lkml.org 
[lkml]   [2021]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Data corruption on i.MX6 IPU in arm_copy_from_user()
Date
"Russell King (Oracle)" <linux@armlinux.org.uk> writes:

> Surely someone is not using copy_*_user() to copy data from userspace
> direct to MMIO space... that would be crazy.

No, it's the other way around: reading MMIO mapped to userspace (mmap
on /dev/mem) and copying it to simple kernel buffer (e.g. pipe buffer).
I.e., the MMIO is the userspace here (thus copy_from_user()).
--
Krzysztof Hałasa

Sieć Badawcza Łukasiewicz
Przemysłowy Instytut Automatyki i Pomiarów PIAP
Al. Jerozolimskie 202, 02-486 Warszawa

\
 
 \ /
  Last update: 2021-05-26 14:29    [W:0.066 / U:0.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site