Re: [PATCH v3 11/12] tee: replace tee_shm_register()

From: Jens Wiklander
Date: Thu Jan 27 2022 - 08:00:56 EST

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In reply to: Sumit Garg: "Re: [PATCH v3 11/12] tee: replace tee_shm_register()"
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On Thu, Jan 27, 2022 at 8:00 AM Sumit Garg <sumit.garg@xxxxxxxxxx> wrote:
>
> On Tue, 25 Jan 2022 at 21:59, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
> >
> > tee_shm_register() is replaced by the previously introduced functions
> > tee_shm_register_user_buf() and tee_shm_register_kernel_buf().
> >
> > Since there are not external callers left we can remove tee_shm_register()
> > and refactor the remains.
> >
> > Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> > ---
> > drivers/tee/tee_shm.c | 156 +++++++++++++++++++++++-----------------
> > include/linux/tee_drv.h | 11 ---
> > 2 files changed, 90 insertions(+), 77 deletions(-)
> >
>
> Other than minor comment below, feel free to add:
>
> Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
>
> > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > index 0b6f7aabbf88..c3a29022ec72 100644
> > --- a/drivers/tee/tee_shm.c
> > +++ b/drivers/tee/tee_shm.c
> > @@ -12,17 +12,43 @@
> > #include <linux/uio.h>
> > #include "tee_private.h"
> >
> > +static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > +{
> > + size_t n;
> > +
> > + for (n = 0; n < page_count; n++)
> > + put_page(pages[n]);
> > +}
> > +
> > +static int shm_get_kernel_pages(unsigned long start, size_t page_count,
> > + struct page **pages)
> > +{
> > + struct kvec *kiov;
> > + size_t n;
> > + int rc;
> > +
> > + kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
> > + if (!kiov)
> > + return -ENOMEM;
> > +
> > + for (n = 0; n < page_count; n++) {
> > + kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
> > + kiov[n].iov_len = PAGE_SIZE;
> > + }
> > +
> > + rc = get_kernel_pages(kiov, page_count, 0, pages);
> > + kfree(kiov);
> > +
> > + return rc;
> > +}
> > +
> > static void release_registered_pages(struct tee_shm *shm)
> > {
> > if (shm->pages) {
> > - if (shm->flags & TEE_SHM_USER_MAPPED) {
> > + if (shm->flags & TEE_SHM_USER_MAPPED)
> > unpin_user_pages(shm->pages, shm->num_pages);
> > - } else {
> > - size_t n;
> > -
> > - for (n = 0; n < shm->num_pages; n++)
> > - put_page(shm->pages[n]);
> > - }
> > + else
> > + shm_put_kernel_pages(shm->pages, shm->num_pages);
> >
> > kfree(shm->pages);
> > }
> > @@ -189,28 +215,24 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
> > }
> > EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
> >
> > -struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > - size_t length, u32 flags)
> > +static struct tee_shm *
> > +register_shm_helper(struct tee_context *ctx, unsigned long addr,
> > + size_t length, u32 flags, int id)
> > {
> > struct tee_device *teedev = ctx->teedev;
> > - const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
> > - const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
> > struct tee_shm *shm;
> > + unsigned long start;
> > + int num_pages;
>
> s/int/size_t/

I'll fix.

Thanks,
Jens

>
> -Sumit
>
> > void *ret;
> > int rc;
> > - int num_pages;
> > - unsigned long start;
> > -
> > - if (flags != req_user_flags && flags != req_kernel_flags)
> > - return ERR_PTR(-ENOTSUPP);
> >
> > if (!tee_device_get(teedev))
> > return ERR_PTR(-EINVAL);
> >
> > if (!teedev->desc->ops->shm_register ||
> > !teedev->desc->ops->shm_unregister) {
> > - tee_device_put(teedev);
> > - return ERR_PTR(-ENOTSUPP);
> > + ret = ERR_PTR(-ENOTSUPP);
> > + goto err_dev_put;
> > }
> >
> > teedev_ctx_get(ctx);
> > @@ -218,13 +240,13 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > shm = kzalloc(sizeof(*shm), GFP_KERNEL);
> > if (!shm) {
> > ret = ERR_PTR(-ENOMEM);
> > - goto err;
> > + goto err_ctx_put;
> > }
> >
> > refcount_set(&shm->refcount, 1);
> > - shm->flags = flags | TEE_SHM_REGISTER;
> > + shm->flags = flags;
> > shm->ctx = ctx;
> > - shm->id = -1;
> > + shm->id = id;
> > addr = untagged_addr(addr);
> > start = rounddown(addr, PAGE_SIZE);
> > shm->offset = addr - start;
> > @@ -233,71 +255,45 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
> > if (!shm->pages) {
> > ret = ERR_PTR(-ENOMEM);
> > - goto err;
> > + goto err_free_shm;
> > }
> >
> > - if (flags & TEE_SHM_USER_MAPPED) {
> > + if (flags & TEE_SHM_USER_MAPPED)
> > rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
> > shm->pages);
> > - } else {
> > - struct kvec *kiov;
> > - int i;
> > -
> > - kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
> > - if (!kiov) {
> > - ret = ERR_PTR(-ENOMEM);
> > - goto err;
> > - }
> > -
> > - for (i = 0; i < num_pages; i++) {
> > - kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
> > - kiov[i].iov_len = PAGE_SIZE;
> > - }
> > -
> > - rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
> > - kfree(kiov);
> > - }
> > + else
> > + rc = shm_get_kernel_pages(start, num_pages, shm->pages);
> > if (rc > 0)
> > shm->num_pages = rc;
> > if (rc != num_pages) {
> > if (rc >= 0)
> > rc = -ENOMEM;
> > ret = ERR_PTR(rc);
> > - goto err;
> > - }
> > -
> > - mutex_lock(&teedev->mutex);
> > - shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
> > - mutex_unlock(&teedev->mutex);
> > -
> > - if (shm->id < 0) {
> > - ret = ERR_PTR(shm->id);
> > - goto err;
> > + goto err_put_shm_pages;
> > }
> >
> > rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
> > shm->num_pages, start);
> > if (rc) {
> > ret = ERR_PTR(rc);
> > - goto err;
> > + goto err_put_shm_pages;
> > }
> >
> > return shm;
> > -err:
> > - if (shm) {
> > - if (shm->id >= 0) {
> > - mutex_lock(&teedev->mutex);
> > - idr_remove(&teedev->idr, shm->id);
> > - mutex_unlock(&teedev->mutex);
> > - }
> > - release_registered_pages(shm);
> > - }
> > +err_put_shm_pages:
> > + if (flags & TEE_SHM_USER_MAPPED)
> > + unpin_user_pages(shm->pages, shm->num_pages);
> > + else
> > + shm_put_kernel_pages(shm->pages, shm->num_pages);
> > + kfree(shm->pages);
> > +err_free_shm:
> > kfree(shm);
> > +err_ctx_put:
> > teedev_ctx_put(ctx);
> > +err_dev_put:
> > tee_device_put(teedev);
> > return ret;
> > }
> > -EXPORT_SYMBOL_GPL(tee_shm_register);
> >
> > /**
> > * tee_shm_register_user_buf() - Register a userspace shared memory buffer
> > @@ -310,8 +306,35 @@ EXPORT_SYMBOL_GPL(tee_shm_register);
> > struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> > unsigned long addr, size_t length)
> > {
> > - return tee_shm_register(ctx, addr, length,
> > - TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
> > + u32 flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED | TEE_SHM_REGISTER;
> > + struct tee_device *teedev = ctx->teedev;
> > + struct tee_shm *shm;
> > + void *ret;
> > + int id;
> > +
> > + mutex_lock(&teedev->mutex);
> > + id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
> > + mutex_unlock(&teedev->mutex);
> > + if (id < 0)
> > + return ERR_PTR(id);
> > +
> > + shm = register_shm_helper(ctx, addr, length, flags, id);
> > + if (IS_ERR(shm)) {
> > + mutex_lock(&teedev->mutex);
> > + idr_remove(&teedev->idr, id);
> > + mutex_unlock(&teedev->mutex);
> > + return shm;
> > + }
> > +
> > + mutex_lock(&teedev->mutex);
> > + ret = idr_replace(&teedev->idr, shm, id);
> > + mutex_unlock(&teedev->mutex);
> > + if (IS_ERR(ret)) {
> > + tee_shm_free(shm);
> > + return ret;
> > + }
> > +
> > + return shm;
> > }
> >
> > /**
> > @@ -327,8 +350,9 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> > void *addr, size_t length)
> > {
> > - return tee_shm_register(ctx, (unsigned long)addr, length,
> > - TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED);
> > + u32 flags = TEE_SHM_REGISTER | TEE_SHM_KERNEL_MAPPED;
> > +
> > + return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
> > }
> > EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
> >
> > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > index c9d2cc32a5ed..a3b663ef0694 100644
> > --- a/include/linux/tee_drv.h
> > +++ b/include/linux/tee_drv.h
> > @@ -276,17 +276,6 @@ void *tee_get_drvdata(struct tee_device *teedev);
> > struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
> > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
> >
> > -/**
> > - * tee_shm_register() - Register shared memory buffer
> > - * @ctx: Context that registers the shared memory
> > - * @addr: Address is userspace of the shared buffer
> > - * @length: Length of the shared buffer
> > - * @flags: Flags setting properties for the requested shared memory.
> > - *
> > - * @returns a pointer to 'struct tee_shm'
> > - */
> > -struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > - size_t length, u32 flags);
> > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> > void *addr, size_t length);
> >
> > --
> > 2.31.1
> >

Next message: Hans de Goede: "Re: acpi_get_devices() crash when acpi_disabled==true (was [PATCH v2] drm/privacy-screen: honor acpi=off in detect_thinkpad_privacy_screen)"
Previous message: Neil Armstrong: "Re: [PATCH] arm64: dts: meson-sm1: fix wrong GPIO domain for GPIOE_2"
In reply to: Sumit Garg: "Re: [PATCH v3 11/12] tee: replace tee_shm_register()"
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