@@ -224,6 +224,7 @@
#include <unistd.h>
#include <stdio.h> /* needed for malloc_stats */
#include <errno.h>
+#include <limits.h>
#include <shlib-compat.h>
@@ -4594,8 +4595,8 @@ int_mallinfo (mstate av, struct mallinfo *m)
mchunkptr p;
INTERNAL_SIZE_T avail;
INTERNAL_SIZE_T fastavail;
- int nblocks;
- int nfastblocks;
+ INTERNAL_SIZE_T nblocks;
+ INTERNAL_SIZE_T nfastblocks;
/* Ensure initialization */
if (av->top == 0)
@@ -4633,18 +4634,38 @@ int_mallinfo (mstate av, struct mallinfo *m)
}
}
- m->smblks += nfastblocks;
- m->ordblks += nblocks;
- m->fordblks += avail;
- m->uordblks += av->system_mem - avail;
- m->arena += av->system_mem;
- m->fsmblks += fastavail;
+/* Saturated add - add ADD to SUM. If the result exceeds the range of
+ "int" (or, wrapped, "unsigned int"), set SUM to UINT_MAX instead
+ ((int)-1). Assumes ADD and SUM reflect positive values, even when
+ they wrap to negative, and that SUM is type "int". The published
+ ABI prevents us from bumping "int" to a larger type. Note: this
+ macro doesn't handle overflow when INTERNAL_SIZE_T is the same size
+ as "int", but in that case, the things we're counting wouldn't
+ cause an overflow anyway.
+
+ The net result is that sums which would wrap around and become
+ misleading positive values again, stop at -1, so any positive value
+ we report is accurate, and any negative number other than -1 we
+ report can be cast to unsigned to become accurate. */
+#define SAT_ADD(SUM, ADD) \
+ ({ INTERNAL_SIZE_T tmp = (INTERNAL_SIZE_T)(unsigned)(SUM) + (INTERNAL_SIZE_T)(ADD); SUM = (tmp > UINT_MAX) ? -1 : tmp; })
+
+/* Likewise, but assign ADD to SUM. */
+#define SAT_SET(SUM, ADD) \
+ ({ SUM = ((INTERNAL_SIZE_T)(ADD) > UINT_MAX) ? -1 : (ADD); })
+
+ SAT_ADD (m->smblks, nfastblocks);
+ SAT_ADD (m->ordblks, nblocks);
+ SAT_ADD (m->fordblks, avail);
+ SAT_ADD (m->uordblks, av->system_mem - avail);
+ SAT_ADD (m->arena, av->system_mem);
+ SAT_ADD (m->fsmblks, fastavail);
if (av == &main_arena)
{
- m->hblks = mp_.n_mmaps;
- m->hblkhd = mp_.mmapped_mem;
- m->usmblks = 0;
- m->keepcost = chunksize (av->top);
+ SAT_SET (m->hblks, mp_.n_mmaps);
+ SAT_SET (m->hblkhd, mp_.mmapped_mem);
+ SAT_SET (m->usmblks, 0);
+ SAT_SET (m->keepcost, chunksize (av->top));
}
}