| Message ID | CAKv+Gu8hcT=_1iF4gaS==uGQWAb9-i0Y=XJ-MqgfQQyn1RmGtQ@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Ard, On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > On 8 September 2017 at 15:57, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >> On 8 September 2017 at 15:56, Gregory CLEMENT >> <gregory.clement@free-electrons.com> wrote: >>> Hi Ard, >>> >>> On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>> >>>> On 8 September 2017 at 15:33, Gregory CLEMENT >>>> <gregory.clement@free-electrons.com> wrote: >>>>> Hi Ard, >>>>> >>>>> On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>> >>>>>> On 8 September 2017 at 14:54, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>>>> On 8 September 2017 at 14:50, Gregory CLEMENT >>>>>>> <gregory.clement@free-electrons.com> wrote: >>>>>>>> Hi Ard, >>>>>>>> >>>>>>>> On jeu., juin 29 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>>>>> >>>>>>>>> To prevent unintended modifications to the kernel text (malicious or >>>>>>>>> otherwise) while running the EFI stub, describe the kernel image as >>>>>>>>> two separate sections: a .text section with read-execute permissions, >>>>>>>>> covering .text, .rodata, .piggytext and the GOT sections (which the >>>>>>>>> stub does not care about anyway), and a .data section with read-write >>>>>>>>> permissions, covering .data and .bss. >>>>>>>>> >>>>>>>>> This relies on the firmware to actually take the section permission >>>>>>>>> flags into account, but this is something that is currently being >>>>>>>>> implemented in EDK2, which means we will likely start seeing it in >>>>>>>>> the wild between one and two years from now. >>>>>>>> >>>>>>>> This patch had been merged in mainline yesterday and now prevent the >>>>>>>> Marvell Armada 370 and the Armada XP based SoC to boot. I also suspect >>>>>>>> that more Socs are impacted because the number of boot fail exploded >>>>>>>> according to kci: >>>>>>>> https://kernelci.org/boot/all/job/mainline/branch/master/kernel/v4.13-8899-g8dc5b3a6cb2f/ >>>>>>>> >>>>>>> >>>>>>> Ouch. >>>>>>> >>>>>>>> I found this patch after bisecting (I can provide the bisect log if >>>>>>>> needed). >>>>>>>> >>>>>>>> The kernel failed to boot only if CONFIG_EFI is enabled so it occurs in >>>>>>>> multi_v7_defconfig but not with mvebu_v7_defconfig. >>>>>>>> >>>>>>>> Currently the solution is to revert this patch. >>>>>>>> >>>>>>>> Have you a better option? >>>>>>>> >>>>>>> >>>>>>> I will investigate. >>>>>> >>>>>> I cannot reproduce this on QEMU or my Beaglebone white. I have tried a >>>>>> locally built zImage as well as the one built by kernelci. >>>>>> >>>>>> Could you please try whether this fixes things? It does not explain >>>>>> anything but it will help me figure out what is going on (hopefully) >>>>> >>>>> I've just tested this change and it didn't fix anything. >>>>> >>>>> Gregory >>>>> >>>>>> >>>>>> >>>>>> diff --git a/arch/arm/boot/compressed/efi-header.S >>>>>> b/arch/arm/boot/compressed/efi-header.S >>>>>> index c94a88ae834d..671a6e5b7b99 100644 >>>>>> --- a/arch/arm/boot/compressed/efi-header.S >>>>>> +++ b/arch/arm/boot/compressed/efi-header.S >>>>>> @@ -127,7 +127,7 @@ section_table: >>>>>> >>>>>> .set section_count, (. - section_table) / 40 >>>>>> >>>>>> - .align 12 >>>>>> + .align 9 >>>>>> __efi_start: >>>>>> #endif >>>>>> .endm >>>>> >>>> >>>> >>>> How about this? >>> >>> It fixed the bug! (I tested with and without your previous patch and it >>> worked in both case) >>> >>> When you will send your patch, you can add my: >>> Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> >>> > > Would you mind checking whether this fixes the issue as well? > > diff --git a/arch/arm/boot/compressed/piggy.S b/arch/arm/boot/compressed/piggy.S > index f72088495f43..5d52c556dd32 100644 > --- a/arch/arm/boot/compressed/piggy.S > +++ b/arch/arm/boot/compressed/piggy.S > @@ -1,5 +1,6 @@ > .section .piggydata,#alloc > .globl input_data > + .align 2 > input_data: > .incbin "arch/arm/boot/compressed/piggy_data" > .globl input_data_end > > There may be other reasons than ksymtab entries that could result in > piggydata ending up unaligned in the decompressor (which is what > caused the issue before) > This is a better fix, because it addresses the root cause. I've tested this single patch and it does not fix the boot issue :( Gregory
On 8 September 2017 at 16:17, Gregory CLEMENT <gregory.clement@free-electrons.com> wrote: > Hi Ard, > > On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > >> On 8 September 2017 at 15:57, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>> On 8 September 2017 at 15:56, Gregory CLEMENT >>> <gregory.clement@free-electrons.com> wrote: >>>> Hi Ard, >>>> >>>> On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>> >>>>> On 8 September 2017 at 15:33, Gregory CLEMENT >>>>> <gregory.clement@free-electrons.com> wrote: >>>>>> Hi Ard, >>>>>> >>>>>> On ven., sept. 08 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>>> >>>>>>> On 8 September 2017 at 14:54, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>>>>> On 8 September 2017 at 14:50, Gregory CLEMENT >>>>>>>> <gregory.clement@free-electrons.com> wrote: >>>>>>>>> Hi Ard, >>>>>>>>> >>>>>>>>> On jeu., juin 29 2017, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >>>>>>>>> >>>>>>>>>> To prevent unintended modifications to the kernel text (malicious or >>>>>>>>>> otherwise) while running the EFI stub, describe the kernel image as >>>>>>>>>> two separate sections: a .text section with read-execute permissions, >>>>>>>>>> covering .text, .rodata, .piggytext and the GOT sections (which the >>>>>>>>>> stub does not care about anyway), and a .data section with read-write >>>>>>>>>> permissions, covering .data and .bss. >>>>>>>>>> >>>>>>>>>> This relies on the firmware to actually take the section permission >>>>>>>>>> flags into account, but this is something that is currently being >>>>>>>>>> implemented in EDK2, which means we will likely start seeing it in >>>>>>>>>> the wild between one and two years from now. >>>>>>>>> >>>>>>>>> This patch had been merged in mainline yesterday and now prevent the >>>>>>>>> Marvell Armada 370 and the Armada XP based SoC to boot. I also suspect >>>>>>>>> that more Socs are impacted because the number of boot fail exploded >>>>>>>>> according to kci: >>>>>>>>> https://kernelci.org/boot/all/job/mainline/branch/master/kernel/v4.13-8899-g8dc5b3a6cb2f/ >>>>>>>>> >>>>>>>> >>>>>>>> Ouch. >>>>>>>> >>>>>>>>> I found this patch after bisecting (I can provide the bisect log if >>>>>>>>> needed). >>>>>>>>> >>>>>>>>> The kernel failed to boot only if CONFIG_EFI is enabled so it occurs in >>>>>>>>> multi_v7_defconfig but not with mvebu_v7_defconfig. >>>>>>>>> >>>>>>>>> Currently the solution is to revert this patch. >>>>>>>>> >>>>>>>>> Have you a better option? >>>>>>>>> >>>>>>>> >>>>>>>> I will investigate. >>>>>>> >>>>>>> I cannot reproduce this on QEMU or my Beaglebone white. I have tried a >>>>>>> locally built zImage as well as the one built by kernelci. >>>>>>> >>>>>>> Could you please try whether this fixes things? It does not explain >>>>>>> anything but it will help me figure out what is going on (hopefully) >>>>>> >>>>>> I've just tested this change and it didn't fix anything. >>>>>> >>>>>> Gregory >>>>>> >>>>>>> >>>>>>> >>>>>>> diff --git a/arch/arm/boot/compressed/efi-header.S >>>>>>> b/arch/arm/boot/compressed/efi-header.S >>>>>>> index c94a88ae834d..671a6e5b7b99 100644 >>>>>>> --- a/arch/arm/boot/compressed/efi-header.S >>>>>>> +++ b/arch/arm/boot/compressed/efi-header.S >>>>>>> @@ -127,7 +127,7 @@ section_table: >>>>>>> >>>>>>> .set section_count, (. - section_table) / 40 >>>>>>> >>>>>>> - .align 12 >>>>>>> + .align 9 >>>>>>> __efi_start: >>>>>>> #endif >>>>>>> .endm >>>>>> >>>>> >>>>> >>>>> How about this? >>>> >>>> It fixed the bug! (I tested with and without your previous patch and it >>>> worked in both case) >>>> >>>> When you will send your patch, you can add my: >>>> Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> >>>> >> >> Would you mind checking whether this fixes the issue as well? >> >> diff --git a/arch/arm/boot/compressed/piggy.S b/arch/arm/boot/compressed/piggy.S >> index f72088495f43..5d52c556dd32 100644 >> --- a/arch/arm/boot/compressed/piggy.S >> +++ b/arch/arm/boot/compressed/piggy.S >> @@ -1,5 +1,6 @@ >> .section .piggydata,#alloc >> .globl input_data >> + .align 2 >> input_data: >> .incbin "arch/arm/boot/compressed/piggy_data" >> .globl input_data_end >> >> There may be other reasons than ksymtab entries that could result in >> piggydata ending up unaligned in the decompressor (which is what >> caused the issue before) >> This is a better fix, because it addresses the root cause. > > I've tested this single patch and it does not fix the boot issue :( > OK, strange. Anyway, thanks for testing. I will post the original fix then.
diff --git a/arch/arm/boot/compressed/piggy.S b/arch/arm/boot/compressed/piggy.S index f72088495f43..5d52c556dd32 100644 --- a/arch/arm/boot/compressed/piggy.S +++ b/arch/arm/boot/compressed/piggy.S @@ -1,5 +1,6 @@ .section .piggydata,#alloc .globl input_data + .align 2 input_data: .incbin "arch/arm/boot/compressed/piggy_data" .globl input_data_end