Fixes the type mixups that cause the following sparse warnings:
CHECK arch/x86/kernel/ds.c
arch/x86/kernel/ds.c:549:19: warning: incorrect type in argument 2 (invalid types)
arch/x86/kernel/ds.c:549:19: expected bad type enum bts_field field
arch/x86/kernel/ds.c:549:19: got int
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:514:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:514:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:514:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:514:7: error: invalid assignment
arch/x86/kernel/ds.c:520:35: error: incompatible types for operation (*)
arch/x86/kernel/ds.c:520:35: left side has type unsigned char static [unsigned] [toplevel] sizeof_ptr_field
arch/x86/kernel/ds.c:520:35: right side has type bad type enum bts_field field
arch/x86/kernel/ds.c:520:7: error: invalid assignment
arch/x86/kernel/ds.c:520:35: error: incompatible types for operation (*)
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <1245494740.8613.12.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The hw-branch-tracer uses debug store functions from an on_each_cpu()
context, which is simply wrong since the functions may sleep.
Add _noirq variants for most functions, which may be called with
interrupts disabled.
Separate per-cpu and per-task tracing and allow per-cpu tracing to be
controlled from any cpu.
Make the hw-branch-tracer use the new debug store interface, synchronize
with hotplug cpu event using get/put_online_cpus(), and remove the
unnecessary spinlock.
Make the ptrace bts and the ds selftest code use the new interface.
Defer the ds selftest.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144555.658136000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Per-task branch tracing installs a debug store context with the traced
task. This immediately results in the branch trace control bits to be
cleared for the next context switch of that task, if not set before.
Either per-cpu or per-task tracing are allowed at the same time.
An active per-cpu tracing would be disabled even if the per-task tracing
request is rejected and the task debug store context removed.
Check the tracing type (per-cpu or per-task) before installing a task
debug store context.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144552.856000000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In order to stop branch tracing for a running task, we need to first
clear the branch tracing control bits before we may free the tracing
buffer.
If the traced task is running, the cpu might still trace that task
after the branch trace control bits have cleared.
Wait until the traced task has been scheduled out before proceeding.
A similar problem affects the task debug store context. We first remove
the context, then we need to wait until the task has been scheduled
out before we can free the context memory.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144551.919636000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the bts tracer is removed while the traced task is running,
the write to clear the bts tracer pointer races with context switch code.
Read the tracer once during a context switch.
When a new tracer is installed, the bts tracer is set in the ds context
before the tracer is initialized in order to claim the context for that
tracer.
This may result in write accesses using an uninitialized trace configuration
when scheduling timestamps have been requested.
Store active tracing flags separately and only set active flags after
the tracing configuration has been initialized.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144548.881338000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ds_request_bts() needs to allocate memory. It uses GFP_KERNEL.
Hw-branch-tracer calls ds_request_bts() within on_each_cpu().
Use atomic memory allocation to allow it to be used in that context.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090318192700.A6038@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: more robust DS feature enumeration
Detect the size of the pointer-type fields in the DS area
configuration via the DTES64 features rather than based on
the cpuid.
Rename a variable to denote that size to reflect that it only
covers the pointer-type fields.
Add more boot-time diagnostics giving the detected size and
the sizes of BTS and PEBS records.
Use the size of the BTS/PEBS record to indicate that the
respective feature is not available (if the record size is zero).
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313104218.A30096@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In case a ptraced task is reaped (while the tracer is still attached),
ds_exit_thread() is called before ptrace_exit(). The latter will
release the bts_tracer and remove the thread's ds_ctx.
The former will WARN() if the context is not NULL.
Oleg Nesterov submitted patches that move ptrace_exit() before
exit_thread() and thus reverse the order of the above calls.
Remove the bad warning. I will add it again when Oleg's changes are in.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090305084954.A22000@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cleanup the cpuid check for DS configuration.
This also fixes a Corei7 CPUID enumeration bug.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: introduce new ptrace facility
Add arch_ptrace_untrace() function that is called when the tracer
detaches (either voluntarily or when the tracing task dies);
ptrace_disable() is only called on a voluntary detach.
Add ptrace_fork() and arch_ptrace_fork(). They are called when a
traced task is forked.
Clear DS and BTS related fields on fork.
Release DS resources and reclaim memory in ptrace_untrace(). This
releases resources already when the tracing task dies. We used to do
that when the traced task dies.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: change the reporting of empty BTS records
Correctly report a cleared BTS record as invalid. Used to be reported
as branch from 0 to 0.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Optimistically allocate a DS context. It is extremely unlikely that
one already existed. This simplifies the code a lot.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix
arch/x86/kernel/ds.c: In function 'ds_request':
arch/x86/kernel/ds.c:236: sorry, unimplemented: inlining failed in call to 'ds_get_context': recursive inlining
but the recursion here is scary ...
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jaswinder Singh Rajput
Markus Metzger
Ingo Molnar