[PATCH v2 15/29] scsi: arcmsr: arcmsr_hba: Make room for the trailing NULL, even if it is over-written

[Lee Jones]

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: supp...@areca.com.tw
Signed-off-by: Lee Jones <lee.jo...@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