[9fans] System call mania

[9fans] System call mania

[Pietro Gagliardi]

Hello. I was recently looking in libc when I noticed a few things
about system calls:

1) brk and sbrk are implemented atop brk_, which is not documented
2) the seek function seems to be a system call, but the alpha folder
defines a function seek which calls _seek
3) Some items in that file have underscores, like BRK_ and _READ

This leads me to the following question: what exactly are the system
calls in Plan 9?

Thanks.

Re: [9fans] System call mania

[Iruata Souza]

On 3/22/08, Pietro Gagliardi <pietro10@mac.com> wrote:
> Hello. I was recently looking in libc when I noticed a few things
>  about system calls:
>
>  1) brk and sbrk are implemented atop brk_, which is not documented
>  2) the seek function seems to be a system call, but the alpha folder
>  defines a function seek which calls _seek
>  3) Some items in that file have underscores, like BRK_ and _READ
>
>  This leads me to the following question: what exactly are the system
>  calls in Plan 9?
>

grep -i syscall /sys/src/9/port

iru

Re: [9fans] System call mania

[Pietro Gagliardi]

That confirmed one suspicion: the REAL calls are those who are simply
named in /sys/src/libc/9syscall/sys.h, and that the USER-LEVEL calls
are a big mess in libc. Thanks!

On Mar 22, 2008, at 12:16 AM, Iruata Souza wrote:

> On 3/22/08, Pietro Gagliardi <pietro10@mac.com> wrote:
>> Hello. I was recently looking in libc when I noticed a few things
>>  about system calls:
>>
>>  1) brk and sbrk are implemented atop brk_, which is not documented
>>  2) the seek function seems to be a system call, but the alpha folder
>>  defines a function seek which calls _seek
>>  3) Some items in that file have underscores, like BRK_ and _READ
>>
>>  This leads me to the following question: what exactly are the system
>>  calls in Plan 9?
>>
>
> grep -i syscall /sys/src/9/port
>
> iru
>

Re: [9fans] System call mania

[Iruata Souza]

On 3/22/08, Pietro Gagliardi <pietro10@mac.com> wrote:
> That confirmed one suspicion: the REAL calls are those who are simply
>  named in /sys/src/libc/9syscall/sys.h, and that the USER-LEVEL calls
>  are a big mess in libc. Thanks!
>

doesn't the name system call suggests you something?

iru

Re: [9fans] System call mania

[Pietro Gagliardi]

It suggests to me that these calls are the lowest level of
communication with the kernel. I once thought that all system calls
could be called by a program :-P

On Mar 22, 2008, at 12:41 AM, Iruata Souza wrote:

> On 3/22/08, Pietro Gagliardi <pietro10@mac.com> wrote:
>> That confirmed one suspicion: the REAL calls are those who are simply
>>  named in /sys/src/libc/9syscall/sys.h, and that the USER-LEVEL calls
>>  are a big mess in libc. Thanks!
>>
>
> doesn't the name system call suggests you something?
>
> iru
>

Re: [9fans] System call mania

[ron minnich]

On Fri, Mar 21, 2008 at 9:44 PM, Pietro Gagliardi <pietro10@mac.com> wrote:
> It suggests to me that these calls are the lowest level of
>  communication with the kernel. I once thought that all system calls
>  could be called by a program :-P
>

why do you think that they can't be?

ron

Re: [9fans] System call mania

[Pietro Gagliardi]

I was tired and I used the wrong words.

On Mar 22, 2008, at 1:32 AM, ron minnich wrote:

> On Fri, Mar 21, 2008 at 9:44 PM, Pietro Gagliardi
> <pietro10@mac.com> wrote:
>> It suggests to me that these calls are the lowest level of
>>  communication with the kernel. I once thought that all system calls
>>  could be called by a program :-P
>>
>
> why do you think that they can't be?
>
> ron
>