From mboxrd@z Thu Jan 1 00:00:00 1970 From: matthias.bgg@gmail.com (Matthias Brugger) Date: Mon, 23 Oct 2017 23:15:18 +0200 Subject: [PATCH] ARM: compressed: discard ksym/kcrctab input section In-Reply-To: <20171023092956.GN20805@n2100.armlinux.org.uk> References: <20170908153143.27279-1-ard.biesheuvel@linaro.org> <33486b3e-8221-92b0-7e18-859be7d0a74b@suse.com> <2b3af288-51b1-561a-a1a9-f5f42f7ca1c4@gmail.com> <20171023092956.GN20805@n2100.armlinux.org.uk> Message-ID: <973a510c-559f-152b-44af-f4ae022f1d60@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/23/2017 11:29 AM, Russell King - ARM Linux wrote: > 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? uImage/zImage > > What does objdump -h arch/arm/boot/vmlinux say? > arch/arm/boot/compressed/vmlinux: file format elf32-littlearm Sections: Idx Name Size VMA LMA File off Algn 0 .text 0000b06c 00000000 00000000 00010000 2**12 CONTENTS, ALLOC, LOAD, READONLY, CODE 1 .rodata 000016cc 0000b06c 0000b06c 0001b06c 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 2 __ksymtab_strings 00000005 0000c738 0000c738 0001c738 2**0 CONTENTS, ALLOC, LOAD, READONLY, DATA 3 .piggydata 007ce9c5 0000c73d 0000c73d 0001c73d 2**0 CONTENTS, ALLOC, LOAD, READONLY, DATA 4 .got.plt 0000000c 007db104 007db104 007eb104 2**2 CONTENTS, ALLOC, LOAD, DATA 5 .got 00000028 007db110 007db110 007eb110 2**2 CONTENTS, ALLOC, LOAD, DATA 6 .pad 00000008 007db138 007db138 007eb138 2**0 CONTENTS, ALLOC, LOAD, DATA 7 .data 00000200 007dc000 007dc000 007ec000 2**12 CONTENTS, ALLOC, LOAD, DATA 8 ___ksymtab+sort 00000008 007dc200 007dc200 007ec200 2**2 CONTENTS, ALLOC, LOAD, DATA 9 .bss 0000001c 007dc208 007dc208 007ec208 2**2 ALLOC 10 .stack 00001000 007dc228 007dc228 007ec208 2**0 ALLOC 11 .comment 0000002d 00000000 00000000 007ec208 2**0 CONTENTS, READONLY 12 .ARM.attributes 0000002d 00000000 00000000 007ec235 2**0 CONTENTS, READONLY 13 .debug_line 00007088 00000000 00000000 007ec262 2**0 CONTENTS, READONLY, DEBUGGING 14 .debug_info 00057677 00000000 00000000 007f32ea 2**0 CONTENTS, READONLY, DEBUGGING 15 .debug_abbrev 00003bc2 00000000 00000000 0084a961 2**0 CONTENTS, READONLY, DEBUGGING 16 .debug_aranges 00000308 00000000 00000000 0084e528 2**3 CONTENTS, READONLY, DEBUGGING 17 .debug_ranges 00000e78 00000000 00000000 0084e830 2**3 CONTENTS, READONLY, DEBUGGING 18 .debug_frame 00002228 00000000 00000000 0084f6a8 2**2 CONTENTS, READONLY, DEBUGGING 19 .debug_loc 00005bff 00000000 00000000 008518d0 2**0 CONTENTS, READONLY, DEBUGGING 20 .debug_str 00008c41 00000000 00000000 008574cf 2**0 CONTENTS, READONLY, DEBUGGING This objdump is with Arnd Bergmans patch applied on top of v4.14-rc5. Beware that Ard provided a patch against efi/libstub which independently fixes the boot regression: "efi/libstub: arm: omit sorting of the UEFI memory map" Regards, Matthias