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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-18 17:33:17 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2018-11-27 20:31:30 -0500
commit18588e1487b19e45bd90bd55ec8d3a1d44f3257f (patch)
treea71093c78f7fd699657faa3e4ec27d08da79eb48 /arch/s390
parente949b6db51dc172a35c962bc4414ca148315fe21 (diff)
downloadlinux-18588e1487b19e45bd90bd55ec8d3a1d44f3257f.tar.bz2
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/s390')
-rw-r--r--arch/s390/kernel/ftrace.c13
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(&current->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;
}