lkml.org 
[lkml]   [2018]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[for-next][PATCH 11/18] s390/function_graph: Simplify with function_graph_entry()
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

The function_graph_entry() 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.

Cc: 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")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/s390/kernel/ftrace.c | 13 ++-----------
1 file 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;
}
--
2.19.1

\
 
 \ /
  Last update: 2018-11-22 01:35    [W:0.232 / U:0.892 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site