Hi!
> what about the do_mmap/do_mmap_pgoff implementation?
> reurn-type: _unsigned_ long (which should be ok cause we've to return
> an adress if len == 0)
> on error: -ERR_*
>
> and the checks in various places are really strange. - well some
> places check for:
> o != NULL
> o > -1024UL
> o ...
>
> guess this nedds some cleanup.
While you are at it... fs/binfmt_elf does mmaps but does not check for errors.
And errors actually do happen there :-(
--
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pavel,
> > what about the do_mmap/do_mmap_pgoff implementation?
> > reurn-type: _unsigned_ long (which should be ok cause we've to return
> > an adress if len == 0)
> > on error: -ERR_*
> >
> > and the checks in various places are really strange. - well some
> > places check for:
> > o != NULL
> > o > -1024UL
> > o ...
> >
> > guess this nedds some cleanup.
>
> While you are at it... fs/binfmt_elf does mmaps but does not check for errors.
> And errors actually do happen there :-(
sure, was tripping over that anyways ... since the compiler spits out tons
of "conversion without a cast" warnings (seems to be a different way to
use grep :)
i just came across one problem: when converting the unsigned longs to
void * pointers, everything works fine, beside the "advanced"
pointer arithmetic. (like aligning the address to a certain
boundary - using address & MASK) ... for that case i need to
cast to an unsigned long in any case :(
is there another way to do it without explicit casting?
should we introduce ptr_addr_t?
can we be sure that an unsigned long is capable to hold
and address (also in the future)
can we be sure about gcc void * pointer arithmetic (like
++ incremets the address by one)
tm
--
in some way i do, and in some way i don't.
pavel,
--snip/snip
> While you are at it... fs/binfmt_elf does mmaps but does not check for errors.
> And errors actually do happen there :-(
ok, had a second look.
it does check for errors, using BAD_ADDR which is: if (addr > TASK_SIZE)
and TASK_SIZE on the other hand is PAGE_OFFSET == 0xC0000000 (for x86)
hmm, which means even if we correctly map an area > PAGE_OFFSET, we will
never free the area (well another question is, if we ever try to map
an area > PAGE_OFFSET) - but nevertheless, the check should be before
trying to mmap, and checking for IS_ERR after mmap.
nyone explain what to do if we cannot map the page for MMAP_PAGE_ZERO?
- we just ignore it for now ...
also another instance: if (addr != req_address) - which means if we have
some alignment with mmap - load_elf_library just bails out.
guess we need to munmap also (if no error occured during mmap)
do_brk() is _never_ checked for return (at least in binfm_elf) ... oh
well ...
any comments?
tm
--
in some way i do, and in some way i don't.
Hi!
> do_brk() is _never_ checked for return (at least in binfm_elf) ... oh
> well ...
That's the bug I had in my mind. It actually bitten me.
Pavel
--
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cryptography in U.S.A. and free speech in Czech Republic.