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Added a front and back wall to each kmalloc() allocation, if USE_WALL is

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set to 1 (which it currently is).
I've only used it with bochs yet, and it lets it crash reliably in some
VFS code.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1261 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2002-09-29 01:58:22 +00:00
parent 2c26aebcd8
commit ebe92efe60
1 changed files with 57 additions and 22 deletions
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79
src/kernel/core/heap.c
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@ -15,14 +15,22 @@
#include <string.h>
#define TRACE_HEAP 0
#if TRACE_HEAP
# define TRACE(x) dprintf x
#else
# define TRACE(x) ;
#endif
/* prevent freeing pointers that were not allocated by kmalloc or are already freeed */
#define PARANOID_POINTER_CHECK 1
/* initialize newly allocated memory with something non zero */
#define PARANOID_KMALLOC 1
/* check if freed pointers are already freed */
#define PARANOID_KFREE 0
/* print more debug infos in kmalloc and kfree */
#define MAKE_NOIZE 0
#define PARANOID_KFREE 1
/* use a back and front wall around each allocation */
#define USE_WALL 1
// heap stuff
// ripped mostly from nujeffos
@ -223,12 +231,16 @@ kmalloc(unsigned int size)
unsigned int i;
struct heap_page *page;
#if MAKE_NOIZE
dprintf("kmalloc: asked to allocate size %d\n", size);
#endif
TRACE(("kmalloc: asked to allocate size %d\n", size));
mutex_lock(&heap_lock);
#if USE_WALL
// The wall uses 4 bytes to store the actual length of the requested
// block, 8 bytes for the front wall, and 8 bytes for the back wall
size += 20;
#endif
for (bin_index = 0; bin_index < bin_count; bin_index++)
if (size <= bins[bin_index].element_size)
break;
@ -257,28 +269,40 @@ kmalloc(unsigned int size)
bins[bin_index].alloc_count++;
page = &heap_alloc_table[((unsigned int)address - heap_base) / PAGE_SIZE];
page[0].free_count--;
#if MAKE_NOIZE
dprintf("kmalloc0: page 0x%x: bin_index %d, free_count %d\n", page, page->bin_index, page->free_count);
#endif
TRACE(("kmalloc0: page %p: bin_index %d, free_count %d\n", page, page->bin_index, page->free_count));
for(i = 1; i < bins[bin_index].element_size / PAGE_SIZE; i++) {
page[i].free_count--;
#if MAKE_NOIZE
dprintf("kmalloc1: page 0x%x: bin_index %d, free_count %d\n", page[i], page[i].bin_index, page[i].free_count);
#endif
TRACE(("kmalloc1: page 0x%x: bin_index %d, free_count %d\n", page[i], page[i].bin_index, page[i].free_count));
}
}
out:
mutex_unlock(&heap_lock);
#if MAKE_NOIZE
dprintf("kmalloc: asked to allocate size %d, returning ptr = %p\n", size, address);
#endif
TRACE(("kmalloc: asked to allocate size %d, returning ptr = %p\n", size, address));
#if PARANOID_KMALLOC
memset(address,0xCC,size);
#endif
#if USE_WALL
{
uint32 *wall = address;
wall[0] = size;
wall[1] = 0xabadcafe;
wall[2] = 0xabadcafe;
address = (uint8 *)address + 12;
size -= 20;
wall = (uint32 *)((uint8 *)address + size);
wall[0] = 0xabadcafe;
wall[1] = 0xabadcafe;
}
#endif
#if PARANOID_POINTER_CHECK
ptrchecklist_store(address);
#endif
@ -300,6 +324,21 @@ kfree(void *address)
if ((addr)address < heap_base || (addr)address >= (heap_base + heap_size))
panic("kfree: asked to free invalid address %p\n", address);
#if USE_WALL
{
uint32 *wall = (uint32 *)((uint8 *)address - 12);
uint32 size = wall[0];
if (wall[1] != 0xabadcafe || wall[2] != 0xabadcafe)
panic("kfree: front wall was overwritten (allocation at %p, %lu bytes): %08lx %08lx\n", address, size, wall[1], wall[2]);
wall = (uint32 *)((uint8 *)address + size);
if (wall[0] != 0xabadcafe || wall[1] != 0xabadcafe)
panic("kfree: back wall was overwritten (allocation at %p, %lu bytes): %08lx %08lx\n", address, size, wall[0], wall[1]);
address = (uint8 *)address - 12;
}
#endif
#if PARANOID_POINTER_CHECK
if (!ptrchecklist_remove(address))
panic("kfree: asked to free invalid pointer %p\n", address);
@ -307,17 +346,13 @@ kfree(void *address)
mutex_lock(&heap_lock);
#if MAKE_NOIZE
dprintf("kfree: asked to free at ptr = %p\n", address);
#endif
TRACE(("kfree: asked to free at ptr = %p\n", address));
page = &heap_alloc_table[((unsigned)address - heap_base) / PAGE_SIZE];
#if MAKE_NOIZE
dprintf("kfree: page 0x%x: bin_index %d, free_count %d\n", page, page->bin_index, page->free_count);
#endif
TRACE(("kfree: page %p: bin_index %d, free_count %d\n", page, page->bin_index, page->free_count));
if(page[0].bin_index >= bin_count)
if (page[0].bin_index >= bin_count)
panic("kfree: page %p: invalid bin_index %d\n", page, page->bin_index);
bin = &bins[page[0].bin_index];