gallatin at cs.duke.edu
Fri Sep 10 10:18:12 PDT 2004
I'm trying to figure out what witness is complaining about in my (out
of tree) driver code:
lock order reversal
1st 0xe672baf0 MX foo mutex (MX foo mutex) @ /home/gallatin/mx/tiki/driver/freebsd/../common/mx_common.c:80
2nd 0xc1c6f878 user map (user map) @ vm/vm_map.c:2994
If I call copyout() holding one of my mutexes, it will always complain
about a LOR, even if the mutex is freshly initiated:
struct mtx foo;
mtx_init(&foo, "MX foo mutex", NULL, MTX_DEF);
/* hacky copyout which should trigger vm_fault() */
mx_copyout(&status, 1, 4);
Is this happening because the vm_map "user map" is an sx lock?
Does this imply that you can't acquire an sx lock while holding a mutex?
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