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authorHeiko Carstens <heiko.carstens@de.ibm.com>2013-10-11 08:55:57 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-10-24 17:17:03 +0200
commit05e0baaf9ba5a2d173c026530154388f0d2da72c (patch)
treee65a96f6a3e986b0b1f41a815dbb31721db24383 /arch/s390
parent5ff4212f194f97b3a0f41745f231525c5c50dcbb (diff)
downloadlinux-linaro-stable-05e0baaf9ba5a2d173c026530154388f0d2da72c.tar.gz
s390/ftrace: prepare_ftrace_return() function call order
Steven Rostedt noted that s390 is the only architecture which calls ftrace_push_return_trace() before ftrace_graph_entry() and therefore has the small advantage that trace.depth gets initialized automatically. However this small advantage isn't worth the difference and possible subtle breakage that may result from this. So change s390 to have the same function call order like all other architectures: first ftrace_graph_entry(), then ftrace_push_return_trace() Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/ftrace.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 1014ad5f7693..224db03e9518 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -151,14 +151,13 @@ unsigned long __kprobes prepare_ftrace_return(unsigned long parent,
if (unlikely(atomic_read(&current->tracing_graph_pause)))
goto out;
ip = (ip & PSW_ADDR_INSN) - MCOUNT_INSN_SIZE;
- if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
- goto out;
trace.func = ip;
+ trace.depth = current->curr_ret_stack + 1;
/* Only trace if the calling function expects to. */
- if (!ftrace_graph_entry(&trace)) {
- current->curr_ret_stack--;
+ if (!ftrace_graph_entry(&trace))
+ goto out;
+ if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
goto out;
- }
parent = (unsigned long) return_to_handler;
out:
return parent;