Patch "[PATCH v2 for-4.9 23/40] powerpc/iommu: Stop using @current in mm_iommu_xxx" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    [PATCH v2 for-4.9 23/40] powerpc/iommu: Stop using @current in mm_iommu_xxx

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-iommu-stop-using-current-in-mm_iommu_xxx.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Mar 20 11:41:01 CET 2017
From: alexander.levin@verizon.com
Date: Fri, 17 Mar 2017 00:48:27 +0000
Subject: [PATCH v2 for-4.9 23/40] powerpc/iommu: Stop using @current in mm_iommu_xxx
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>
Message-ID: <20170317004812.26960-23-alexander.levin@verizon.com>

From: Alexey Kardashevskiy <aik@ozlabs.ru>

[ Upstream commit d7baee6901b34c4895eb78efdbf13a49079d7404 ]

This changes mm_iommu_xxx helpers to take mm_struct as a parameter
instead of getting it from @current which in some situations may
not have a valid reference to mm.

This changes helpers to receive @mm and moves all references to @current
to the caller, including checks for !current and !current->mm;
checks in mm_iommu_preregistered() are removed as there is no caller
yet.

This moves the mm_iommu_adjust_locked_vm() call to the caller as
it receives mm_iommu_table_group_mem_t but it needs mm.

This should cause no behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/include/asm/mmu_context.h |   16 ++++++-----
 arch/powerpc/mm/mmu_context_iommu.c    |   46 ++++++++++++---------------------
 drivers/vfio/vfio_iommu_spapr_tce.c    |   14 +++++++---
 3 files changed, 36 insertions(+), 40 deletions(-)

--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -19,16 +19,18 @@ extern void destroy_context(struct mm_st
 struct mm_iommu_table_group_mem_t;
 
 extern int isolate_lru_page(struct page *page);	/* from internal.h */
-extern bool mm_iommu_preregistered(void);
-extern long mm_iommu_get(unsigned long ua, unsigned long entries,
+extern bool mm_iommu_preregistered(struct mm_struct *mm);
+extern long mm_iommu_get(struct mm_struct *mm,
+		unsigned long ua, unsigned long entries,
 		struct mm_iommu_table_group_mem_t **pmem);
-extern long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem);
+extern long mm_iommu_put(struct mm_struct *mm,
+		struct mm_iommu_table_group_mem_t *mem);
 extern void mm_iommu_init(struct mm_struct *mm);
 extern void mm_iommu_cleanup(struct mm_struct *mm);
-extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua,
-		unsigned long size);
-extern struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua,
-		unsigned long entries);
+extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
+		unsigned long ua, unsigned long size);
+extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
+		unsigned long ua, unsigned long entries);
 extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
 		unsigned long ua, unsigned long *hpa);
 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
--- a/arch/powerpc/mm/mmu_context_iommu.c
+++ b/arch/powerpc/mm/mmu_context_iommu.c
@@ -56,7 +56,7 @@ static long mm_iommu_adjust_locked_vm(st
 	}
 
 	pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n",
-			current->pid,
+			current ? current->pid : 0,
 			incr ? '+' : '-',
 			npages << PAGE_SHIFT,
 			mm->locked_vm << PAGE_SHIFT,
@@ -66,12 +66,9 @@ static long mm_iommu_adjust_locked_vm(st
 	return ret;
 }
 
-bool mm_iommu_preregistered(void)
+bool mm_iommu_preregistered(struct mm_struct *mm)
 {
-	if (!current || !current->mm)
-		return false;
-
-	return !list_empty(&current->mm->context.iommu_group_mem_list);
+	return !list_empty(&mm->context.iommu_group_mem_list);
 }
 EXPORT_SYMBOL_GPL(mm_iommu_preregistered);
 
@@ -124,19 +121,16 @@ static int mm_iommu_move_page_from_cma(s
 	return 0;
 }
 
-long mm_iommu_get(unsigned long ua, unsigned long entries,
+long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
 		struct mm_iommu_table_group_mem_t **pmem)
 {
 	struct mm_iommu_table_group_mem_t *mem;
 	long i, j, ret = 0, locked_entries = 0;
 	struct page *page = NULL;
 
-	if (!current || !current->mm)
-		return -ESRCH; /* process exited */
-
 	mutex_lock(&mem_list_mutex);
 
-	list_for_each_entry_rcu(mem, &current->mm->context.iommu_group_mem_list,
+	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,
 			next) {
 		if ((mem->ua == ua) && (mem->entries == entries)) {
 			++mem->used;
@@ -154,7 +148,7 @@ long mm_iommu_get(unsigned long ua, unsi
 
 	}
 
-	ret = mm_iommu_adjust_locked_vm(current->mm, entries, true);
+	ret = mm_iommu_adjust_locked_vm(mm, entries, true);
 	if (ret)
 		goto unlock_exit;
 
@@ -215,11 +209,11 @@ populate:
 	mem->entries = entries;
 	*pmem = mem;
 
-	list_add_rcu(&mem->next, &current->mm->context.iommu_group_mem_list);
+	list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);
 
 unlock_exit:
 	if (locked_entries && ret)
-		mm_iommu_adjust_locked_vm(current->mm, locked_entries, false);
+		mm_iommu_adjust_locked_vm(mm, locked_entries, false);
 
 	mutex_unlock(&mem_list_mutex);
 
@@ -264,17 +258,13 @@ static void mm_iommu_free(struct rcu_hea
 static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem)
 {
 	list_del_rcu(&mem->next);
-	mm_iommu_adjust_locked_vm(current->mm, mem->entries, false);
 	call_rcu(&mem->rcu, mm_iommu_free);
 }
 
-long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem)
+long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
 {
 	long ret = 0;
 
-	if (!current || !current->mm)
-		return -ESRCH; /* process exited */
-
 	mutex_lock(&mem_list_mutex);
 
 	if (mem->used == 0) {
@@ -297,6 +287,8 @@ long mm_iommu_put(struct mm_iommu_table_
 	/* @mapped became 0 so now mappings are disabled, release the region */
 	mm_iommu_release(mem);
 
+	mm_iommu_adjust_locked_vm(mm, mem->entries, false);
+
 unlock_exit:
 	mutex_unlock(&mem_list_mutex);
 
@@ -304,14 +296,12 @@ unlock_exit:
 }
 EXPORT_SYMBOL_GPL(mm_iommu_put);
 
-struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua,
-		unsigned long size)
+struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
+		unsigned long ua, unsigned long size)
 {
 	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;
 
-	list_for_each_entry_rcu(mem,
-			&current->mm->context.iommu_group_mem_list,
-			next) {
+	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
 		if ((mem->ua <= ua) &&
 				(ua + size <= mem->ua +
 				 (mem->entries << PAGE_SHIFT))) {
@@ -324,14 +314,12 @@ struct mm_iommu_table_group_mem_t *mm_io
 }
 EXPORT_SYMBOL_GPL(mm_iommu_lookup);
 
-struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua,
-		unsigned long entries)
+struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
+		unsigned long ua, unsigned long entries)
 {
 	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;
 
-	list_for_each_entry_rcu(mem,
-			&current->mm->context.iommu_group_mem_list,
-			next) {
+	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
 		if ((mem->ua == ua) && (mem->entries == entries)) {
 			ret = mem;
 			break;
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -107,14 +107,17 @@ static long tce_iommu_unregister_pages(s
 {
 	struct mm_iommu_table_group_mem_t *mem;
 
+	if (!current || !current->mm)
+		return -ESRCH; /* process exited */
+
 	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
 		return -EINVAL;
 
-	mem = mm_iommu_find(vaddr, size >> PAGE_SHIFT);
+	mem = mm_iommu_find(current->mm, vaddr, size >> PAGE_SHIFT);
 	if (!mem)
 		return -ENOENT;
 
-	return mm_iommu_put(mem);
+	return mm_iommu_put(current->mm, mem);
 }
 
 static long tce_iommu_register_pages(struct tce_container *container,
@@ -124,11 +127,14 @@ static long tce_iommu_register_pages(str
 	struct mm_iommu_table_group_mem_t *mem = NULL;
 	unsigned long entries = size >> PAGE_SHIFT;
 
+	if (!current || !current->mm)
+		return -ESRCH; /* process exited */
+
 	if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
 			((vaddr + size) < vaddr))
 		return -EINVAL;
 
-	ret = mm_iommu_get(vaddr, entries, &mem);
+	ret = mm_iommu_get(current->mm, vaddr, entries, &mem);
 	if (ret)
 		return ret;
 
@@ -375,7 +381,7 @@ static int tce_iommu_prereg_ua_to_hpa(un
 	long ret = 0;
 	struct mm_iommu_table_group_mem_t *mem;
 
-	mem = mm_iommu_lookup(tce, size);
+	mem = mm_iommu_lookup(current->mm, tce, size);
 	if (!mem)
 		return -EINVAL;
 


Patches currently in stable-queue which might be from gregkh@linuxfoundation.org are

queue-4.9/pci-add-comments-about-rom-bar-updating.patch
queue-4.9/acpi-blacklist-make-dell-latitude-3350-ethernet-work.patch
queue-4.9/s390-zcrypt-introduce-cex6-toleration.patch
queue-4.9/dccp-tcp-fix-routing-redirect-race.patch
queue-4.9/vrf-fix-use-after-free-in-vrf_xmit.patch
queue-4.9/tcp-fix-various-issues-for-sockets-morphing-to-listen-state.patch
queue-4.9/block-allow-write_same-commands-with-the-sg_io-ioctl.patch
queue-4.9/strparser-destroy-workqueue-on-module-exit.patch
queue-4.9/powerpc-mm-fix-build-break-when-cma-n-spapr_tce_iommu-y.patch
queue-4.9/vfio-spapr-postpone-default-window-creation.patch
queue-4.9/vfio-spapr-add-a-helper-to-create-default-dma-window.patch
queue-4.9/pci-do-any-vf-bar-updates-before-enabling-the-bars.patch
queue-4.9/usb-gadget-udc-atmel-remove-memory-leak.patch
queue-4.9/x86-hyperv-handle-unknown-nmis-on-one-cpu-when-unknown_nmi_panic.patch
queue-4.9/net-tunnel-set-inner-protocol-in-network-gro-hooks.patch
queue-4.9/serial-8250_pci-detach-low-level-driver-during-pci-error-recovery.patch
queue-4.9/powerpc-iommu-stop-using-current-in-mm_iommu_xxx.patch
queue-4.9/tun-fix-premature-pollout-notification-on-tun-devices.patch
queue-4.9/vxlan-correctly-validate-vxlan-id-against-vxlan_n_vid.patch
queue-4.9/bpf-fix-regression-on-verifier-pruning-wrt-map-lookups.patch
queue-4.9/tcp-dccp-block-bh-for-syn-processing.patch
queue-4.9/net-sched-act_skbmod-remove-unneeded-rcu_read_unlock-in-tcf_skbmod_dump.patch
queue-4.9/dccp-fix-memory-leak-during-tear-down-of-unsuccessful-connection-request.patch
queue-4.9/xen-do-not-re-use-pirq-number-cached-in-pci-device-msi-msg-data.patch
queue-4.9/vxlan-lock-rcu-on-tx-path.patch
queue-4.9/mlxsw-spectrum_router-avoid-potential-packets-loss.patch
queue-4.9/mpls-do-not-decrement-alive-counter-for-unregister-events.patch
queue-4.9/net-phy-avoid-deadlock-during-phy_error.patch
queue-4.9/uapi-fix-linux-packet_diag.h-userspace-compilation-error.patch
queue-4.9/pci-separate-vf-bar-updates-from-standard-bar-updates.patch
queue-4.9/pci-ignore-bar-updates-on-virtual-functions.patch
queue-4.9/geneve-lock-rcu-on-tx-path.patch
queue-4.9/dccp-fix-use-after-free-in-dccp_feat_activate_values.patch
queue-4.9/l2tp-avoid-use-after-free-caused-by-l2tp_ip_backlog_recv.patch
queue-4.9/powerpc-mm-iommu-vfio-spapr-put-pages-on-vfio-container-shutdown.patch
queue-4.9/bpf-fix-state-equivalence.patch
queue-4.9/scsi-ibmvscsis-clean-up-properly-if-target_submit_cmd-tmr-fails.patch
queue-4.9/drm-nouveau-disp-gp102-fix-cursor-overlay-immediate-channel-indices.patch
queue-4.9/pci-update-bars-using-property-bits-appropriate-for-type.patch
queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-remove-time.patch
queue-4.9/vfio-spapr-postpone-allocation-of-userspace-version-of-tce-table.patch
queue-4.9/ibmveth-calculate-gso_segs-for-large-packets.patch
queue-4.9/net-mlx5e-do-not-reduce-lro-wqe-size-when-not-using-build_skb.patch
queue-4.9/net-sched-actions-decrement-module-reference-count-after-table-flush.patch
queue-4.9/pci-don-t-update-vf-bars-while-vf-memory-space-is-enabled.patch
queue-4.9/ipv4-mask-tos-for-input-route.patch
queue-4.9/net-fix-socket-refcounting-in-skb_complete_tx_timestamp.patch
queue-4.9/net-bridge-allow-ipv6-when-multicast-flood-is-disabled.patch
queue-4.9/net-mlx5e-fix-wrong-cqe-decompression.patch
queue-4.9/net-net_enable_timestamp-can-be-called-from-irq-contexts.patch
queue-4.9/igb-workaround-for-igb-i210-firmware-issue.patch
queue-4.9/drivers-hv-ring_buffer-count-on-wrap-around-mappings-in-get_next_pkt_raw-v2.patch
queue-4.9/drm-nouveau-disp-nv50-specify-ctrl-user-separately-when-constructing-classes.patch
queue-4.9/ipv6-make-ecmp-route-replacement-less-greedy.patch
queue-4.9/ipv6-avoid-write-to-a-possibly-cloned-skb.patch
queue-4.9/pci-remove-pci_resource_bar-and-pci_iov_resource_bar.patch
queue-4.9/mpls-send-route-delete-notifications-when-router-module-is-unloaded.patch
queue-4.9/dmaengine-iota-ioat_alloc_chan_resources-should-not-perform-sleeping-allocations.patch
queue-4.9/scsi-ibmvscsis-return-correct-partition-name-to-client.patch
queue-4.9/vti6-return-gre_key-for-vti6.patch
queue-4.9/vfio-spapr-reference-mm-in-tce_container.patch
queue-4.9/scsi-ibmvscsis-rearrange-functions-for-future-patches.patch
queue-4.9/dccp-unlock-sock-before-calling-sk_free.patch
queue-4.9/bpf-fix-mark_reg_unknown_value-for-spilled-regs-on-map-value-marking.patch
queue-4.9/powerpc-iommu-pass-mm_struct-to-init-cleanup-helpers.patch
queue-4.9/slub-move-synchronize_sched-out-of-slab_mutex-on-shrink.patch
queue-4.9/net-mlx5e-register-unregister-vport-representors-on-interface-attach-detach.patch
queue-4.9/pci-decouple-ioresource_rom_enable-and-pci_rom_address_enable.patch
queue-4.9/net-don-t-call-strlen-on-the-user-buffer-in-packet_bind_spkt.patch
queue-4.9/bpf-detect-identical-ptr_to_map_value_or_null-registers.patch
queue-4.9/scsi-ibmvscsis-issues-from-dan-carpenter-smatch.patch
queue-4.9/vxlan-don-t-allow-overwrite-of-config-src-addr.patch
queue-4.9/acpi-blacklist-add-_rev-quirks-for-dell-precision-5520-and-3520.patch
queue-4.9/bridge-drop-netfilter-fake-rtable-unconditionally.patch
queue-4.9/igb-add-i211-to-i210-phy-workaround.patch
queue-4.9/drm-nouveau-disp-nv50-split-chid-into-chid.ctrl-and-chid.user.patch
queue-4.9/net-fix-socket-refcounting-in-skb_complete_wifi_ack.patch
queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-tpg_enable_store-time.patch
queue-4.9/ipv6-orphan-skbs-in-reassembly-unit.patch
queue-4.9/act_connmark-avoid-crashing-on-malformed-nlattrs-with-null-parms.patch
queue-4.9/uvcvideo-uvc_scan_fallback-for-webcams-with-broken-chain.patch