[PATCH 3.2 034/153] scsi: aacraid: Fix udev inquiry race condition

[Ben Hutchings]

3.2.102-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Raghava Aditya Renukunta <raghavaaditya.renuku...@microsemi.com>

commit f4e8708d3104437fd7716e957f38c265b0c509ef upstream.

When udev requests for a devices inquiry string, it might create multiple
threads causing a race condition on the shared inquiry resource string.

Created a buffer with the string for each thread.

Fixes: 3bc8070fb75b3315 ([SCSI] aacraid: SMC vendor identification)
Signed-off-by: Raghava Aditya Renukunta <raghavaaditya.renuku...@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
[bwh: Backported to 3.2:
 - 
s/sup_adap_info->adapter_type_text/dev->supplement_adapter_info.AdapterTypeText/
 - Adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -758,8 +758,16 @@ static void setinqstr(struct aac_dev *de
        memset(str, ' ', sizeof(*str));
 
        if (dev->supplement_adapter_info.AdapterTypeText[0]) {
-               char * cp = dev->supplement_adapter_info.AdapterTypeText;
                int c;
+               char *cp;
+               char *cname = 
kmemdup(dev->supplement_adapter_info.AdapterTypeText,
+                               
sizeof(dev->supplement_adapter_info.AdapterTypeText),
+                                                               GFP_ATOMIC);
+
+               if (!cname)
+                       return;
+
+               cp = cname;
                if ((cp[0] == 'A') && (cp[1] == 'O') && (cp[2] == 'C'))
                        inqstrcpy("SMC", str->vid);
                else {
@@ -768,8 +776,7 @@ static void setinqstr(struct aac_dev *de
                                ++cp;
                        c = *cp;
                        *cp = '\0';
-                       inqstrcpy (dev->supplement_adapter_info.AdapterTypeText,
-                                  str->vid);
+                       inqstrcpy(cname, str->vid);
                        *cp = c;
                        while (*cp && *cp != ' ')
                                ++cp;
@@ -783,8 +790,8 @@ static void setinqstr(struct aac_dev *de
                        cp[sizeof(str->pid)] = '\0';
                }
                inqstrcpy (cp, str->pid);
-               if (c)
-                       cp[sizeof(str->pid)] = c;
+
+               kfree(cname);
        } else {
                struct aac_driver_ident *mp = 
aac_get_driver_ident(dev->cardtype);