On Tue, Dec 03, 2019 at 01:03:04PM +0100, Greg KH wrote:
On Tue, Dec 03, 2019 at 12:44:15PM +0530, Amol Grover wrote:
On Tue, Dec 03, 2019 at 07:40:52AM +0100, Greg KH wrote:
On Tue, Dec 03, 2019 at 11:55:03AM +0530, Amol Grover wrote:
Compiled, Booted, however I'm getting the following errors when running "make kselftest"
sudo dmesg -l alert
[34381.903893] BUG: kernel NULL pointer dereference, address: 0000000000000008 [34381.903904] #PF: supervisor read access in kernel mode [34381.903908] #PF: error_code(0x0000) - not-present page
Which test causes this problem?
IIRC I didn't run make kselftest with summary=1 option. Is there any other way to get that information? The logs that kselftest generated also don't seem to help in this.
Watch the output when you run this? I don't know, try re-running it with that option.
I did. The tls test under tools/testing/selftests/net seems to be the culprit. More information below.
ANd is it new in 5.3.13?
I previously ran kselftest on 5.4-rc7 and 5.3.9 (default kernel shipped by openSUSE), both were fine. However, a bit of backstory:
A day ago I used kselftest from the linux/next branch and ran it (w/o sudo). It showed me the exact same error. However, I was running a modified version of 5.3.13, but those modifications were actually trivial (5 lines changed) and shouldn't have resulted in this kernel error. So, I switched to the vanilla 5.3.13 and ran kselftest (w/o sudo) again. I ran it 3 times (w/o any errors), switched back to the modified kernel and ran kselftest (w/o root) 2 more times and everything was fine. Then I decided to test the vanilla one again for the 4th time, but this time I ran kselftest as root where this BUG popped again.
Try a kernel.org 5.3.9 and if that works, then try 5.3.13 and if that fails, run 'git bisect' and try to find the offending kernel commit.
After finding the test that was resulting in the BUG, I decided to check again against 5.3.13 (= BUG). I had recently compiled 5.4.1 as well so I decided to run this test against 5.4.1 (= BUG). After this I realized I had 5.3.9 kernel kept away so I decided to run the test against that too (= BUG). After 5.3.9's error something didn't feel right. Mind you I was using kselftest from linux/next so I got suspicious about the test it-self. I ran kselftest from 5.4.1 on kernels 5.4.1 and 5.3.13 and none of them resulted in the BUG this time. After a bit of digging I found out the next branch had 2 additional test cases for the tls test, and one of them (sendmsg_fragmented) is the actual culprit that was causing all this.
TL;DR: tools/testing/selftests/net/tls.ci:sendmsg_fragmented from the next tree appears to be broken(?)
Thanks Amol
thanks,
greg k-h