From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mario Smarduch Date: Wed, 05 May 2004 15:53:10 +0000 Subject: Re: mmap() of /dev/kmem issue Message-Id: <40990DE6.72969C72@email.mot.com> List-Id: References: <4097C51D.71EA0BEA@email.mot.com> In-Reply-To: <4097C51D.71EA0BEA@email.mot.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Matthew Wilcox wrote: > On Wed, May 05, 2004 at 08:08:21AM -0700, Luck, Tony wrote: > > Mapping kernel memory as uncacheable into a user process > > seems like a recipe for disaster (well at least for an > > MCA when the processor catches you using mixed attributes). > > ... which is why we don't do that. > > See drivers/char/mem.c::mmap_mem(). We call uncached_access() which does: > > #elif defined(CONFIG_IA64) > /* > * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute > aliases. > */ > return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); That's great but what release is that in? - mario. > > > -- > "Next the statesmen will invent cheap lies, putting the blame upon > the nation that is attacked, and every man will be glad of those > conscience-soothing falsities, and will diligently study them, and refuse > to examine any refutations of them; and thus he will by and by convince > himself that the war is just, and will thank God for the better sleep > he enjoys after this process of grotesque self-deception." -- Mark Twain > - > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html