net/xdp/xdp_umem.c - kernel/msm-4.19 - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /* XDP user-space packet buffer
  * Copyright(c) 2018 Intel Corporation.
  */

 #include <linux/init.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <linux/bpf.h>
 #include <linux/mm.h>
 #include <linux/netdevice.h>
 #include <linux/rtnetlink.h>

 #include "xdp_umem.h"
 #include "xsk_queue.h"

 #define XDP_UMEM_MIN_CHUNK_SIZE 2048

 void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&umem->xsk_list_lock, flags);
 	list_add_rcu(&xs->list, &umem->xsk_list);
 	spin_unlock_irqrestore(&umem->xsk_list_lock, flags);
 }

 void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
 {
 	unsigned long flags;

 	if (xs->dev) {
 		spin_lock_irqsave(&umem->xsk_list_lock, flags);
 		list_del_rcu(&xs->list);
 		spin_unlock_irqrestore(&umem->xsk_list_lock, flags);

 		if (umem->zc)
 			synchronize_net();
 	}
 }

 int xdp_umem_query(struct net_device *dev, u16 queue_id)
 {
 	struct netdev_bpf bpf;

 	ASSERT_RTNL();

 	memset(&bpf, 0, sizeof(bpf));
 	bpf.command = XDP_QUERY_XSK_UMEM;
 	bpf.xsk.queue_id = queue_id;

 	if (!dev->netdev_ops->ndo_bpf)
 		return 0;
 	return dev->netdev_ops->ndo_bpf(dev, &bpf) ?: !!bpf.xsk.umem;
 }

 int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
 			u32 queue_id, u16 flags)
 {
 	bool force_zc, force_copy;
 	struct netdev_bpf bpf;
 	int err;

 	force_zc = flags & XDP_ZEROCOPY;
 	force_copy = flags & XDP_COPY;

 	if (force_zc && force_copy)
 		return -EINVAL;

 	if (force_copy)
 		return 0;

 	if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_async_xmit)
 		return force_zc ? -ENOTSUPP : 0; /* fail or fallback */

 	bpf.command = XDP_QUERY_XSK_UMEM;

 	rtnl_lock();
 	err = xdp_umem_query(dev, queue_id);
 	if (err) {
 		err = err < 0 ? -ENOTSUPP : -EBUSY;
 		goto err_rtnl_unlock;
 	}

 	bpf.command = XDP_SETUP_XSK_UMEM;
 	bpf.xsk.umem = umem;
 	bpf.xsk.queue_id = queue_id;

 	err = dev->netdev_ops->ndo_bpf(dev, &bpf);
 	if (err)
 		goto err_rtnl_unlock;
 	rtnl_unlock();

 	dev_hold(dev);
 	umem->dev = dev;
 	umem->queue_id = queue_id;
 	umem->zc = true;
 	return 0;

 err_rtnl_unlock:
 	rtnl_unlock();
 	return force_zc ? err : 0; /* fail or fallback */
 }

 static void xdp_umem_clear_dev(struct xdp_umem *umem)
 {
 	struct netdev_bpf bpf;
 	int err;

 	if (umem->dev) {
 		bpf.command = XDP_SETUP_XSK_UMEM;
 		bpf.xsk.umem = NULL;
 		bpf.xsk.queue_id = umem->queue_id;

 		rtnl_lock();
 		err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
 		rtnl_unlock();

 		if (err)
 			WARN(1, "failed to disable umem!\n");

 		dev_put(umem->dev);
 		umem->dev = NULL;
 	}
 }

 static void xdp_umem_unpin_pages(struct xdp_umem *umem)
 {
 	unsigned int i;

 	for (i = 0; i < umem->npgs; i++) {
 		struct page *page = umem->pgs[i];

 		set_page_dirty_lock(page);
 		put_page(page);
 	}

 	kfree(umem->pgs);
 	umem->pgs = NULL;
 }

 static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
 {
 	if (umem->user) {
 		atomic_long_sub(umem->npgs, &umem->user->locked_vm);
 		free_uid(umem->user);
 	}
 }

 static void xdp_umem_release(struct xdp_umem *umem)
 {
 	struct task_struct *task;
 	struct mm_struct *mm;

 	xdp_umem_clear_dev(umem);

 	if (umem->fq) {
 		xskq_destroy(umem->fq);
 		umem->fq = NULL;
 	}

 	if (umem->cq) {
 		xskq_destroy(umem->cq);
 		umem->cq = NULL;
 	}

 	xdp_umem_unpin_pages(umem);

 	task = get_pid_task(umem->pid, PIDTYPE_PID);
 	put_pid(umem->pid);
 	if (!task)
 		goto out;
 	mm = get_task_mm(task);
 	put_task_struct(task);
 	if (!mm)
 		goto out;

 	mmput(mm);
 	kfree(umem->pages);
 	umem->pages = NULL;

 	xdp_umem_unaccount_pages(umem);
 out:
 	kfree(umem);
 }

 static void xdp_umem_release_deferred(struct work_struct *work)
 {
 	struct xdp_umem *umem = container_of(work, struct xdp_umem, work);

 	xdp_umem_release(umem);
 }

 void xdp_get_umem(struct xdp_umem *umem)
 {
 	refcount_inc(&umem->users);
 }

 void xdp_put_umem(struct xdp_umem *umem)
 {
 	if (!umem)
 		return;

 	if (refcount_dec_and_test(&umem->users)) {
 		INIT_WORK(&umem->work, xdp_umem_release_deferred);
 		schedule_work(&umem->work);
 	}
 }

 static int xdp_umem_pin_pages(struct xdp_umem *umem)
 {
 	unsigned int gup_flags = FOLL_WRITE;
 	long npgs;
 	int err;

 	umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs),
 			    GFP_KERNEL | __GFP_NOWARN);
 	if (!umem->pgs)
 		return -ENOMEM;

 	down_write(&current->mm->mmap_sem);
 	npgs = get_user_pages(umem->address, umem->npgs,
 			      gup_flags, &umem->pgs[0], NULL);
 	up_write(&current->mm->mmap_sem);

 	if (npgs != umem->npgs) {
 		if (npgs >= 0) {
 			umem->npgs = npgs;
 			err = -ENOMEM;
 			goto out_pin;
 		}
 		err = npgs;
 		goto out_pgs;
 	}
 	return 0;

 out_pin:
 	xdp_umem_unpin_pages(umem);
 out_pgs:
 	kfree(umem->pgs);
 	umem->pgs = NULL;
 	return err;
 }

 static int xdp_umem_account_pages(struct xdp_umem *umem)
 {
 	unsigned long lock_limit, new_npgs, old_npgs;

 	if (capable(CAP_IPC_LOCK))
 		return 0;

 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 	umem->user = get_uid(current_user());

 	do {
 		old_npgs = atomic_long_read(&umem->user->locked_vm);
 		new_npgs = old_npgs + umem->npgs;
 		if (new_npgs > lock_limit) {
 			free_uid(umem->user);
 			umem->user = NULL;
 			return -ENOBUFS;
 		}
 	} while (atomic_long_cmpxchg(&umem->user->locked_vm, old_npgs,
 				     new_npgs) != old_npgs);
 	return 0;
 }

 static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 {
 	u32 chunk_size = mr->chunk_size, headroom = mr->headroom;
 	unsigned int chunks, chunks_per_page;
 	u64 addr = mr->addr, size = mr->len;
 	int size_chk, err, i;

 	if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) {
 		/* Strictly speaking we could support this, if:
 		 * - huge pages, or*
 		 * - using an IOMMU, or
 		 * - making sure the memory area is consecutive
 		 * but for now, we simply say "computer says no".
 		 */
 		return -EINVAL;
 	}

 	if (!is_power_of_2(chunk_size))
 		return -EINVAL;

 	if (!PAGE_ALIGNED(addr)) {
 		/* Memory area has to be page size aligned. For
 		 * simplicity, this might change.
 		 */
 		return -EINVAL;
 	}

 	if ((addr + size) < addr)
 		return -EINVAL;

 	chunks = (unsigned int)div_u64(size, chunk_size);
 	if (chunks == 0)
 		return -EINVAL;

 	chunks_per_page = PAGE_SIZE / chunk_size;
 	if (chunks < chunks_per_page || chunks % chunks_per_page)
 		return -EINVAL;

 	headroom = ALIGN(headroom, 64);

 	size_chk = chunk_size - headroom - XDP_PACKET_HEADROOM;
 	if (size_chk < 0)
 		return -EINVAL;

 	umem->pid = get_task_pid(current, PIDTYPE_PID);
 	umem->address = (unsigned long)addr;
 	umem->props.chunk_mask = ~((u64)chunk_size - 1);
 	umem->props.size = size;
 	umem->headroom = headroom;
 	umem->chunk_size_nohr = chunk_size - headroom;
 	umem->npgs = size / PAGE_SIZE;
 	umem->pgs = NULL;
 	umem->user = NULL;
 	INIT_LIST_HEAD(&umem->xsk_list);
 	spin_lock_init(&umem->xsk_list_lock);

 	refcount_set(&umem->users, 1);

 	err = xdp_umem_account_pages(umem);
 	if (err)
 		goto out;

 	err = xdp_umem_pin_pages(umem);
 	if (err)
 		goto out_account;

 	umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL);
 	if (!umem->pages) {
 		err = -ENOMEM;
 		goto out_account;
 	}

 	for (i = 0; i < umem->npgs; i++)
 		umem->pages[i].addr = page_address(umem->pgs[i]);

 	return 0;

 out_account:
 	xdp_umem_unaccount_pages(umem);
 out:
 	put_pid(umem->pid);
 	return err;
 }

 struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr)
 {
 	struct xdp_umem *umem;
 	int err;

 	umem = kzalloc(sizeof(*umem), GFP_KERNEL);
 	if (!umem)
 		return ERR_PTR(-ENOMEM);

 	err = xdp_umem_reg(umem, mr);
 	if (err) {
 		kfree(umem);
 		return ERR_PTR(err);
 	}

 	return umem;
 }

 bool xdp_umem_validate_queues(struct xdp_umem *umem)
 {
 	return umem->fq && umem->cq;
 }
	// SPDX-License-Identifier: GPL-2.0
	/* XDP user-space packet buffer
	* Copyright(c) 2018 Intel Corporation.
	*/

	#include <linux/init.h>
	#include <linux/sched/mm.h>
	#include <linux/sched/signal.h>
	#include <linux/sched/task.h>
	#include <linux/uaccess.h>
	#include <linux/slab.h>
	#include <linux/bpf.h>
	#include <linux/mm.h>
	#include <linux/netdevice.h>
	#include <linux/rtnetlink.h>

	#include "xdp_umem.h"
	#include "xsk_queue.h"

	#define XDP_UMEM_MIN_CHUNK_SIZE 2048

	void xdp_add_sk_umem(struct xdp_umem umem, struct xdp_sock xs)
	{
	unsigned long flags;

	spin_lock_irqsave(&umem->xsk_list_lock, flags);
	list_add_rcu(&xs->list, &umem->xsk_list);
	spin_unlock_irqrestore(&umem->xsk_list_lock, flags);
	}

	void xdp_del_sk_umem(struct xdp_umem umem, struct xdp_sock xs)
	{
	unsigned long flags;

	if (xs->dev) {
	spin_lock_irqsave(&umem->xsk_list_lock, flags);
	list_del_rcu(&xs->list);
	spin_unlock_irqrestore(&umem->xsk_list_lock, flags);

	if (umem->zc)
	synchronize_net();
	}
	}

	int xdp_umem_query(struct net_device *dev, u16 queue_id)
	{
	struct netdev_bpf bpf;

	ASSERT_RTNL();

	memset(&bpf, 0, sizeof(bpf));
	bpf.command = XDP_QUERY_XSK_UMEM;
	bpf.xsk.queue_id = queue_id;

	if (!dev->netdev_ops->ndo_bpf)
	return 0;
	return dev->netdev_ops->ndo_bpf(dev, &bpf) ?: !!bpf.xsk.umem;
	}

	int xdp_umem_assign_dev(struct xdp_umem umem, struct net_device dev,
	u32 queue_id, u16 flags)
	{
	bool force_zc, force_copy;
	struct netdev_bpf bpf;
	int err;

	force_zc = flags & XDP_ZEROCOPY;
	force_copy = flags & XDP_COPY;

	if (force_zc && force_copy)
	return -EINVAL;

	if (force_copy)
	return 0;

	if (!dev->netdev_ops->ndo_bpf \|\| !dev->netdev_ops->ndo_xsk_async_xmit)
	return force_zc ? -ENOTSUPP : 0; /* fail or fallback */

	bpf.command = XDP_QUERY_XSK_UMEM;

	rtnl_lock();
	err = xdp_umem_query(dev, queue_id);
	if (err) {
	err = err < 0 ? -ENOTSUPP : -EBUSY;
	goto err_rtnl_unlock;
	}

	bpf.command = XDP_SETUP_XSK_UMEM;
	bpf.xsk.umem = umem;
	bpf.xsk.queue_id = queue_id;

	err = dev->netdev_ops->ndo_bpf(dev, &bpf);
	if (err)
	goto err_rtnl_unlock;
	rtnl_unlock();

	dev_hold(dev);
	umem->dev = dev;
	umem->queue_id = queue_id;
	umem->zc = true;
	return 0;

	err_rtnl_unlock:
	rtnl_unlock();
	return force_zc ? err : 0; /* fail or fallback */
	}

	static void xdp_umem_clear_dev(struct xdp_umem *umem)
	{
	struct netdev_bpf bpf;
	int err;

	if (umem->dev) {
	bpf.command = XDP_SETUP_XSK_UMEM;
	bpf.xsk.umem = NULL;
	bpf.xsk.queue_id = umem->queue_id;

	rtnl_lock();
	err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
	rtnl_unlock();

	if (err)
	WARN(1, "failed to disable umem!\n");

	dev_put(umem->dev);
	umem->dev = NULL;
	}
	}

	static void xdp_umem_unpin_pages(struct xdp_umem *umem)
	{
	unsigned int i;

	for (i = 0; i < umem->npgs; i++) {
	struct page *page = umem->pgs[i];

	set_page_dirty_lock(page);
	put_page(page);
	}

	kfree(umem->pgs);
	umem->pgs = NULL;
	}

	static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
	{
	if (umem->user) {
	atomic_long_sub(umem->npgs, &umem->user->locked_vm);
	free_uid(umem->user);
	}
	}

	static void xdp_umem_release(struct xdp_umem *umem)
	{
	struct task_struct *task;
	struct mm_struct *mm;

	xdp_umem_clear_dev(umem);

	if (umem->fq) {
	xskq_destroy(umem->fq);
	umem->fq = NULL;
	}

	if (umem->cq) {
	xskq_destroy(umem->cq);
	umem->cq = NULL;
	}

	xdp_umem_unpin_pages(umem);

	task = get_pid_task(umem->pid, PIDTYPE_PID);
	put_pid(umem->pid);
	if (!task)
	goto out;
	mm = get_task_mm(task);
	put_task_struct(task);
	if (!mm)
	goto out;

	mmput(mm);
	kfree(umem->pages);
	umem->pages = NULL;

	xdp_umem_unaccount_pages(umem);
	out:
	kfree(umem);
	}

	static void xdp_umem_release_deferred(struct work_struct *work)
	{
	struct xdp_umem *umem = container_of(work, struct xdp_umem, work);

	xdp_umem_release(umem);
	}

	void xdp_get_umem(struct xdp_umem *umem)
	{
	refcount_inc(&umem->users);
	}

	void xdp_put_umem(struct xdp_umem *umem)
	{
	if (!umem)
	return;

	if (refcount_dec_and_test(&umem->users)) {
	INIT_WORK(&umem->work, xdp_umem_release_deferred);
	schedule_work(&umem->work);
	}
	}

	static int xdp_umem_pin_pages(struct xdp_umem *umem)
	{
	unsigned int gup_flags = FOLL_WRITE;
	long npgs;
	int err;

	umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs),
	GFP_KERNEL \| __GFP_NOWARN);
	if (!umem->pgs)
	return -ENOMEM;

	down_write(&current->mm->mmap_sem);
	npgs = get_user_pages(umem->address, umem->npgs,
	gup_flags, &umem->pgs[0], NULL);
	up_write(&current->mm->mmap_sem);

	if (npgs != umem->npgs) {
	if (npgs >= 0) {
	umem->npgs = npgs;
	err = -ENOMEM;
	goto out_pin;
	}
	err = npgs;
	goto out_pgs;
	}
	return 0;

	out_pin:
	xdp_umem_unpin_pages(umem);
	out_pgs:
	kfree(umem->pgs);
	umem->pgs = NULL;
	return err;
	}

	static int xdp_umem_account_pages(struct xdp_umem *umem)
	{
	unsigned long lock_limit, new_npgs, old_npgs;

	if (capable(CAP_IPC_LOCK))
	return 0;

	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
	umem->user = get_uid(current_user());

	do {
	old_npgs = atomic_long_read(&umem->user->locked_vm);
	new_npgs = old_npgs + umem->npgs;
	if (new_npgs > lock_limit) {
	free_uid(umem->user);
	umem->user = NULL;
	return -ENOBUFS;
	}
	} while (atomic_long_cmpxchg(&umem->user->locked_vm, old_npgs,
	new_npgs) != old_npgs);
	return 0;
	}

	static int xdp_umem_reg(struct xdp_umem umem, struct xdp_umem_reg mr)
	{
	u32 chunk_size = mr->chunk_size, headroom = mr->headroom;
	unsigned int chunks, chunks_per_page;
	u64 addr = mr->addr, size = mr->len;
	int size_chk, err, i;

	if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE \|\| chunk_size > PAGE_SIZE) {
	/* Strictly speaking we could support this, if:
	* - huge pages, or*
	* - using an IOMMU, or
	* - making sure the memory area is consecutive
	* but for now, we simply say "computer says no".
	*/
	return -EINVAL;
	}

	if (!is_power_of_2(chunk_size))
	return -EINVAL;

	if (!PAGE_ALIGNED(addr)) {
	/* Memory area has to be page size aligned. For
	* simplicity, this might change.
	*/
	return -EINVAL;
	}

	if ((addr + size) < addr)
	return -EINVAL;

	chunks = (unsigned int)div_u64(size, chunk_size);
	if (chunks == 0)
	return -EINVAL;

	chunks_per_page = PAGE_SIZE / chunk_size;
	if (chunks < chunks_per_page \|\| chunks % chunks_per_page)
	return -EINVAL;

	headroom = ALIGN(headroom, 64);

	size_chk = chunk_size - headroom - XDP_PACKET_HEADROOM;
	if (size_chk < 0)
	return -EINVAL;

	umem->pid = get_task_pid(current, PIDTYPE_PID);
	umem->address = (unsigned long)addr;
	umem->props.chunk_mask = ~((u64)chunk_size - 1);
	umem->props.size = size;
	umem->headroom = headroom;
	umem->chunk_size_nohr = chunk_size - headroom;
	umem->npgs = size / PAGE_SIZE;
	umem->pgs = NULL;
	umem->user = NULL;
	INIT_LIST_HEAD(&umem->xsk_list);
	spin_lock_init(&umem->xsk_list_lock);

	refcount_set(&umem->users, 1);

	err = xdp_umem_account_pages(umem);
	if (err)
	goto out;

	err = xdp_umem_pin_pages(umem);
	if (err)
	goto out_account;

	umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL);
	if (!umem->pages) {
	err = -ENOMEM;
	goto out_account;
	}

	for (i = 0; i < umem->npgs; i++)
	umem->pages[i].addr = page_address(umem->pgs[i]);

	return 0;

	out_account:
	xdp_umem_unaccount_pages(umem);
	out:
	put_pid(umem->pid);
	return err;
	}

	struct xdp_umem xdp_umem_create(struct xdp_umem_reg mr)
	{
	struct xdp_umem *umem;
	int err;

	umem = kzalloc(sizeof(*umem), GFP_KERNEL);
	if (!umem)
	return ERR_PTR(-ENOMEM);

	err = xdp_umem_reg(umem, mr);
	if (err) {
	kfree(umem);
	return ERR_PTR(err);
	}

	return umem;
	}

	bool xdp_umem_validate_queues(struct xdp_umem *umem)
	{
	return umem->fq && umem->cq;
	}