Based on a patch from Alexandre Oliva, make sure _dl_malloc returns a nicely

aligned pointer that may be aligned up to page_size.  Also add _dl_free,

1 files changed, 44 insertions, 8 deletions

diff --git a/ldso/ldso/dl-elf.c b/ldso/ldso/dl-elf.c
index d27e4ccb3..7f0f76c35 100644
--- a/ldso/ldso/dl-elf.c
+++ b/ldso/ldso/dl-elf.c
@@ -31,6 +31,7 @@
 
 
 #include "ldso.h"
+void *(*_dl_malloc_function) (size_t size) = NULL;
 
 #ifdef USE_CACHE
 
@@ -405,7 +406,7 @@ struct elf_resolve *_dl_load_elf_shared_library(int secure,
 	tpnt = _dl_check_hashed_files(libname);
 	if (tpnt) {
 		if (*rpnt) {
-			(*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
+			(*rpnt)->next = (struct dyn_elf *) _dl_malloc_function(sizeof(struct dyn_elf));
 			_dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 			(*rpnt)->next->prev = (*rpnt);
 			*rpnt = (*rpnt)->next;
@@ -691,7 +692,7 @@ struct elf_resolve *_dl_load_elf_shared_library(int secure,
 	 * Add this object into the symbol chain
 	 */
 	if (*rpnt) {
-		(*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
+		(*rpnt)->next = (struct dyn_elf *) _dl_malloc_function(sizeof(struct dyn_elf));
 		_dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 		(*rpnt)->next->prev = (*rpnt);
 		*rpnt = (*rpnt)->next;
@@ -883,12 +884,21 @@ char *_dl_strdup(const char *string)
 	int len;
 
 	len = _dl_strlen(string);
-	retval = _dl_malloc(len + 1);
+	retval = _dl_malloc_function(len + 1);
 	_dl_strcpy(retval, string);
 	return retval;
 }
 
-void *(*_dl_malloc_function) (size_t size) = NULL;
+union __align_type
+{
+  void *p;
+  void (*fp)(void);
+  long long ll;
+#if defined __UCLIBC_HAS_FLOATS__ && ! defined __UCLIBC_HAS_SOFT_FLOAT__
+  double d;
+#endif
+};
+
 void *_dl_malloc(int size)
 {
 	void *retval;
@@ -902,11 +912,29 @@ void *_dl_malloc(int size)
 	if (_dl_malloc_function)
 		return (*_dl_malloc_function) (size);
 
-	if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
+	if ((int)(_dl_malloc_addr - _dl_mmap_zero + size) > (int)_dl_pagesize) {
+		int rounded_size;
+
+		/* Since the above assumes we get a full page even if
+		   we request less than that, make sure we request a
+		   full page, since uClinux may give us less than than
+		   a full page.  We might round even
+		   larger-than-a-page sizes, but we end up never
+		   reusing _dl_mmap_zero/_dl_malloc_addr in that case,
+		   so we don't do it.
+
+		   The actual page size doesn't really matter; as long
+		   as we're self-consistent here, we're safe.  */
+		if (size < (int)_dl_pagesize)
+			rounded_size = (size + _dl_pagesize - 1) & _dl_pagesize;
+		else
+			rounded_size = size;
+
+
 #ifdef __SUPPORT_LD_DEBUG_EARLY__
 		_dl_dprintf(2, "malloc: mmapping more memory\n");
 #endif
-		_dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
+		_dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
 				PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		if (_dl_mmap_check_error(_dl_mmap_zero)) {
 			_dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
@@ -920,8 +948,16 @@ void *_dl_malloc(int size)
 	 * Align memory to 4 byte boundary.  Some platforms require this, others
 	 * simply get better performance.
 	 */
-	_dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
+	_dl_malloc_addr = (unsigned char *)
+		(((unsigned long) _dl_malloc_addr +
+		  __alignof__(union __align_type) - 1)
+		 & ~(__alignof__(union __align_type) - 1));
 	return retval;
 }
 
-
+void (*_dl_free_function) (void *p) = NULL;
+void
+_dl_free (void *p) {
+	if (_dl_free_function)
+		(*_dl_free_function) (p);
+}