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Write more memory mapping tests

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Microsoft claims to support COW but it's probably not true.
This commit is contained in:
Justine Tunney 2021-02-04 18:24:33 -08:00
parent 74d48f7cb6
commit 2fdc19e7a7
6 changed files with 83 additions and 29 deletions
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71
libc/runtime/directmapnt.c
View file

@ -18,35 +18,70 @@
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/macros.h"
#include "libc/nt/enum/filemapflags.h"
#include "libc/nt/enum/pageflags.h"
#include "libc/nt/memory.h"
#include "libc/nt/runtime.h"
#include "libc/nt/struct/overlapped.h"
#include "libc/runtime/directmap.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
textwindows noasan struct DirectMap __sys_mmap_nt(void *addr, size_t size,
unsigned prot, int64_t handle,
int64_t off) {
textwindows noasan struct DirectMap sys_mmap_nt(void *addr, size_t size,
int prot, int flags,
int64_t handle, int64_t off) {
uint32_t got;
size_t i, upsize;
struct DirectMap dm;
if ((dm.maphandle = CreateFileMappingNuma(
handle, &kNtIsInheritable,
(prot & PROT_WRITE) ? kNtPageExecuteReadwrite : kNtPageExecuteRead,
handle != -1 ? 0 : size >> 32, handle != -1 ? 0 : size, NULL,
kNtNumaNoPreferredNode))) {
if (!(dm.addr = MapViewOfFileExNuma(
dm.maphandle,
(prot & PROT_WRITE)
? kNtFileMapWrite | kNtFileMapExecute | kNtFileMapRead
: kNtFileMapExecute | kNtFileMapRead,
off >> 32, off, size, addr, kNtNumaNoPreferredNode))) {
struct NtOverlapped op;
if ((prot & PROT_WRITE) && (flags & MAP_PRIVATE) && handle != -1) {
/*
* WIN32 claims it can do COW mappings but we still haven't found a
* combination of flags, that'll cause Windows to actually do this!
*/
upsize = ROUNDUP(size, FRAMESIZE);
if ((dm.maphandle = CreateFileMappingNuma(
-1, &kNtIsInheritable, kNtPageExecuteReadwrite, upsize >> 32,
upsize, NULL, kNtNumaNoPreferredNode))) {
if ((dm.addr = MapViewOfFileExNuma(
dm.maphandle, kNtFileMapWrite | kNtFileMapExecute, 0, 0, upsize,
addr, kNtNumaNoPreferredNode))) {
for (i = 0; i < size; i += got) {
got = 0;
op.Internal = 0;
op.InternalHigh = 0;
op.Pointer = (void *)(uintptr_t)i;
op.hEvent = 0;
if (!ReadFile(handle, (char *)dm.addr + i, size - i, &got, &op)) {
break;
}
}
if (i == size) {
return dm;
}
UnmapViewOfFile(dm.addr);
}
CloseHandle(dm.maphandle);
dm.maphandle = kNtInvalidHandleValue;
dm.addr = (void *)(intptr_t)__winerr();
}
} else {
dm.maphandle = kNtInvalidHandleValue;
dm.addr = (void *)(intptr_t)__winerr();
if ((dm.maphandle = CreateFileMappingNuma(
handle, &kNtIsInheritable,
(prot & PROT_WRITE) ? kNtPageExecuteReadwrite : kNtPageExecuteRead,
handle != -1 ? 0 : size >> 32, handle != -1 ? 0 : size, NULL,
kNtNumaNoPreferredNode))) {
if ((dm.addr = MapViewOfFileExNuma(
dm.maphandle,
(prot & PROT_WRITE) ? kNtFileMapWrite | kNtFileMapExecute
: kNtFileMapRead | kNtFileMapExecute,
off >> 32, off, size, addr, kNtNumaNoPreferredNode))) {
return dm;
} else {
CloseHandle(dm.maphandle);
}
}
}
dm.maphandle = kNtInvalidHandleValue;
dm.addr = (void *)(intptr_t)__winerr();
return dm;
}