[PATCH v3 1/4] soc: qcom: smem: add IN_PARTITION_RANGE helper

[Albert Esteve]

From: Sarannya S <quic_sarannya@xxxxxxxxxxxxxxxx>

Add IN_PARTITION_RANGE() to test that a pointer lies in [start, end]
and that pointer + size does not wrap.

Signed-off-by: Sarannya S <quic_sarannya@xxxxxxxxxxxxxxxx>
Signed-off-by: Pranav Mahesh Phansalkar <quic_pphansal@xxxxxxxxxxxxxxxx>
Signed-off-by: Sudeepgoud Patil <quic_sudeepgo@xxxxxxxxxxxxxxxx>
Signed-off-by: Albert Esteve <aesteve@xxxxxxxxxx>
---
 drivers/soc/qcom/smem.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index b5e7bd8c1512..6783a3c533f0 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -2,6 +2,7 @@
 /*
  * Copyright (c) 2015, Sony Mobile Communications AB.
  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
  */
 
 #include <linux/debugfs.h>
@@ -88,6 +89,17 @@
 /* Processor/host identifier for the global partition */
 #define SMEM_GLOBAL_HOST	0xfffe
 
+/* Entry range check
+ * ptr >= start : Checks if ptr is greater than the start of access region
+ * ptr + size >= ptr: Check for integer overflow (On 32bit system where ptr
+ * and size are 32bits, ptr + size can wrap around to be a small integer)
+ * ptr + size <= end: Checks if ptr+size is less than the end of access region
+ */
+#define IN_PARTITION_RANGE(ptr, size, start, end)		\
+	(((void *)(ptr) >= (void *)(start)) &&			\
+	 (((void *)(ptr) + (size)) >= (void *)(ptr)) &&	\
+	 (((void *)(ptr) + (size)) <= (void *)(end)))
+
 /**
   * struct smem_proc_comm - proc_comm communication struct (legacy)
   * @command:	current command to be executed

-- 
2.55.0