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author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-11-19 01:33:17 +0300 |
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committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-11-28 04:31:30 +0300 |
commit | 18588e1487b19e45bd90bd55ec8d3a1d44f3257f (patch) | |
tree | a71093c78f7fd699657faa3e4ec27d08da79eb48 /arch | |
parent | e949b6db51dc172a35c962bc4414ca148315fe21 (diff) | |
download | linux-18588e1487b19e45bd90bd55ec8d3a1d44f3257f.tar.xz |
s390/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have s390 use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Julian Wiedmann <jwi@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: stable@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/s390/kernel/ftrace.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 84be7f02d0c2..39b13d71a8fe 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -203,22 +203,13 @@ device_initcall(ftrace_plt_init); */ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip) { - struct ftrace_graph_ent trace; - if (unlikely(ftrace_graph_is_dead())) goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; ip -= MCOUNT_INSN_SIZE; - trace.func = ip; - trace.depth = current->curr_ret_stack + 1; - /* Only trace if the calling function expects to. */ - if (!ftrace_graph_entry(&trace)) - goto out; - if (ftrace_push_return_trace(parent, ip, &trace.depth, 0, - NULL) == -EBUSY) - goto out; - parent = (unsigned long) return_to_handler; + if (!function_graph_enter(parent, ip, 0, NULL)) + parent = (unsigned long) return_to_handler; out: return parent; } |