Open qjerome opened 3 months ago
Similar behavior has been observed for
Linux Kernel: 6.6.28-lts
Attach point: ___sys_recvmsg
, ____sys_recvmsg
and sock_recvmsg
I spent several hours trying to find more about this issue but I really have no inspiration to find where this comes from exactly ... I really want to find what happens here but lacking inspiration ! IDK maybe @dave-tucker or @alessandrod have ideas ?
I am currently thinking that to fix this I should actually add a probe to system resume and actually reload the program on resume ! But it would just fix the symptom, not the root cause.
cc: @vadorovsky
Minimal repro code for the issue:
1) sudo bpftrace -e 'kretprobe:__sys_recvmsg { printf("%s\n", comm); }'
2) systemctl suspend
3) Resume
4) see that nothing gets printed anymore on stdout
The issue is very likely located in Linux Kernel, an bug report as been filled and can be tracked at https://bugzilla.kernel.org/show_bug.cgi?id=218775
Linux Kernel: 6.6.25-1-lts
I came across a very strange issue, which may not be caused by Aya but may be solvable in Aya.
Issue description: I noticed that when a
kretprobe
is attached to__sys_recvmsg
and the system is suspended (in RAM) the probe stops working when the system resumes. It is yet impossible for me to explain this behavior.Steps to reproduce:
__sys_recvmsg
kernel function (___sys_recvmsg
also suffers from the same issue)sudo bpftool prog profile tag $PROG_TAG duration 5 cycles
and observe the result, you should see non null values.systemctl suspend
sudo bpftool prog profile tag $PROG_TAG duration 5 cycles
, you should see all zeros (that's what I see) even though the program is still alive.