On Tue, Sep 22, 2009 at 6:49 PM, Andrea Gasparini <gaspa@xxxxxxxxxxx> wrote: >> You may want to take a look at this page, >> >> http://www.scs.ch/~frey/linux/memorymap.html >> >> This also contains a sample source code, here, >> http://www.scs.ch/~frey/linux/mmap.example.tar >> I tried this code on ARM architecture on a swapless board which works >> fine. >> >> If you could share exact code, that would be easy to debug the problem >> you are facing. > > Oh, solved!! \o/ > Don't know why, but it didn't take correctly PROT_NONE flag on (userspace) > mmap. > > with: > mmapped_ptr = mmap(NULL,SIZE,PROT_READ, MAP_SHARED ,fd,0); > ( or PROT_WRITE, or both) it works. > > thanks. > -- > -gaspa- > ----------------------------------------------- > -------- https://launchpad.net/~gaspa --------- > ------ HomePage: iogaspa.altervista.org ------- > -Il lunedi'dell'arrampicatore: www.lunedi.org - > huh? the code which you gave to us already had mmap with "PROT_READ|PROT_WRITE" and it even worked with my setup. But, if I use PROT_NONE then it crashes with segfault, which is perfectly correct as such pages are not meant to be accessed <snip> PROT_EXEC Pages may be executed. PROT_READ Pages may be read. PROT_WRITE Pages may be written. PROT_NONE Pages may not be accessed. <\snip> -Vinit -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
