[PATCH 16/30] scsi: arcmsr: arcmsr_hba: Make room for the trailing NULL, even if it is over-written

[Lee Jones <lee.jones@linaro.org>]

Ensure we do not copy the final one (which is not overwitten).

Fixes the following W=1 kernel build warning(s):

 In file included from include/linux/bitmap.h:9,
 from include/linux/nodemask.h:95,
 from include/linux/mmzone.h:17,
 from include/linux/gfp.h:6,
 from include/linux/umh.h:4,
 from include/linux/kmod.h:9,
 from include/linux/module.h:16,
 from drivers/scsi/arcmsr/arcmsr_hba.c:47:
 In function ‘strncpy’,
 inlined from ‘arcmsr_handle_virtual_command’ at drivers/scsi/arcmsr/arcmsr_hba.c:3055:3:
 include/linux/string.h:297:30: warning: ‘__builtin_strncpy’ output truncated before terminating nul copying 4 bytes from a string of the same length [-Wstringop-truncation]
 297 | #define __underlying_strncpy __builtin_strncpy
 | ^
 include/linux/string.h:307:9: note: in expansion of macro ‘__underlying_strncpy’
 307 | return __underlying_strncpy(p, q, size);
 | ^~~~~~~~~~~~~~~~~~~~
 In function ‘strncpy’,
 inlined from ‘arcmsr_handle_virtual_command’ at drivers/scsi/arcmsr/arcmsr_hba.c:3053:3:
 include/linux/string.h:297:30: warning: ‘__builtin_strncpy’ output truncated before terminating nul copying 16 bytes from a string of the same length [-Wstringop-truncation]
 297 | #define __underlying_strncpy __builtin_strncpy
 | ^
 include/linux/string.h:307:9: note: in expansion of macro ‘__underlying_strncpy’
 307 | return __underlying_strncpy(p, q, size);
 | ^~~~~~~~~~~~~~~~~~~~
 In function ‘strncpy’,
 inlined from ‘arcmsr_handle_virtual_command’ at drivers/scsi/arcmsr/arcmsr_hba.c:3051:3:
 include/linux/string.h:297:30: warning: ‘__builtin_strncpy’ output truncated before terminating nul copying 8 bytes from a string of the same length [-Wstringop-truncation]
 297 | #define __underlying_strncpy __builtin_strncpy
 | ^
 include/linux/string.h:307:9: note: in expansion of macro ‘__underlying_strncpy’
 307 | return __underlying_strncpy(p, q, size);
 | ^~~~~~~~~~~~~~~~~~~~

Cc: support@areca.com.tw
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/scsi/arcmsr/arcmsr_hba.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 1c252934409c7..5feed135eb26c 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -3031,7 +3031,7 @@ static void arcmsr_handle_virtual_command(struct AdapterControlBlock *acb,
 {
 	switch (cmd->cmnd[0]) {
 	case INQUIRY: {
-		unsigned char inqdata[36];
+		unsigned char inqdata[37];
 		char *buffer;
 		struct scatterlist *sg;
 
@@ -3048,16 +3048,16 @@ static void arcmsr_handle_virtual_command(struct AdapterControlBlock *acb,
 		/* ISO, ECMA, & ANSI versions */
 		inqdata[4] = 31;
 		/* length of additional data */
-		strncpy(&inqdata[8], "Areca   ", 8);
+		strncpy(&inqdata[8], "Areca   ", 9);
 		/* Vendor Identification */
-		strncpy(&inqdata[16], "RAID controller ", 16);
+		strncpy(&inqdata[16], "RAID controller ", 17);
 		/* Product Identification */
-		strncpy(&inqdata[32], "R001", 4); /* Product Revision */
+		strncpy(&inqdata[32], "R001", 5); /* Product Revision */
 
 		sg = scsi_sglist(cmd);
 		buffer = kmap_atomic(sg_page(sg)) + sg->offset;
 
-		memcpy(buffer, inqdata, sizeof(inqdata));
+		memcpy(buffer, inqdata, sizeof(inqdata) - 1);
 		sg = scsi_sglist(cmd);
 		kunmap_atomic(buffer - sg->offset);
 
-- 
2.25.1