Re: How arguments are stored on pages linux_bprm (Kernel 2.4)

[Dang <linuxdang@xxxxxxxxx>]

Thanks for the reply Prashant. What is the purpose of leaving
sizeof(void*) bytes?

Regards,
Dang

On 6/7/06, s prashant <sprashant16@xxxxxxxxx> wrote:
> The arguments are copied onto the bprm.pages using the copy_strings api.
> bprm.p = PAGE_SIZE*MAX_ARG_PAGES-sizeof (void*) indicates the total
> bytes that the pages can accomadate. The arrangement of the arguments onto
> the pages is as shown in the figure.
>
>  pages
>  ------------------------- ---
>  | sizeof (void*) | ^
>  |-----------------------| |
>  | argv[0] | |
>  |-----------------------| 31
>  | argv[1] | |
>  |-----------------------| |
>  | argv[2] | |
>  |=======================| ---
>  | argv[3] | ^
>  |-----------------------| |
>  | argv[4] | |
>  |-----------------------| 30
>  | | | |
>  |-----------------------| |
>  | | | |
>  |=======================| ---
>  | | |
>  | | |
>  | | |
>  | | |
>  | | |
>  | | |
>  |=======================| ---
>  | | ^
>  | | |
>  | | |
>  | | 0
>  | | |
>  | | |
>  ------------------------ ---
>
>
>
> The above info is w.r.t 2.4.21 kernel.
> Anybody please correct me if i am wrong.
>
> regards
> prashant.
>
>
> On 6/5/06, Dang <linuxdang@xxxxxxxxx> wrote:
> >
> >
> >
> > Hi,
> >     I have a requirement of reading command line arguments passed while
> invoking a binary, inside load_elf_binary(). I tried to read kernel 2.4 code
> but i am confused how data is stored inside the pages (linux_bprm)
> > Can anybody point to some document / tutorial or if possible brief me
> about how it is done?
> >
> > Regards,
> > Dang
>
>
>
> --
> S Prashant
> email:- prashant@xxxxxxxxxxxxx
> SolidCore Techsoft Systems India(Pvt)Ltd
> A-16, Mohan Co-operative Industrial Estate,
> Mathura Road,
> New Delhi, 11 00 44
> Phone:91 11 51678443


--

Regards,
Dang

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