Changes between Version 1 and Version 2 of Ticket #11718, comment 7


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Timestamp:
Mar 10, 2015, 2:07:17 AM (5 years ago)
Author:
anevilyak

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  • Ticket #11718, comment 7

    v1 v2  
    66The 0xdeadbeef in the panics here implies that someone is freeing kernel memory that's still in use/referenced somewhere. The main difference when cdda is invoked via userlandfs rather than via the kernel directly is that most of the meat of cdda runs in userland. However, userlandfs must still forward all of the kernel/VFS interactions back and forth (i.e. when the ripper requests to open a file, read a block, etc.). As such, there are two likely possibilities here. Either 1) cdda isn't doing some bookkeeping correctly when it interacts with the VFS, such as calling put_vnode() in a case where it shouldn't, or 2) the way cdda is interacting with the VFS is triggering a corner case/bug in the VFS itself. An outside edge case is that it could also be an issue with the ATAPI code, but that would suggest a similar problem could be triggered with data CDs, which to my knowledge has not been reported to be the case, so that one seems less likely.
    77
    8 The first case would probably be the easier one to try to investigate/eliminate first since that would mainly require review of the cdda code on its own, whereas the second would obviously require reviewing the VFS and related code, which there is considerably more of, and is also significantly more complex, so I'd suggest the former route first.
     8The first case would probably be the easier one to try to investigate/eliminate since that would mainly require review of the cdda code on its own, whereas the second would obviously require reviewing the VFS and related code, which there is considerably more of, and is also significantly more complex.