[Xenomai-git] Philippe Gerum : copperplate/heapobj-pshared: fix and sanitize extent management
Module: xenomai-3
Branch: next
Commit: 65f16f4a3f0d4de3be221bea6b4545b2b4d74321
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=65f16f4a3f0d4de3be221bea6b4545b2b4d74321
Author: Philippe Gerum
Date: Wed Aug 12 18:27:22 2015 +0200
copperplate/heapobj-pshared: fix and sanitize extent management
---
lib/copperplate/heapobj-pshared.c | 278 +
lib/copperplate/internal.h|3 -
2 files changed, 159 insertions(+), 122 deletions(-)
diff --git a/lib/copperplate/heapobj-pshared.c
b/lib/copperplate/heapobj-pshared.c
index 5fe899a..0df08c3 100644
--- a/lib/copperplate/heapobj-pshared.c
+++ b/lib/copperplate/heapobj-pshared.c
@@ -57,17 +57,17 @@ enum {
page_list =2
};
-struct page_map {
+struct page_entry {
unsigned int type : 8;/* free, cont, list or log2 */
unsigned int bcount : 24; /* Number of active blocks. */
};
struct shared_extent {
struct holder link;
- memoff_t membase; /* Base address of the page array */
- memoff_t memlim;/* Memory limit of page array */
- memoff_t freelist; /* Head of the free page list */
- struct page_map pagemap[1]; /* Start of page map */
+ memoff_t membase; /* Base offset of page array */
+ memoff_t memlim;/* Offset limit of page array */
+ memoff_t freelist; /* Head of free page list */
+ struct page_entry pagemap[1]; /* Start of page map */
};
/*
@@ -75,7 +75,7 @@ struct shared_extent {
* additional session-wide information.
*/
struct session_heap {
- struct shared_heap base;
+ struct shared_heap heap;
int cpid;
memoff_t maplen;
struct hash_table catalog;
@@ -91,6 +91,12 @@ struct session_heap {
*/
void *__main_heap;
#define main_heap (*(struct session_heap *)__main_heap)
+/*
+ * Base address for offset-based addressing, which is the start of
+ * the session heap since all memory objects are allocated from it,
+ * including other (sub-)heaps.
+ */
+#define main_base __main_heap
/* A table of shared clusters for the session. */
struct hash_table *__main_catalog;
@@ -100,10 +106,10 @@ struct sysgroup *__main_sysgroup;
static struct heapobj main_pool;
-#define __shoff(h, p) ((caddr_t)(p) - (caddr_t)(h))
-#define __shoff_check(h, p)((p) ? __shoff(h, p) : 0)
-#define __shref(h, o) ((void *)((caddr_t)(h) + (o)))
-#define __shref_check(h, o)((o) ? __shref(h, o) : NULL)
+#define __shoff(b, p) ((caddr_t)(p) - (caddr_t)(b))
+#define __shoff_check(b, p)((p) ? __shoff(b, p) : 0)
+#define __shref(b, o) ((void *)((caddr_t)(b) + (o)))
+#define __shref_check(b, o)((o) ? __shref(b, o) : NULL)
static inline size_t __align_to(size_t size, size_t al)
{
@@ -111,33 +117,39 @@ static inline size_t __align_to(size_t size, size_t al)
return ((size+al-1)&(~(al-1)));
}
-static inline size_t internal_overhead(size_t hsize)
+static inline size_t get_pagemap_size(size_t h)
{
- /* o = (h - o) * m / p + e
- o * p = (h - o) * m + e * p
- o * (p + m) = h * m + e * p
- o = (h * m + e *p) / (p + m)
- */
- return __align_to((sizeof(struct shared_extent) * HOBJ_PAGE_SIZE
- + sizeof(struct page_map) * hsize)
- / (HOBJ_PAGE_SIZE + sizeof(struct page_map)),
HOBJ_PAGE_SIZE);
+ /*
+* Return the size of the meta data required to map 'h' bytes
+* of user memory in pages of HOBJ_PAGE_SIZE bytes. The meta
+* data includes the length of the extent descriptor, plus the
+* length of the page mapping array. 'h' must be a multiple of
+* HOBJ_PAGE_SIZE on entry.
+*/
+ assert((h & ~HOBJ_PAGE_MASK) == 0);
+ return __align_to((h >> HOBJ_PAGE_SHIFT) * sizeof(struct page_entry)
+ + sizeof(struct shared_extent), HOBJ_PAGE_SIZE);
}
-static void init_extent(struct shared_heap *heap, struct shared_extent *extent)
+static void init_extent(void *base, struct shared_extent *extent)
{
caddr_t freepage;
int n, lastpgnum;
- __holder_init_nocheck(heap, &extent->link);
+ __holder_init_nocheck(base, &extent->link);
- /* The initial extent starts right after the header. */
- extent->membase = __shoff(heap, extent) + heap->hdrsize;
- lastpgnum = heap->npages - 1;
+ lastpgnum = ((extent->memlim - extent->membase) >> HOBJ_PAGE_SHIFT) - 1;
+ /*
+* An extent must contain at least two addressable pages to
+* cope with allocation sizes between PAGESIZE and 2 *
+* PAGESIZE.
+*/
+ assert(lastpgnum >= 1);
/* Mark each page as free in the page map. */
- for (n = 0, freepage = __shref(heap, extent->membase);
+ for (n = 0, freepage = __shref(base, extent->membase);
n < lastpgnum; n++, freepage += HOBJ_PAGE_SIZE) {
[Xenomai-git] Philippe Gerum : copperplate/heapobj-pshared: fix and sanitize extent management
Module: xenomai-3
Branch: master
Commit: 65f16f4a3f0d4de3be221bea6b4545b2b4d74321
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=65f16f4a3f0d4de3be221bea6b4545b2b4d74321
Author: Philippe Gerum
Date: Wed Aug 12 18:27:22 2015 +0200
copperplate/heapobj-pshared: fix and sanitize extent management
---
lib/copperplate/heapobj-pshared.c | 278 +
lib/copperplate/internal.h|3 -
2 files changed, 159 insertions(+), 122 deletions(-)
diff --git a/lib/copperplate/heapobj-pshared.c
b/lib/copperplate/heapobj-pshared.c
index 5fe899a..0df08c3 100644
--- a/lib/copperplate/heapobj-pshared.c
+++ b/lib/copperplate/heapobj-pshared.c
@@ -57,17 +57,17 @@ enum {
page_list =2
};
-struct page_map {
+struct page_entry {
unsigned int type : 8;/* free, cont, list or log2 */
unsigned int bcount : 24; /* Number of active blocks. */
};
struct shared_extent {
struct holder link;
- memoff_t membase; /* Base address of the page array */
- memoff_t memlim;/* Memory limit of page array */
- memoff_t freelist; /* Head of the free page list */
- struct page_map pagemap[1]; /* Start of page map */
+ memoff_t membase; /* Base offset of page array */
+ memoff_t memlim;/* Offset limit of page array */
+ memoff_t freelist; /* Head of free page list */
+ struct page_entry pagemap[1]; /* Start of page map */
};
/*
@@ -75,7 +75,7 @@ struct shared_extent {
* additional session-wide information.
*/
struct session_heap {
- struct shared_heap base;
+ struct shared_heap heap;
int cpid;
memoff_t maplen;
struct hash_table catalog;
@@ -91,6 +91,12 @@ struct session_heap {
*/
void *__main_heap;
#define main_heap (*(struct session_heap *)__main_heap)
+/*
+ * Base address for offset-based addressing, which is the start of
+ * the session heap since all memory objects are allocated from it,
+ * including other (sub-)heaps.
+ */
+#define main_base __main_heap
/* A table of shared clusters for the session. */
struct hash_table *__main_catalog;
@@ -100,10 +106,10 @@ struct sysgroup *__main_sysgroup;
static struct heapobj main_pool;
-#define __shoff(h, p) ((caddr_t)(p) - (caddr_t)(h))
-#define __shoff_check(h, p)((p) ? __shoff(h, p) : 0)
-#define __shref(h, o) ((void *)((caddr_t)(h) + (o)))
-#define __shref_check(h, o)((o) ? __shref(h, o) : NULL)
+#define __shoff(b, p) ((caddr_t)(p) - (caddr_t)(b))
+#define __shoff_check(b, p)((p) ? __shoff(b, p) : 0)
+#define __shref(b, o) ((void *)((caddr_t)(b) + (o)))
+#define __shref_check(b, o)((o) ? __shref(b, o) : NULL)
static inline size_t __align_to(size_t size, size_t al)
{
@@ -111,33 +117,39 @@ static inline size_t __align_to(size_t size, size_t al)
return ((size+al-1)&(~(al-1)));
}
-static inline size_t internal_overhead(size_t hsize)
+static inline size_t get_pagemap_size(size_t h)
{
- /* o = (h - o) * m / p + e
- o * p = (h - o) * m + e * p
- o * (p + m) = h * m + e * p
- o = (h * m + e *p) / (p + m)
- */
- return __align_to((sizeof(struct shared_extent) * HOBJ_PAGE_SIZE
- + sizeof(struct page_map) * hsize)
- / (HOBJ_PAGE_SIZE + sizeof(struct page_map)),
HOBJ_PAGE_SIZE);
+ /*
+* Return the size of the meta data required to map 'h' bytes
+* of user memory in pages of HOBJ_PAGE_SIZE bytes. The meta
+* data includes the length of the extent descriptor, plus the
+* length of the page mapping array. 'h' must be a multiple of
+* HOBJ_PAGE_SIZE on entry.
+*/
+ assert((h & ~HOBJ_PAGE_MASK) == 0);
+ return __align_to((h >> HOBJ_PAGE_SHIFT) * sizeof(struct page_entry)
+ + sizeof(struct shared_extent), HOBJ_PAGE_SIZE);
}
-static void init_extent(struct shared_heap *heap, struct shared_extent *extent)
+static void init_extent(void *base, struct shared_extent *extent)
{
caddr_t freepage;
int n, lastpgnum;
- __holder_init_nocheck(heap, &extent->link);
+ __holder_init_nocheck(base, &extent->link);
- /* The initial extent starts right after the header. */
- extent->membase = __shoff(heap, extent) + heap->hdrsize;
- lastpgnum = heap->npages - 1;
+ lastpgnum = ((extent->memlim - extent->membase) >> HOBJ_PAGE_SHIFT) - 1;
+ /*
+* An extent must contain at least two addressable pages to
+* cope with allocation sizes between PAGESIZE and 2 *
+* PAGESIZE.
+*/
+ assert(lastpgnum >= 1);
/* Mark each page as free in the page map. */
- for (n = 0, freepage = __shref(heap, extent->membase);
+ for (n = 0, freepage = __shref(base, extent->membase);
n < lastpgnum; n++, freepage += HOBJ_PAGE_SIZE)
