Get address sanitizer mostly working

third_party/dlmalloc/dlmalloc.c

@@ -3,7 +3,6 @@
 #include "libc/calls/internal.h"
 #include "libc/calls/struct/sysinfo.h"
 #include "libc/conv/conv.h"
-#include "libc/conv/sizemultiply.h"
 #include "libc/dce.h"
 #include "libc/limits.h"
 #include "libc/macros.h"
@@ -861,6 +860,22 @@ void dlfree(void *mem) {
 #endif /* FOOTERS */
 }
 
+/**
+ * Multiplies sizes w/ saturation and overflow detection.
+ *
+ * @param count may be 0 to for realloc() → free() behavior
+ * @param opt_out set to count*itemsize or SIZE_MAX on overflow
+ * @return true on success or false on overflow
+ */
+static bool sizemultiply(size_t *opt_out, size_t count, size_t itemsize) {
+  size_t result;
+  bool overflowed;
+  overflowed = __builtin_mul_overflow(count, itemsize, &result);
+  if (overflowed) result = SIZE_MAX;
+  if (opt_out) *opt_out = result;
+  return !overflowed;
+}
+
 void *dlcalloc(size_t n_elements, size_t elem_size) {
   void *mem;
   size_t req;

third_party/dlmalloc/dlmalloc.mk

@@ -25,6 +25,7 @@ THIRD_PARTY_DLMALLOC_A_CHECKS =					\
 	$(THIRD_PARTY_DLMALLOC_A_HDRS:%=o/$(MODE)/%.ok)
 
 THIRD_PARTY_DLMALLOC_A_DIRECTDEPS =				\
+	LIBC_BITS						\
 	LIBC_CALLS						\
 	LIBC_CONV						\
 	LIBC_FMT						\
@@ -47,6 +48,10 @@ $(THIRD_PARTY_DLMALLOC_A).pkg:					\
 		$(THIRD_PARTY_DLMALLOC_A_OBJS)			\
 		$(foreach x,$(THIRD_PARTY_DLMALLOC_A_DIRECTDEPS),$($(x)_A).pkg)
 
+$(THIRD_PARTY_DLMALLOC_A_OBJS):					\
+		OVERRIDE_CFLAGS +=				\
+			$(NO_MAGIC)
+
 THIRD_PARTY_DLMALLOC_LIBS = $(foreach x,$(THIRD_PARTY_DLMALLOC_ARTIFACTS),$($(x)))
 THIRD_PARTY_DLMALLOC_SRCS = $(foreach x,$(THIRD_PARTY_DLMALLOC_ARTIFACTS),$($(x)_SRCS))
 THIRD_PARTY_DLMALLOC_HDRS = $(foreach x,$(THIRD_PARTY_DLMALLOC_ARTIFACTS),$($(x)_HDRS))

third_party/dlmalloc/dlmemalign-impl.c

@@ -1,15 +1,15 @@
+#include "libc/bits/bits.h"
 #include "libc/mem/mem.h"
 #include "libc/sysv/errfuns.h"
 #include "third_party/dlmalloc/dlmalloc.h"
 
 void* dlmemalign$impl(mstate m, size_t alignment, size_t bytes) {
   void* mem = 0;
-  if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */
-    alignment = MIN_CHUNK_SIZE;
+  if (alignment < MIN_CHUNK_SIZE) { /* must be at least a minimum chunk size */
+    alignment = MIN_CHUNK_SIZE;     /* is 32 bytes on NexGen32e */
+  }
   if ((alignment & (alignment - SIZE_T_ONE)) != 0) { /* Ensure a power of 2 */
-    size_t a = MALLOC_ALIGNMENT << 1;
-    while (a < alignment) a <<= 1;
-    alignment = a;
+    alignment = roundup2pow(alignment);
   }
   if (bytes >= MAX_REQUEST - alignment) {
     if (m != 0) { /* Test isn't needed but avoids compiler warning */

third_party/dlmalloc/dlmemalign.c

@@ -1,9 +1,7 @@
-#include "third_party/dlmalloc/dlmalloc.h"
 #include "libc/mem/mem.h"
+#include "third_party/dlmalloc/dlmalloc.h"
 
 void *dlmemalign(size_t alignment, size_t bytes) {
-  if (alignment <= MALLOC_ALIGNMENT) {
-    return dlmalloc(bytes);
-  }
+  if (alignment <= MALLOC_ALIGNMENT) return dlmalloc(bytes);
   return dlmemalign$impl(gm, alignment, bytes);
 }

third_party/dlmalloc/dlposix_memalign.c

@@ -1,24 +1,27 @@
 #include "libc/errno.h"
 #include "libc/mem/mem.h"
+#include "libc/sysv/errfuns.h"
 #include "third_party/dlmalloc/dlmalloc.h"
 
 int dlposix_memalign(void** pp, size_t alignment, size_t bytes) {
-  void* mem = 0;
-  if (alignment == MALLOC_ALIGNMENT)
+  void* mem;
+  size_t d, r;
+  mem = NULL;
+  if (alignment == MALLOC_ALIGNMENT) {
     mem = dlmalloc(bytes);
-  else {
-    size_t d = alignment / sizeof(void*);
-    size_t r = alignment % sizeof(void*);
-    if (r != 0 || d == 0 || (d & (d - SIZE_T_ONE)) != 0)
-      return EINVAL;
-    else if (bytes <= MAX_REQUEST - alignment) {
+  } else {
+    d = alignment / sizeof(void*);
+    r = alignment % sizeof(void*);
+    if (r != 0 || d == 0 || (d & (d - SIZE_T_ONE)) != 0) {
+      return einval();
+    } else if (bytes <= MAX_REQUEST - alignment) {
       if (alignment < MIN_CHUNK_SIZE) alignment = MIN_CHUNK_SIZE;
       mem = dlmemalign$impl(gm, alignment, bytes);
     }
   }
-  if (mem == 0)
-    return ENOMEM;
-  else {
+  if (mem == 0) {
+    return enomem();
+  } else {
     *pp = mem;
     return 0;
   }