ref: 66c512248c5cda63b04e2c74e35d5711756b180f
parent: 5487c4119cec517c5cc6039eb1f6f670f4a7c846
author: Ori Bernstein <ori@eigenstate.org>
date: Mon Mar 9 04:02:22 EDT 2020
fix alignment in ape malloc We used to have a padding int in the structure after the next pointer, to align it to 16 bytes. On 64 bit architectures, the pointer was already 8 bits, so the padding misaligned things to 20 bytes. This fixes it so that we're explcit about the data alignment we want, instead of hoping that the various sizes line up.
--- a/sys/src/ape/lib/ap/plan9/malloc.c
+++ b/sys/src/ape/lib/ap/plan9/malloc.c
@@ -11,13 +11,22 @@
CUTOFF = 12,
};
+#define NPAD(t, align) \
+ ((sizeof(t) + align - 1) & ~(align - 1))
typedef struct Bucket Bucket;
-struct Bucket
-{+typedef struct Header Header;
+struct Header {int size;
int magic;
Bucket *next;
- int pad;
+};
+
+struct Bucket
+{+ union {+ Header;
+ char _pad[NPAD(Header, 16)];
+ };
char data[1];
};
--
⑨