[openbeos] Re: memset ---> user_memset ?
- From: "François Revol" <revol@xxxxxxx>
- To: openbeos@xxxxxxxxxxxxx
- Date: Thu, 07 Sep 2006 11:54:46 +0200 CEST
> Siarzhuk Zharski <zharik@xxxxxx> wrote:
> > Building my usb_scsi under Haiku I was warned that memset, memcpy
> > functions have no prototypes. In KernelExports.h I found only
> > user_memset, user_memcpy ones. Are any peculiarities using those
> > mem*
> > in
> > kernel modules? Should I use user_mem* analogues instead? Are any
> > technical details about it somewhere to read? Thanks!
>
> You can still just include <string.h> for those.
> The user_*() versions have to be used whenever you're accessing
> unsafe
> user memory. In BeOS, the memory you get in read/write/etc. hooks is
> already safe - but the one that got passed into ioctl() never was. Be
> never published how to make memory safe, so you can use the user_*()
> functions to access it.
Actually they did once (is_valid_range(), in an example serial driver
IIRC) but the prototype wasn't public and they didn't really used it
much themselves, plus the is_valid_string() version was actually unsafe
(only checked the first byte).
François.
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