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#include <kernel/arch/generic.h>
#include <kernel/malloc.h>
#include <kernel/panic.h>
#include <kernel/util.h>
#include <shared/mem.h>
#include <stdbool.h>
#include <stdint.h>
#define MALLOC_MAGIC 0x616c6c6f63686472 /* "allochdr" */
#define DESCLEN 8
typedef struct Allocation Allocation;
struct Allocation {
uint64_t magic;
uint64_t len;
Allocation *next, *prev;
void *stacktrace[4];
char desc[DESCLEN];
};
static Allocation *malloc_last = NULL;
static size_t
page_amt(size_t bytes)
{
return (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
}
void
kmalloc_debugprint(void)
{
size_t count = 0, bytes = 0, pages = 0;
kprintf("[kern] current allocations:\n");
for (Allocation *iter = malloc_last; iter; iter = iter->prev) {
kprintf(
"%08p %6dB %.8s ",
((void*)iter) + sizeof(Allocation),
iter->len - sizeof(Allocation),
iter->desc
);
for (size_t i = 0; i < 4; i++) {
kprintf(" k/%08x", iter->stacktrace[i]);
}
kprintf("\n");
count++;
bytes += iter->len;
pages += page_amt(iter->len);
}
kprintf(
"%d in total, %d bytes, %d pages = %dB used\n",
count, bytes, pages, pages*PAGE_SIZE
);
}
static void
kmalloc_sanity(const void *addr)
{
assert(addr);
const Allocation *hdr = addr - sizeof(Allocation);
assert(hdr->magic == MALLOC_MAGIC);
if (hdr->next) assert(hdr->next->prev == hdr);
if (hdr->prev) assert(hdr->prev->next == hdr);
}
void *
kmalloc(size_t len, const char *desc)
{
Allocation *hdr;
void *addr;
if (KMALLOC_MAX < len) {
panic_invalid_state();
}
len += sizeof(Allocation);
assert(len <= PAGE_SIZE);
hdr = page_alloc(page_amt(len));
hdr->magic = MALLOC_MAGIC;
hdr->len = len;
memset(hdr->desc, ' ', DESCLEN);
if (desc) {
for (int i = 0; i < DESCLEN; i++) {
if (desc[i] == '\0') break;
hdr->desc[i] = desc[i];
}
}
hdr->next = NULL;
hdr->prev = malloc_last;
if (hdr->prev) {
assert(!hdr->prev->next);
hdr->prev->next = hdr;
}
for (size_t i = 0; i < 4; i++)
hdr->stacktrace[i] = debug_caller(i);
malloc_last = hdr;
addr = (void*)hdr + sizeof(Allocation);
#ifndef NDEBUG
memset(addr, 0xCC, len);
#endif
kmalloc_sanity(addr);
return addr;
}
void
kfree(void *ptr)
{
Allocation *hdr;
size_t len;
if (ptr == NULL) return;
kmalloc_sanity(ptr);
hdr = ptr - sizeof(Allocation);
len = hdr->len;
if (hdr->next)
hdr->next->prev = hdr->prev;
if (hdr->prev)
hdr->prev->next = hdr->next;
if (malloc_last == hdr)
malloc_last = hdr->prev;
#ifndef NDEBUG
memset(hdr, 0xC0, len);
#else
hdr->magic = ~MALLOC_MAGIC; /* (hopefully) detect double frees */
#endif
page_free(hdr, page_amt(len));
}
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