/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/likely.h"
#include "libc/bits/weaken.h"
#include "libc/calls/calls.h"
#include "libc/calls/strace.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/macros.internal.h"
#include "libc/nt/runtime.h"
#include "libc/runtime/directmap.internal.h"
#include "libc/runtime/memtrack.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/mremap.h"
#include "libc/sysv/errfuns.h"
#define IP(X) (intptr_t)(X)
#define VIP(X) (void *)IP(X)
#define ALIGNED(p) (!(IP(p) & (FRAMESIZE - 1)))
#define ADDR(x) ((int64_t)((uint64_t)(x) << 32) >> 16)
#define SHADE(x) (((intptr_t)(x) >> 3) + 0x7fff8000)
#define FRAME(x) ((int)((intptr_t)(x) >> 16))
static size_t GetMapSize(size_t i, size_t *j) {
size_t n;
n = (size_t)(_mmi.p[i].y - _mmi.p[i].x + 1) << 16;
while (i + 1 < _mmi.i) {
if (_mmi.p[i + 1].x != _mmi.p[i].y + 1) break;
++i;
n += (size_t)(_mmi.p[i].y - _mmi.p[i].x + 1) << 16;
}
*j = i;
return n;
}
static bool MustMoveMap(intptr_t y, size_t j) {
return ADDR(_mmi.p[j].y) + FRAMESIZE > y ||
(j + 1 < _mmi.i && ADDR(_mmi.p[j + 1].x) < y);
}
/**
* Extends and/or relocates memory pages.
*
* @param p is old address
* @param n is old size
* @param m is new size
* @param f should have MREMAP_MAYMOVE and may have MAP_FIXED
* @param q is new address
*/
void *mremap(void *p, size_t n, size_t m, int f, ... /* void *q */) {
enosys();
return MAP_FAILED;
#if 0
va_list va;
void *res, *q;
if (f & MREMAP_FIXED) {
va_start(va, f);
q = va_arg(va, void *);
va_end(va);
} else {
q = 0;
}
enosys();
res = MAP_FAILED;
STRACE("mremap(%p, %'zu, %'zu, %s, %p) → %p% m", p, n, m,
DescribeRemapFlags(f), q, res);
return res;
// TODO(jart): perhaps some day?
// probably not a big perf gain at this point :|
size_t i, j, k;
struct DirectMap dm;
int a, b, prot, flags;
assert(!__vforked);
if (UNLIKELY(!m)) {
STRACE("m=0");
return VIP(einval());
} else if (UNLIKELY(!n)) {
STRACE("n=0");
return VIP(eopnotsupp());
} else if (UNLIKELY(!ALIGNED(n))) {
STRACE("n align");
return VIP(eopnotsupp());
} else if (UNLIKELY(!ALIGNED(m))) {
STRACE("n align");
return VIP(eopnotsupp());
} else if (UNLIKELY(!ALIGNED(p))) {
STRACE("64kb align");
return VIP(einval());
} else if (UNLIKELY(!IsLegalSize(n))) {
STRACE("n too big");
return VIP(enomem());
} else if (UNLIKELY(!IsLegalSize(m))) {
STRACE("m too big");
return VIP(enomem());
} else if (f & ~(MREMAP_MAYMOVE | MREMAP_FIXED)) {
STRACE("bad flag");
return VIP(einval());
} else if (!IsMemtracked(FRAME(p), FRAME((intptr_t)p + (n - 1)))) {
STRACE("interval not tracked");
return VIP(efault());
}
STRACE("mremap(%p, %'zu, %'zu, %#b)", p, n, m, f);
i = FindMemoryInterval(&_mmi, FRAME(p));
if (i >= _mmi.i) return VIP(efault());
flags = _mmi.p[i].flags;
if (!(flags & MAP_ANONYMOUS)) {
return VIP(eopnotsupp()); /* TODO */
}
if (f & MREMAP_FIXED) {
if (!ALIGNED(q)) return VIP(einval());
return VIP(eopnotsupp()); /* TODO */
}
prot = _mmi.p[i].prot;
for (k = i + 1; k <= j; ++k) {
prot |= _mmi.p[k].prot;
if (_mmi.p[k].flags != flags) {
return VIP(enomem());
}
}
if (m == n) {
return p;
} else if (m < n) {
if (munmap((char *)p + n, m - n) != -1) {
return p;
} else {
return MAP_FAILED;
}
} else if (!MustMoveMap(j, (intptr_t)p + n)) {
dm = sys_mmap((char *)p + n, m - n, prot, flags | MAP_FIXED, -1, 0);
if (dm.addr == MAP_FAILED) return 0;
if (TrackMemoryInterval(&_mmi, ((uintptr_t)p + n) >> 16,
((uintptr_t)p + m - FRAMESIZE) >> 16, dm.maphandle,
prot, flags, false, false, 0, m - n) != -1) {
if (weaken(__asan_map_shadow)) {
weaken(__asan_map_shadow)((uintptr_t)dm.addr, m - n);
}
return p;
} else {
abort();
}
} else if (!(f & MREMAP_MAYMOVE)) {
return VIP(enomem());
} else if (IsLinux()) {
a = (uint32_t)(kAutomapStart >> 16);
i = FindMemoryInterval(&_mmi, a);
if (i < _mmi.i) {
for (; i + 1 < _mmi.i; ++i) {
if (((size_t)(_mmi.p[i + 1].x - _mmi.p[i].y - 1) << 16) >= m) {
break;
}
}
if (__builtin_add_overflow(_mmi.p[i].y, 1, &a)) {
return VIP(enomem());
}
}
if (__builtin_add_overflow(a, (int)((m >> 16) - 1), &b)) {
return VIP(enomem());
}
q = sys_mremap((void *)p, n, m, MREMAP_MAYMOVE | MREMAP_FIXED,
(void *)ADDR(a));
KERNTRACE("sys_mremap(%p, %'zu, %'zu, %#b, %p) → %p", p, n, m,
MREMAP_MAYMOVE | MREMAP_FIXED, ADDR(a), q);
if (q == MAP_FAILED) return 0;
if (ReleaseMemoryIntervals(&_mmi, (uintptr_t)p >> 16,
((uintptr_t)p + n - FRAMESIZE) >> 16, 0) != -1 &&
TrackMemoryInterval(&_mmi, a, b, -1, prot, flags, false, false, 0, m) !=
-1) {
if (weaken(__asan_poison)) {
if (!OverlapsShadowSpace(p, n)) {
weaken(__asan_poison)((intptr_t)p, n, kAsanUnmapped);
}
if (!OverlapsShadowSpace(q, m)) {
weaken(__asan_map_shadow)((intptr_t)q, m);
}
}
return (void *)ADDR(a);
} else {
abort();
}
} else if ((q = mmap(0, m, prot, flags, -1, 0)) != MAP_FAILED) {
memcpy(q, p, n);
munmap(p, n);
return q;
} else {
return q;
}
#endif
}