Merge pull request #312 from doctashay/fix-realloc-leak

Wolfgang Thaller committed 3 months ago

Commit f99ecb52 parents 335fa54 17407693 files · +138 −13Browse files

Unified · Split

3 files

AutomatedTests/CMakeLists.txt +2 −0
AutomatedTests/Realloc.c +120 −0
libretro/malloc.c +16 −13

@@ -59,6 +59,8 @@ test(Empty.c) · 58 unmodified lines
59		59
60	test(File.c PROPERTIES PASS_REGULAR_EXPRESSION "OK")	60	test(File.c PROPERTIES PASS_REGULAR_EXPRESSION "OK")
61		61
		62	test(Realloc.c PROPERTIES PASS_REGULAR_EXPRESSION "OK")
		63
62	#test(Timeout.c PROPERTIES PASS_REGULAR_EXPRESSION "One" DISABLED TRUE)	64	#test(Timeout.c PROPERTIES PASS_REGULAR_EXPRESSION "One" DISABLED TRUE)
63		65
64	test(Log.c PROPERTIES PASS_REGULAR_EXPRESSION "One\nTwo\nThree")	66	test(Log.c PROPERTIES PASS_REGULAR_EXPRESSION "One\nTwo\nThree")

AutomatedTests/Realloc.c+120−0

@@ -0,0 +1,120 @@
	1	#include "Test.h"
	2
	3	#include <MacMemory.h>
	4	#include <stdlib.h>
	5	#include <string.h>
	6
	7	enum
	8	{
	9	initialSize = 64 * 1024,
	10	grownSize = 128 * 1024,
	11	blockerSize = 8 * 1024,
	12	blockerCount = 96,
	13	releasedBlockers = (grownSize / blockerSize) + 4,
	14	freeMemoryTolerance = 1024
	15	};
	16
	17	int main(void)
	18	{
	19	Size freeBefore = FreeMem();
	20	unsigned char *allocation = malloc(initialSize);
	21	void *blockers[blockerCount];
	22	unsigned char *grown;
	23	Size freeAfter;
	24	int failure = 0;
	25	int numBlockers = 0;
	26	int ok = allocation != NULL;
	27	int i;
	28
	29	memset(blockers, 0, sizeof(blockers));
	30
	31	if(!ok)
	32	failure = 1;
	33
	34	if(ok)
	35	{
	36	for(i = 0; i < initialSize; ++i)
	37	allocation[i] = (unsigned char)(i * 37 + 11);
	38
	39	while(numBlockers < blockerCount &&
	40	(blockers[numBlockers] = malloc(blockerSize)) != NULL)
	41	{
	42	memset(blockers[numBlockers], 0x5a, blockerSize);
	43	++numBlockers;
	44	}
	45
	46	if(numBlockers <= releasedBlockers)
	47	{
	48	ok = 0;
	49	failure = 6;
	50	}
	51
	52	for(i = numBlockers - releasedBlockers; i < numBlockers; ++i)
	53	{
	54	if(i >= 0)
	55	{
	56	free(blockers[i]);
	57	blockers[i] = NULL;
	58	}
	59	}
	60
	61	grown = realloc(allocation, grownSize);
	62	if(!grown)
	63	{
	64	ok = 0;
	65	failure = 2;
	66	}
	67	else if(grown == allocation)
	68	{
	69	ok = 0;
	70	failure = 3;
	71	}
	72
	73	if(grown)
	74	{
	75	for(i = 0; ok && i < initialSize; ++i)
	76	{
	77	if(grown[i] != (unsigned char)(i * 37 + 11))
	78	{
	79	ok = 0;
	80	failure = 4;
	81	}
	82	}
	83	free(grown);
	84	}
	85	else
	86	{
	87	free(allocation);
	88	}
	89
	90	}
	91	else
	92	{
	93	free(allocation);
	94	}
	95
	96	for(i = 0; i < numBlockers; ++i)
	97	free(blockers[i]);
	98
	99	freeAfter = FreeMem();
	100	if(ok && freeAfter + freeMemoryTolerance < freeBefore)
	101	{
	102	ok = 0;
	103	failure = 5;
	104	}
	105
	106	if(ok)
	107	{
	108	TEST_LOG_OK();
	109	}
	110	else
	111	{
	112	char result[3];
	113	result[0] = 'N';
	114	result[1] = (char)('0' + failure);
	115	result[2] = '\0';
	116	TEST_LOG_SIZED(result, 2);
	117	}
	118
	119	return ok ? 0 : 1;
	120	}

libretro/malloc.c+16−13

     }
     else
     {
+        if(sz == 0)
+        {
+            DisposePtr(ptr);
+            return NULL;
+        }
+        /* Save this now in case the block has to be moved. */
+        size_t oldSz = GetPtrSize(ptr);
         MemError();
         SetPtrSize(ptr, sz);
         if(MemError())
         {
-            size_t oldSz = GetPtrSize(ptr);
+            void *newPtr = NewPtr(sz);
-            if(sz > oldSz)
+            if(!newPtr)
-            {
-                void *newPtr = NewPtr(sz);
-                if(!newPtr)
-                {
-                    reent_ptr->_errno = ENOMEM;
-                    return NULL;
-                }
-                memcpy(newPtr, ptr, oldSz);
-                return newPtr;
-            }
-            else
             {
                 reent_ptr->_errno = ENOMEM;
                 return NULL;
             }
+            memcpy(newPtr, ptr, sz < oldSz ? sz : oldSz);
+            /* The new block owns the data, so the old one can be released. */
+            DisposePtr(ptr);
+            return newPtr;
         }
         else
             return ptr;

Merge pull request #312 from doctashay/fix-realloc-leak

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