Date: Mon, 22 Apr 2002 18:02:39 +0200 From: Reifenberger Michael EXT <Michael.Reifenberger.gp@icn.siemens.de> To: "'Andrew Gallatin'" <gallatin@cs.duke.edu>, Kenneth Culver <culverk@yumyumyum.org> Cc: freebsd-emulation@FreeBSD.ORG Subject: AW: implementing linux mmap2 syscall Message-ID: <67E0BE167008D31185F60008C7289DA0E13189@MCHH218E>
index | next in thread | raw e-mail
Hi, BTW: NETBSD seems so have the newer syscalls implemented. Take a look at: http://cvsweb.netbsd.org/bsdweb.cgi/syssrc/sys/compat/linux/common/linux_misc.c?rev=1.107&content-type=text/x-cvsweb-markup versus old mmap at: http://cvsweb.netbsd.org/bsdweb.cgi/syssrc/sys/compat/linux/common/linux_oldmmap.c?rev=1.58&content-type=text/x-cvsweb-markup Bye/2 ------ Michael Reifenberger - IT, UNIX, R/3-Basis Work: Michael.Reifenberger@plaut.de Proj: Michael.Reifenberger.gp@icn.siemens.de Pers: Michael@Reifenberger.com Webspace: http://www.reifenberger.com -----Ursprüngliche Nachricht----- Von: Andrew Gallatin [mailto:gallatin@cs.duke.edu] Gesendet: Montag, 22. April 2002 16:07 An: Kenneth Culver Cc: freebsd-hackers@FreeBSD.ORG; freebsd-emulation@FreeBSD.ORG Betreff: Re: implementing linux mmap2 syscall Kenneth Culver writes: > static inline unsigned long do_mmap(struct file *file, unsigned long addr, <..> > ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT); > out: > return ret; > } > > This is what mmap2 does: > > andstatic inline long do_mmap2( > unsigned long addr, unsigned long len, > unsigned long prot, unsigned long flags, > unsigned long fd, unsigned long pgoff) <...> > error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); > > So what it looks like to me is that mmap2 expects an offset that's already > page-aligned (I'm not sure if this is the right way to say it), where mmap > doesn't. the FreeBSD code in the linuxulator basically just takes the offset To me, it looks like mmap2 takes an offset that's a page index, rather than a byte position. Since linux passes the offset with a 32-bit long, rather than a 64-bit off_t like we do, they need to do this in order to be able to map offsets larger than 4GB into a file. For linux_mmap2, I'd think we want to do roughly the same things as linux_mmap, but with bsd_args.pos = ctob((off_t)linux_args.pos) Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-emulation" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-emulation" in the body of the messagehelp
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?67E0BE167008D31185F60008C7289DA0E13189>