Date: Mon, 24 Feb 2003 22:50:41 +0100 From: Ulrich Spoerlein <q@uni.de> To: Luoqi Chen <lchen@briontech.com> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: How to debug mmap(2) with pcm(3)? Message-ID: <20030224215041.GA289@galgenberg.net> In-Reply-To: <AHEKICEOIHLOGINAFIINEENCCAAA.lchen@briontech.com> References: <20030224210726.GC87555@galgenberg.net> <AHEKICEOIHLOGINAFIINEENCCAAA.lchen@briontech.com>
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--AhhlLboLdkugWU4S Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, 24.02.2003 at 13:30:30 -0800, Luoqi Chen wrote: > This is a "feature" of ia32 architecture, there isn't a notion of > write-only memory access, write access implies read access. If you > want to "fix" the problem with pcm device, very simple, go to file > sys/i386/trap.c and replace all occurrences of PROT_READ|PROT_WRITE > with PROT_WRITE. Hmm, I only have a few occurrences of VM_PROT_READ/_WRITE in that file. Well, why is the piece of OSS Code working on -CURRENT? And why does the man-page say nothing about implicit read-access when trying to write? Why does the mmap() not fail, but _always_ return a pointer with value 0x28104000? Couln't someone with more knowledge look into this issue? --AhhlLboLdkugWU4S Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (FreeBSD) iD8DBQE+WpOxmArGtfDbn0QRAhUKAKDbyXs/I64M7XF4FGGsVQL7J4v+NwCgurDc iPvzQZxPoGpyQq1CoYseZn4= =rKva -----END PGP SIGNATURE----- --AhhlLboLdkugWU4S-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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