| Message ID | 20210622133414.132754-1-rm.skakun@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] dma-mapping: use vmalloc_to_page for vmalloc addresses | expand |
On Tue, Jun 22, 2021 at 04:34:14PM +0300, Roman Skakun wrote: > This commit is dedicated to fix incorrect conversion from > cpu_addr to page address in cases when we get virtual > address which allocated in the vmalloc range. > As the result, virt_to_page() cannot convert this address > properly and return incorrect page address. > > Need to detect such cases and obtains the page address using > vmalloc_to_page() instead. > > Signed-off-by: Roman Skakun <roman_skakun@epam.com> > Reviewed-by: Andrii Anisov <andrii_anisov@epam.com> > --- > Hey! > Thanks for suggestions, Christoph! > I updated the patch according to your advice. > But, I'm so surprised because nobody catches this problem > in the common code before. It looks a bit strange as for me. This looks like it wasn't picked up? Should it go in rc1? > > > kernel/dma/ops_helpers.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > index 910ae69cae77..782728d8a393 100644 > --- a/kernel/dma/ops_helpers.c > +++ b/kernel/dma/ops_helpers.c > @@ -5,6 +5,14 @@ > */ > #include <linux/dma-map-ops.h> > > +static struct page *cpu_addr_to_page(void *cpu_addr) > +{ > + if (is_vmalloc_addr(cpu_addr)) > + return vmalloc_to_page(cpu_addr); > + else > + return virt_to_page(cpu_addr); > +} > + > /* > * Create scatter-list for the already allocated DMA buffer. > */ > @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - struct page *page = virt_to_page(cpu_addr); > + struct page *page = cpu_addr_to_page(cpu_addr); > int ret; > > ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > return -ENXIO; > > return remap_pfn_range(vma, vma->vm_start, > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, > user_count << PAGE_SHIFT, vma->vm_page_prot); > #else > return -ENXIO; > -- > 2.25.1 >
On Tue, 22 Jun 2021, Roman Skakun wrote: > This commit is dedicated to fix incorrect conversion from > cpu_addr to page address in cases when we get virtual > address which allocated in the vmalloc range. > As the result, virt_to_page() cannot convert this address > properly and return incorrect page address. > > Need to detect such cases and obtains the page address using > vmalloc_to_page() instead. > > Signed-off-by: Roman Skakun <roman_skakun@epam.com> > Reviewed-by: Andrii Anisov <andrii_anisov@epam.com> > --- > Hey! > Thanks for suggestions, Christoph! > I updated the patch according to your advice. > But, I'm so surprised because nobody catches this problem > in the common code before. It looks a bit strange as for me. > > > kernel/dma/ops_helpers.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > index 910ae69cae77..782728d8a393 100644 > --- a/kernel/dma/ops_helpers.c > +++ b/kernel/dma/ops_helpers.c > @@ -5,6 +5,14 @@ > */ > #include <linux/dma-map-ops.h> > > +static struct page *cpu_addr_to_page(void *cpu_addr) > +{ > + if (is_vmalloc_addr(cpu_addr)) > + return vmalloc_to_page(cpu_addr); > + else > + return virt_to_page(cpu_addr); > +} We have the same thing in xen_swiotlb_free_coherent. Can we find a way to call cpu_addr_to_page() from xen_swiotlb_free_coherent? Maybe we can make cpu_addr_to_page non-static? No problem if it is too much trouble. > /* > * Create scatter-list for the already allocated DMA buffer. > */ > @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - struct page *page = virt_to_page(cpu_addr); > + struct page *page = cpu_addr_to_page(cpu_addr); > int ret; > > ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > return -ENXIO; > > return remap_pfn_range(vma, vma->vm_start, > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, > user_count << PAGE_SHIFT, vma->vm_page_prot); > #else > return -ENXIO; > -- > 2.25.1 >
Hi, Stefano! > We have the same thing in xen_swiotlb_free_coherent. Can we find a way > to call cpu_addr_to_page() from xen_swiotlb_free_coherent? > Maybe we can make cpu_addr_to_page non-static? Yes, right, If we want to reuse this helper instead of the same code block in xen_swiotlb_free_coherent() need to make cpu_addr_to_page() as global and add a new declaration for this helper in include/linux/dma-map-ops.h. What do you think? Cheers! ср, 14 июл. 2021 г. в 04:23, Stefano Stabellini <sstabellini@kernel.org>: > > On Tue, 22 Jun 2021, Roman Skakun wrote: > > This commit is dedicated to fix incorrect conversion from > > cpu_addr to page address in cases when we get virtual > > address which allocated in the vmalloc range. > > As the result, virt_to_page() cannot convert this address > > properly and return incorrect page address. > > > > Need to detect such cases and obtains the page address using > > vmalloc_to_page() instead. > > > > Signed-off-by: Roman Skakun <roman_skakun@epam.com> > > Reviewed-by: Andrii Anisov <andrii_anisov@epam.com> > > --- > > Hey! > > Thanks for suggestions, Christoph! > > I updated the patch according to your advice. > > But, I'm so surprised because nobody catches this problem > > in the common code before. It looks a bit strange as for me. > > > > > > kernel/dma/ops_helpers.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > > index 910ae69cae77..782728d8a393 100644 > > --- a/kernel/dma/ops_helpers.c > > +++ b/kernel/dma/ops_helpers.c > > @@ -5,6 +5,14 @@ > > */ > > #include <linux/dma-map-ops.h> > > > > +static struct page *cpu_addr_to_page(void *cpu_addr) > > +{ > > + if (is_vmalloc_addr(cpu_addr)) > > + return vmalloc_to_page(cpu_addr); > > + else > > + return virt_to_page(cpu_addr); > > +} > > We have the same thing in xen_swiotlb_free_coherent. Can we find a way > to call cpu_addr_to_page() from xen_swiotlb_free_coherent? Maybe we can > make cpu_addr_to_page non-static? No problem if it is too much trouble. > > > > /* > > * Create scatter-list for the already allocated DMA buffer. > > */ > > @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > > void *cpu_addr, dma_addr_t dma_addr, size_t size, > > unsigned long attrs) > > { > > - struct page *page = virt_to_page(cpu_addr); > > + struct page *page = cpu_addr_to_page(cpu_addr); > > int ret; > > > > ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > > @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > > return -ENXIO; > > > > return remap_pfn_range(vma, vma->vm_start, > > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > > + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, > > user_count << PAGE_SHIFT, vma->vm_page_prot); > > #else > > return -ENXIO; > > -- > > 2.25.1 > >
> This looks like it wasn't picked up? Should it go in rc1? Hi, Konrad! This looks like an unambiguous bug, and should be in rc1. Cheers! ср, 14 июл. 2021 г. в 03:15, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>: > > On Tue, Jun 22, 2021 at 04:34:14PM +0300, Roman Skakun wrote: > > This commit is dedicated to fix incorrect conversion from > > cpu_addr to page address in cases when we get virtual > > address which allocated in the vmalloc range. > > As the result, virt_to_page() cannot convert this address > > properly and return incorrect page address. > > > > Need to detect such cases and obtains the page address using > > vmalloc_to_page() instead. > > > > Signed-off-by: Roman Skakun <roman_skakun@epam.com> > > Reviewed-by: Andrii Anisov <andrii_anisov@epam.com> > > --- > > Hey! > > Thanks for suggestions, Christoph! > > I updated the patch according to your advice. > > But, I'm so surprised because nobody catches this problem > > in the common code before. It looks a bit strange as for me. > > This looks like it wasn't picked up? Should it go in rc1? > > > > > > kernel/dma/ops_helpers.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > > index 910ae69cae77..782728d8a393 100644 > > --- a/kernel/dma/ops_helpers.c > > +++ b/kernel/dma/ops_helpers.c > > @@ -5,6 +5,14 @@ > > */ > > #include <linux/dma-map-ops.h> > > > > +static struct page *cpu_addr_to_page(void *cpu_addr) > > +{ > > + if (is_vmalloc_addr(cpu_addr)) > > + return vmalloc_to_page(cpu_addr); > > + else > > + return virt_to_page(cpu_addr); > > +} > > + > > /* > > * Create scatter-list for the already allocated DMA buffer. > > */ > > @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > > void *cpu_addr, dma_addr_t dma_addr, size_t size, > > unsigned long attrs) > > { > > - struct page *page = virt_to_page(cpu_addr); > > + struct page *page = cpu_addr_to_page(cpu_addr); > > int ret; > > > > ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > > @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > > return -ENXIO; > > > > return remap_pfn_range(vma, vma->vm_start, > > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > > + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, > > user_count << PAGE_SHIFT, vma->vm_page_prot); > > #else > > return -ENXIO; > > -- > > 2.25.1 > >
On 7/15/21 3:39 AM, Roman Skakun wrote: >> This looks like it wasn't picked up? Should it go in rc1? > Hi, Konrad! > > This looks like an unambiguous bug, and should be in rc1. Looks like you didn't copy Christoph which could be part of the problem. Adding him. -boris > > Cheers! > > ср, 14 июл. 2021 г. в 03:15, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>: >> On Tue, Jun 22, 2021 at 04:34:14PM +0300, Roman Skakun wrote: >>> This commit is dedicated to fix incorrect conversion from >>> cpu_addr to page address in cases when we get virtual >>> address which allocated in the vmalloc range. >>> As the result, virt_to_page() cannot convert this address >>> properly and return incorrect page address. >>> >>> Need to detect such cases and obtains the page address using >>> vmalloc_to_page() instead. >>> >>> Signed-off-by: Roman Skakun <roman_skakun@epam.com> >>> Reviewed-by: Andrii Anisov <andrii_anisov@epam.com> >>> --- >>> Hey! >>> Thanks for suggestions, Christoph! >>> I updated the patch according to your advice. >>> But, I'm so surprised because nobody catches this problem >>> in the common code before. It looks a bit strange as for me. >> This looks like it wasn't picked up? Should it go in rc1? >>> >>> kernel/dma/ops_helpers.c | 12 ++++++++++-- >>> 1 file changed, 10 insertions(+), 2 deletions(-) >>> >>> diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c >>> index 910ae69cae77..782728d8a393 100644 >>> --- a/kernel/dma/ops_helpers.c >>> +++ b/kernel/dma/ops_helpers.c >>> @@ -5,6 +5,14 @@ >>> */ >>> #include <linux/dma-map-ops.h> >>> >>> +static struct page *cpu_addr_to_page(void *cpu_addr) >>> +{ >>> + if (is_vmalloc_addr(cpu_addr)) >>> + return vmalloc_to_page(cpu_addr); >>> + else >>> + return virt_to_page(cpu_addr); >>> +} >>> + >>> /* >>> * Create scatter-list for the already allocated DMA buffer. >>> */ >>> @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, >>> void *cpu_addr, dma_addr_t dma_addr, size_t size, >>> unsigned long attrs) >>> { >>> - struct page *page = virt_to_page(cpu_addr); >>> + struct page *page = cpu_addr_to_page(cpu_addr); >>> int ret; >>> >>> ret = sg_alloc_table(sgt, 1, GFP_KERNEL); >>> @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, >>> return -ENXIO; >>> >>> return remap_pfn_range(vma, vma->vm_start, >>> - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, >>> + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, >>> user_count << PAGE_SHIFT, vma->vm_page_prot); >>> #else >>> return -ENXIO; >>> -- >>> 2.25.1 >>> > >
On Thu, Jul 15, 2021 at 12:58:53PM -0400, Boris Ostrovsky wrote: > > On 7/15/21 3:39 AM, Roman Skakun wrote: > >> This looks like it wasn't picked up? Should it go in rc1? > > Hi, Konrad! > > > > This looks like an unambiguous bug, and should be in rc1. > > > Looks like you didn't copy Christoph which could be part of the problem. Adding him. Can someone just send a clean patch that I can review and hopefully apply?
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c index 910ae69cae77..782728d8a393 100644 --- a/kernel/dma/ops_helpers.c +++ b/kernel/dma/ops_helpers.c @@ -5,6 +5,14 @@ */ #include <linux/dma-map-ops.h> +static struct page *cpu_addr_to_page(void *cpu_addr) +{ + if (is_vmalloc_addr(cpu_addr)) + return vmalloc_to_page(cpu_addr); + else + return virt_to_page(cpu_addr); +} + /* * Create scatter-list for the already allocated DMA buffer. */ @@ -12,7 +20,7 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) { - struct page *page = virt_to_page(cpu_addr); + struct page *page = cpu_addr_to_page(cpu_addr); int ret; ret = sg_alloc_table(sgt, 1, GFP_KERNEL); @@ -43,7 +51,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, return -ENXIO; return remap_pfn_range(vma, vma->vm_start, - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, + page_to_pfn(cpu_addr_to_page(cpu_addr)) + vma->vm_pgoff, user_count << PAGE_SHIFT, vma->vm_page_prot); #else return -ENXIO;