The previous flat /proc file system has been restructured into a directory hierarchy that contains additional sub-directories for state information and control functions.
It also provides a watchpoint facility that is used to remap read/write permissions on the individual pages of a process's address space. This facility has no restrictions and is MT-safe.
The new /proc file structure provides complete binary compatibility with the old /proc interface except that the new watchpoint facility cannot be used with the old interface.
Debugging tools have been modified to use /proc's new watchpoint facility, which means the entire watchpoint process is faster.
The following restrictions have been removed when setting watchpoints using the dbx debugging tool:
Setting watchpoints on local variables on the stack due to SPARC register windows
Setting watchpoints on multi-threaded processes
See proc(4), core(4), adb(4) for more information.