Date: Wed, 08 Jan 2003 13:15:50 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: omestre <omestre@SDF.LONESTAR.ORG> Cc: freebsd-hackers@freebsd.org Subject: Re: read in kernel mode... Message-ID: <3E1C9506.FD69C710@mindspring.com> References: <Pine.NEB.4.33.0301081946050.2678-100000@sdf.lonestar.org>
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omestre wrote: > Hello, > I need read some data in kernel mode... Somebody can help me? > I have tried with read function, but i got segmentation fault... > And i can't use the stdio.h :) then, how can i do this job??? The problem you are having is because you do not have a process address space context for the copyout() to user space that's built into the read(2) routine: you can not use the read(2) routine directly from a kernel context, and you can only use it from an adopted process context if you expend a great deal of effort. You probably need to ask yourself three things: 1) What problem are you really trying to solve here, that makes you think you need to do file I/O in the kernel? 2) Have you considered other solutions to the problem, ones which do not require file I/O in the kernel? 3) Have you looked at the mailing list archives, to see the three documented methods of doing this evil thing, which people have already hashed out? -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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