[char-misc v2] mei: trace: treat reg parameter as string

[Alexander Usyskin]

Use the string wrapper to check sanity of the reg parameters,
store it value independently and prevent internal kernel data leaks.
Trace subsystem refuses to emit event with plain char*,
without the wrapper.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: a0a927d06d79 ("mei: me: add io register tracing")
Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
---

V2: reword commit message
    add Fixes and stable

 drivers/misc/mei/mei-trace.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/mei/mei-trace.h b/drivers/misc/mei/mei-trace.h
index 5312edbf5190..24fa321d88bd 100644
--- a/drivers/misc/mei/mei-trace.h
+++ b/drivers/misc/mei/mei-trace.h
@@ -21,18 +21,18 @@ TRACE_EVENT(mei_reg_read,
 	TP_ARGS(dev, reg, offs, val),
 	TP_STRUCT__entry(
 		__string(dev, dev_name(dev))
-		__field(const char *, reg)
+		__string(reg, reg)
 		__field(u32, offs)
 		__field(u32, val)
 	),
 	TP_fast_assign(
 		__assign_str(dev);
-		__entry->reg  = reg;
+		__assign_str(reg);
 		__entry->offs = offs;
 		__entry->val = val;
 	),
 	TP_printk("[%s] read %s:[%#x] = %#x",
-		  __get_str(dev), __entry->reg, __entry->offs, __entry->val)
+		  __get_str(dev), __get_str(reg), __entry->offs, __entry->val)
 );
 
 TRACE_EVENT(mei_reg_write,
@@ -40,18 +40,18 @@ TRACE_EVENT(mei_reg_write,
 	TP_ARGS(dev, reg, offs, val),
 	TP_STRUCT__entry(
 		__string(dev, dev_name(dev))
-		__field(const char *, reg)
+		__string(reg, reg)
 		__field(u32, offs)
 		__field(u32, val)
 	),
 	TP_fast_assign(
 		__assign_str(dev);
-		__entry->reg = reg;
+		__assign_str(reg);
 		__entry->offs = offs;
 		__entry->val = val;
 	),
 	TP_printk("[%s] write %s[%#x] = %#x",
-		  __get_str(dev), __entry->reg,  __entry->offs, __entry->val)
+		  __get_str(dev), __get_str(reg),  __entry->offs, __entry->val)
 );
 
 TRACE_EVENT(mei_pci_cfg_read,
@@ -59,18 +59,18 @@ TRACE_EVENT(mei_pci_cfg_read,
 	TP_ARGS(dev, reg, offs, val),
 	TP_STRUCT__entry(
 		__string(dev, dev_name(dev))
-		__field(const char *, reg)
+		__string(reg, reg)
 		__field(u32, offs)
 		__field(u32, val)
 	),
 	TP_fast_assign(
 		__assign_str(dev);
-		__entry->reg  = reg;
+		__assign_str(reg);
 		__entry->offs = offs;
 		__entry->val = val;
 	),
 	TP_printk("[%s] pci cfg read %s:[%#x] = %#x",
-		  __get_str(dev), __entry->reg, __entry->offs, __entry->val)
+		  __get_str(dev), __get_str(reg), __entry->offs, __entry->val)
 );
 
 #endif /* _MEI_TRACE_H_ */
-- 
2.43.0