From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: "Verma, Vishal L" <vishal.l.verma@intel.com>,
"Williams, Dan J" <dan.j.williams@intel.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
"Busch, Keith" <keith.busch@intel.com>,
"Weiny, Ira" <ira.weiny@intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>
Subject: Re: [PATCH] libnvdimm, region: Use struct_size() in kzalloc()
Date: Wed, 28 Aug 2019 14:36:59 -0500 [thread overview]
Message-ID: <d940183a-c00d-3a96-37bb-9553583f160a@embeddedor.com> (raw)
In-Reply-To: <3e80b36c86942278ee66aebdd5ea2632f104083a.camel@intel.com>
Hi Vishal,
On 8/28/19 1:51 PM, Verma, Vishal L wrote:
[..]
>
> Hi Gustavo,
>
> The patch looks good to me, however it looks like it might've missed
> some instances where this replacement can be performed?
>
struct_size() does not apply to those scenarios. See below...
>
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git/tree/drivers/nvdimm/region_devs.c#n1030
struct_size() only applies to structures of the following kind:
struct foo {
int stuff;
struct boo entry[];
};
and this scenario includes two different structures:
struct nd_region {
...
struct nd_mapping mapping[0];
};
struct nd_blk_region {
...
struct nd_region nd_region;
};
> [2]: https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git/tree/drivers/nvdimm/region_devs.c#n96
>
In this scenario struct_size() does not apply directly because of the following
logic before the call to devm_kzalloc():
size_t flush_data_size = sizeof(void *);
[..]
for (i = 0; i < nd_region->ndr_mappings; i++) {
[..]
/* at least one null hint slot per-dimm for the "no-hint" case */
flush_data_size += sizeof(void *);
[..]
flush_data_size += nvdimm->num_flush * sizeof(void *);
}
Thanks
--
Gustavo
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next prev parent reply other threads:[~2019-08-28 19:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-10 21:06 [PATCH] libnvdimm, region: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-08-28 18:30 ` Gustavo A. R. Silva
2019-08-28 20:25 ` Kees Cook
2019-08-28 18:51 ` Verma, Vishal L
2019-08-28 19:36 ` Gustavo A. R. Silva [this message]
2019-08-28 20:24 ` Verma, Vishal L
2019-08-29 21:04 ` Dan Williams
-- strict thread matches above, loose matches on Subject: below --
2019-02-21 15:23 [PATCH] libnvdimm, region: use " Gustavo A. R. Silva
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