Re: bpf selftest failed in 5.4.210 kernel

From: RAJESH DASARI
Date: Thu Aug 18 2022 - 14:34:06 EST


I tried with git bisect between v5.4.210(bad) and v5.4.209(good).
Everytime I did bisect I compiled the kernel , booted my instance with
the new kernel and ran the selftests after trying out for 3 times ,
git bisect pointed to the below commit as a first bad commit.

git bisect bad
9d6f67365d9cdb389fbdac2bb5b00e59e345930e is the first bad commit
commit 9d6f67365d9cdb389fbdac2bb5b00e59e345930e
Author: John Fastabend <john.fastabend@xxxxxxxxx>
Date: Wed Aug 3 17:50:03 2022 +0300

bpf: Test_verifier, #70 error message updates for 32-bit right shift

Thanks,
Rajesh Dasari.

On Thu, Aug 18, 2022 at 8:24 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Aug 17, 2022 at 09:22:00PM +0300, RAJESH DASARI wrote:
> > Hi ,
> >
> > We are running bpf selftests on 5.4.210 kernel version and we see that
> > test case 11 of test_align failed. Please find the below error.
> >
> > selftests: bpf: test_align
> > Test 11: pointer variable subtraction ... Failed to find match 16:
> > R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2;
> > 0xfffffffc)
> > # func#0 @0
> > # 0: R1=ctx(id=0,off=0,imm=0) R10=fp0
> > # 0: (61) r2 = *(u32 *)(r1 +76)
> > # 1: R1=ctx(id=0,off=0,imm=0) R2_w=pkt(id=0,off=0,r=0,imm=0) R10=fp0
> > # 1: (61) r3 = *(u32 *)(r1 +80)
> >
> > For complete errors please see the attached file. The same test case
> > execution was successful in the 5.4.209 version , could you please let
> > me know any known issue with the recent changes in 5.4.210 and how to
> > fix these errors.
>
> Can you use 'git bisect' to find the offending commit?
>
> thanks,
>
> greg k-h