From: David Given <dg@cowlark.com>
Date: Wed, 20 Jan 2016 22:32:12 +0000 (+0100)
Subject: Fix alignment issues primarily with the malloc() alignment payload.
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=3ffaaab316ac9b0165f7df0ad36d80322d67b238;p=FUZIX.git

Fix alignment issues primarily with the malloc() alignment payload.
---

diff --git a/Library/libs/error.c b/Library/libs/error.c
index 7cdc5303..e3281f3f 100644
--- a/Library/libs/error.c
+++ b/Library/libs/error.c
@@ -11,6 +11,7 @@
 #include <paths.h>
 #include <errno.h>
 #include <fcntl.h>
+#include "malloc-l.h"
 
 static uint8_t *__sys_errlist;
 static uint16_t *__sys_errptr;
@@ -25,7 +26,7 @@ static void _load_errlist(void)
 		return;
 	if (fstat(fd, &st) < 0 || !S_ISREG(st.st_mode))
 		goto bad;
-	__sys_errlist = sbrk((st.st_size + 3)&~3);
+	__sys_errlist = sbrk(ALIGNUP(st.st_size));
 	if (__sys_errlist == (void *) -1)
 		goto bad;
 	if (read(fd,__sys_errlist, st.st_size) == st.st_size) {
diff --git a/Library/libs/free.c b/Library/libs/free.c
index 1fd24485..021868a5 100644
--- a/Library/libs/free.c
+++ b/Library/libs/free.c
@@ -135,8 +135,13 @@ void *__mini_malloc(size_t size)
 	if (size == 0)
 		return 0;
 
+	/* Ensure size is aligned, otherwise our memory nodes become unaligned
+	 * and we get hard-to-debug errors on platforms which require
+	 * aligned accesses. */
+	size = ALIGNUP(size + sizeof(struct mem_cell));
+
 	/* Minor oops here, sbrk has a signed argument */
-	if (size > (((unsigned) -1) >> 1) - sizeof(struct mem_cell) * 3) {
+	if (size > (((unsigned) -1) >> 1) - sizeof(struct mem_cell) * 2) {
 	      nomem:errno = ENOMEM;
 		return 0;
 	}
diff --git a/Library/libs/malloc-l.h b/Library/libs/malloc-l.h
index 42ad35d0..b8af5131 100644
--- a/Library/libs/malloc-l.h
+++ b/Library/libs/malloc-l.h
@@ -14,6 +14,26 @@
 
 #define __MINI_MALLOC__
 
+union maximally_aligned {
+	uint8_t b;
+	uint16_t s;
+	uint32_t i;
+	#if !defined(NO_64BIT)
+		uint64_t l;
+	#endif
+	float f;
+	double d;
+};
+
+struct malloc_alignment_tester
+{
+	char b;
+	union maximally_aligned u;
+};
+
+#define ALIGNMENT ((int)&(((struct malloc_alignment_tester*)NULL)->u))
+#define ALIGNUP(s) (((s) + ALIGNMENT - 1) & ~(ALIGNMENT - 1))
+
 #define MCHUNK		512	/* Allocation unit in 'mem' elements */
 #undef LAZY_FREE		/* If set frees can be infinitly defered */
 #undef MINALLOC	/* 32 */	/* Smallest chunk to alloc in 'mem's */
@@ -29,9 +49,10 @@
 #endif
 
 typedef struct mem_cell {
-	struct mem_cell *next;	/* A pointer to the next mem */
-	unsigned int size;	/* An int >= sizeof pointer */
-	char *depth;		/* For the alloca hack */
+	struct mem_cell *next;              /* A pointer to the next mem */
+	unsigned int size;                  /* An int >= sizeof pointer */
+	char *depth;                        /* For the alloca hack */
+	union maximally_aligned padding[0]; /* Ensures alignment of payload */
 } mem;
 
 #define m_size(p)  ((p)[0].size)		/* For malloc */
diff --git a/Library/libs/malloc.c b/Library/libs/malloc.c
index 6b735a07..72b6a7d9 100644
--- a/Library/libs/malloc.c
+++ b/Library/libs/malloc.c
@@ -24,12 +24,10 @@ void *malloc(size_t size)
 	if (size == 0)
 		return 0;	/* ANSI STD */
 
-	/* Ensure size is aligned, otherwise our memory nodes become unaligned
-	 * and we get hard-to-debug errors on platforms which require
-	 * aligned accesses. */
-	size = (size + sizeof(void*) - 1) & ~(sizeof(void*) - 1);
-
-	sz = size + sizeof(struct mem_cell);
+	/* Ensure the size is aligned, otherwise our memory nodes become unaligned
+	 * and we get hard-to-debug errors on platforms which require aligned
+	 * accesses. */
+	sz = ALIGNUP(size + sizeof(struct mem_cell));
 
 #ifdef MINALLOC
 	if (sz < MINALLOC)