Hello Johannes, On Tue, Mar 13, 2018 at 11:01:02AM +0100, Johannes Kliemann wrote: > I have sent this mail before but it was timed unfortunately and got lost > in the 18.02 release.
Sorry for leaving you in the lurch! I read your last posting but was distracted in the middle of my investigation. > While testing the IO_MEM session on Linux with ACPI I noticed that the > acpi_drv segfaults when freeing its io memory on > repos/os/src/drivers/acpi/acpi.cc:1304 [1]. The crash happens then in > repos/base/include/base/allocator.h:319 [2] at > > > operator delete (obj, dealloc); > > I noticed that this is called many times without problems but not from > free_io_mem. Unfortunately I have to admit that my C++ knowledge is > insufficient to really grasp what happens in this expression. > Is there any difference in how io memory is freed or should there be any > (at least on Linux)? The intention of free_io_mem() is to free all Io_mem objects which were accumulated in previous calls to phys_to_virt(). Those objects reside in the _heap and must therefore be delete'd, which means all destructors are executed and memory is deallocated. The unanswered question is: What is the reason for the segmentation fault as delete should always work? Is it a dangling pointer in Io_mem (incl. its members)? Do you have any chance to run GDB on the target platform to produce a backtrace or investigate online? Did you try to instrument the destructors of Io_mem and its aggregated objects? Sorry that I have more questions than answers but you see me in the dark currently. Greets -- Christian Helmuth Genode Labs https://www.genode-labs.com/ · https://genode.org/ https://twitter.com/GenodeLabs · /ˈdʒiː.nəʊd/ Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
