Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
On 8 September 2017 at 15:33, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:54, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:50, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On jeu., juin 29 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
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.
quoted
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
quoted
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 <redacted>
Thanks,
Gregory
quoted hunk
diff --git a/arch/arm/boot/compressed/vmlinux.lds.S
b/arch/arm/boot/compressed/vmlinux.lds.S
index 7a4c59154361..dfcc2baa0077 100644
--- a/arch/arm/boot/compressed/vmlinux.lds.S
+++ b/arch/arm/boot/compressed/vmlinux.lds.S
@@ -29,6 +29,11 @@ SECTIONS
* of the text/got segments.
*/
*(.data)
+ /*
+ * C code that is shared with the kernel proper (but rebuilt for the
+ * decompressor) may contain exports that we have no use for here.
+ */
+ *(*ksymtab* *kcrctab*)
}
. = TEXT_START;
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
On 8 September 2017 at 15:56, Gregory CLEMENT
[off-list ref] wrote:
Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 15:33, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:54, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:50, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On jeu., juin 29 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
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.
quoted
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
quoted
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 <redacted>
Thanks,
Gregory
Thanks a lot. I will send it out today.
On 8 September 2017 at 15:57, Ard Biesheuvel [off-list ref] wrote:
On 8 September 2017 at 15:56, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 15:33, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On ven., sept. 08 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:54, Ard Biesheuvel [off-list ref] wrote:
quoted
On 8 September 2017 at 14:50, Gregory CLEMENT
[off-list ref] wrote:
quoted
Hi Ard,
On jeu., juin 29 2017, Ard Biesheuvel [off-list ref] wrote:
quoted
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.
quoted
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
quoted
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 <redacted>
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.