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* perf, powerpc: Fix build borkagePeter Zijlstra2011-07-011-1/+1
| | | | | | | | | | | | | The patch a8b0ca17b80e ("perf: Remove the nmi parameter from the swevent and overflow interface") missed a spot in the ppc hw_breakpoint code, fix this up so things compile again. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: Anton Blanchard <anton@samba.org> Cc: Eric B Munson <emunson@mgebm.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-09pfip95g88s70iwkxu6nnbt@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* powerpc, hw_breakpoint: Tell generic code we have no instruction breakpointsPaul Mackerras2010-06-301-4/+1
| | | | | | | | | | | | | | | | | | | | | | At present, hw_breakpoint_slots() returns 1 regardless of what type of breakpoint is specified in the type argument. Since we don't define CONFIG_HAVE_MIXED_BREAKPOINTS_REGS, there are separate values for TYPE_INST and TYPE_DATA, and hw_breakpoint_slots() returns 1 for both, effectively advertising instruction breakpoint support which doesn't exist. This fixes it by making hw_breakpoint_slots return 1 for TYPE_DATA and 0 for TYPE_INST. This moves hw_breakpoint_slots() from the powerpc hw_breakpoint.h to hw_breakpoint.c because the definitions of TYPE_INST and TYPE_DATA aren't available in <asm/hw_breakpoint.h>. They are defined in <linux/hw_breakpoint.h> but we can't include that header in <asm/hw_breakpoint.h>, and nor can we rely on <linux/hw_breakpoint.h> being included before <asm/hw_breakpoint.h>. Since hw_breakpoint_slots() is only called at boot time, there is no performance impact from making it a real function rather than a static inline. Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc, hw_breakpoint: Discard extraneous interrupt due to accesses outside ↵K.Prasad2010-06-221-0/+1
| | | | | | | | | | | | | | | | | symbol length Many a times, the requested breakpoint length can be less than the fixed breakpoint length i.e. 8 bytes supported by PowerPC 64-bit server (Book III S) processors. This could lead to extraneous interrupts resulting in false breakpoint notifications. This detects and discards such interrupts for non-ptrace requests. We don't change ptrace behaviour to avoid breaking compatability. [Suggestion from Paul Mackerras <paulus@samba.org> to add a new flag in 'struct arch_hw_breakpoint' to identify extraneous interrupts] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc, hw_breakpoint: Enable hw-breakpoints while handling intervening signalsK.Prasad2010-06-221-0/+3
| | | | | | | | | | | | | | | | | | | | A signal delivered between a hw_breakpoint_handler() and the single_step_dabr_instruction() will not have the breakpoint active while the signal handler is running -- the signal delivery will set up a new MSR value which will not have MSR_SE set, so we won't get the signal step interrupt until and unless the signal handler returns (which it may never do). To fix this, we restore the breakpoint when delivering a signal -- we clear the MSR_SE bit and set the DABR again. If the signal handler returns, the DABR interrupt will occur again when the instruction that we were originally trying to single-step gets re-executed. [Paul Mackerras <paulus@samba.org> pointed out the need to do this.] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processorsK.Prasad2010-06-221-0/+73
Implement perf-events based hw-breakpoint interfaces for PowerPC 64-bit server (Book III S) processors. This allows access to a given location to be used as an event that can be counted or profiled by the perf_events subsystem. This is done using the DABR (data breakpoint register), which can also be used for process debugging via ptrace. When perf_event hw_breakpoint support is configured in, the perf_event subsystem manages the DABR and arbitrates access to it, and ptrace then creates a perf_event when it is requested to set a data breakpoint. [Adopted suggestions from Paul Mackerras <paulus@samba.org> to - emulate_step() all system-wide breakpoints and single-step only the per-task breakpoints - perform arch-specific cleanup before unregistration through arch_unregister_hw_breakpoint() ] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>