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Diffstat (limited to 'Documentation/trace/ftrace-design.rst')
| -rw-r--r-- | Documentation/trace/ftrace-design.rst | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/Documentation/trace/ftrace-design.rst b/Documentation/trace/ftrace-design.rst index 6893399157f0..8f4fab3f9324 100644 --- a/Documentation/trace/ftrace-design.rst +++ b/Documentation/trace/ftrace-design.rst @@ -217,18 +217,6 @@ along to ftrace_push_return_trace() instead of a stub value of 0. Similarly, when you call ftrace_return_to_handler(), pass it the frame pointer. -HAVE_FUNCTION_GRAPH_RET_ADDR_PTR --------------------------------- - -An arch may pass in a pointer to the return address on the stack. This -prevents potential stack unwinding issues where the unwinder gets out of -sync with ret_stack and the wrong addresses are reported by -ftrace_graph_ret_addr(). - -Adding support for it is easy: just define the macro in asm/ftrace.h and -pass the return address pointer as the 'retp' argument to -ftrace_push_return_trace(). - HAVE_SYSCALL_TRACEPOINTS ------------------------ @@ -250,19 +238,15 @@ You need very few things to get the syscalls tracing in an arch. - Tag this arch as HAVE_SYSCALL_TRACEPOINTS. -HAVE_FTRACE_MCOUNT_RECORD -------------------------- +HAVE_DYNAMIC_FTRACE +------------------- See scripts/recordmcount.pl for more info. Just fill in the arch-specific details for how to locate the addresses of mcount call sites via objdump. This option doesn't make much sense without also implementing dynamic ftrace. - -HAVE_DYNAMIC_FTRACE -------------------- - -You will first need HAVE_FTRACE_MCOUNT_RECORD and HAVE_FUNCTION_TRACER, so -scroll your reader back up if you got over eager. +You will first need HAVE_FUNCTION_TRACER, so scroll your reader back up if you +got over eager. Once those are out of the way, you will need to implement: - asm/ftrace.h: |