Date: Wed, 24 Apr 2002 11:47:27 -0400 (EDT) From: Andrew Gallatin <gallatin@cs.duke.edu> To: Brandon S Allbery KF8NH <allbery@ece.cmu.edu> Cc: Kenneth Culver <culverk@alpha.yumyumyum.org>, freebsd-hackers@FreeBSD.ORG, FreeBSD-CURRENT List <freebsd-current@FreeBSD.ORG> Subject: Re: implementing linux mmap2 syscall Message-ID: <15558.54159.737973.56540@grasshopper.cs.duke.edu> In-Reply-To: <1019662269.6094.1.camel@pyanfar.ece.cmu.edu> References: <15557.27747.802212.659760@grasshopper.cs.duke.edu> <20020423181748.W31638-100000@alpha.yumyumyum.org> <15558.46600.351433.784766@grasshopper.cs.duke.edu> <1019662269.6094.1.camel@pyanfar.ece.cmu.edu>
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Brandon S Allbery KF8NH writes: > On Wed, 2002-04-24 at 10:41, Andrew Gallatin wrote: > > Maybe the argument isn't where you expect it to be, but is there. > > Can you make a test program which calls mmap2 with its 6th arg as > > something unique like 0xdeadbeef? Then print out (in hex :) the trapframe > > from the linux prepsyscall routine & see if you can find the deadbeef. > > My recollection is that beyond 5 arguments, a pointer to the remaining > ones is passed. (But my recollection may be wrong and I don't wish to > subject myself to the source cesspool at the moment....) > I think that's how it used to work. Apparently, they've changed it recently and they now pass 6 args in registers. Eg, in the linux kernel sources, old_mmap() fetches its args via copy_from_user(), whereas the newer sys_mmap2() doesn't. Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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