From: Christoph Hellwig <hch@infradead.org>
To: Ruihan Li <lrh2000@pku.edu.cn>
Cc: linux-mm@kvack.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org,
Pasha Tatashin <pasha.tatashin@soleen.com>,
David Hildenbrand <david@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@infradead.org>,
Alan Stern <stern@rowland.harvard.edu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
syzbot+fcf1a817ceb50935ce99@syzkaller.appspotmail.comm,
stable@vger.kernel.org
Subject: Re: [PATCH v2 1/4] usb: usbfs: Enforce page requirements for mmap
Date: Tue, 16 May 2023 23:22:56 -0700 [thread overview]
Message-ID: <ZGRywDdN97RN1s/9@infradead.org> (raw)
In-Reply-To: <20230515130958.32471-2-lrh2000@pku.edu.cn>
On Mon, May 15, 2023 at 09:09:55PM +0800, Ruihan Li wrote:
> To address these issues, this patch introduces hcd_alloc_coherent_pages,
> which addresses the above two problems. Specifically,
> hcd_alloc_coherent_pages uses gen_pool_dma_alloc_align instead of
> gen_pool_dma_alloc to ensure that the memory is page-aligned. To replace
> kmalloc, hcd_alloc_coherent_pages directly allocates pages by calling
> __get_free_pages.
This looks reasonable in that it fixes the bug. But I really don't
like how it makes the mess of USB allocation APIs even messier :P
Not really your faul, but someone really needs to look into the usb
memory allocators and DMA mapping, which is tied to that and just as
bad.
next prev parent reply other threads:[~2023-05-17 6:23 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230515130958.32471-1-lrh2000@pku.edu.cn>
2023-05-15 13:09 ` Ruihan Li
2023-05-15 14:07 ` Alan Stern
2023-05-17 6:22 ` Christoph Hellwig [this message]
2023-05-15 13:09 ` [PATCH v2 2/4] usb: usbfs: Use consistent mmap functions Ruihan Li
2023-05-15 16:07 ` David Laight
2023-05-16 11:42 ` Ruihan Li
2023-05-15 13:09 ` [PATCH v2 3/4] mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM Ruihan Li
2023-05-15 16:36 ` Pasha Tatashin
2023-05-16 12:55 ` David Hildenbrand
2023-05-15 13:09 ` [PATCH v2 4/4] mm: page_table_check: Ensure user pages are not slab pages Ruihan Li
2023-05-15 16:28 ` Pasha Tatashin
2023-05-16 11:51 ` Ruihan Li
2023-05-16 12:54 ` David Hildenbrand
2023-05-16 14:14 ` Pasha Tatashin
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