[Patch 0/6] PPC64-HWBKPT: Hardware Breakpoint interfaces - ver V

K.Prasad prasad at linux.vnet.ibm.com
Thu Jun 4 02:33:42 EST 2009

Hi David,
	Please find a new patchset that addresses your comments and contains
the changes as listed below.

Changelog - ver V
(Ver I: http://ozlabs.org/pipermail/linuxppc-dev/2009-May/071942.html) 
(Ver II: http://ozlabs.org/pipermail/linuxppc-dev/2009-May/072106.html)
(Ver III: http://ozlabs.org/pipermail/linuxppc-dev/2009-May/072387.html
(Ver IV: http://ozlabs.org/pipermail/linuxppc-dev/2009-May/072518.html

- Breakpoint requests from ptrace (for user-space) are designed to be one-shot
in PPC64. The patch contains changes to retain this behaviour by returning early
in hw_breakpoint_handler() [without re-initialising DABR] and unregistering the
user-space request in ptrace_triggered(). It is safe to make a
unregister_user_hw_breakpoint() call from the breakpoint exception context
[through ptrace_triggered()] without giving rise to circular locking-dependancy.
This is because there can be no kernel code running on the CPU (which received
the exception) with the same spinlock held.

- Minor change in 'type' member of 'struct arch_hw_breakpoint' from u8 to 'int'.

Kindly let me know if you think that the patchset is ready for upstream


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