2017-11-21 10:34:05

by Chunyan Zhang

[permalink] [raw]
Subject: [PATCH V2] clk: fix a panic error caused by accessing NULL pointer

From: Cai Li <[email protected]>

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 <[email protected]>
Signed-off-by: Chunyan Zhang <[email protected]>
---
Changes from v1:
Revised the tracepoint code instead of clk driver.
---
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 7586072..2cd4493 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))
--
2.7.4


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