Returns: 1 if it was a shared PMD table and it got unmapped, or 0 if it + * was not a shared PMD table. */ -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { unsigned long sz = huge_page_size(hstate_vma(vma)); + struct mm_struct *mm = vma->vm_mm; pgd_t *pgd = pgd_offset(mm, addr); p4d_t *p4d = p4d_offset(pgd, addr); pud_t *pud = pud_offset(p4d, addr); @@ -6927,18 +6919,36 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, i_mmap_assert_write_locked(vma->vm_file->f_mapping); hugetlb_vma_assert_locked(vma); pud_clear(pud); - /* - * Once our caller drops the rmap lock, some other process might be - * using this page table as a normal, non-hugetlb page table. - * Wait for pending gup_fast() in other threads to finish before letting - * that happen. - */ - tlb_remove_table_sync_one(); - ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); + + tlb_unshare_pmd_ptdesc(tlb, virt_to_ptdesc(ptep), addr); + mm_dec_nr_pmds(mm); return 1; } +/* + * huge_pmd_unshare_flush - Complete a sequence of huge_pmd_unshare() calls + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * + * Perform necessary TLB flushes or IPI broadcasts to synchronize PMD table + * unsharing with concurrent page table walkers (TLB, GUP-fast, etc.). + * + * This function must be called after a sequence of huge_pmd_unshare() + * calls while still holding the i_mmap_rwsem. + */ +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + /* + * We must synchronize page table unsharing such that nobody will + * try reusing a previously-shared page table while it might still + * be in use by previous sharers (TLB, GUP_fast). + */ + i_mmap_assert_write_locked(vma->vm_file->f_mapping); + + tlb_flush_unshared_tables(tlb); +} + #else /* !CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, @@ -6947,12 +6957,16 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return NULL; } -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { return 0; } +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ +} + void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end) { @@ -7219,6 +7233,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); struct mm_struct *mm = vma->vm_mm; struct mmu_notifier_range range; + struct mmu_gather tlb; unsigned long address; spinlock_t *ptl; pte_t *ptep; @@ -7229,6 +7244,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (start >= end) return; + tlb_gather_mmu(&tlb, mm); flush_cache_range(vma, start, end); /* * No need to call adjust_range_if_pmd_sharing_possible(), because @@ -7248,10 +7264,10 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (!ptep) continue; ptl = huge_pte_lock(h, mm, ptep); - huge_pmd_unshare(mm, vma, address, ptep); + huge_pmd_unshare(&tlb, vma, address, ptep); spin_unlock(ptl); } - flush_hugetlb_tlb_range(vma, start, end); + huge_pmd_unshare_flush(&tlb, vma); if (take_locks) { i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); @@ -7261,6 +7277,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, * Documentation/mm/mmu_notifier.rst. */ mmu_notifier_invalidate_range_end(&range); + tlb_finish_mmu(&tlb); } /* diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index 247e3f9db6c7a..822a790127375 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -468,6 +468,12 @@ void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) */ void tlb_finish_mmu(struct mmu_gather *tlb) { + /* + * We expect an earlier huge_pmd_unshare_flush() call to sort this out, + * due to complicated locking requirements with page table unsharing. + */ + VM_WARN_ON_ONCE(tlb->fully_unshared_tables); + /* * If there are parallel threads are doing PTE changes on same range * under non-exclusive lock (e.g., mmap_lock read-side) but defer TLB diff --git a/mm/mprotect.c b/mm/mprotect.c index 283889e4f1cec..5c330e817129e 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -652,7 +652,7 @@ long change_protection(struct mmu_gather *tlb, #endif if (is_vm_hugetlb_page(vma)) - pages = hugetlb_change_protection(vma, start, end, newprot, + pages = hugetlb_change_protection(tlb, vma, start, end, newprot, cp_flags); else pages = change_protection_range(tlb, vma, start, end, newprot, diff --git a/mm/rmap.c b/mm/rmap.c index 748f48727a162..d6799afe11147 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -76,7 +76,7 @@ #include <linux/mm_inline.h> #include <linux/oom.h> -#include <asm/tlbflush.h> +#include <asm/tlb.h> #define CREATE_TRACE_POINTS #include <trace/events/migrate.h> @@ -2008,13 +2008,17 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, * if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) goto walk_abort; - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { + + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2022,6 +2026,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, goto walk_done; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); if (pte_dirty(pteval)) @@ -2398,17 +2403,20 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, * fail if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) { page_vma_mapped_walk_done(&pvmw); ret = false; break; } - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { - hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + tlb_gather_mmu(&tlb, mm); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { + hugetlb_vma_unlock_write(vma); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2417,6 +2425,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, break; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } /* Nuke the hugetlb page table entry */ pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); -- 2.52.0

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Re: Patch "media: ov02c10: Fix default vertical flip" has been added to the 6.18-stable tree

by Hans de Goede

Hi Sasha, On 13-Dec-25 10:35, Sasha Levin wrote: > This is a note to let you know that I've just added the patch titled > > media: ov02c10: Fix default vertical flip This fix is incomplete, leading to wrong colors and it causes the image to be upside down on some Dell XPS models where it currently is the right way up. There is a series of fixes which applies on top of this to fix both issues: https://lore.kernel.org/linux-media/20251210112436.167212-1-johannes.goede@… For now (without the fixes on top) we are better of not adding this patch to the stable series. Can you drop this patch please? Same for 6.17 and other stable series. Regards, Hans > > to the 6.18-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… > > The filename of the patch is: > media-ov02c10-fix-default-vertical-flip.patch > and it can be found in the queue-6.18 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable(a)vger.kernel.org> know about it. > > > > commit 14cc4474799a595caeccdb8fdf2ca4b867cef972 > Author: Sebastian Reichel <sre(a)kernel.org> > Date: Wed Aug 20 02:13:19 2025 +0200 > > media: ov02c10: Fix default vertical flip > > [ Upstream commit d5ebe3f7d13d4cee3ff7e718de23564915aaf163 ] > > The driver right now defaults to setting the vertical flip bit. This > conflicts with proper handling of the rotation property defined in > ACPI or device tree, so drop the VFLIP bit. It should be handled via > V4L2_CID_VFLIP instead. > > Reported-by: Frederic Stuyk <fstuyk(a)runbox.com> > Closes: https://lore.kernel.org/all/b6df9ae7-ea9f-4e5a-8065-5b130f534f37@runbox.com/ > Fixes: 44f89010dae0 ("media: i2c: Add Omnivision OV02C10 sensor driver") > Signed-off-by: Sebastian Reichel <sre(a)kernel.org> > Reviewed-by: Bryan O'Donoghue <bod(a)kernel.org> > Signed-off-by: Sakari Ailus <sakari.ailus(a)linux.intel.com> > Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> > Signed-off-by: Sasha Levin <sashal(a)kernel.org> > > diff --git a/drivers/media/i2c/ov02c10.c b/drivers/media/i2c/ov02c10.c > index 8c4d85dc7922e..8e22ff446b0c4 100644 > --- a/drivers/media/i2c/ov02c10.c > +++ b/drivers/media/i2c/ov02c10.c > @@ -174,7 +174,7 @@ static const struct reg_sequence sensor_1928x1092_30fps_setting[] = { > {0x3816, 0x01}, > {0x3817, 0x01}, > > - {0x3820, 0xb0}, > + {0x3820, 0xa0}, > {0x3821, 0x00}, > {0x3822, 0x80}, > {0x3823, 0x08},

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[PATCH 6.12 00/49] 6.12.62-rc1 review

by Greg Kroah-Hartman

This is the start of the stable review cycle for the 6.12.62 release. There are 49 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know. Responses should be made by Fri, 12 Dec 2025 07:29:38 +0000. Anything received after that time might be too late. The whole patch series can be found in one patch at: https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.12.62-rc… or in the git tree and branch at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.12.y and the diffstat can be found below. thanks, greg k-h ------------- Pseudo-Shortlog of commits: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Linux 6.12.62-rc1 Daniele Palmas <dnlplm(a)gmail.com> bus: mhi: host: pci_generic: Add Telit FN990B40 modem support Daniele Palmas <dnlplm(a)gmail.com> bus: mhi: host: pci_generic: Add Telit FN920C04 modem support Navaneeth K <knavaneeth786(a)gmail.com> staging: rtl8723bs: fix out-of-bounds read in OnBeacon ESR IE parsing Navaneeth K <knavaneeth786(a)gmail.com> staging: rtl8723bs: fix stack buffer overflow in OnAssocReq IE parsing Navaneeth K <knavaneeth786(a)gmail.com> staging: rtl8723bs: fix out-of-bounds read in rtw_get_ie() parser Nikita Zhandarovich <n.zhandarovich(a)fintech.ru> comedi: check device's attached status in compat ioctls Nikita Zhandarovich <n.zhandarovich(a)fintech.ru> comedi: multiq3: sanitize config options in multiq3_attach() Ian Abbott <abbotti(a)mev.co.uk> comedi: c6xdigio: Fix invalid PNP driver unregistration Zenm Chen <zenmchen(a)gmail.com> wifi: rtw88: Add USB ID 2001:3329 for D-Link AC13U rev. A1 Zenm Chen <zenmchen(a)gmail.com> wifi: rtl8xxxu: Add USB ID 2001:3328 for D-Link AN3U rev. A1 Linus Torvalds <torvalds(a)linux-foundation.org> samples: work around glibc redefining some of our defines wrong Huacai Chen <chenhuacai(a)kernel.org> LoongArch: Mask all interrupts during kexec/kdump Naoki Ueki <naoki25519(a)gmail.com> HID: elecom: Add support for ELECOM M-XT3URBK (018F) Antheas Kapenekakis <lkml(a)antheas.dev> platform/x86/amd/pmc: Add spurious_8042 to Xbox Ally Antheas Kapenekakis <lkml(a)antheas.dev> platform/x86/amd: pmc: Add Lenovo Legion Go 2 to pmc quirk list Jia Ston <ston.jia(a)outlook.com> platform/x86: huawei-wmi: add keys for HONOR models April Grimoire <april(a)aprilg.moe> HID: apple: Add SONiX AK870 PRO to non_apple_keyboards quirk list Armin Wolf <W_Armin(a)gmx.de> platform/x86: acer-wmi: Ignore backlight event Praveen Talari <praveen.talari(a)oss.qualcomm.com> pinctrl: qcom: msm: Fix deadlock in pinmux configuration Keith Busch <kbusch(a)kernel.org> nvme: fix admin request_queue lifetime Mario Limonciello (AMD) <superm1(a)kernel.org> HID: hid-input: Extend Elan ignore battery quirk to USB Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> bfs: Reconstruct file type when loading from disk Lushih Hsieh <bruce(a)mail.kh.edu.tw> ALSA: usb-audio: Add native DSD quirks for PureAudio DAC series Harish Kasiviswanathan <Harish.Kasiviswanathan(a)amd.com> drm/amdkfd: Fix GPU mappings for APU after prefetch Yiqi Sun <sunyiqixm(a)gmail.com> smb: fix invalid username check in smb3_fs_context_parse_param() Max Chou <max.chou(a)realtek.com> Bluetooth: btrtl: Avoid loading the config file on security chips Ian Forbes <ian.forbes(a)broadcom.com> drm/vmwgfx: Use kref in vmw_bo_dirty Robin Gong <yibin.gong(a)nxp.com> spi: imx: keep dma request disabled before dma transfer setup Alvaro Gamez Machado <alvaro.gamez(a)hazent.com> spi: xilinx: increase number of retries before declaring stall Song Liu <song(a)kernel.org> ftrace: bpf: Fix IPMODIFY + DIRECT in modify_ftrace_direct() Johan Hovold <johan(a)kernel.org> USB: serial: kobil_sct: fix TIOCMBIS and TIOCMBIC Johan Hovold <johan(a)kernel.org> USB: serial: belkin_sa: fix TIOCMBIS and TIOCMBIC Magne Bruno <magne.bruno(a)addi-data.com> serial: add support of CPCI cards Johan Hovold <johan(a)kernel.org> USB: serial: ftdi_sio: match on interface number for jtag Fabio Porcedda <fabio.porcedda(a)gmail.com> USB: serial: option: move Telit 0x10c7 composition in the right place Fabio Porcedda <fabio.porcedda(a)gmail.com> USB: serial: option: add Telit Cinterion FE910C04 new compositions Slark Xiao <slark_xiao(a)163.com> USB: serial: option: add Foxconn T99W760 Omar Sandoval <osandov(a)fb.com> KVM: SVM: Don't skip unrelated instruction if INT3/INTO is replaced Nikita Zhandarovich <n.zhandarovich(a)fintech.ru> comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel() Alexey Nepomnyashih <sdl(a)nppct.ru> ext4: add i_data_sem protection in ext4_destroy_inline_data_nolock() Alexander Sverdlin <alexander.sverdlin(a)siemens.com> locking/spinlock/debug: Fix data-race in do_raw_write_lock Qianchang Zhao <pioooooooooip(a)gmail.com> ksmbd: ipc: fix use-after-free in ipc_msg_send_request Deepanshu Kartikey <kartikey406(a)gmail.com> ext4: refresh inline data size before write operations Ye Bin <yebin10(a)huawei.com> jbd2: avoid bug_on in jbd2_journal_get_create_access() when file system corrupted Bagas Sanjaya <bagasdotme(a)gmail.com> Documentation: process: Also mention Sasha Levin as stable tree maintainer Sabrina Dubroca <sd(a)queasysnail.net> xfrm: flush all states in xfrm_state_fini Sabrina Dubroca <sd(a)queasysnail.net> xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added Sabrina Dubroca <sd(a)queasysnail.net> Revert "xfrm: destroy xfrm_state synchronously on net exit path" Sabrina Dubroca <sd(a)queasysnail.net> xfrm: delete x->tunnel as we delete x ------------- Diffstat: Documentation/process/2.Process.rst | 6 ++- Makefile | 4 +- arch/loongarch/kernel/machine_kexec.c | 2 + arch/x86/include/asm/kvm_host.h | 9 ++++ arch/x86/kvm/svm/svm.c | 24 +++++---- arch/x86/kvm/x86.c | 21 ++++++++ drivers/bluetooth/btrtl.c | 24 +++++---- drivers/bus/mhi/host/pci_generic.c | 52 +++++++++++++++++++ drivers/comedi/comedi_fops.c | 42 ++++++++++++--- drivers/comedi/drivers/c6xdigio.c | 46 ++++++++++++---- drivers/comedi/drivers/multiq3.c | 9 ++++ drivers/comedi/drivers/pcl818.c | 5 +- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 + drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 12 ++--- drivers/hid/hid-apple.c | 1 + drivers/hid/hid-elecom.c | 6 ++- drivers/hid/hid-ids.h | 3 +- drivers/hid/hid-input.c | 5 +- drivers/hid/hid-quirks.c | 3 +- drivers/net/wireless/realtek/rtl8xxxu/core.c | 3 ++ drivers/net/wireless/realtek/rtw88/rtw8822cu.c | 2 + drivers/nvme/host/core.c | 3 +- drivers/pinctrl/qcom/pinctrl-msm.c | 2 +- drivers/platform/x86/acer-wmi.c | 4 ++ drivers/platform/x86/amd/pmc/pmc-quirks.c | 25 +++++++++ drivers/platform/x86/huawei-wmi.c | 4 ++ drivers/spi/spi-imx.c | 15 ++++-- drivers/spi/spi-xilinx.c | 2 +- drivers/staging/rtl8723bs/core/rtw_ieee80211.c | 14 ++--- drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 13 +++-- drivers/tty/serial/8250/8250_pci.c | 37 +++++++++++++ drivers/usb/serial/belkin_sa.c | 28 ++++++---- drivers/usb/serial/ftdi_sio.c | 72 +++++++++----------------- drivers/usb/serial/kobil_sct.c | 18 +++---- drivers/usb/serial/option.c | 22 ++++++-- fs/bfs/inode.c | 19 ++++++- fs/ext4/inline.c | 14 ++++- fs/jbd2/transaction.c | 19 +++++-- fs/smb/client/fs_context.c | 2 +- fs/smb/server/transport_ipc.c | 7 ++- include/net/xfrm.h | 13 ++--- kernel/locking/spinlock_debug.c | 4 +- kernel/trace/ftrace.c | 40 ++++++++++---- net/ipv4/ipcomp.c | 2 + net/ipv6/ipcomp6.c | 2 + net/ipv6/xfrm6_tunnel.c | 2 +- net/key/af_key.c | 2 +- net/xfrm/xfrm_ipcomp.c | 1 - net/xfrm/xfrm_state.c | 41 ++++++--------- net/xfrm/xfrm_user.c | 2 +- samples/vfs/test-statx.c | 6 +++ samples/watch_queue/watch_test.c | 6 +++ sound/usb/quirks.c | 6 +++ 53 files changed, 521 insertions(+), 207 deletions(-)

1 day, 8 hours

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[PATCH] [STABLE ONLY] firmware: arm_scmi: Fix unused notifier-block in unregister

by Amitai Gottlieb

In function `scmi_devm_notifier_unregister` the notifier-block parameter was unused and therefore never passed to `devres_release`. This causes the function to always return -ENOENT and fail to unregister the notifier. In drivers that rely on this function for cleanup this causes unexpected failures including kernel-panic. This is not needed upstream becaues the bug was fixed in a refactor by commit 264a2c520628 ("firmware: arm_scmi: Simplify scmi_devm_notifier_unregister"). It is needed for the 5.15, 6.1 and 6.6 kernels. Cc: <stable(a)vger.kernel.org> # 5.15.x, 6.1.x, and 6.6.x Fixes: 5ad3d1cf7d34 ("firmware: arm_scmi: Introduce new devres notification ops") Reviewed-by: Dan Carpenter <dan.carpenter(a)linaro.org> Reviewed-by: Cristian Marussi <cristian.marussi(a)arm.com> Signed-off-by: Amitai Gottlieb <amitaig(a)hailo.ai> --- drivers/firmware/arm_scmi/notify.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c index 0efd20cd9d69..4782b115e6ec 100644 --- a/drivers/firmware/arm_scmi/notify.c +++ b/drivers/firmware/arm_scmi/notify.c @@ -1539,6 +1539,7 @@ static int scmi_devm_notifier_unregister(struct scmi_device *sdev, dres.handle = sdev->handle; dres.proto_id = proto_id; dres.evt_id = evt_id; + dres.nb = nb; if (src_id) { dres.__src_id = *src_id; dres.src_id = &dres.__src_id; -- 2.34.1

1 day, 9 hours

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[PATCH 2/2 RESEND] mailbox: Make mbox_send_message() return error code when tx fails

by Joonwon Kang

Previously, when the mailbox controller failed transmitting message, the error code was only passed to the client's tx done handler and not to mbox_send_message(). For this reason, the function could return a false success. This commit resolves the issue by introducing the tx status and checking it before mbox_send_message() returns. Cc: stable(a)vger.kernel.org Signed-off-by: Joonwon Kang <joonwonkang(a)google.com> --- drivers/mailbox/mailbox.c | 17 +++++++++++++---- include/linux/mailbox_controller.h | 2 ++ 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c index 0afe3ae3bfdc..05808ecff774 100644 --- a/drivers/mailbox/mailbox.c +++ b/drivers/mailbox/mailbox.c @@ -23,7 +23,8 @@ static LIST_HEAD(mbox_cons); static DEFINE_MUTEX(con_mutex); -static int add_to_rbuf(struct mbox_chan *chan, void *mssg, struct completion *tx_complete) +static int add_to_rbuf(struct mbox_chan *chan, void *mssg, struct completion *tx_complete, + int *tx_status) { int idx; @@ -36,6 +37,7 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg, struct completion *tx idx = chan->msg_free; chan->msg_data[idx].data = mssg; chan->msg_data[idx].tx_complete = tx_complete; + chan->msg_data[idx].tx_status = tx_status; chan->msg_count++; if (idx == MBOX_TX_QUEUE_LEN - 1) @@ -87,12 +89,14 @@ static void tx_tick(struct mbox_chan *chan, int r) int idx; void *mssg = NULL; struct completion *tx_complete = NULL; + int *tx_status = NULL; scoped_guard(spinlock_irqsave, &chan->lock) { idx = chan->active_req; if (idx >= 0) { mssg = chan->msg_data[idx].data; tx_complete = chan->msg_data[idx].tx_complete; + tx_status = chan->msg_data[idx].tx_status; chan->active_req = -1; } } @@ -107,8 +111,10 @@ static void tx_tick(struct mbox_chan *chan, int r) if (chan->cl->tx_done) chan->cl->tx_done(chan->cl, mssg, r); - if (r != -ETIME && chan->cl->tx_block) + if (r != -ETIME && chan->cl->tx_block) { + *tx_status = r; complete(tx_complete); + } } static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer) @@ -253,15 +259,16 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg) { int t; struct completion tx_complete; + int tx_status = 0; if (!chan || !chan->cl) return -EINVAL; if (chan->cl->tx_block) { init_completion(&tx_complete); - t = add_to_rbuf(chan, mssg, &tx_complete); + t = add_to_rbuf(chan, mssg, &tx_complete, &tx_status); } else { - t = add_to_rbuf(chan, mssg, NULL); + t = add_to_rbuf(chan, mssg, NULL, NULL); } if (t < 0) { @@ -284,6 +291,8 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg) if (ret == 0) { t = -ETIME; tx_tick(chan, t); + } else if (tx_status < 0) { + t = tx_status; } } diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h index 67e08a440f5f..6929774d3129 100644 --- a/include/linux/mailbox_controller.h +++ b/include/linux/mailbox_controller.h @@ -109,10 +109,12 @@ struct mbox_controller { * struct mbox_message - Internal representation of a mailbox message * @data: Data packet * @tx_complete: Pointer to the transmission completion + * @tx_status: Pointer to the transmission status */ struct mbox_message { void *data; struct completion *tx_complete; + int *tx_status; }; /** -- 2.52.0.239.gd5f0c6e74e-goog

1 day, 10 hours

1
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[PATCH 1/2 RESEND] mailbox: Use per-thread completion to fix wrong completion order

by Joonwon Kang

Previously, a sender thread in mbox_send_message() could be woken up at a wrong time in blocking mode. It is because there was only a single completion for a channel whereas messages from multiple threads could be sent on the same channel in any order; since the shared completion could be signalled in any order, it could wake up a wrong sender thread. This commit resolves the false wake-up issue with the following changes: - Completions are created just as many as the number of concurrent sender threads - A completion is created on a sender thread's stack - Each slot of the message queue, i.e. `msg_data`, contains a pointer to its target completion - tx_tick() signals the completion of the currently active slot of the message queue Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/all/1490809381-28869-1-git-send-email-jaswinder.sin… Signed-off-by: Joonwon Kang <joonwonkang(a)google.com> --- Link -> v1: The previous solution in the Link tries to have per-message completion: `tx_cmpl[MBOX_TX_QUEUE_LEN]`; each completion belongs to each slot of the message queue: `msg_data[i]`. Those completions take up additional memory even when they are not used. Instead, this patch tries to have per-"thread" completion; each completion belongs to each sender thread and each slot of the message queue has a pointer to that completion; `struct mbox_message` has the "pointer" field `struct completion *tx_complete` which points to the completion which is created on the stack of the sender, instead of owning the completion by `struct completion tx_complete`. This way, we could avoid additional memory use since a completion will be allocated only when necessary. Plus, more importantly, we could avoid the window where the same completion is reused by different sender threads which the previous solution still has. drivers/mailbox/mailbox.c | 43 +++++++++++++++++++----------- drivers/mailbox/tegra-hsp.c | 2 +- include/linux/mailbox_controller.h | 20 +++++++++----- 3 files changed, 43 insertions(+), 22 deletions(-) diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c index 617ba505691d..0afe3ae3bfdc 100644 --- a/drivers/mailbox/mailbox.c +++ b/drivers/mailbox/mailbox.c @@ -23,7 +23,7 @@ static LIST_HEAD(mbox_cons); static DEFINE_MUTEX(con_mutex); -static int add_to_rbuf(struct mbox_chan *chan, void *mssg) +static int add_to_rbuf(struct mbox_chan *chan, void *mssg, struct completion *tx_complete) { int idx; @@ -34,7 +34,8 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg) return -ENOBUFS; idx = chan->msg_free; - chan->msg_data[idx] = mssg; + chan->msg_data[idx].data = mssg; + chan->msg_data[idx].tx_complete = tx_complete; chan->msg_count++; if (idx == MBOX_TX_QUEUE_LEN - 1) @@ -52,7 +53,7 @@ static void msg_submit(struct mbox_chan *chan) int err = -EBUSY; scoped_guard(spinlock_irqsave, &chan->lock) { - if (!chan->msg_count || chan->active_req) + if (!chan->msg_count || chan->active_req >= 0) break; count = chan->msg_count; @@ -62,14 +63,14 @@ static void msg_submit(struct mbox_chan *chan) else idx += MBOX_TX_QUEUE_LEN - count; - data = chan->msg_data[idx]; + data = chan->msg_data[idx].data; if (chan->cl->tx_prepare) chan->cl->tx_prepare(chan->cl, data); /* Try to submit a message to the MBOX controller */ err = chan->mbox->ops->send_data(chan, data); if (!err) { - chan->active_req = data; + chan->active_req = idx; chan->msg_count--; } } @@ -83,11 +84,17 @@ static void msg_submit(struct mbox_chan *chan) static void tx_tick(struct mbox_chan *chan, int r) { - void *mssg; + int idx; + void *mssg = NULL; + struct completion *tx_complete = NULL; scoped_guard(spinlock_irqsave, &chan->lock) { - mssg = chan->active_req; - chan->active_req = NULL; + idx = chan->active_req; + if (idx >= 0) { + mssg = chan->msg_data[idx].data; + tx_complete = chan->msg_data[idx].tx_complete; + chan->active_req = -1; + } } /* Submit next message */ @@ -101,7 +108,7 @@ static void tx_tick(struct mbox_chan *chan, int r) chan->cl->tx_done(chan->cl, mssg, r); if (r != -ETIME && chan->cl->tx_block) - complete(&chan->tx_complete); + complete(tx_complete); } static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer) @@ -114,7 +121,7 @@ static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer) for (i = 0; i < mbox->num_chans; i++) { struct mbox_chan *chan = &mbox->chans[i]; - if (chan->active_req && chan->cl) { + if (chan->active_req >= 0 && chan->cl) { txdone = chan->mbox->ops->last_tx_done(chan); if (txdone) tx_tick(chan, 0); @@ -245,11 +252,18 @@ EXPORT_SYMBOL_GPL(mbox_client_peek_data); int mbox_send_message(struct mbox_chan *chan, void *mssg) { int t; + struct completion tx_complete; if (!chan || !chan->cl) return -EINVAL; - t = add_to_rbuf(chan, mssg); + if (chan->cl->tx_block) { + init_completion(&tx_complete); + t = add_to_rbuf(chan, mssg, &tx_complete); + } else { + t = add_to_rbuf(chan, mssg, NULL); + } + if (t < 0) { dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n"); return t; @@ -266,7 +280,7 @@ int mbox_send_message(struct mbox_chan *chan, void *mssg) else wait = msecs_to_jiffies(chan->cl->tx_tout); - ret = wait_for_completion_timeout(&chan->tx_complete, wait); + ret = wait_for_completion_timeout(&tx_complete, wait); if (ret == 0) { t = -ETIME; tx_tick(chan, t); @@ -319,9 +333,8 @@ static int __mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl) scoped_guard(spinlock_irqsave, &chan->lock) { chan->msg_free = 0; chan->msg_count = 0; - chan->active_req = NULL; + chan->active_req = -1; chan->cl = cl; - init_completion(&chan->tx_complete); if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) chan->txdone_method = TXDONE_BY_ACK; @@ -477,7 +490,7 @@ void mbox_free_channel(struct mbox_chan *chan) /* The queued TX requests are simply aborted, no callbacks are made */ scoped_guard(spinlock_irqsave, &chan->lock) { chan->cl = NULL; - chan->active_req = NULL; + chan->active_req = -1; if (chan->txdone_method == TXDONE_BY_ACK) chan->txdone_method = TXDONE_BY_POLL; } diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c index ed9a0bb2bcd8..de7494ce0a9f 100644 --- a/drivers/mailbox/tegra-hsp.c +++ b/drivers/mailbox/tegra-hsp.c @@ -497,7 +497,7 @@ static int tegra_hsp_mailbox_flush(struct mbox_chan *chan, mbox_chan_txdone(chan, 0); /* Wait until channel is empty */ - if (chan->active_req != NULL) + if (chan->active_req >= 0) continue; return 0; diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h index 80a427c7ca29..67e08a440f5f 100644 --- a/include/linux/mailbox_controller.h +++ b/include/linux/mailbox_controller.h @@ -105,16 +105,25 @@ struct mbox_controller { */ #define MBOX_TX_QUEUE_LEN 20 +/** + * struct mbox_message - Internal representation of a mailbox message + * @data: Data packet + * @tx_complete: Pointer to the transmission completion + */ +struct mbox_message { + void *data; + struct completion *tx_complete; +}; + /** * struct mbox_chan - s/w representation of a communication chan * @mbox: Pointer to the parent/provider of this channel * @txdone_method: Way to detect TXDone chosen by the API * @cl: Pointer to the current owner of this channel - * @tx_complete: Transmission completion - * @active_req: Currently active request hook + * @active_req: Index of the currently active slot in the queue * @msg_count: No. of mssg currently queued * @msg_free: Index of next available mssg slot - * @msg_data: Hook for data packet + * @msg_data: Queue of data packets * @lock: Serialise access to the channel * @con_priv: Hook for controller driver to attach private data */ @@ -122,10 +131,9 @@ struct mbox_chan { struct mbox_controller *mbox; unsigned txdone_method; struct mbox_client *cl; - struct completion tx_complete; - void *active_req; + int active_req; unsigned msg_count, msg_free; - void *msg_data[MBOX_TX_QUEUE_LEN]; + struct mbox_message msg_data[MBOX_TX_QUEUE_LEN]; spinlock_t lock; /* Serialise access to the channel */ void *con_priv; }; -- 2.52.0.239.gd5f0c6e74e-goog

1 day, 10 hours

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