On June 23, 2009 3:03 PM, David Daney [mailto:ddaney@xxxxxxxxxxxxxxxxxx] > I wonder if it is another instance of: > > http://www.linux-mips.org/git?p=linux.git;a=commitdiff;h=49cf0 > e2d68dd98dbb28eaca0284e8460ab6ad86d Thanks for digging that up. The patch fixes it for me. Clearly, it's not just for init. Any process can ignore signals that shouldn't be ignored. I'm surprised this has only been discovered so recently. It's amazing how we sometimes find things at around the same time. If I may pontificate now, someone said my little program was silly. Of course; it's a repro test case! Nobody would deliberately block SIGBUS and then deliberately trigger a bus error. But this situation happened in a large and complex real application, leaving some of my developers scratching their heads, and distracting them from looking for the bad pointer! ``Hey look, we can break this 100% CPU thread with gdb, but it always stops on the same location, which is an indirect load through a register containing a bad pointer! And it's spinning mostly in the kernel. Hmm!'' I gave them that little program to demonstrate how the behavior can occur. They are now working out how SIGBUS came to be ignored, and, of course, the cause of the bad pointer.
