jehanne/sys/src/lib/jehanne/port/malloc.c

336 lines
6.6 KiB
C

/*
* Copyright (C) 2016 Giacomo Tesio <giacomo@tesio.it>
*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <libc.h>
#include <pool.h>
static void* sbrkalloc(uint32_t);
static int sbrkmerge(void*, void*);
static void plock(Pool*);
static void punlock(Pool*);
static void pprint(Pool*, char*, ...);
static void ppanic(Pool*, char*, ...);
typedef struct Private Private;
struct Private {
Lock lk;
int32_t pid;
int32_t printfd; /* gets debugging output if set */
};
Private sbrkmempriv;
static Pool sbrkmem = {
.name= "sbrkmem",
.maxsize= (3840UL-1)*1024*1024, /* up to ~0xf0000000 */
.minarena= 4*1024,
.quantum= 32,
.alloc= sbrkalloc,
.merge= sbrkmerge,
.flags= 0,
.lock= plock,
.unlock= punlock,
.print= pprint,
.panic= ppanic,
.private= &sbrkmempriv,
};
Pool *mainmem = &sbrkmem;
Pool *imagmem = &sbrkmem;
/*
* we do minimal bookkeeping so we can tell pool
* whether two blocks are adjacent and thus mergeable.
*/
static void*
sbrkalloc(uint32_t n)
{
uint32_t *x;
n += 2*sizeof(uint32_t); /* two longs for us */
x = sbrk(n);
if(x == (void*)-1)
return nil;
x[0] = (n+7)&~7; /* sbrk rounds size up to mult. of 8 */
x[1] = 0xDeadBeef;
return x+2;
}
static int
sbrkmerge(void *x, void *y)
{
uint32_t *lx, *ly;
lx = x;
if(lx[-1] != 0xDeadBeef)
abort();
if((uint8_t*)lx+lx[-2] == (uint8_t*)y) {
ly = y;
lx[-2] += ly[-2];
return 1;
}
return 0;
}
static void
plock(Pool *p)
{
Private *pv;
pv = p->private;
jehanne_lock(&pv->lk);
if(pv->pid != 0)
abort();
pv->pid = jehanne_getmainpid();
}
static void
punlock(Pool *p)
{
Private *pv;
pv = p->private;
if(pv->pid != jehanne_getmainpid())
abort();
pv->pid = 0;
jehanne_unlock(&pv->lk);
}
static int
checkenv(void)
{
int n, fd;
char buf[20];
fd = sys_open("/env/MALLOCFD", OREAD);
if(fd < 0)
return -1;
if((n = jehanne_read(fd, buf, sizeof buf)) < 0) {
sys_close(fd);
return -1;
}
sys_close(fd);
if(n >= sizeof buf)
n = sizeof(buf)-1;
buf[n] = 0;
n = jehanne_atoi(buf);
if(n == 0)
n = -1;
return n;
}
static void
pprint(Pool *p, char *fmt, ...)
{
va_list v;
Private *pv;
pv = p->private;
if(pv->printfd == 0)
pv->printfd = checkenv();
if(pv->printfd <= 0)
pv->printfd = 2;
va_start(v, fmt);
jehanne_vfprint(pv->printfd, fmt, v);
va_end(v);
}
static char panicbuf[256];
static void
ppanic(Pool *p, char *fmt, ...)
{
va_list v;
int n;
char *msg;
Private *pv;
pv = p->private;
assert(jehanne_canlock(&pv->lk)==0);
if(pv->printfd == 0)
pv->printfd = checkenv();
if(pv->printfd <= 0)
pv->printfd = 2;
msg = panicbuf;
va_start(v, fmt);
n = jehanne_vseprint(msg, msg+sizeof panicbuf, fmt, v) - msg;
jehanne_write(2, "panic: ", 7);
jehanne_write(2, msg, n);
jehanne_write(2, "\n", 1);
if(pv->printfd != 2){
jehanne_write(pv->printfd, "panic: ", 7);
jehanne_write(pv->printfd, msg, n);
jehanne_write(pv->printfd, "\n", 1);
}
va_end(v);
// jehanne_unlock(&pv->lk);
abort();
}
/* - everything from here down should be the same in libc, libdebugmalloc, and the kernel - */
/* - except the code for jehanne_malloc(), which alternately doesn't clear or does. - */
/*
* Npadlong is the number of uintptrs to leave at the beginning of
* each allocated buffer for our own bookkeeping. We return to the callers
* a pointer that points immediately after our bookkeeping area. Incoming pointers
* must be decremented by that much, and outgoing pointers incremented.
* The malloc tag is stored at MallocOffset from the beginning of the block,
* and the realloc tag at ReallocOffset. The offsets are from the true beginning
* of the block, not the beginning the caller sees.
*
* The extra if(Npadlong != 0) in various places is a hint for the compiler to
* compile out function calls that would otherwise be no-ops.
*/
/* tracing */
enum {
Npadlong = 2,
MallocOffset = 0,
ReallocOffset = 1
};
void*
jehanne_malloc(size_t size)
{
void *v;
v = poolalloc(mainmem, size+Npadlong*sizeof(uintptr_t));
if(Npadlong && v != nil) {
v = (uintptr_t*)v+Npadlong;
jehanne_setmalloctag(v, jehanne_getcallerpc());
jehanne_setrealloctag(v, 0);
}
return v;
}
void*
jehanne_mallocz(uint32_t size, int clr)
{
void *v;
v = poolalloc(mainmem, size+Npadlong*sizeof(uintptr_t));
if(Npadlong && v != nil){
v = (uintptr_t*)v+Npadlong;
jehanne_setmalloctag(v, jehanne_getcallerpc());
jehanne_setrealloctag(v, 0);
}
if(clr && v != nil)
jehanne_memset(v, 0, size);
return v;
}
void*
jehanne_mallocalign(uint32_t size, uint32_t align, int32_t offset, uint32_t span)
{
void *v;
v = poolallocalign(mainmem, size+Npadlong*sizeof(uintptr_t), align,
offset-Npadlong*sizeof(uintptr_t), span);
if(Npadlong && v != nil){
v = (uintptr_t*)v+Npadlong;
jehanne_setmalloctag(v, jehanne_getcallerpc());
jehanne_setrealloctag(v, 0);
}
return v;
}
void
jehanne_free(void *v)
{
if(v != nil)
poolfree(mainmem, (uintptr_t*)v-Npadlong);
}
void*
jehanne_realloc(void *v, size_t size)
{
void *nv;
if(size == 0){
jehanne_free(v);
return nil;
}
if(v)
v = (uintptr_t*)v-Npadlong;
size += Npadlong*sizeof(uintptr_t);
if((nv = poolrealloc(mainmem, v, size))){
nv = (uintptr_t*)nv+Npadlong;
jehanne_setrealloctag(nv, jehanne_getcallerpc());
if(v == nil)
jehanne_setmalloctag(nv, jehanne_getcallerpc());
}
return nv;
}
uint32_t
jehanne_msize(void *v)
{
return poolmsize(mainmem, (uintptr_t*)v-Npadlong)-Npadlong*sizeof(uintptr_t);
}
void*
jehanne_calloc(uint32_t n, size_t szelem)
{
void *v;
if(n > 1 && ((uint64_t)-1)/n < szelem)
return nil;
if((v = jehanne_mallocz(n*szelem, 1)))
jehanne_setmalloctag(v, jehanne_getcallerpc());
return v;
}
void
jehanne_setmalloctag(void *v, uintptr_t pc)
{
if(Npadlong <= MallocOffset || v == nil)
return;
((uintptr_t*)v)[-Npadlong+MallocOffset] = pc;
}
void
jehanne_setrealloctag(void *v, uintptr_t pc)
{
if(Npadlong <= ReallocOffset || v == nil)
return;
((uintptr_t*)v)[-Npadlong+ReallocOffset] = pc;
}
uintptr_t
jehanne_getmalloctag(void *v)
{
if(Npadlong <= MallocOffset)
return ~0;
return ((uintptr_t*)v)[-Npadlong+MallocOffset];
}
uintptr_t
jehanne_getrealloctag(void *v)
{
if(Npadlong <= ReallocOffset)
return ~0;
return ((uintptr_t*)v)[-Npadlong+ReallocOffset];
}
void*
jehanne_malloctopoolblock(void *v)
{
if(v == nil)
return nil;
return &((uintptr_t*)v)[-Npadlong];
}