linux-kernel - malloc() size in CMA region seems to be aligned to CMA

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: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+a3UFfGxJajS3Lqkp8M4kaikTWHprUXbUvECYC9dojgazQ8pg@mail.gmail.com>
Date:	Tue, 17 May 2016 23:37:55 +0800
From:	lunar12 lunartwix <lunartwix@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: malloc() size in CMA region seems to be aligned to CMA_ALIGNMENT

A 4MB dma_alloc_coherent  in kernel after malloc(2*1024) 40 times in
CMA region by user space will cause an error on our ARM 3.18 kernel
platform with a 32MB CMA.

It seems that the malloc in CMA region will be aligned to
CMA_ALIGNMENT everytime even if the requested malloc size is very
small so the CMA region is not available after the malloc operations.

Is there any configuraiton that can change this behavior??

Thanks

Cheers
Ken