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Revert "Revert "linker: get rid of the buddy allocator""

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This reverts commit f9a9cda23a6afc1c2dfdfd624cde23b61941eb5e.
This revert is promised once b/5039224, b/5036755, b/5036610 are resolved.
This commit is contained in:
Shih-wei Liao 2011-07-17 12:32:43 -07:00
parent de75876c3f
commit 48527c3f74
5 changed files with 15 additions and 277 deletions
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3
linker/Android.mk
View File

@ -8,8 +8,7 @@ LOCAL_SRC_FILES:= \
linker_format.c \
rt.c \
dlfcn.c \
debugger.c \
ba.c
debugger.c
ifeq ($(TARGET_ARCH),sh)
# SH-4A series virtual address range from 0x00000000 to 0x7FFFFFFF.

156
linker/ba.c
View File

@ -1,156 +0,0 @@
/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "linker.h"
#include "linker_debug.h"
#include "ba.h"
#undef min
#define min(a,b) ((a)<(b)?(a):(b))
#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 unsigned long ba_order(struct ba *ba, unsigned long len);
void ba_init(struct ba *ba)
{
int i, index = 0;
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(struct ba *ba, int index)
{
int buddy, curr = index;
/* clean up the bitmap, merging any buddies */
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
*/
do {
buddy = BA_BUDDY_INDEX(curr);
if (BA_IS_FREE(buddy) &&
BA_ORDER(buddy) == BA_ORDER(curr)) {
BA_ORDER(buddy)++;
BA_ORDER(curr)++;
curr = min(buddy, curr);
} else {
break;
}
} while (curr < ba->num_entries);
return 0;
}
static unsigned long ba_order(struct ba *ba, unsigned long len)
{
unsigned long i;
len = (len + ba->min_alloc - 1) / ba->min_alloc;
len--;
for (i = 0; i < sizeof(len)*8; i++)
if (len >> i == 0)
break;
return i;
}
int ba_allocate(struct ba *ba, unsigned long len)
{
int curr = 0;
int end = ba->num_entries;
int best_fit = -1;
unsigned long order = ba_order(ba, len);
if (order > ba->max_order)
return -1;
/* look through the bitmap:
* if you find a free slot of the correct order use it
* otherwise, use the best fit (smallest with size > order) slot
*/
while (curr < end) {
if (BA_IS_FREE(curr)) {
if (BA_ORDER(curr) == (unsigned char)order) {
/* set the not free bit and clear others */
best_fit = curr;
break;
}
if (BA_ORDER(curr) > (unsigned char)order &&
(best_fit < 0 ||
BA_ORDER(curr) < BA_ORDER(best_fit)))
best_fit = curr;
}
curr = BA_NEXT_INDEX(curr);
}
/* if best_fit < 0, there are no suitable slots,
* return an error
*/
if (best_fit < 0)
return -1;
/* now partition the best fit:
* split the slot into 2 buddies of order - 1
* repeat until the slot is of the correct order
*/
while (BA_ORDER(best_fit) > (unsigned char)order) {
int buddy;
BA_ORDER(best_fit) -= 1;
buddy = BA_BUDDY_INDEX(best_fit);
BA_ORDER(buddy) = BA_ORDER(best_fit);
}
ba->bitmap[best_fit].allocated = 1;
return best_fit;
}
unsigned long ba_start_addr(struct ba *ba, int index)
{
return BA_START_ADDR(index);
}
unsigned long ba_len(struct ba *ba, int index)
{
return BA_LEN(index);
}

59
linker/ba.h
View File

@ -1,59 +0,0 @@
/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef __LINKER_BA_H
#define __LINKER_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 {
/* 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

60
linker/linker.c
View File

@ -51,8 +51,6 @@
#include "linker_environ.h"
#include "linker_format.h"
#include "ba.h"
#define ALLOW_SYMBOLS_FROM_MAIN 1
#define SO_MAX 128
@ -96,17 +94,6 @@ static soinfo *somain; /* main process, always the one after libdl_info */
#endif
/* Set up for the buddy allocator managing the non-prelinked libraries. */
static struct ba_bits ba_nonprelink_bitmap[(LIBLAST - LIBBASE) / LIBINC];
static struct ba ba_nonprelink = {
.base = LIBBASE,
.size = LIBLAST - LIBBASE,
.min_alloc = LIBINC,
/* max_order will be determined automatically */
.bitmap = ba_nonprelink_bitmap,
.num_entries = sizeof(ba_nonprelink_bitmap)/sizeof(ba_nonprelink_bitmap[0]),
};
static inline int validate_soinfo(soinfo *si)
{
return (si >= sopool && si < sopool + SO_MAX) ||
@ -292,7 +279,6 @@ static soinfo *alloc_info(const char *name)
memset(si, 0, sizeof(soinfo));
strlcpy((char*) si->name, name, sizeof(si->name));
sonext->next = si;
si->ba_index = -1; /* by default, prelinked */
si->next = NULL;
si->refcount = 0;
sonext = si;
@ -844,28 +830,25 @@ alloc_mem_region(soinfo *si)
{
if (si->base) {
/* Attempt to mmap a prelinked library. */
si->ba_index = -1;
return reserve_mem_region(si);
}
/* This is not a prelinked library, so we attempt to allocate space
for it from the buddy allocator, which manages the area between
LIBBASE and LIBLAST.
/* This is not a prelinked library, so we use the kernel's default
allocator.
*/
si->ba_index = ba_allocate(&ba_nonprelink, si->size);
if(si->ba_index >= 0) {
si->base = ba_start_addr(&ba_nonprelink, 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(&ba_nonprelink, si->ba_index);
si->ba_index = -1;
si->base = 0;
goto err;
}
return 0;
void *base = mmap(NULL, si->size, PROT_READ | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (base == MAP_FAILED) {
DL_ERR("%5d mmap of library '%s' failed: %d (%s)\n",
pid, si->name,
errno, strerror(errno));
goto err;
}
si->base = (unsigned) base;
PRINT("%5d mapped library '%s' to %08x via kernel allocator.\n",
pid, si->name, si->base);
return 0;
err:
DL_ERR("OOPS: %5d cannot map library '%s'. no vspace available.",
@ -1154,10 +1137,6 @@ 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(&ba_nonprelink, si->ba_index);
si->ba_index = -1;
}
goto fail;
}
@ -1187,9 +1166,6 @@ init_library(soinfo *si)
TRACE("[ %5d init_library base=0x%08x sz=0x%08x name='%s') ]\n",
pid, si->base, si->size, si->name);
if (si->base < LIBBASE || si->base >= LIBLAST)
si->flags |= FLAG_PRELINKED;
if(link_image(si, wr_offset)) {
/* We failed to link. However, we can only restore libbase
** if no additional libraries have moved it since we updated it.
@ -1264,12 +1240,6 @@ unsigned unload_library(soinfo *si)
}
munmap((char *)si->base, si->size);
if (si->ba_index >= 0) {
PRINT("%5d releasing library '%s' address space at %08x "\
"through buddy allocator.\n",
pid, si->name, si->base);
ba_free(&ba_nonprelink, si->ba_index);
}
notify_gdb_of_unload(si);
free_info(si);
si->refcount = 0;
@ -2213,8 +2183,6 @@ unsigned __linker_init(unsigned **elfdata)
vecs += 2;
}
ba_init(&ba_nonprelink);
si->base = 0;
si->dynamic = (unsigned *)-1;
si->wrprotect_start = 0xffffffff;

14
linker/linker.h
View File

@ -83,7 +83,6 @@ typedef struct soinfo soinfo;
#define FLAG_LINKED 0x00000001
#define FLAG_ERROR 0x00000002
#define FLAG_EXE 0x00000004 // The main executable
#define FLAG_PRELINKED 0x00000008 // This is a pre-linked lib
#define SOINFO_NAME_LEN 128
@ -95,8 +94,6 @@ struct soinfo
unsigned entry;
unsigned base;
unsigned size;
// buddy-allocator index, negative for prelinked libraries
int ba_index;
unsigned *dynamic;
@ -154,17 +151,6 @@ struct soinfo
extern soinfo libdl_info;
/* these must all be powers of two */
#ifdef ARCH_SH
#define LIBBASE 0x60000000
#define LIBLAST 0x70000000
#define LIBINC 0x00100000
#else
#define LIBBASE 0x80000000
#define LIBLAST 0x90000000
#define LIBINC 0x00100000
#endif
#ifdef ANDROID_ARM_LINKER
#define R_ARM_COPY 20