[PATCH v4 31/57] x86/dumpstack/ftrace: don't print unreliable addresses in print_context_stack_bp()

From: Josh Poimboeuf
Date: Thu Aug 18 2016 - 09:27:33 EST


When function graph tracing is enabled, print_context_stack_bp() can
report return_to_handler() as an unreliable address, which is confusing
and misleading: return_to_handler() is really only useful as a hint for
debugging, whereas print_context_stack_bp() users only care about the
actual 'reliable' call path.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/kernel/dumpstack.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 33f2899..c6c6c39 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -127,8 +127,6 @@ print_context_stack_bp(struct task_struct *task,
break;

real_addr = ftrace_graph_ret_addr(task, graph, addr, retp);
- if (real_addr != addr && ops->address(data, addr, 0))
- break;
if (ops->address(data, real_addr, 1))
break;

--
2.7.4