It is not possible to register buffers allocated with vmalloc.
Use iov_iter and associated helper functions to manage the page
registration for all type of memories.
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: Arnaud Pouliquen <[email protected]>
---
Update from V2 to V3:
- break lines longer than 80 columns.
Update from V1 to V2:
- replace ITER_SOURCE by ITER_DEST flag in tee_shm_register_user_buf(),
- replace IS_ERR_OR NULL(shm) by IS_ERR(shm) in tee_shm_register_user_buf().
V1:
The support of buffer registration allocated with vmalloc is no more
available since c83900393aa1 ("tee: Remove vmalloc page support").
This patch is an alternative to a revert and resulted from a discussion
with Christopher Hellwig [1].
This patch has been tested using xtest tool in optee qemu environment [2]
and using the series related to the remoteproc tee that should be
proposed soon [3].
References:
[1] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#m8ec683c44fcd9b69c2aee42eaed0793afac9dd18in
[2] https://optee.readthedocs.io/en/latest/building/devices/qemu.html#build-instructions
[3] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#maca0a1fc897aadd54c7deac432e11473fe970d1d
---
drivers/tee/tee_shm.c | 77 ++++++++++++++++++++++++-------------------
1 file changed, 43 insertions(+), 34 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 673cf0359494..fe0a205be7ef 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -22,23 +22,16 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count)
put_page(pages[n]);
}
-static int shm_get_kernel_pages(unsigned long start, size_t page_count,
- struct page **pages)
+static void shm_get_kernel_pages(struct page **pages, size_t page_count)
{
- struct page *page;
size_t n;
- if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
- is_kmap_addr((void *)start)))
- return -EINVAL;
-
- page = virt_to_page((void *)start);
- for (n = 0; n < page_count; n++) {
- pages[n] = page + n;
+ /*
+ * iov_iter_extract_kvec_pages does not get reference on the pages,
+ * get a pin on them.
+ */
+ for (n = 0; n < page_count; n++)
get_page(pages[n]);
- }
-
- return page_count;
}
static void release_registered_pages(struct tee_shm *shm)
@@ -214,13 +207,13 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
static struct tee_shm *
-register_shm_helper(struct tee_context *ctx, unsigned long addr,
- size_t length, u32 flags, int id)
+register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
+ int id)
{
struct tee_device *teedev = ctx->teedev;
struct tee_shm *shm;
- unsigned long start;
- size_t num_pages;
+ unsigned long start, addr;
+ size_t num_pages, length, len, off;
void *ret;
int rc;
@@ -245,31 +238,32 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr,
shm->flags = flags;
shm->ctx = ctx;
shm->id = id;
- addr = untagged_addr(addr);
+ addr = (unsigned long)iter_iov_addr(iter);
+ length = iter_iov_len(iter);
start = rounddown(addr, PAGE_SIZE);
- shm->offset = addr - start;
- shm->size = length;
- num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
+ num_pages = iov_iter_npages(iter, INT_MAX);
+ if (!num_pages) {
+ ret = ERR_PTR(-ENOMEM);
+ goto err_ctx_put;
+ }
+
shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
if (!shm->pages) {
ret = ERR_PTR(-ENOMEM);
goto err_free_shm;
}
- if (flags & TEE_SHM_USER_MAPPED)
- rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
- shm->pages);
- 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);
+ len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
+ &off);
+ if (len != length) {
+ ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
goto err_put_shm_pages;
}
+ shm->offset = off;
+ shm->size = len;
+ shm->num_pages = num_pages;
+
rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
shm->num_pages, start);
if (rc) {
@@ -307,6 +301,8 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
struct tee_device *teedev = ctx->teedev;
struct tee_shm *shm;
+ struct iovec iov;
+ struct iov_iter iter;
void *ret;
int id;
@@ -319,7 +315,10 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
if (id < 0)
return ERR_PTR(id);
- shm = register_shm_helper(ctx, addr, length, flags, id);
+ iov.iov_base = (void __user *)addr;
+ iov.iov_len = length;
+ iov_iter_init(&iter, ITER_DEST, &iov, 1, length);
+ shm = register_shm_helper(ctx, &iter, flags, id);
if (IS_ERR(shm)) {
mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, id);
@@ -351,9 +350,19 @@ 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)
{
+ struct tee_shm *shm;
u32 flags = TEE_SHM_DYNAMIC;
+ struct kvec kvec;
+ struct iov_iter iter;
- return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
+ kvec.iov_base = addr;
+ kvec.iov_len = length;
+ iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
+ shm = register_shm_helper(ctx, &iter, flags, -1);
+ if (!IS_ERR(shm))
+ shm_get_kernel_pages(shm->pages, shm->num_pages);
+
+ return shm;
}
EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
--
2.25.1
Hi Arnaud,
On Tue, 28 Nov 2023 at 13:49, Arnaud Pouliquen
<[email protected]> wrote:
>
> It is not possible to register buffers allocated with vmalloc.
I would rephrase it as:
Currently it's not possible to register kernel buffers with TEE
which are allocated via vmalloc.
> Use iov_iter and associated helper functions to manage the page
> registration for all type of memories.
>
> Suggested-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Arnaud Pouliquen <[email protected]>
> ---
>
> Update from V2 to V3:
> - break lines longer than 80 columns.
>
> Update from V1 to V2:
> - replace ITER_SOURCE by ITER_DEST flag in tee_shm_register_user_buf(),
> - replace IS_ERR_OR NULL(shm) by IS_ERR(shm) in tee_shm_register_user_buf().
>
> V1:
> The support of buffer registration allocated with vmalloc is no more
> available since c83900393aa1 ("tee: Remove vmalloc page support").
>
> This patch is an alternative to a revert and resulted from a discussion
> with Christopher Hellwig [1].
>
> This patch has been tested using xtest tool in optee qemu environment [2]
> and using the series related to the remoteproc tee that should be
> proposed soon [3].
>
> References:
> [1] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#m8ec683c44fcd9b69c2aee42eaed0793afac9dd18in
> [2] https://optee.readthedocs.io/en/latest/building/devices/qemu.html#build-instructions
> [3] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#maca0a1fc897aadd54c7deac432e11473fe970d1d
> ---
> drivers/tee/tee_shm.c | 77 ++++++++++++++++++++++++-------------------
> 1 file changed, 43 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 673cf0359494..fe0a205be7ef 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -22,23 +22,16 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> put_page(pages[n]);
> }
>
> -static int shm_get_kernel_pages(unsigned long start, size_t page_count,
> - struct page **pages)
> +static void shm_get_kernel_pages(struct page **pages, size_t page_count)
> {
> - struct page *page;
> size_t n;
>
> - if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
> - is_kmap_addr((void *)start)))
> - return -EINVAL;
> -
> - page = virt_to_page((void *)start);
> - for (n = 0; n < page_count; n++) {
> - pages[n] = page + n;
> + /*
> + * iov_iter_extract_kvec_pages does not get reference on the pages,
> + * get a pin on them.
> + */
> + for (n = 0; n < page_count; n++)
> get_page(pages[n]);
> - }
> -
> - return page_count;
> }
>
> static void release_registered_pages(struct tee_shm *shm)
> @@ -214,13 +207,13 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
> EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
>
> static struct tee_shm *
> -register_shm_helper(struct tee_context *ctx, unsigned long addr,
> - size_t length, u32 flags, int id)
> +register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
> + int id)
> {
> struct tee_device *teedev = ctx->teedev;
> struct tee_shm *shm;
> - unsigned long start;
> - size_t num_pages;
> + unsigned long start, addr;
> + size_t num_pages, length, len, off;
> void *ret;
> int rc;
>
> @@ -245,31 +238,32 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr,
> shm->flags = flags;
> shm->ctx = ctx;
> shm->id = id;
> - addr = untagged_addr(addr);
> + addr = (unsigned long)iter_iov_addr(iter);
Why did you drop untagged_addr() here?
> + length = iter_iov_len(iter);
> start = rounddown(addr, PAGE_SIZE);
> - shm->offset = addr - start;
> - shm->size = length;
> - num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
> + num_pages = iov_iter_npages(iter, INT_MAX);
> + if (!num_pages) {
> + ret = ERR_PTR(-ENOMEM);
> + goto err_ctx_put;
> + }
> +
> shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
> if (!shm->pages) {
> ret = ERR_PTR(-ENOMEM);
> goto err_free_shm;
> }
>
> - if (flags & TEE_SHM_USER_MAPPED)
> - rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
> - shm->pages);
> - 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);
> + len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
> + &off);
> + if (len != length) {
Any particular reason for this check?
> + ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
> goto err_put_shm_pages;
> }
>
> + shm->offset = off;
> + shm->size = len;
> + shm->num_pages = num_pages;
> +
> rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
> shm->num_pages, start);
> if (rc) {
> @@ -307,6 +301,8 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
> struct tee_device *teedev = ctx->teedev;
> struct tee_shm *shm;
> + struct iovec iov;
> + struct iov_iter iter;
> void *ret;
> int id;
>
> @@ -319,7 +315,10 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> if (id < 0)
> return ERR_PTR(id);
>
> - shm = register_shm_helper(ctx, addr, length, flags, id);
> + iov.iov_base = (void __user *)addr;
> + iov.iov_len = length;
> + iov_iter_init(&iter, ITER_DEST, &iov, 1, length);
We should rather use import_ubuf() instead of this and the above
access_ok() check.
> + shm = register_shm_helper(ctx, &iter, flags, id);
> if (IS_ERR(shm)) {
> mutex_lock(&teedev->mutex);
> idr_remove(&teedev->idr, id);
> @@ -351,9 +350,19 @@ 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)
> {
> + struct tee_shm *shm;
> u32 flags = TEE_SHM_DYNAMIC;
> + struct kvec kvec;
> + struct iov_iter iter;
>
> - return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
> + kvec.iov_base = addr;
> + kvec.iov_len = length;
> + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
> + shm = register_shm_helper(ctx, &iter, flags, -1);
> + if (!IS_ERR(shm))
> + shm_get_kernel_pages(shm->pages, shm->num_pages);
The kernel pages reference should be taken before invoking
teedev->desc->ops->shm_register(). So you should move this to
register_shm_helper() instead. You can use iov_iter_is_kvec() to know
if you have to get a reference or not.
-Sumit
> +
> + return shm;
> }
> EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
>
> --
> 2.25.1
>
Hi Sumit,
On 11/29/23 07:57, Sumit Garg wrote:
> Hi Arnaud,
>
> On Tue, 28 Nov 2023 at 13:49, Arnaud Pouliquen
> <[email protected]> wrote:
>>
>> It is not possible to register buffers allocated with vmalloc.
>
> I would rephrase it as:
>
> Currently it's not possible to register kernel buffers with TEE
> which are allocated via vmalloc.
>
>> Use iov_iter and associated helper functions to manage the page
>> registration for all type of memories.
>>
>> Suggested-by: Christoph Hellwig <[email protected]>
>> Signed-off-by: Arnaud Pouliquen <[email protected]>
>> ---
>>
>> Update from V2 to V3:
>> - break lines longer than 80 columns.
>>
>> Update from V1 to V2:
>> - replace ITER_SOURCE by ITER_DEST flag in tee_shm_register_user_buf(),
>> - replace IS_ERR_OR NULL(shm) by IS_ERR(shm) in tee_shm_register_user_buf().
>>
>> V1:
>> The support of buffer registration allocated with vmalloc is no more
>> available since c83900393aa1 ("tee: Remove vmalloc page support").
>>
>> This patch is an alternative to a revert and resulted from a discussion
>> with Christopher Hellwig [1].
>>
>> This patch has been tested using xtest tool in optee qemu environment [2]
>> and using the series related to the remoteproc tee that should be
>> proposed soon [3].
>>
>> References:
>> [1] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#m8ec683c44fcd9b69c2aee42eaed0793afac9dd18in
>> [2] https://optee.readthedocs.io/en/latest/building/devices/qemu.html#build-instructions
>> [3] https://lore.kernel.org/linux-arm-kernel/[email protected]/T/#maca0a1fc897aadd54c7deac432e11473fe970d1d
>> ---
>> drivers/tee/tee_shm.c | 77 ++++++++++++++++++++++++-------------------
>> 1 file changed, 43 insertions(+), 34 deletions(-)
>>
>> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
>> index 673cf0359494..fe0a205be7ef 100644
>> --- a/drivers/tee/tee_shm.c
>> +++ b/drivers/tee/tee_shm.c
>> @@ -22,23 +22,16 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count)
>> put_page(pages[n]);
>> }
>>
>> -static int shm_get_kernel_pages(unsigned long start, size_t page_count,
>> - struct page **pages)
>> +static void shm_get_kernel_pages(struct page **pages, size_t page_count)
>> {
>> - struct page *page;
>> size_t n;
>>
>> - if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
>> - is_kmap_addr((void *)start)))
>> - return -EINVAL;
>> -
>> - page = virt_to_page((void *)start);
>> - for (n = 0; n < page_count; n++) {
>> - pages[n] = page + n;
>> + /*
>> + * iov_iter_extract_kvec_pages does not get reference on the pages,
>> + * get a pin on them.
>> + */
>> + for (n = 0; n < page_count; n++)
>> get_page(pages[n]);
>> - }
>> -
>> - return page_count;
>> }
>>
>> static void release_registered_pages(struct tee_shm *shm)
>> @@ -214,13 +207,13 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
>> EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
>>
>> static struct tee_shm *
>> -register_shm_helper(struct tee_context *ctx, unsigned long addr,
>> - size_t length, u32 flags, int id)
>> +register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
>> + int id)
>> {
>> struct tee_device *teedev = ctx->teedev;
>> struct tee_shm *shm;
>> - unsigned long start;
>> - size_t num_pages;
>> + unsigned long start, addr;
>> + size_t num_pages, length, len, off;
>> void *ret;
>> int rc;
>>
>> @@ -245,31 +238,32 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr,
>> shm->flags = flags;
>> shm->ctx = ctx;
>> shm->id = id;
>> - addr = untagged_addr(addr);
>> + addr = (unsigned long)iter_iov_addr(iter);
>
> Why did you drop untagged_addr() here?
Right, better too keep it
>
>> + length = iter_iov_len(iter);
>> start = rounddown(addr, PAGE_SIZE);
>> - shm->offset = addr - start;
>> - shm->size = length;
>> - num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
>> + num_pages = iov_iter_npages(iter, INT_MAX);
>> + if (!num_pages) {
>> + ret = ERR_PTR(-ENOMEM);
>> + goto err_ctx_put;
>> + }
>> +
>> shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
>> if (!shm->pages) {
>> ret = ERR_PTR(-ENOMEM);
>> goto err_free_shm;
>> }
>>
>> - if (flags & TEE_SHM_USER_MAPPED)
>> - rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
>> - shm->pages);
>> - 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);
>> + len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
>> + &off);
>> + if (len != length) {
>
> Any particular reason for this check?
Cross-checking to answer to your comment, I just released that
iov_iter_extract_pages returns ssize_t not size_t.
Therefore, I need to change the type of len and replace the check with
(len <= 0).
>
>> + ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
>> goto err_put_shm_pages;
>> }
>>
>> + shm->offset = off;
>> + shm->size = len;
>> + shm->num_pages = num_pages;
>> +
>> rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
>> shm->num_pages, start);
>> if (rc) {
>> @@ -307,6 +301,8 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
>> u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
>> struct tee_device *teedev = ctx->teedev;
>> struct tee_shm *shm;
>> + struct iovec iov;
>> + struct iov_iter iter;
>> void *ret;
>> int id;
>>
>> @@ -319,7 +315,10 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
>> if (id < 0)
>> return ERR_PTR(id);
>>
>> - shm = register_shm_helper(ctx, addr, length, flags, id);
>> + iov.iov_base = (void __user *)addr;
>> + iov.iov_len = length;
>> + iov_iter_init(&iter, ITER_DEST, &iov, 1, length);
>
> We should rather use import_ubuf() instead of this and the above
> access_ok() check.
Thanks for the advice, I will test it.
>
>> + shm = register_shm_helper(ctx, &iter, flags, id);
>> if (IS_ERR(shm)) {
>> mutex_lock(&teedev->mutex);
>> idr_remove(&teedev->idr, id);
>> @@ -351,9 +350,19 @@ 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)
>> {
>> + struct tee_shm *shm;
>> u32 flags = TEE_SHM_DYNAMIC;
>> + struct kvec kvec;
>> + struct iov_iter iter;
>>
>> - return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
>> + kvec.iov_base = addr;
>> + kvec.iov_len = length;
>> + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
>> + shm = register_shm_helper(ctx, &iter, flags, -1);
>> + if (!IS_ERR(shm))
>> + shm_get_kernel_pages(shm->pages, shm->num_pages);
>
> The kernel pages reference should be taken before invoking
> teedev->desc->ops->shm_register(). So you should move this to
> register_shm_helper() instead. You can use iov_iter_is_kvec() to know
> if you have to get a reference or not.
Yes much better
Thanks!
Arnaud
>
> -Sumit
>
>> +
>> + return shm;
>> }
>> EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
>>
>> --
>> 2.25.1
>>