Hi Kees and Clang team,

We found there's no kernel logs after commit a52f8a59ae if compiling
with clang. I have attached the dmesg and parent-commit-dmesg for your
comparison.

Below is the report from kernel test robot:

Greeting,

FYI, we noticed the following commit (built with clang-15):

commit: a52f8a59aef46b59753e583bf4b28fccb069ce64 ("fortify: Explicitly 
disable Clang support")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master

in testcase: trinity
version: trinity-static-i386-x86_64-1c734c75-1_2020-01-06
with following parameters:

	runtime: 300s
	group: group-03

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G

caused below changes (please refer to attached dmesg/kmsg for entire 
log/backtrace):


+--------------------------------------------------------------------------+------------+------------+
| 
    | c430f60036 | a52f8a59ae |
+--------------------------------------------------------------------------+------------+------------+
| boot_successes 
    | 22         | 55         |
| boot_failures 
    | 190        | 218        |
| Mem-Info 
    | 14         |            |
| BUG:kernel_NULL_pointer_dereference,address 
    | 164        |            |
| Oops:#[##] 
    | 171        |            |
| EIP:__ubsan_handle_shift_out_of_bounds 
    | 168        |            |
| Kernel_panic-not_syncing:Fatal_exception 
    | 171        |            |
| UBSAN:shift-out-of-bounds_in(null) 
    | 10         |            |
| WARNING:at_lib/ubsan.c:#val_is_negative 
    | 5          |            |
| EIP:val_is_negative 
    | 5          |            |
| WARNING:at_lib/ubsan.c:#get_signed_val 
    | 3          |            |
| EIP:get_signed_val 
    | 3          |            |
| WARNING:at_lib/ubsan.c:#__ubsan_handle_shift_out_of_bounds 
    | 4          |            |
| invoked_oom-killer:gfp_mask=0x 
    | 8          |            |
| BUG:unable_to_handle_page_fault_for_address 
    | 7          |            |
| EIP:val_to_string 
    | 3          |            |
| Out_of_memory_and_no_killable_processes 
    | 1          |            |
| Kernel_panic-not_syncing:System_is_deadlocked_on_memory 
    | 1          |            |
| 
BUG:sleeping_function_called_from_invalid_context_at_arch/x86/mm/fault.c 
| 4          |            |
| EIP:string_nocheck 
    | 4          |            |
| BUG:kernel_reboot-without-warning_in_test_stage 
    | 0          | 218        |
+--------------------------------------------------------------------------+------------+------------+


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <rong.a.chen@intel.com>


Starting udev
/lkp/lkp/src/bin/lkp-setup-rootfs: line 78: can't create 
/sys/devices/system/cpu/microcode/reload: nonexistent directory
LKP: ttyS0: 390: Kernel tests: Boot OK!
LKP: ttyS0: 390: HOSTNAME vm-snb-i386-17, MAC 52:54:00:12:34:56, kernel 
5.15.0-rc2-00016-ga52f8a59aef4 1
Poky (Yocto Project Reference Distro) 2.7+snapshot vm-snb-i386-17 /dev/ttyS0
BUG: kernel reboot-without-warning in test stage
Linux version 5.15.0-rc2-00016-ga52f8a59aef4 #1
Command line: ip=::::vm-snb-i386-17::dhcp root=/dev/ram0 
RESULT_ROOT=/result/trinity/group-03-300s/vm-snb-i386/yocto-i386-minimal-20190520.cgz/i386-randconfig-a014-20220620/clang-15/a52f8a59aef46b59753e583bf4b28fccb069ce64/21 
BOOT_IMAGE=/pkg/linux/i386-randconfig-a014-20220620/clang-15/a52f8a59aef46b59753e583bf4b28fccb069ce64/vmlinuz-5.15.0-rc2-00016-ga52f8a59aef4 
branch=linus/master 
job=/lkp/jobs/scheduled/vm-snb-i386-17/trinity-group-03-300s-yocto-i386-minimal-20190520.cgz-a52f8a59aef46b59753e583bf4b28fccb069ce64-20220623-19556-segv88-3.yaml 
user=lkp ARCH=i386 kconfig=i386-randconfig-a014-20220620 
commit=a52f8a59aef46b59753e583bf4b28fccb069ce64 vmalloc=256M 
initramfs_async=0 page_owner=on max_uptime=2100 LKP_SERVER=10.239.97.5 
selinux=0 debug apic=debug sysrq_always_enabled 
rcupdate.rcu_cpu_stall_timeout=100 net.ifnames=0 printk.devkmsg=on 
panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 
prompt_ramdisk=0 drbd.minor_count=8 systemd.log_level=err 
ignore_loglevel console=tty0 earlyprintk=ttyS0,115200 
console=ttyS0,115200 vga=normal rw rcuperf.shutdown=0 watchdog_thresh=240

Kboot worker: lkp-worker16
Elapsed time: 60


To reproduce:

         # build kernel
	cd linux
	cp config-5.15.0-rc2-00016-ga52f8a59aef4 .config
	make HOSTCC=clang-15 CC=clang-15 ARCH=i386 olddefconfig prepare 
modules_prepare bzImage modules
	make HOSTCC=clang-15 CC=clang-15 ARCH=i386 
INSTALL_MOD_PATH=<mod-install-dir> modules_install
	cd <mod-install-dir>
	find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz


         git clone https://github.com/intel/lkp-tests.git
         cd lkp-tests
         bin/lkp qemu -k <bzImage> -m modules.cgz job-script # 
job-script is attached in this email

         # if come across any failure that blocks the test,
         # please remove ~/.lkp and /lkp dir to run from a clean state.



-- 
0-DAY CI Kernel Test Service
https://01.org/lkp