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-rw-r--r--linker/ba.c76
-rw-r--r--linker/ba.h31
-rw-r--r--linker/linker.c24
3 files changed, 70 insertions, 61 deletions
diff --git a/linker/ba.c b/linker/ba.c
index bea6f84..db49c4b 100644
--- a/linker/ba.c
+++ b/linker/ba.c
@@ -30,65 +30,41 @@
#include "linker_debug.h"
#include "ba.h"
-struct ba_bits {
- unsigned allocated:1; /* 1 if allocated, 0 if free */
- unsigned order:7; /* size of the region in ba space */
-};
-
-struct ba_info {
- /* start address of the ba space */
- unsigned long base;
- /* total size of the ba space */
- unsigned long size;
- /* number of entries in the ba space */
- int num_entries;
- /* the bitmap for the region indicating which entries are allocated
- * and which are free */
- struct ba_bits *bitmap;
-};
-
#undef min
#define min(a,b) ((a)<(b)?(a):(b))
-#define BA_MIN_ALLOC LIBINC
-#define BA_MAX_ORDER 128
-#define BA_START LIBBASE
-#define BA_SIZE (LIBLAST - LIBBASE)
-
-#define BA_IS_FREE(index) (!(ba.bitmap[index].allocated))
-#define BA_ORDER(index) ba.bitmap[index].order
+#define BA_IS_FREE(index) (!(ba->bitmap[index].allocated))
+#define BA_ORDER(index) ba->bitmap[index].order
#define BA_BUDDY_INDEX(index) ((index) ^ (1 << BA_ORDER(index)))
#define BA_NEXT_INDEX(index) ((index) + (1 << BA_ORDER(index)))
-#define BA_OFFSET(index) ((index) * BA_MIN_ALLOC)
-#define BA_START_ADDR(index) (BA_OFFSET(index) + ba.base)
-#define BA_LEN(index) ((1 << BA_ORDER(index)) * BA_MIN_ALLOC)
-
-static struct ba_bits ba_bitmap[BA_SIZE / BA_MIN_ALLOC];
+#define BA_OFFSET(index) ((index) * ba->min_alloc)
+#define BA_START_ADDR(index) (BA_OFFSET(index) + ba->base)
+#define BA_LEN(index) ((1 << BA_ORDER(index)) * ba->min_alloc)
-static struct ba_info ba = {
- .base = BA_START,
- .size = BA_SIZE,
- .bitmap = ba_bitmap,
- .num_entries = sizeof(ba_bitmap)/sizeof(ba_bitmap[0]),
-};
+static unsigned long ba_order(struct ba *ba, unsigned long len);
-void ba_init(void)
+void ba_init(struct ba *ba)
{
int i, index = 0;
- for (i = sizeof(ba.num_entries) * 8 - 1; i >= 0; i--) {
- if (ba.num_entries & 1<<i) {
+
+ unsigned long max_order = ba_order(ba, ba->size);
+ if (ba->max_order == 0 || ba->max_order > max_order)
+ ba->max_order = max_order;
+
+ for (i = sizeof(ba->num_entries) * 8 - 1; i >= 0; i--) {
+ if (ba->num_entries & 1<<i) {
BA_ORDER(index) = i;
index = BA_NEXT_INDEX(index);
}
}
}
-int ba_free(int index)
+int ba_free(struct ba *ba, int index)
{
int buddy, curr = index;
/* clean up the bitmap, merging any buddies */
- ba.bitmap[curr].allocated = 0;
+ ba->bitmap[curr].allocated = 0;
/* find a slots buddy Buddy# = Slot# ^ (1 << order)
* if the buddy is also free merge them
* repeat until the buddy is not free or end of the bitmap is reached
@@ -103,16 +79,16 @@ int ba_free(int index)
} else {
break;
}
- } while (curr < ba.num_entries);
+ } while (curr < ba->num_entries);
return 0;
}
-static unsigned long ba_order(unsigned long len)
+static unsigned long ba_order(struct ba *ba, unsigned long len)
{
unsigned long i;
- len = (len + BA_MIN_ALLOC - 1) / BA_MIN_ALLOC;
+ len = (len + ba->min_alloc - 1) / ba->min_alloc;
len--;
for (i = 0; i < sizeof(len)*8; i++)
if (len >> i == 0)
@@ -120,14 +96,14 @@ static unsigned long ba_order(unsigned long len)
return i;
}
-int ba_allocate(unsigned long len)
+int ba_allocate(struct ba *ba, unsigned long len)
{
int curr = 0;
- int end = ba.num_entries;
+ int end = ba->num_entries;
int best_fit = -1;
- unsigned long order = ba_order(len);
+ unsigned long order = ba_order(ba, len);
- if (order > BA_MAX_ORDER)
+ if (order > ba->max_order)
return -1;
/* look through the bitmap:
@@ -165,16 +141,16 @@ int ba_allocate(unsigned long len)
buddy = BA_BUDDY_INDEX(best_fit);
BA_ORDER(buddy) = BA_ORDER(best_fit);
}
- ba.bitmap[best_fit].allocated = 1;
+ ba->bitmap[best_fit].allocated = 1;
return best_fit;
}
-unsigned long ba_start_addr(int index)
+unsigned long ba_start_addr(struct ba *ba, int index)
{
return BA_START_ADDR(index);
}
-unsigned long ba_len(int index)
+unsigned long ba_len(struct ba *ba, int index)
{
return BA_LEN(index);
}
diff --git a/linker/ba.h b/linker/ba.h
index 78f4626..c11017b 100644
--- a/linker/ba.h
+++ b/linker/ba.h
@@ -29,10 +29,31 @@
#ifndef __LINKER_BA_H
#define __LINKER_BA_H
-extern void ba_init(void);
-extern int ba_allocate(unsigned long len);
-extern int ba_free(int index);
-extern unsigned long ba_start_addr(int index);
-extern unsigned long ba_len(int index);
+struct ba_bits {
+ unsigned allocated:1; /* 1 if allocated, 0 if free */
+ unsigned order:7; /* size of the region in ba space */
+};
+
+struct ba {
+ /* start address of the ba space */
+ unsigned long base;
+ /* total size of the ba space */
+ unsigned long size;
+ /* the smaller allocation that can be made */
+ unsigned long min_alloc;
+ /* the order of the largest allocation that can be made */
+ unsigned long max_order;
+ /* number of entries in the ba space */
+ int num_entries;
+ /* the bitmap for the region indicating which entries are allocated
+ * and which are free */
+ struct ba_bits *bitmap;
+};
+
+extern void ba_init(struct ba *ba);
+extern int ba_allocate(struct ba *ba, unsigned long len);
+extern int ba_free(struct ba *ba, int index);
+extern unsigned long ba_start_addr(struct ba *ba, int index);
+extern unsigned long ba_len(struct ba *ba, int index);
#endif
diff --git a/linker/linker.c b/linker/linker.c
index a6ecd1a..5090b11 100644
--- a/linker/linker.c
+++ b/linker/linker.c
@@ -91,6 +91,18 @@ static soinfo *sonext = &libdl_info;
static soinfo *somain; /* main process, always the one after libdl_info */
#endif
+
+/* Set up for the buddy allocator managing the prelinked libraries. */
+static struct ba_bits ba_prelink_bitmap[(LIBLAST - LIBBASE) / LIBINC];
+static struct ba ba_prelink = {
+ .base = LIBBASE,
+ .size = LIBLAST - LIBBASE,
+ .min_alloc = LIBINC,
+ /* max_order will be determined automatically */
+ .bitmap = ba_prelink_bitmap,
+ .num_entries = sizeof(ba_prelink_bitmap)/sizeof(ba_prelink_bitmap[0]),
+};
+
static inline int validate_soinfo(soinfo *si)
{
return (si >= sopool && si < sopool + SO_MAX) ||
@@ -783,14 +795,14 @@ alloc_mem_region(soinfo *si)
for it from the buddy allocator, which manages the area between
LIBBASE and LIBLAST.
*/
- si->ba_index = ba_allocate(si->size);
+ si->ba_index = ba_allocate(&ba_prelink, si->size);
if(si->ba_index >= 0) {
- si->base = ba_start_addr(si->ba_index);
+ si->base = ba_start_addr(&ba_prelink, si->ba_index);
PRINT("%5d mapping library '%s' at %08x (index %d) " \
"through buddy allocator.\n",
pid, si->name, si->base, si->ba_index);
if (reserve_mem_region(si) < 0) {
- ba_free(si->ba_index);
+ ba_free(&ba_prelink, si->ba_index);
si->ba_index = -1;
si->base = 0;
goto err;
@@ -1086,7 +1098,7 @@ load_library(const char *name)
/* Now actually load the library's segments into right places in memory */
if (load_segments(fd, &__header[0], si) < 0) {
if (si->ba_index >= 0) {
- ba_free(si->ba_index);
+ ba_free(&ba_prelink, si->ba_index);
si->ba_index = -1;
}
goto fail;
@@ -1189,7 +1201,7 @@ unsigned unload_library(soinfo *si)
PRINT("%5d releasing library '%s' address space at %08x "\
"through buddy allocator.\n",
pid, si->name, si->base);
- ba_free(si->ba_index);
+ ba_free(&ba_prelink, si->ba_index);
}
notify_gdb_of_unload(si);
free_info(si);
@@ -1897,7 +1909,7 @@ unsigned __linker_init(unsigned **elfdata)
vecs += 2;
}
- ba_init();
+ ba_init(&ba_prelink);
si->base = 0;
si->dynamic = (unsigned *)-1;
generated by cgit v1.1 at 2024-12-22 23:58:40 +0000