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-rw-r--r--bin/ksh/alloc.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/bin/ksh/alloc.c b/bin/ksh/alloc.c
new file mode 100644
index 0000000..c8f2251
--- /dev/null
+++ b/bin/ksh/alloc.c
@@ -0,0 +1,136 @@
+/* $OpenBSD: alloc.c,v 1.15 2016/06/01 10:29:20 espie Exp $ */
+
+/* Public domain, like most of the rest of ksh */
+
+/*
+ * area-based allocation built on malloc/free
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "sh.h"
+
+struct link {
+ struct link *prev;
+ struct link *next;
+};
+
+Area *
+ainit(Area *ap)
+{
+ ap->freelist = NULL;
+ return ap;
+}
+
+void
+afreeall(Area *ap)
+{
+ struct link *l, *l2;
+
+ for (l = ap->freelist; l != NULL; l = l2) {
+ l2 = l->next;
+ free(l);
+ }
+ ap->freelist = NULL;
+}
+
+#define L2P(l) ( (void *)(((char *)(l)) + sizeof(struct link)) )
+#define P2L(p) ( (struct link *)(((char *)(p)) - sizeof(struct link)) )
+
+void *
+alloc(size_t size, Area *ap)
+{
+ struct link *l;
+
+ /* ensure that we don't overflow by allocating space for link */
+ if (size > SIZE_MAX - sizeof(struct link))
+ internal_errorf(1, "unable to allocate memory");
+
+ l = malloc(sizeof(struct link) + size);
+ if (l == NULL)
+ internal_errorf(1, "unable to allocate memory");
+ l->next = ap->freelist;
+ l->prev = NULL;
+ if (ap->freelist)
+ ap->freelist->prev = l;
+ ap->freelist = l;
+
+ return L2P(l);
+}
+
+/*
+ * Copied from calloc().
+ *
+ * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
+ * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
+ */
+#define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4))
+
+void *
+areallocarray(void *ptr, size_t nmemb, size_t size, Area *ap)
+{
+ /* condition logic cloned from calloc() */
+ if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+ nmemb > 0 && SIZE_MAX / nmemb < size) {
+ internal_errorf(1, "unable to allocate memory");
+ }
+
+ return aresize(ptr, nmemb * size, ap);
+}
+
+void *
+aresize(void *ptr, size_t size, Area *ap)
+{
+ struct link *l, *l2, *lprev, *lnext;
+
+ if (ptr == NULL)
+ return alloc(size, ap);
+
+ /* ensure that we don't overflow by allocating space for link */
+ if (size > SIZE_MAX - sizeof(struct link))
+ internal_errorf(1, "unable to allocate memory");
+
+ l = P2L(ptr);
+ lprev = l->prev;
+ lnext = l->next;
+
+ l2 = realloc(l, sizeof(struct link) + size);
+ if (l2 == NULL)
+ internal_errorf(1, "unable to allocate memory");
+ if (lprev)
+ lprev->next = l2;
+ else
+ ap->freelist = l2;
+ if (lnext)
+ lnext->prev = l2;
+
+ return L2P(l2);
+}
+
+void
+afree(void *ptr, Area *ap)
+{
+ struct link *l, *l2;
+
+ if (!ptr)
+ return;
+
+ l = P2L(ptr);
+
+ for (l2 = ap->freelist; l2 != NULL; l2 = l2->next) {
+ if (l == l2)
+ break;
+ }
+ if (l2 == NULL)
+ internal_errorf(1, "afree: %p not present in area %p", ptr, ap);
+
+ if (l->prev)
+ l->prev->next = l->next;
+ else
+ ap->freelist = l->next;
+ if (l->next)
+ l->next->prev = l->prev;
+
+ free(l);
+}