* [PATCH] USB: usbfs: check cpu address range before remap
@ 2019-09-04 8:17 ` Nagarjuna Kristam
0 siblings, 0 replies; 3+ messages in thread
From: Nagarjuna Kristam @ 2019-09-04 8:17 UTC (permalink / raw)
To: gregkh, stern, dmitry.torokhov
Cc: linux-tegra, linux-kernel, linux-usb, Nagarjuna Kristam
In usbfs mmap, usb_alloc_coherent is used to allocate memory.
This Memory is then remapped to user space memory using remap_pfn_range.
remap_pfn_range needs phy address of memory, for which virt_to_phy API
is used. This API works only if memory is allocated using kmalloc. But
usb_alloc_coherent can allocate memory in vmalloc range and this causes
wrong remap of user memory.
Check if address returned by usb_alloc_coherent failed in vmalloc range
and if yes, use remap_vmalloc_range API, else use remap_pfn_range to remap
address to user space.
Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
---
drivers/usb/core/devio.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index a945ad7..20999de 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -250,7 +250,12 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
usbm->vma_use_count = 1;
INIT_LIST_HEAD(&usbm->memlist);
- if (remap_pfn_range(vma, vma->vm_start,
+ if (is_vmalloc_addr(usbm->mem)) {
+ if (remap_vmalloc_range(vma, usbm->mem, 0) < 0) {
+ dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
+ return -EAGAIN;
+ }
+ } else if (remap_pfn_range(vma, vma->vm_start,
virt_to_phys(usbm->mem) >> PAGE_SHIFT,
size, vma->vm_page_prot) < 0) {
dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] USB: usbfs: check cpu address range before remap
@ 2019-09-04 8:17 ` Nagarjuna Kristam
0 siblings, 0 replies; 3+ messages in thread
From: Nagarjuna Kristam @ 2019-09-04 8:17 UTC (permalink / raw)
To: gregkh, stern, dmitry.torokhov
Cc: linux-tegra, linux-kernel, linux-usb, Nagarjuna Kristam
In usbfs mmap, usb_alloc_coherent is used to allocate memory.
This Memory is then remapped to user space memory using remap_pfn_range.
remap_pfn_range needs phy address of memory, for which virt_to_phy API
is used. This API works only if memory is allocated using kmalloc. But
usb_alloc_coherent can allocate memory in vmalloc range and this causes
wrong remap of user memory.
Check if address returned by usb_alloc_coherent failed in vmalloc range
and if yes, use remap_vmalloc_range API, else use remap_pfn_range to remap
address to user space.
Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
---
drivers/usb/core/devio.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index a945ad7..20999de 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -250,7 +250,12 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
usbm->vma_use_count = 1;
INIT_LIST_HEAD(&usbm->memlist);
- if (remap_pfn_range(vma, vma->vm_start,
+ if (is_vmalloc_addr(usbm->mem)) {
+ if (remap_vmalloc_range(vma, usbm->mem, 0) < 0) {
+ dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
+ return -EAGAIN;
+ }
+ } else if (remap_pfn_range(vma, vma->vm_start,
virt_to_phys(usbm->mem) >> PAGE_SHIFT,
size, vma->vm_page_prot) < 0) {
dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] USB: usbfs: check cpu address range before remap
2019-09-04 8:17 ` Nagarjuna Kristam
(?)
@ 2019-10-04 12:21 ` Greg KH
-1 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2019-10-04 12:21 UTC (permalink / raw)
To: Nagarjuna Kristam
Cc: stern, dmitry.torokhov, linux-tegra, linux-kernel, linux-usb
On Wed, Sep 04, 2019 at 01:47:31PM +0530, Nagarjuna Kristam wrote:
> In usbfs mmap, usb_alloc_coherent is used to allocate memory.
> This Memory is then remapped to user space memory using remap_pfn_range.
> remap_pfn_range needs phy address of memory, for which virt_to_phy API
> is used. This API works only if memory is allocated using kmalloc. But
> usb_alloc_coherent can allocate memory in vmalloc range and this causes
> wrong remap of user memory.
>
> Check if address returned by usb_alloc_coherent failed in vmalloc range
> and if yes, use remap_vmalloc_range API, else use remap_pfn_range to remap
> address to user space.
>
> Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
> ---
> drivers/usb/core/devio.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index a945ad7..20999de 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -250,7 +250,12 @@ static int usbdev_mmap(struct file *file, struct vm_area_struct *vma)
> usbm->vma_use_count = 1;
> INIT_LIST_HEAD(&usbm->memlist);
>
> - if (remap_pfn_range(vma, vma->vm_start,
> + if (is_vmalloc_addr(usbm->mem)) {
> + if (remap_vmalloc_range(vma, usbm->mem, 0) < 0) {
> + dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
> + return -EAGAIN;
> + }
> + } else if (remap_pfn_range(vma, vma->vm_start,
> virt_to_phys(usbm->mem) >> PAGE_SHIFT,
> size, vma->vm_page_prot) < 0) {
> dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
> --
> 2.7.4
>
With the recent dma changes, is this patch still needed and correct?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-10-04 12:21 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-04 8:17 [PATCH] USB: usbfs: check cpu address range before remap Nagarjuna Kristam
2019-09-04 8:17 ` Nagarjuna Kristam
2019-10-04 12:21 ` Greg KH
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.