Alfred Perlstein wrote:
>
> * Greg Lehey <[EMAIL PROTECTED]> [010712 21:08] wrote:
> > On Thursday, 12 July 2001 at 6:58:09 -0500, [EMAIL PROTECTED] wrote:
> > > Dear Friends
> > >
> > > I have some questions about kernel programming:
> >
Alfred Perlstein wrote:
> > write() doesn't exist in the kernel. The simple answer is "you're
> > going to have to read what the send() syscall does and emulate it".
> > First, though, you need to answer the question "why do I want to do
> > this in the kernel?"
>
> it actually exists, however t
* Eugene L. Vorokov <[EMAIL PROTECTED]> [010713 10:24] wrote:
> > ch = fubyte(uaddr);
>
> And one more question, does this mean that I can't use things x = *uaddr
> and *uaddr = x for userspace, but always have to use fubyte() and subyte () ?
> If so, what is the reason it was done li
* Eugene L. Vorokov <[EMAIL PROTECTED]> [010713 10:16] wrote:
> > /*
> > * return number of characters in a userland address string
> > * or -1 if an illegal access occurs.
> > */
> Then I don't get it. Won't this piece of code cycle forever fetching
> first byte of the string again and again
In message <[EMAIL PROTECTED]>, [EMAIL PROTECTED] w
rites:
>> ch = fubyte(uaddr);
>
>And one more question, does this mean that I can't use things x = *uaddr
>and *uaddr = x for userspace, but always have to use fubyte() and subyte () ?
Right.
>If so, what is the reason it was done
> ch = fubyte(uaddr);
And one more question, does this mean that I can't use things x = *uaddr
and *uaddr = x for userspace, but always have to use fubyte() and subyte () ?
If so, what is the reason it was done like that ?
Regards,
Eugene
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> /*
> * return number of characters in a userland address string
> * or -1 if an illegal access occurs.
> */
> int
> user_strlen(uaddr)
> char *uaddr;
> {
> int ret;
>
> ret = -1;
> do {
> ch = fubyte(uaddr);
> ret++;
> } while (ch !=
> Have a look at the digi driver in -current where I did this. The
> caveat is that the kernel code looks ugly. From the driver's ioctl
> routine:
>
> case DIGIIO_IDENT:
> return (copyout(sc->name, *(char **)data,
> strlen(sc
> > write() doesn't exist in the kernel. The simple answer is "you're
> > going to have to read what the send() syscall does and emulate it".
> > First, though, you need to answer the question "why do I want to do
> > this in the kernel?"
>
> it actually exists, however the problem is that copyi
* Eugene L. Vorokov <[EMAIL PROTECTED]> [010713 01:33] wrote:
> Forgot to Cc: here:
>
> > You can't call kernel strlen on a userland address, you must do
> > something like this:
>
> How so ? It seems to work for me. For instance, I used userland
> address space buffer to simulate __getcwd() sys
Forgot to Cc: here:
> You can't call kernel strlen on a userland address, you must do
> something like this:
How so ? It seems to work for me. For instance, I used userland
address space buffer to simulate __getcwd() syscall on the current
process (I was hacking open() syscall and log full path
* Greg Lehey <[EMAIL PROTECTED]> [010712 21:08] wrote:
> On Thursday, 12 July 2001 at 6:58:09 -0500, [EMAIL PROTECTED] wrote:
> > Dear Friends
> >
> > I have some questions about kernel programming:
>
> You'd be better off sending mail like this to -hacke
On Thursday, 12 July 2001 at 6:58:09 -0500, [EMAIL PROTECTED] wrote:
> Dear Friends
>
> I have some questions about kernel programming:
You'd be better off sending mail like this to -hackers. I've followed
up there.
> 1. Why I can call some system calls functio
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