[PATCH v1 1/1] smb: client: Rework memcpy() to avoid compilation error

From: Andy Shevchenko
Date: Mon Jul 17 2023 - 06:00:15 EST


In function ‘fortify_memcpy_chk’,
inlined from ‘CIFS_open’ at fs/smb/client/cifssmb.c:1249:3:
include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning]
592 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Instead of memcpy() use member-by-member copy. Let compiler do its job
on optimisation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
fs/smb/client/cifssmb.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
index 9dee267f1893..33ebb63826d3 100644
--- a/fs/smb/client/cifssmb.c
+++ b/fs/smb/client/cifssmb.c
@@ -1245,8 +1245,11 @@ CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms, int *oplock,
*oplock |= CIFS_CREATE_ACTION;

if (buf) {
- /* copy from CreationTime to Attributes */
- memcpy((char *)buf, (char *)&rsp->CreationTime, 36);
+ buf->CreationTime = rsp->CreationTime;
+ buf->LastAccessTime = rsp->LastAccessTime;
+ buf->LastWriteTime = rsp->LastWriteTime;
+ buf->ChangeTime = rsp->ChangeTime;
+ buf->FileAttributes = rsp->FileAttributes;
/* the file_info buf is endian converted by caller */
buf->AllocationSize = rsp->AllocationSize;
buf->EndOfFile = rsp->EndOfFile;
--
2.40.0.1.gaa8946217a0b