Messages in this thread | | | Subject | Re: [PATCH 2/4] arm64: hide more compat_vdso code | From | Dmitry Safonov <> | Date | Thu, 29 Oct 2020 13:54:22 +0000 |
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On 10/29/20 1:35 PM, Arnd Bergmann wrote: > On Mon, Oct 26, 2020 at 5:55 PM Mark Rutland <mark.rutland@arm.com> wrote: >> On Mon, Oct 26, 2020 at 05:03:29PM +0100, Arnd Bergmann wrote: >>> From: Arnd Bergmann <arnd@arndb.de> >>> >>> When CONFIG_COMPAT_VDSO is disabled, we get a warning >>> about a potential out-of-bounds access: >>> >>> arch/arm64/kernel/vdso.c: In function 'aarch32_vdso_mremap': >>> arch/arm64/kernel/vdso.c:86:37: warning: array subscript 1 is above array bounds of 'struct vdso_abi_info[1]' [-Warray-bounds] >>> 86 | unsigned long vdso_size = vdso_info[abi].vdso_code_end - >>> | ~~~~~~~~~^~~~~ >>> >>> This is all in dead code however that the compiler is unable to >>> eliminate by itself. >>> >>> Change the array to individual local variables that can be >>> dropped in dead code elimination to let the compiler understand >>> this better. >>> >>> Fixes: 0cbc2659123e ("arm64: vdso32: Remove a bunch of #ifdef CONFIG_COMPAT_VDSO guards") >>> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> >> This looks like a nice cleanup to me! I agree we don't need the array >> here. >> >> Reviewed-by: Mark Rutland <mark.rutland@arm.com> > > Thanks! > > I see the patch now conflicts with "mm: forbid splitting special mappings" > in -mm, by Dmitry Safonov. I have rebased my patch on top, should > I send it to Andrew for inclusion in -mm then?
Makes sense to me. I plan to add some more patches on top that will make tracking of user landing (on vdso/sigpage/etc) common between architectures in generic code. So, I think it's probably good idea to keep it in one place, -mm tree seems like a proper place for it.
Thanks, Dmitry
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