lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240806134708.0034c4b9@kernel.org>
Date: Tue, 6 Aug 2024 13:47:08 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Mina Almasry <almasrymina@...gle.com>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-doc@...r.kernel.org, linux-alpha@...r.kernel.org,
 linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org,
 sparclinux@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
 linux-arch@...r.kernel.org, linux-kselftest@...r.kernel.org,
 bpf@...r.kernel.org, linux-media@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, Donald Hunter <donald.hunter@...il.com>,
 "David S. Miller" <davem@...emloft.net>, Eric Dumazet
 <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, Jonathan Corbet
 <corbet@....net>, Richard Henderson <richard.henderson@...aro.org>, Ivan
 Kokshaysky <ink@...assic.park.msu.ru>, Matt Turner <mattst88@...il.com>,
 Thomas Bogendoerfer <tsbogend@...ha.franken.de>, "James E.J. Bottomley"
 <James.Bottomley@...senPartnership.com>, Helge Deller <deller@....de>,
 Andreas Larsson <andreas@...sler.com>, Jesper Dangaard Brouer
 <hawk@...nel.org>, Ilias Apalodimas <ilias.apalodimas@...aro.org>, Steven
 Rostedt <rostedt@...dmis.org>, Masami Hiramatsu <mhiramat@...nel.org>,
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, Arnd Bergmann
 <arnd@...db.de>, Steffen Klassert <steffen.klassert@...unet.com>, Herbert
 Xu <herbert@...dor.apana.org.au>, David Ahern <dsahern@...nel.org>, Willem
 de Bruijn <willemdebruijn.kernel@...il.com>, Shuah Khan <shuah@...nel.org>,
 Sumit Semwal <sumit.semwal@...aro.org>, "Christian König"
 <christian.koenig@....com>, Bagas Sanjaya <bagasdotme@...il.com>, Christoph
 Hellwig <hch@...radead.org>, Nikolay Aleksandrov <razor@...ckwall.org>,
 Taehee Yoo <ap420073@...il.com>, Pavel Begunkov <asml.silence@...il.com>,
 David Wei <dw@...idwei.uk>, Jason Gunthorpe <jgg@...pe.ca>, Yunsheng Lin
 <linyunsheng@...wei.com>, Shailend Chand <shailend@...gle.com>, Harshitha
 Ramamurthy <hramamurthy@...gle.com>, Shakeel Butt <shakeel.butt@...ux.dev>,
 Jeroen de Borst <jeroendb@...gle.com>, Praveen Kaligineedi
 <pkaligineedi@...gle.com>, Willem de Bruijn <willemb@...gle.com>, Kaiyuan
 Zhang <kaiyuanz@...gle.com>
Subject: Re: [PATCH net-next v18 04/14] netdev: netdevice devmem allocator

On Mon,  5 Aug 2024 21:25:17 +0000 Mina Almasry wrote:
> +struct net_iov *
> +net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding)
> +{
> +	struct dmabuf_genpool_chunk_owner *owner;
> +	unsigned long dma_addr;
> +	struct net_iov *niov;
> +	ssize_t offset;
> +	ssize_t index;
> +
> +	dma_addr = gen_pool_alloc_owner(binding->chunk_pool, PAGE_SIZE,
> +					(void **)&owner);
> +	if (!dma_addr)
> +		return NULL;
> +
> +	offset = dma_addr - owner->base_dma_addr;
> +	index = offset / PAGE_SIZE;
> +	niov = &owner->niovs[index];
> +
> +	niov->dma_addr = 0;

Is the dma_addr not constant for a given niov for the entire lifetime
of the binding? Why flip it back and forth between its value and 0?

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ