Commits
Peter Zijlstra committed d4078e23226
x86, trace: Further robustify CR2 handling vs tracing
Building on commit 0ac09f9f8cd1 ("x86, trace: Fix CR2 corruption when
tracing page faults") this patch addresses another few issues:
- Now that read_cr2() is lifted into trace_do_page_fault(), we should
pass the address to trace_page_fault_entries() to avoid it
re-reading a potentially changed cr2.
- Put both trace_do_page_fault() and trace_page_fault_entries() under
CONFIG_TRACING.
- Mark both fault entry functions {,trace_}do_page_fault() as notrace
to avoid getting __mcount or other function entry trace callbacks
before we've observed CR2.
- Mark __do_page_fault() as noinline to guarantee the function tracer
does get to see the fault.
Cc: <jolsa@redhat.com>
Cc: <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306145300.GO9987@twins.programming.kicks-ass.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>