Greeting,

FYI, we noticed the following commit (built with gcc-7):

commit: 98666f218f188f9cbd60560cc40eb4c4bdb67c0b ("bpf: Fix tnum constraints for 32-bit comparisons")
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable-rc.git linux-5.6.y

in testcase: kernel-selftests
with following parameters:

	group: kselftests-bpf

test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel.
test-url: https://www.kernel.org/doc/Documentation/kselftest.txt


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

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




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



# #555/p jgt32: range bound deduction, reg op imm FAIL
# Unexpected success to load!
# verification time 59 usec
# stack depth 8
# processed 21 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
# #556/p jgt32: range bound deduction, reg1 op reg2, reg1 unknown FAIL
# Unexpected success to load!
# verification time 64 usec
# stack depth 8
# processed 22 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
# #557/p jle32: range bound deduction, reg1 op reg2, reg2 unknown FAIL
# Unexpected success to load!
# verification time 80 usec
# stack depth 8
# processed 22 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1


To reproduce:

        # build kernel
	cd linux
	cp config-5.6.4-00255-g98666f218f188 .config
	make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage

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



Thanks,
Rong Chen