/*-*- 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/intrin/likely.h" #include "libc/intrin/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 }