tree 51aaa8765d68749e2a364ede5f21150e91b23190
parent daf6f56870c6386ecb1c43b0b9aaa4cc78e4d424
author Arun P. Mohanan <arun.p.m@linux.intel.com> 1635519626 +0530
committer gokulsanker <gokul.sanker.v.g@intel.com> 1638388800 +0530

cpuSensor:Check object validity in async callback

Sometimes the cpusensor crash was observed. The coredump was pointing
to segmentation fault while executing callback function inside
setupRead().
Similar issue was observed in adcsensor.
Reference to the fix: 1afda6bbb6db0e266795af3229b962c32775b928

The timer cancel() in destructor cannot cancel the expired callback
handlers. In such cases if the callback handler is executed, the
object is deleted already.

Use weak_ptr to check if the object is still valid before using these
member variables/functions.
The buffer used by async_read_util must guarantee that they remain
valid until the handler is called.

Tested: Stress tested by restarting the service. Service restart will
force re-creating the CPUSensor objects.
`count=0; \
 while true; \
 do systemctl restart xyz.openbmc_project.cpusensor.service; \
 count=$((count + 1)); \
 echo $count; \
 sleep 40; \
 done `

Signed-off-by: gokulsanker <gokul.sanker.v.g@intel.com>
Signed-off-by: Arun P. Mohanan <arun.p.m@linux.intel.com>
Change-Id: I7410feb0e17c5f6d555cd042f5e5b327de1910c5