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package/binutils: Cortex-M targets require version <2.29

PATCH New Laurent GONZALEZ 2 participants 6 messages Apr 16, 2018 – Apr 17, 2018

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Laurent GONZALEZ

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#0 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

binutils 2.29 changed the implementation of adr pseudo instruction it breaks linux kernel and impacts Cortex-M targets (eg. stm32)

Signed-off-by Laurent GONZALEZ <[email protected]>
---
 package/binutils/Config.in.host | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
package/binutils/Config.in.host +3 -2
index 22478d917a..ef957777ee 100644
@@ -2,8 +2,9 @@ comment "Binutils Options"
 
 choice
 	prompt "Binutils Version"
-	default BR2_BINUTILS_VERSION_2_29_X if !BR2_arc
-	default BR2_BINUTILS_VERSION_ARC if BR2_arc
+	default BR2_BINUTILS_VERSION_2_28_X if BR2_ARM_CPU_ARMV7M
+	default BR2_BINUTILS_VERSION_2_29_X if !BR2_arc && !BR2_ARM_CPU_ARMV7M
+	default BR2_BINUTILS_VERSION_ARC if BR2_arc && !BR2_ARM_CPU_ARMV7M
 	help
 	  Select the version of binutils you wish to use.
Signature · 1 line
2.11.0
#1 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

Hello Laurent,

Thanks for this bug report and patch!

Quoted 2 lines · Laurent GONZALEZ

binutils 2.29 changed the implementation of adr pseudo instruction it breaks linux kernel and impacts Cortex-M targets (eg. stm32)

Do you have a reference for this issue ? I assume it is going to be fixed at some point, because it is not possible to stay forever with older binutils version, right ? Is there a binutils bug filled in for this problem ?

package/binutils/Config.in.host comment "Binutils Options" · line 7

Quoted 7 lines

choice

package/binutils/Config.in.host +3 -2
 	prompt "Binutils Version"
-	default BR2_BINUTILS_VERSION_2_29_X if !BR2_arc
-	default BR2_BINUTILS_VERSION_ARC if BR2_arc
+	default BR2_BINUTILS_VERSION_2_28_X if BR2_ARM_CPU_ARMV7M
+	default BR2_BINUTILS_VERSION_2_29_X if !BR2_arc && !BR2_ARM_CPU_ARMV7M
+	default BR2_BINUTILS_VERSION_ARC if BR2_arc && !BR2_ARM_CPU_ARMV7M

This solution only ensures that the default is not binutils 2.29, but it does not prevent the user from choosing 2.29 for a Cortex-M target. Instead, we would need to add some "depends on !BR2_ARM_CPU_ARMV7M" on the binutils 2.29 option. However, I'd like to first understand better the issue, and see if there is already a patch in upstream binutils to fix it.

Thanks!

Thomas

Signature · 3 lines
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
author
#2 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

Quoted 1 line · Thomas Petazzoni

Hello Laurent, > > Thanks for this bug report and patch! > > On Mon, 16 Apr 2018 14:21:18 +0200, Laurent GONZALEZ wrote: >> binutils 2.29 changed the implementation of adr pseudo instruction >> it breaks linux kernel and impacts Cortex-M targets (eg. stm32) > > Do you have a reference for this issue ? I assume it is going to be > fixed at some point, because it is not possible to stay forever with > older binutils version, right ? Is there a binutils bug filled in for > this problem ? Unfortunately, I think binutils will not change. The new adr behavior

broke linux kernel, ffmpeg and ssl. Nowadays, only linux kernel has not been fixed. We can either avoid bintutils <2.29 or patch the kernel.

Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line

choice prompt "Binutils Version" - default >> BR2_BINUTILS_VERSION_2_29_X if !BR2_arc - default >> BR2_BINUTILS_VERSION_ARC if BR2_arc + default >> BR2_BINUTILS_VERSION_2_28_X if BR2_ARM_CPU_ARMV7M + default >> BR2_BINUTILS_VERSION_2_29_X if !BR2_arc && !BR2_ARM_CPU_ARMV7M + >> default BR2_BINUTILS_VERSION_ARC if BR2_arc && !BR2_ARM_CPU_ARMV7M > > This solution only ensures that the default is not binutils 2.29, > but it does not prevent the user from choosing 2.29 for a Cortex-M > target. Instead, we would need to add some "depends on > !BR2_ARM_CPU_ARMV7M" on the binutils 2.29 option. Good catch, i'll submit a new patch asap.

--
Laurent

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#3 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

Hello Laurent,

Could you ask Thunderbird to not send a HTML version of your e-mails when sending to this mailing list?

Quoted 4 lines · Laurent GONZALEZ

Unfortunately, I think binutils will not change. The new adr behavior broke linux kernel, ffmpeg and ssl. Nowadays, only linux kernel has not been fixed. We can either avoid bintutils <2.29 or patch the kernel.

Do you have some pointers/references about this issue ?

Quoted 1 line

Good catch, i'll submit a new patch asap.

Well, as I said, I'm not really convinced by a solution that consists in excluding binutils 2.29 and binutils 2.30 for ARMv7-M. Indeed, once binutils 2.31 is released, we will make binutils 2.30 the default version, and remove support for binutils 2.28.

Hence the proper solution is to move forward and fix the kernel problem, rather than force the use of older binutils.

Best regards,

Thomas Petazzoni

Signature · 3 lines
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
author
#4 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

Quoted 1 line · Thomas Petazzoni

On Tue, 17 Apr 2018 09:04:39 +0200, Laurent GONZALEZ wrote: > >> Unfortunately, I think binutils will not change. The new adr >> behavior broke linux kernel, ffmpeg and ssl. Nowadays, only linux >> kernel has not been fixed. We can either avoid bintutils <2.29 or >> patch the kernel. > > Do you have some pointers/references about this issue ? This lkml message is probably the most interresting one in the thread:

http://lists.infradead.org/pipermail/linux-arm-kernel/2017-November/543467.html

Quoted 1 line

Well, as I said, I'm not really convinced by a solution that > consists in excluding binutils 2.29 and binutils 2.30 for ARMv7-M. > Indeed, once binutils 2.31 is released, we will make binutils 2.30 > the default version, and remove support for binutils 2.28. > > Hence the proper solution is to move forward and fix the kernel > problem, rather than force the use of older binutils. What about:

http://lists.infradead.org/pipermail/linux-arm-kernel/2018-March/565390.html

--
Laurent

author
#5 lore raw

PATCH 1/1 package/binutils: Cortex-M targets require version <2.29

In reply to Thomas Petazzoni

I resend my previous mail for clarity.

Quoted 4 lines · Thomas Petazzoni

Hello Laurent,

Could you ask Thunderbird to not send a HTML version of your e-mails when sending to this mailing list?

Thunderbird does so many things on my behalf !

Quoted 7 lines · Laurent GONZALEZ
Quoted 5 lines

Unfortunately, I think binutils will not change. The new adr behavior broke linux kernel, ffmpeg and ssl. Nowadays, only linux kernel has not been fixed. We can either avoid bintutils <2.29 or patch the kernel.

Do you have some pointers/references about this issue ?

This lkml message is probably the most interresting one in the thread:

http://lists.infradead.org/pipermail/linux-arm-kernel/2017-November/543467.html

Quoted 8 lines
Quoted 1 line

Good catch, i'll submit a new patch asap.

Well, as I said, I'm not really convinced by a solution that consists in excluding binutils 2.29 and binutils 2.30 for ARMv7-M. Indeed, once binutils 2.31 is released, we will make binutils 2.30 the default version, and remove support for binutils 2.28.

Hence the proper solution is to move forward and fix the kernel problem, rather than force the use of older binutils.

What about:

http://lists.infradead.org/pipermail/linux-arm-kernel/2018-March/565390.html

--
Laurent