tree c7a5530a39825df3e0d3ed9eda4d2caa975a0b57
parent 0b1ae9ff7ff61f8e562307b72db220d91e830117
author Andrew Jeffery <andrew@aj.id.au> 1651458423 +0930
committer Andrew Jeffery <andrew@aj.id.au> 1651709768 +0000

NVMeContext: Rework sensor removal concurrent to polling

Concurrent removal of a sensor's configuration while the sensor list is
being iterated for polling can lead to undefined behaviour via access
through a deleted iterator:

    Program terminated with signal SIGSEGV, Segmentation fault.
    #0  std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count (__r=..., this=<optimised out>, this=<optimised out>, __r=...)
        at /usr/include/c++/11.2.0/bits/stl_list.h:224
    224     /usr/include/c++/11.2.0/bits/stl_list.h: No such file or directory.
    [Current thread is 1 (LWP 6649)]
    #0  std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count (__r=..., this=<optimised out>, this=<optimised out>, __r=...)
        at /usr/include/c++/11.2.0/bits/stl_list.h:224
    #1  std::__shared_ptr<NVMeSensor, (__gnu_cxx::_Lock_policy)2>::__shared_ptr (this=<optimised out>, this=<optimised out>)
        at /usr/include/c++/11.2.0/bits/shared_ptr_base.h:1152
    #2  std::shared_ptr<NVMeSensor>::shared_ptr (this=<optimised out>, this=<optimised out>) at /usr/include/c++/11.2.0/bits/shared_ptr.h:150
    #3  NVMeBasicContext::readAndProcessNVMeSensor (this=0x1ac8a90, iter=non-dereferenceable iterator for std::list) at ../git/src/NVMeBasicContext.cpp:299
    #4  0x004dd8b8 in NVMeBasicContext::readAndProcessNVMeSensor (this=0x1ac8a90, iter=non-dereferenceable iterator for std::list) at ../git/src/NVMeBasicContext.cpp:312
    #5  0x004dd8b8 in NVMeBasicContext::readAndProcessNVMeSensor (this=0x1ac8a90, iter=std::shared_ptr<NVMeSensor> (use count 26, weak count 28153871) = {get() = 0x1ad8db0})
        at ../git/src/NVMeBasicContext.cpp:312

Rework polling and sensor removal to uphold the requirement that the
iterator remains valid.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I69b005fe3dad7ddf21d1762731f9cdfd2408cae1