From 2cf523d202f4f04b3dcc17e23f9a59d6dafbe282 Mon Sep 17 00:00:00 2001
From: Mostafa Salman <mostafas@synopsys.com>
Date: Sun, 28 Apr 2024 15:20:12 +0300
Subject: [PATCH] tinystdio: Resolve issue with tmpnam

The tmpname() function should generate a different temporary file name each time it is called up.
But, the original implementation of tmpnam function generates identical file names on subsequent calls.

So, we need to fix this implementation to generate a different temporary file name upon each invocation.

Signed-off-by: Mostafa Salman <mostafas@synopsys.com>
---
 newlib/libc/tinystdio/mktemp.c | 54 +++++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 17 deletions(-)

diff --git a/newlib/libc/tinystdio/mktemp.c b/newlib/libc/tinystdio/mktemp.c
index 8266d9ec1a..2fbea38602 100644
--- a/newlib/libc/tinystdio/mktemp.c
+++ b/newlib/libc/tinystdio/mktemp.c
@@ -98,8 +98,12 @@ _gettemp (char *path,
           int *doopen,
           int flags)
 {
-  char *start, *trv;
+  char *trv;
   char *end;
+  static char inc = 0;
+  static char pos = 1;
+
+  __LIBC_LOCK();
 
   end = path + strlen(path) - suffixlen;
   trv = end;
@@ -112,13 +116,35 @@ _gettemp (char *path,
   if (end - trv < 6)
     {
       errno = EINVAL;
+      __LIBC_UNLOCK();
       return 0;
     }
 
-  start = trv + 1;
+  trv += pos;
 
   for (;;)
     {
+      /* Increment the string of letters to generate another name */
+      for(;;)
+      {
+        if (trv == end)
+        {
+          __LIBC_UNLOCK();
+          return 0;
+        }
+        
+        if ((*trv + inc - 1) == 'z') {
+          *trv++ = 'a';
+          pos++;
+          inc = 1;
+        }
+        else {
+          *trv += inc;
+          inc++;
+          break;
+        }
+      }
+
       /*
        * Use open to check if the file exists to avoid depending on
        * stat or access. Don't rely on O_EXCL working, although if it
@@ -128,39 +154,33 @@ _gettemp (char *path,
       if (fd < 0) {
         if (errno != EACCES) {
           if (errno != ENOENT)
+          {
+            __LIBC_UNLOCK();
             return 0;
+          }
           if (doopen)
           {
             fd = open (path, flags | O_CREAT | O_EXCL | O_RDWR,
                        0600);
             if (fd >= 0) {
               *doopen = fd;
+              __LIBC_UNLOCK();
               return 1;
             }
             if (errno != EEXIST)
+            {
+              __LIBC_UNLOCK();
               return 0;
+            }
           } else {
+            __LIBC_UNLOCK();
             return 1;
           }
         }
       } else
         close(fd);
-
-      /* Increment the string of letters to generate another name */
-      trv = start;
-      for(;;)
-	{
-	  if (trv == end)
-	    return 0;
-	  if (*trv == 'z')
-	    *trv++ = 'a';
-	  else {
-            ++ * trv;
-            break;
-          }
-	}
     }
-  /*NOTREACHED*/
+    __LIBC_UNLOCK();
 }
 
 int