From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@armlinux.org.uk (Russell King - ARM Linux) Date: Mon, 23 Oct 2017 10:29:56 +0100 Subject: [PATCH] ARM: compressed: discard ksym/kcrctab input section In-Reply-To: <2b3af288-51b1-561a-a1a9-f5f42f7ca1c4@gmail.com> References: <20170908153143.27279-1-ard.biesheuvel@linaro.org> <33486b3e-8221-92b0-7e18-859be7d0a74b@suse.com> <2b3af288-51b1-561a-a1a9-f5f42f7ca1c4@gmail.com> Message-ID: <20171023092956.GN20805@n2100.armlinux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Oct 23, 2017 at 12:00:46AM +0200, Matthias Brugger wrote: > Hi Ard, > > On 10/21/2017 10:14 AM, Ard Biesheuvel wrote: > > On 21 October 2017 at 08:56, Matthias Brugger wrote: > >> On 09/08/2017 05:31 PM, Ard Biesheuvel wrote: > >>> As it turns out, building the ARM kernel with EFI support pulls in > >>> a couple of sections that we don't really need in the decompressor. > >>> This is due to the fact the the UEFI stub uses sort() to sort the UEFI > >>> memory map, which is an exported symbol pulled in from lib/sort.c. > >>> > >>> Before commit e4bae4d0b5f3 ("arm/efi: Split zImage code and data into > >>> separate PE/COFF sections"), this resulted in the following layout > >>> for the decompressor ELF binary. > >>> > >>> [Nr] Name Type Addr Off Size ES Flg Lk Inf Al > >>> [ 0] NULL 00000000 000000 000000 00 0 0 0 > >>> [ 1] .text PROGBITS 00000000 010000 009b3c 00 AX 0 0 512 > >>> [ 2] .rodata PROGBITS 00009b3c 019b3c 001684 00 A 0 0 4 > >>> [ 3] __ksymtab_strings PROGBITS 0000b1c0 01b1c0 000005 00 A 0 0 1 > >>> [ 4] .data PROGBITS 0000b1c8 01b1c8 000020 00 WA 0 0 8 > >>> [ 5] ___ksymtab+sort PROGBITS 0000b1e8 01b1e8 000008 00 WA 0 0 4 > >>> [ 6] .piggydata PROGBITS 0000b1f0 01b1f0 77ac38 00 A 0 0 1 > >>> [ 7] .got.plt PROGBITS 00785e28 795e28 00000c 04 WA 0 0 4 > >>> [ 8] .got PROGBITS 00785e34 795e34 000028 00 WA 0 0 4 > >>> [ 9] .pad PROGBITS 00785e5c 795e5c 000004 00 WA 0 0 1 > >>> [10] .bss NOBITS 00785e60 795e60 00001c 00 WA 0 0 4 > >>> [11] .stack NOBITS 00785e80 795e60 001000 00 WA 0 0 1 > >>> > >>> Commit e4bae4d0b5f3 made some changes to the linker script to allow the > >>> UEFI firmware to map the decompressor with strict R-X/RW- permissions > >>> before invoking it. Unfortunately, this turns out to break the boot on > >>> some systems, because the linker now also moves the ksymtab/kcrctab > >>> sections around, resulting in .piggydata to appear misaligned. > >>> > >>> [Nr] Name Type Addr Off Size ES Flg Lk Inf Al > >>> [ 0] NULL 00000000 000000 000000 00 0 0 0 > >>> [ 1] .text PROGBITS 00000000 010000 00a93c 00 AX 0 0 4096 > >>> [ 2] .rodata PROGBITS 0000a93c 01a93c 001684 00 A 0 0 4 > >>> [ 3] __ksymtab_strings PROGBITS 0000bfc0 01bfc0 000005 00 A 0 0 1 > >>> [ 4] .piggydata PROGBITS 0000bfc5 01bfc5 77ac47 00 A 0 0 1 > >>> [ 5] .got.plt PROGBITS 00786c0c 796c0c 00000c 04 WA 0 0 4 > >>> [ 6] .got PROGBITS 00786c18 796c18 000028 00 WA 0 0 4 > >>> [ 7] .pad PROGBITS 00786c40 796c40 000008 00 WA 0 0 1 > >>> [ 8] .data PROGBITS 00787000 797000 000200 00 WA 0 0 4096 > >>> [ 9] ___ksymtab+sort PROGBITS 00787200 797200 000008 00 WA 0 0 4 > >>> [10] .bss NOBITS 00787208 797208 00001c 00 WA 0 0 4 > >>> [11] .stack NOBITS 00787228 797208 001000 00 WA 0 0 1 > >>> > >>> So let's align piggydata explicitly, and discard these sections from the > >>> binary. > >>> > >>> Cc: Russell King > >>> Fixes: e4bae4d0b5f3 ("arm/efi: Split zImage code and data into separate ...") > >>> Tested-by: Gregory CLEMENT > >>> Signed-off-by: Ard Biesheuvel > >>> --- > >>> arch/arm/boot/compressed/piggy.S | 1 + > >>> arch/arm/boot/compressed/vmlinux.lds.S | 1 + > >>> 2 files changed, 2 insertions(+) > >>> > >> > >> This fixes the boot regression on bananapi-r2. > >> Thanks! Feel free to add: > >> > >> Tested-by: Matthias Brugger > >> > > > > Thanks for confirming Matthias. Could you please check whether this > > patch from Arnd > > > > https://marc.info/?l=linux-kernel&m=150852980119217&w=2 > > > > fixes the issue as well? (after reverting this one) > > > > After only applying this patch on top of v4.14-rc5 I was not able to boot. Which decompression method are you using? What does objdump -h arch/arm/boot/vmlinux say? Thanks. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up