From 2ca408d9c749c32288bc28725f9f12ba30299e8f Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Mon, 30 Nov 2020 17:30:59 -0500 Subject: fanotify: Fix sys_fanotify_mark() on native x86-32 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") converted native x86-32 which take 64-bit arguments to use the compat handlers to allow conversion to passing args via pt_regs. sys_fanotify_mark() was however missed, as it has a general compat handler. Add a config option that will use the syscall wrapper that takes the split args for native 32-bit. [ bp: Fix typo in Kconfig help text. ] Fixes: 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") Reported-by: Paweł Jasiak Signed-off-by: Brian Gerst Signed-off-by: Borislav Petkov Acked-by: Jan Kara Acked-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20201130223059.101286-1-brgerst@gmail.com --- include/linux/syscalls.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index f3929aff39cf..7688bc983de5 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -251,6 +251,30 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) #endif /* __SYSCALL_DEFINEx */ +/* For split 64-bit arguments on 32-bit architectures */ +#ifdef __LITTLE_ENDIAN +#define SC_ARG64(name) u32, name##_lo, u32, name##_hi +#else +#define SC_ARG64(name) u32, name##_hi, u32, name##_lo +#endif +#define SC_VAL64(type, name) ((type) name##_hi << 32 | name##_lo) + +#ifdef CONFIG_COMPAT +#define SYSCALL32_DEFINE1 COMPAT_SYSCALL_DEFINE1 +#define SYSCALL32_DEFINE2 COMPAT_SYSCALL_DEFINE2 +#define SYSCALL32_DEFINE3 COMPAT_SYSCALL_DEFINE3 +#define SYSCALL32_DEFINE4 COMPAT_SYSCALL_DEFINE4 +#define SYSCALL32_DEFINE5 COMPAT_SYSCALL_DEFINE5 +#define SYSCALL32_DEFINE6 COMPAT_SYSCALL_DEFINE6 +#else +#define SYSCALL32_DEFINE1 SYSCALL_DEFINE1 +#define SYSCALL32_DEFINE2 SYSCALL_DEFINE2 +#define SYSCALL32_DEFINE3 SYSCALL_DEFINE3 +#define SYSCALL32_DEFINE4 SYSCALL_DEFINE4 +#define SYSCALL32_DEFINE5 SYSCALL_DEFINE5 +#define SYSCALL32_DEFINE6 SYSCALL_DEFINE6 +#endif + /* * Called before coming back to user-mode. Returning to user-mode with an * address limit different than USER_DS can allow to overwrite kernel memory. -- cgit v1.2.3 From e89eed02a5f1b864fa5abafc8e8e71bd9fd66d1f Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Tue, 5 Jan 2021 20:53:42 +0100 Subject: kcov, usb: hide in_serving_softirq checks in __usb_hcd_giveback_urb Done opencode in_serving_softirq() checks in in_serving_softirq() to avoid cluttering the code, hide them in kcov helpers instead. Fixes: aee9ddb1d371 ("kcov, usb: only collect coverage from __usb_hcd_giveback_urb in softirq") Signed-off-by: Andrey Konovalov Link: https://lore.kernel.org/r/aeb430c5bb90b0ccdf1ec302c70831c1a47b9c45.1609876340.git.andreyknvl@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 8 +++----- include/linux/kcov.h | 21 +++++++++++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 60886a7464c3..ad5a0f405a75 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1649,14 +1649,12 @@ static void __usb_hcd_giveback_urb(struct urb *urb) urb->status = status; /* * This function can be called in task context inside another remote - * coverage collection section, but KCOV doesn't support that kind of + * coverage collection section, but kcov doesn't support that kind of * recursion yet. Only collect coverage in softirq context for now. */ - if (in_serving_softirq()) - kcov_remote_start_usb((u64)urb->dev->bus->busnum); + kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum); urb->complete(urb); - if (in_serving_softirq()) - kcov_remote_stop(); + kcov_remote_stop_softirq(); usb_anchor_resume_wakeups(anchor); atomic_dec(&urb->use_count); diff --git a/include/linux/kcov.h b/include/linux/kcov.h index a10e84707d82..4e3037dc1204 100644 --- a/include/linux/kcov.h +++ b/include/linux/kcov.h @@ -52,6 +52,25 @@ static inline void kcov_remote_start_usb(u64 id) kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id)); } +/* + * The softirq flavor of kcov_remote_*() functions is introduced as a temporary + * work around for kcov's lack of nested remote coverage sections support in + * task context. Adding suport for nested sections is tracked in: + * https://bugzilla.kernel.org/show_bug.cgi?id=210337 + */ + +static inline void kcov_remote_start_usb_softirq(u64 id) +{ + if (in_serving_softirq()) + kcov_remote_start_usb(id); +} + +static inline void kcov_remote_stop_softirq(void) +{ + if (in_serving_softirq()) + kcov_remote_stop(); +} + #else static inline void kcov_task_init(struct task_struct *t) {} @@ -66,6 +85,8 @@ static inline u64 kcov_common_handle(void) } static inline void kcov_remote_start_common(u64 id) {} static inline void kcov_remote_start_usb(u64 id) {} +static inline void kcov_remote_start_usb_softirq(u64 id) {} +static inline void kcov_remote_stop_softirq(void) {} #endif /* CONFIG_KCOV */ #endif /* _LINUX_KCOV_H */ -- cgit v1.2.3 From 9ad9f45b3b91162b33abfe175ae75ab65718dbf5 Mon Sep 17 00:00:00 2001 From: Liu Yi L Date: Thu, 7 Jan 2021 00:03:55 +0800 Subject: iommu/vt-d: Move intel_iommu info from struct intel_svm to struct intel_svm_dev 'struct intel_svm' is shared by all devices bound to a give process, but records only a single pointer to a 'struct intel_iommu'. Consequently, cache invalidations may only be applied to a single DMAR unit, and are erroneously skipped for the other devices. In preparation for fixing this, rework the structures so that the iommu pointer resides in 'struct intel_svm_dev', allowing 'struct intel_svm' to track them in its device list. Fixes: 1c4f88b7f1f9 ("iommu/vt-d: Shared virtual address in scalable mode") Cc: Lu Baolu Cc: Jacob Pan Cc: Raj Ashok Cc: David Woodhouse Reported-by: Guo Kaijie Reported-by: Xin Zeng Signed-off-by: Guo Kaijie Signed-off-by: Xin Zeng Signed-off-by: Liu Yi L Tested-by: Guo Kaijie Cc: stable@vger.kernel.org # v5.0+ Acked-by: Lu Baolu Link: https://lore.kernel.org/r/1609949037-25291-2-git-send-email-yi.l.liu@intel.com Signed-off-by: Will Deacon --- drivers/iommu/intel/svm.c | 9 +++++---- include/linux/intel-iommu.h | 2 +- 2 files changed, 6 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 9bcedd360235..790ef3497e7e 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -142,7 +142,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d } desc.qw2 = 0; desc.qw3 = 0; - qi_submit_sync(svm->iommu, &desc, 1, 0); + qi_submit_sync(sdev->iommu, &desc, 1, 0); if (sdev->dev_iotlb) { desc.qw0 = QI_DEV_EIOTLB_PASID(svm->pasid) | @@ -166,7 +166,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d } desc.qw2 = 0; desc.qw3 = 0; - qi_submit_sync(svm->iommu, &desc, 1, 0); + qi_submit_sync(sdev->iommu, &desc, 1, 0); } } @@ -211,7 +211,7 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) */ rcu_read_lock(); list_for_each_entry_rcu(sdev, &svm->devs, list) - intel_pasid_tear_down_entry(svm->iommu, sdev->dev, + intel_pasid_tear_down_entry(sdev->iommu, sdev->dev, svm->pasid, true); rcu_read_unlock(); @@ -364,6 +364,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, } sdev->dev = dev; sdev->sid = PCI_DEVID(info->bus, info->devfn); + sdev->iommu = iommu; /* Only count users if device has aux domains */ if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX)) @@ -548,6 +549,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, goto out; } sdev->dev = dev; + sdev->iommu = iommu; ret = intel_iommu_enable_pasid(iommu, dev); if (ret) { @@ -577,7 +579,6 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, kfree(sdev); goto out; } - svm->iommu = iommu; if (pasid_max > intel_pasid_max_id) pasid_max = intel_pasid_max_id; diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index d956987ed032..94522685a0d9 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -758,6 +758,7 @@ struct intel_svm_dev { struct list_head list; struct rcu_head rcu; struct device *dev; + struct intel_iommu *iommu; struct svm_dev_ops *ops; struct iommu_sva sva; u32 pasid; @@ -771,7 +772,6 @@ struct intel_svm { struct mmu_notifier notifier; struct mm_struct *mm; - struct intel_iommu *iommu; unsigned int flags; u32 pasid; int gpasid; /* In case that guest PASID is different from host PASID */ -- cgit v1.2.3 From 18abda7a2d555783d28ea1701f3ec95e96237a86 Mon Sep 17 00:00:00 2001 From: Liu Yi L Date: Thu, 7 Jan 2021 00:03:56 +0800 Subject: iommu/vt-d: Fix general protection fault in aux_detach_device() The aux-domain attach/detach are not tracked, some data structures might be used after free. This causes general protection faults when multiple subdevices are created and assigned to a same guest machine: | general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] SMP NOPTI | RIP: 0010:intel_iommu_aux_detach_device+0x12a/0x1f0 | [...] | Call Trace: | iommu_aux_detach_device+0x24/0x70 | vfio_mdev_detach_domain+0x3b/0x60 | ? vfio_mdev_set_domain+0x50/0x50 | iommu_group_for_each_dev+0x4f/0x80 | vfio_iommu_detach_group.isra.0+0x22/0x30 | vfio_iommu_type1_detach_group.cold+0x71/0x211 | ? find_exported_symbol_in_section+0x4a/0xd0 | ? each_symbol_section+0x28/0x50 | __vfio_group_unset_container+0x4d/0x150 | vfio_group_try_dissolve_container+0x25/0x30 | vfio_group_put_external_user+0x13/0x20 | kvm_vfio_group_put_external_user+0x27/0x40 [kvm] | kvm_vfio_destroy+0x45/0xb0 [kvm] | kvm_put_kvm+0x1bb/0x2e0 [kvm] | kvm_vm_release+0x22/0x30 [kvm] | __fput+0xcc/0x260 | ____fput+0xe/0x10 | task_work_run+0x8f/0xb0 | do_exit+0x358/0xaf0 | ? wake_up_state+0x10/0x20 | ? signal_wake_up_state+0x1a/0x30 | do_group_exit+0x47/0xb0 | __x64_sys_exit_group+0x18/0x20 | do_syscall_64+0x57/0x1d0 | entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix the crash by tracking the subdevices when attaching and detaching aux-domains. Fixes: 67b8e02b5e76 ("iommu/vt-d: Aux-domain specific domain attach/detach") Co-developed-by: Xin Zeng Signed-off-by: Xin Zeng Signed-off-by: Liu Yi L Acked-by: Lu Baolu Link: https://lore.kernel.org/r/1609949037-25291-3-git-send-email-yi.l.liu@intel.com Signed-off-by: Will Deacon --- drivers/iommu/intel/iommu.c | 95 +++++++++++++++++++++++++++++++++------------ include/linux/intel-iommu.h | 16 +++++--- 2 files changed, 82 insertions(+), 29 deletions(-) (limited to 'include/linux') diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 788119c5b021..d7720a836268 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1877,6 +1877,7 @@ static struct dmar_domain *alloc_domain(int flags) domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL; domain->has_iotlb_device = false; INIT_LIST_HEAD(&domain->devices); + INIT_LIST_HEAD(&domain->subdevices); return domain; } @@ -2547,7 +2548,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, info->iommu = iommu; info->pasid_table = NULL; info->auxd_enabled = 0; - INIT_LIST_HEAD(&info->auxiliary_domains); + INIT_LIST_HEAD(&info->subdevices); if (dev && dev_is_pci(dev)) { struct pci_dev *pdev = to_pci_dev(info->dev); @@ -4475,33 +4476,61 @@ is_aux_domain(struct device *dev, struct iommu_domain *domain) domain->type == IOMMU_DOMAIN_UNMANAGED; } -static void auxiliary_link_device(struct dmar_domain *domain, - struct device *dev) +static inline struct subdev_domain_info * +lookup_subdev_info(struct dmar_domain *domain, struct device *dev) +{ + struct subdev_domain_info *sinfo; + + if (!list_empty(&domain->subdevices)) { + list_for_each_entry(sinfo, &domain->subdevices, link_domain) { + if (sinfo->pdev == dev) + return sinfo; + } + } + + return NULL; +} + +static int auxiliary_link_device(struct dmar_domain *domain, + struct device *dev) { struct device_domain_info *info = get_domain_info(dev); + struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev); assert_spin_locked(&device_domain_lock); if (WARN_ON(!info)) - return; + return -EINVAL; + + if (!sinfo) { + sinfo = kzalloc(sizeof(*sinfo), GFP_ATOMIC); + sinfo->domain = domain; + sinfo->pdev = dev; + list_add(&sinfo->link_phys, &info->subdevices); + list_add(&sinfo->link_domain, &domain->subdevices); + } - domain->auxd_refcnt++; - list_add(&domain->auxd, &info->auxiliary_domains); + return ++sinfo->users; } -static void auxiliary_unlink_device(struct dmar_domain *domain, - struct device *dev) +static int auxiliary_unlink_device(struct dmar_domain *domain, + struct device *dev) { struct device_domain_info *info = get_domain_info(dev); + struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev); + int ret; assert_spin_locked(&device_domain_lock); - if (WARN_ON(!info)) - return; + if (WARN_ON(!info || !sinfo || sinfo->users <= 0)) + return -EINVAL; - list_del(&domain->auxd); - domain->auxd_refcnt--; + ret = --sinfo->users; + if (!ret) { + list_del(&sinfo->link_phys); + list_del(&sinfo->link_domain); + kfree(sinfo); + } - if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_put(domain->default_pasid); + return ret; } static int aux_domain_add_dev(struct dmar_domain *domain, @@ -4530,6 +4559,19 @@ static int aux_domain_add_dev(struct dmar_domain *domain, } spin_lock_irqsave(&device_domain_lock, flags); + ret = auxiliary_link_device(domain, dev); + if (ret <= 0) + goto link_failed; + + /* + * Subdevices from the same physical device can be attached to the + * same domain. For such cases, only the first subdevice attachment + * needs to go through the full steps in this function. So if ret > + * 1, just goto out. + */ + if (ret > 1) + goto out; + /* * iommu->lock must be held to attach domain to iommu and setup the * pasid entry for second level translation. @@ -4548,10 +4590,9 @@ static int aux_domain_add_dev(struct dmar_domain *domain, domain->default_pasid); if (ret) goto table_failed; - spin_unlock(&iommu->lock); - - auxiliary_link_device(domain, dev); + spin_unlock(&iommu->lock); +out: spin_unlock_irqrestore(&device_domain_lock, flags); return 0; @@ -4560,8 +4601,10 @@ table_failed: domain_detach_iommu(domain, iommu); attach_failed: spin_unlock(&iommu->lock); + auxiliary_unlink_device(domain, dev); +link_failed: spin_unlock_irqrestore(&device_domain_lock, flags); - if (!domain->auxd_refcnt && domain->default_pasid > 0) + if (list_empty(&domain->subdevices) && domain->default_pasid > 0) ioasid_put(domain->default_pasid); return ret; @@ -4581,14 +4624,18 @@ static void aux_domain_remove_dev(struct dmar_domain *domain, info = get_domain_info(dev); iommu = info->iommu; - auxiliary_unlink_device(domain, dev); - - spin_lock(&iommu->lock); - intel_pasid_tear_down_entry(iommu, dev, domain->default_pasid, false); - domain_detach_iommu(domain, iommu); - spin_unlock(&iommu->lock); + if (!auxiliary_unlink_device(domain, dev)) { + spin_lock(&iommu->lock); + intel_pasid_tear_down_entry(iommu, dev, + domain->default_pasid, false); + domain_detach_iommu(domain, iommu); + spin_unlock(&iommu->lock); + } spin_unlock_irqrestore(&device_domain_lock, flags); + + if (list_empty(&domain->subdevices) && domain->default_pasid > 0) + ioasid_put(domain->default_pasid); } static int prepare_domain_attach_device(struct iommu_domain *domain, diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 94522685a0d9..09c6a0bf3892 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -533,11 +533,10 @@ struct dmar_domain { /* Domain ids per IOMMU. Use u16 since * domain ids are 16 bit wide according * to VT-d spec, section 9.3 */ - unsigned int auxd_refcnt; /* Refcount of auxiliary attaching */ bool has_iotlb_device; struct list_head devices; /* all devices' list */ - struct list_head auxd; /* link to device's auxiliary list */ + struct list_head subdevices; /* all subdevices' list */ struct iova_domain iovad; /* iova's that belong to this domain */ struct dma_pte *pgd; /* virtual address */ @@ -610,14 +609,21 @@ struct intel_iommu { struct dmar_drhd_unit *drhd; }; +/* Per subdevice private data */ +struct subdev_domain_info { + struct list_head link_phys; /* link to phys device siblings */ + struct list_head link_domain; /* link to domain siblings */ + struct device *pdev; /* physical device derived from */ + struct dmar_domain *domain; /* aux-domain */ + int users; /* user count */ +}; + /* PCI domain-device relationship */ struct device_domain_info { struct list_head link; /* link to domain siblings */ struct list_head global; /* link to global list */ struct list_head table; /* link to pasid table */ - struct list_head auxiliary_domains; /* auxiliary domains - * attached to this device - */ + struct list_head subdevices; /* subdevices sibling */ u32 segment; /* PCI segment number */ u8 bus; /* PCI bus number */ u8 devfn; /* PCI devfn number */ -- cgit v1.2.3 From ee61cfd955a64a58ed35cbcfc54068fcbd486945 Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Thu, 31 Dec 2020 19:35:25 +0800 Subject: ACPI: scan: add stub acpi_create_platform_device() for !CONFIG_ACPI It adds a stub acpi_create_platform_device() for !CONFIG_ACPI build, so that caller doesn't have to deal with !CONFIG_ACPI build issue. Reported-by: kernel test robot Signed-off-by: Shawn Guo Signed-off-by: Rafael J. Wysocki --- include/linux/acpi.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 2630c2e953f7..053bf05fb1f7 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -885,6 +885,13 @@ static inline int acpi_device_modalias(struct device *dev, return -ENODEV; } +static inline struct platform_device * +acpi_create_platform_device(struct acpi_device *adev, + struct property_entry *properties) +{ + return NULL; +} + static inline bool acpi_dma_supported(struct acpi_device *adev) { return false; -- cgit v1.2.3 From 29766bcffad03da66892bef82674883e31f78fec Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Sat, 9 Jan 2021 17:18:32 -0500 Subject: net: support kmap_local forced debugging in skb_frag_foreach Skb frags may be backed by highmem and/or compound pages. Highmem pages need kmap_atomic mappings to access. But kmap_atomic maps a single page, not the entire compound page. skb_foreach_page iterates over an skb frag, in one step in the common case, page by page only if kmap_atomic must be called for each page. The decision logic is captured in skb_frag_must_loop. CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP extends kmap from highmem to all pages, to increase code coverage. Extend skb_frag_must_loop to this new condition. Link: https://lore.kernel.org/linux-mm/20210106180132.41dc249d@gandalf.local.home/ Fixes: 0e91a0c6984c ("mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP") Reported-by: Steven Rostedt (VMware) Signed-off-by: Linus Torvalds Signed-off-by: Willem de Bruijn Tested-by: Steven Rostedt (VMware) Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 333bcdc39635..c858adfb5a82 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -366,7 +366,7 @@ static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) static inline bool skb_frag_must_loop(struct page *p) { #if defined(CONFIG_HIGHMEM) - if (PageHighMem(p)) + if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p)) return true; #endif return false; -- cgit v1.2.3 From 97550f6fa59254435d864b92603de3ca4b5a99f8 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Sat, 9 Jan 2021 17:18:33 -0500 Subject: net: compound page support in skb_seq_read skb_seq_read iterates over an skb, returning pointer and length of the next data range with each call. It relies on kmap_atomic to access highmem pages when needed. An skb frag may be backed by a compound page, but kmap_atomic maps only a single page. There are not enough kmap slots to always map all pages concurrently. Instead, if kmap_atomic is needed, iterate over each page. As this increases the number of calls, avoid this unless needed. The necessary condition is captured in skb_frag_must_loop. I tried to make the change as obvious as possible. It should be easy to verify that nothing changes if skb_frag_must_loop returns false. Tested: On an x86 platform with CONFIG_HIGHMEM=y CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y CONFIG_NETFILTER_XT_MATCH_STRING=y Run ip link set dev lo mtu 1500 iptables -A OUTPUT -m string --string 'badstring' -algo bm -j ACCEPT dd if=/dev/urandom of=in bs=1M count=20 nc -l -p 8000 > /dev/null & nc -w 1 -q 0 localhost 8000 < in Signed-off-by: Willem de Bruijn Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 28 +++++++++++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c858adfb5a82..5f60c9e907c9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1203,6 +1203,7 @@ struct skb_seq_state { struct sk_buff *root_skb; struct sk_buff *cur_skb; __u8 *frag_data; + __u32 frag_off; }; void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b6f2b520a9b7..0da035c1e53f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3442,6 +3442,7 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, st->root_skb = st->cur_skb = skb; st->frag_idx = st->stepped_offset = 0; st->frag_data = NULL; + st->frag_off = 0; } EXPORT_SYMBOL(skb_prepare_seq_read); @@ -3496,14 +3497,27 @@ next_skb: st->stepped_offset += skb_headlen(st->cur_skb); while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { + unsigned int pg_idx, pg_off, pg_sz; + frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; - block_limit = skb_frag_size(frag) + st->stepped_offset; + pg_idx = 0; + pg_off = skb_frag_off(frag); + pg_sz = skb_frag_size(frag); + + if (skb_frag_must_loop(skb_frag_page(frag))) { + pg_idx = (pg_off + st->frag_off) >> PAGE_SHIFT; + pg_off = offset_in_page(pg_off + st->frag_off); + pg_sz = min_t(unsigned int, pg_sz - st->frag_off, + PAGE_SIZE - pg_off); + } + + block_limit = pg_sz + st->stepped_offset; if (abs_offset < block_limit) { if (!st->frag_data) - st->frag_data = kmap_atomic(skb_frag_page(frag)); + st->frag_data = kmap_atomic(skb_frag_page(frag) + pg_idx); - *data = (u8 *) st->frag_data + skb_frag_off(frag) + + *data = (u8 *)st->frag_data + pg_off + (abs_offset - st->stepped_offset); return block_limit - abs_offset; @@ -3514,8 +3528,12 @@ next_skb: st->frag_data = NULL; } - st->frag_idx++; - st->stepped_offset += skb_frag_size(frag); + st->stepped_offset += pg_sz; + st->frag_off += pg_sz; + if (st->frag_off == skb_frag_size(frag)) { + st->frag_off = 0; + st->frag_idx++; + } } if (st->frag_data) { -- cgit v1.2.3