ecm loadhigh

shell/loadhigh.c

@@ -53,6 +53,10 @@
 #define mcbNext(mcb)	mcbAssign(mcb, nxtMCB(FP_SEG(mcb)))
 #define DosAlloc(value)	DOSalloc((value), 0xF)
 
+#define BLOCKMAX 256
+#define AVAILBLOCKMAX 256
+#define REGIONMAX 64
+
 enum error_codes
 {
   err_help = -1, OK,
@@ -154,7 +158,7 @@ static int initialise(void)
   optS = 0;
 
   /* Allocate dynamic memory for some arrays */
-  if ((block = malloc(256 * sizeof(*block))) == 0)
+  if ((block = malloc(BLOCKMAX * sizeof(*block))) == 0)
     return err_out_of_memory;
 
 #ifdef FEATURE_XMS_SWAP
@@ -177,7 +181,7 @@ static int initialise(void)
 	}
 #endif
 
-  if ((umbRegion = malloc(64 * sizeof(*umbRegion))) == 0)
+  if ((umbRegion = malloc(REGIONMAX * sizeof(*umbRegion))) == 0)
     return err_out_of_memory;
 
   /* find the UMB regions */
@@ -339,14 +343,21 @@ static int findUMBRegions(void)
     {
       sig = mcb->mcb_type;
 
-      if (mcb->mcb_ownerPSP == 8 && !_fmemcmp(mcb->mcb_name, "SC", 2))
+      if (mcb->mcb_ownerPSP == 8
+        && (!_fmemcmp(mcb->mcb_name, "SC", 2)
+          || !_fmemcmp(mcb->mcb_name, "S\x00\x30", 3))) /* lDOS S MCB type 30h */
       {
         /* this is a 'hole' in memory */
         if (region->start)
         {
           region->end = FP_SEG(mcb) - 1;
-          region++;
-          region->start = 0;
+          if (! (mcb->mcb_type == 'Z' && 0 == mcb->mcb_size)) {
+            if ((region - umbRegion) >= REGIONMAX) {
+              return err_out_of_memory;
+            }
+            region++;
+            region->start = 0;
+          }
         }
       }
       else
@@ -367,6 +378,9 @@ static int findUMBRegions(void)
             region->end = umb_mcb->mcb_ownerPSP + umb_mcb->mcb_size - 1;
             if ((sig = umb_mcb->mcb_type) == 'M')
               region->end--;
+            if ((region - umbRegion) >= REGIONMAX) {
+              return err_out_of_memory;
+            }
             region++;
             region->start = 0;
             mcbAssign(mcb, FP_SEG(umb_mcb) + umb_mcb->mcb_size);
@@ -381,6 +395,9 @@ static int findUMBRegions(void)
       if (sig == 'Z')
       {
         region->end = FP_SEG(mcb) + mcb->mcb_size;
+        if ((region - umbRegion) >= REGIONMAX) {
+          return err_out_of_memory;
+        }
         region++;
         break;
       }
@@ -424,7 +441,7 @@ static int loadhigh_prepare(void)
   dosSetUMBLinkState(1);
   dosSetAllocStrategy(0);
 
-  if ((availBlock = malloc(256 * sizeof(*availBlock))) == 0)
+  if ((availBlock = malloc(AVAILBLOCKMAX * sizeof(*availBlock))) == 0)
     return err_out_of_memory;
 
   /* Call to force DOS to catenate any successive free memory blocks */
@@ -454,16 +471,21 @@ static int loadhigh_prepare(void)
     int found_one = 0;
 
     for (mcbAssign(mcb, region->start)
-     ; FP_SEG(mcb) < region->end && mcb->mcb_type == 'M' && mcb->mcb_size > 0
+     ; FP_SEG(mcb) < region->end && mcb->mcb_type == 'M'
      ; mcbNext(mcb))
     {
       if (!mcb->mcb_ownerPSP)
       {
         /* Found a free memory block: allocate it */
         word bl = DosAlloc(mcb->mcb_size);
 
-        if (bl != FP_SEG(mcb) + 1)  /* Did we get the block we wanted? */
+        if (bl != FP_SEG(mcb) + 1) {  /* Did we get the block we wanted? */
+          DOSfree(bl);
+          for (i = 0; i < availBlocks; i++)
+            DOSfree(availBlock[i]);
+          free(availBlock);
           return err_mcb_chain;
+        }
 
         if (region->access)		/* /L option allows access to this region */
         {
@@ -478,6 +500,13 @@ static int loadhigh_prepare(void)
                mcb->mcb_size >= region->minSize))
           {
 
+            if (availBlocks >= AVAILBLOCKMAX) {
+              DOSfree(bl);
+              for (i = 0; i < availBlocks; i++)
+                DOSfree(availBlock[i]);
+              free(availBlock);
+              return err_out_of_memory;
+            }
             availBlock[availBlocks++] = bl;
 
             if (optS)
@@ -498,6 +527,13 @@ static int loadhigh_prepare(void)
             continue;
           }
         }
+        if (allocatedBlocks >= BLOCKMAX) {
+          DOSfree(bl);
+          for (i = 0; i < availBlocks; i++)
+            DOSfree(availBlock[i]);
+          free(availBlock);
+          return err_out_of_memory;
+        }
         block[allocatedBlocks++] = bl;  /* no access to this block */
       }
     }
@@ -570,6 +606,10 @@ static int loadfix_prepare(void)
 
 		dprintf(("loadfix: allocated 0x%04x\n",bl));
 		DOSresize(bl, 0x1000 - bl);  		
+	        if (allocatedBlocks >= BLOCKMAX) {
+	          DOSfree(bl);
+	          return err_out_of_memory;
+	        }
 		block[allocatedBlocks++] = bl;
 	}
 
@@ -618,7 +658,7 @@ static int parseArgs(char *cmdline, char **fnam, char **rest)
 
     /* Disable access to all UMB regions not listed here */
     for (i = 1; i < umbRegions; i++)
-    umbRegion[i].access = 0;
+      umbRegion[i].access = 0;
 
     r = 0;