[SRU][K/raspi][PATCH 0/3] armhf kernels are compiled with gcc-11 (LP: #1995853)

[Juerg Haefliger]

[Impact]

We currently compile the Kinetic raspi armhf kernels with gcc-11 because a gcc-12-compiled armhf raspi kernel won't boot or hang. We need to figure out what's going on and fix it to be able to go back to the default compiler.

Turns out that the downstream dwc_otg driver is broken when compiled with gcc-12 and 'standard' kernel compiler flags. I confirmed that the system seems to work reliably after switching to the upstream dwc2 driver. 

Relevant gcc-12 changes:

arm
    Support is added for accessing the stack canary value via the TLS register through the -fstack-protector-guard=tls and -mstack-protector-guard-offset= options. This intended for use in Linux kernel development. Please refer to the documentation for more details.

[Test Case]

Boot armhf kernel and exercise the system. It either won't come up at all or hang/freeze later on.

[Fix]
1a62e5b2363d ("drivers: dwc_otg: stop GCC from patching FIQ functions") from github.com/raspberrypi/linux

[Regression Potential]

Setting a specific compiler flag and switching to a new GCC version. What could possibly go wrong?

Jonathan Bell (1):
  drivers: dwc_otg: stop GCC from patching FIQ functions

Juerg Haefliger (2):
  UBUNTU: Revert "UBUNTU: [Packaging] raspi: Use gcc-11 for armhf"
  UBUNTU: [Config] raspi: updateconfigs for gcc-12 for armhf

 debian.raspi/config/arm64/config.common.arm64 | 1 -
 debian.raspi/config/armhf/config.common.armhf | 3 +--
 debian.raspi/config/config.common.ubuntu      | 2 ++
 debian/rules.d/0-common-vars.mk               | 9 ++-------
 debian/scripts/misc/kernelconfig              | 9 +--------
 drivers/usb/host/dwc_otg/Makefile             | 1 +
 drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c    | 2 +-
 7 files changed, 8 insertions(+), 19 deletions(-)

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2.34.1