[PATCH AUTOSEL for 4.14 080/100] clk: fix a panic error caused by accessing NULL pointer

Sasha Levin
2018-01-28T23:01:05Z

From: Cai Li <cai.li@spreadtrum.com>

[ Upstream commit 975b820b6836b6b6c42fb84cd2e772e2b41bca67 ]

In some cases the clock parent would be set NULL when doing re-parent,
it will cause a NULL pointer accessing if clk_set trace event is
enabled.

This patch sets the parent as "none" if the input parameter is NULL.

Fixes: dfc202ead312 (clk: Add tracepoints for hardware operations)
Signed-off-by: Cai Li <cai.li@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
include/trace/events/clk.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/clk.h b/include/trace/events/clk.h
index 758607226bfd..2cd449328aee 100644
--- a/include/trace/events/clk.h
+++ b/include/trace/events/clk.h
@@ -134,12 +134,12 @@ DECLARE_EVENT_CLASS(clk_parent,

TP_STRUCT__entry(
__string( name, core->name )
- __string( pname, parent->name )
+ __string( pname, parent ? parent->name : "none" )
),

TP_fast_assign(
__assign_str(name, core->name);
- __assign_str(pname, parent->name);
+ __assign_str(pname, parent ? parent->name : "none");
),

TP_printk("%s %s", __get_str(name), __get_str(pname))
--
2.11.0