From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Fri, 12 Feb 2016 15:26:41 +0000 Subject: [PATCH v5sub1 7/8] arm64: move kernel image to base of vmalloc area In-Reply-To: References: <1454324093-15998-1-git-send-email-ard.biesheuvel@linaro.org> <1454324093-15998-8-git-send-email-ard.biesheuvel@linaro.org> <20160212145844.GI31665@e104818-lin.cambridge.arm.com> <20160212151006.GJ31665@e104818-lin.cambridge.arm.com> Message-ID: <20160212152641.GK31665@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Feb 12, 2016 at 04:17:09PM +0100, Ard Biesheuvel wrote: > On 12 February 2016 at 16:10, Catalin Marinas wrote: > > On Fri, Feb 12, 2016 at 04:02:58PM +0100, Ard Biesheuvel wrote: > >> On 12 February 2016 at 15:58, Catalin Marinas wrote: > >> > On Mon, Feb 01, 2016 at 11:54:52AM +0100, Ard Biesheuvel wrote: > >> >> This moves the module area to right before the vmalloc area, and > >> >> moves the kernel image to the base of the vmalloc area. This is > >> >> an intermediate step towards implementing KASLR, which allows the > >> >> kernel image to be located anywhere in the vmalloc area. > >> >> > >> >> Signed-off-by: Ard Biesheuvel > >> > > >> > This patch is causing lots of KASAN warnings on Juno (interestingly, it > >> > doesn't seem to trigger on Seattle, though we only tried for-next/core). > >> > I pushed the branch that I'm currently using here: > >> > > >> > git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux for-next/kernmap > >> > > >> > > >> > A typical error (though its place varies based on the config options, > >> > kernel layout): > >> > > >> > BUG: KASAN: stack-out-of-bounds in clockevents_program_event+0x28/0x1b0 at addr ffffffc936257cc8 > >> > >> Can you confirm that these are stack accesses? I was having similar > >> errors before, and I ended up creating the kasan zero page patch > >> because it turned out the kasan shadow page in question was aliased > >> and the stack writes were occurring elsewhere. > > > > It's possible, we are looking into this. Is there any other patch I miss on > > the above branch? > > I don't think so but I will check Commit 7b1af9795773 ("arm64: kasan: ensure that the KASAN zero page is mapped read-only") was merged in -rc2 while the branch above is based on -rc1. Anyway, I merged it into -rc2 and the errors are similar. -- Catalin