Fix madvise() on Windows

libc/calls/madvise-nt.c

@@ -17,46 +17,43 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/syscall_support-nt.internal.h"
-#include "libc/macros.internal.h"
 #include "libc/nt/enum/offerpriority.h"
-#include "libc/nt/memory.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/struct/memoryrangeentry.h"
 #include "libc/sysv/consts/madv.h"
 #include "libc/sysv/errfuns.h"
 
-forceinline typeof(PrefetchVirtualMemory) *GetPrefetchVirtualMemory(void) {
-  static bool once;
-  static typeof(PrefetchVirtualMemory) *PrefetchVirtualMemory_;
-  if (!once) {
+typedef bool32 (*__msabi PrefetchVirtualMemoryPtr)(
+    int64_t hProcess, uintptr_t NumberOfEntries,
+    struct NtMemoryRangeEntry *VirtualAddresses, uint32_t reserved_Flags);
+
+textwindows static PrefetchVirtualMemoryPtr GetPrefetchVirtualMemory(void) {
+  static PrefetchVirtualMemoryPtr PrefetchVirtualMemory_;
+  if (!PrefetchVirtualMemory_) {
     PrefetchVirtualMemory_ = /* win8.1+ */
         GetProcAddressModule("Kernel32.dll", "PrefetchVirtualMemory");
-    once = true;
   }
   return PrefetchVirtualMemory_;
 }
 
-forceinline typeof(OfferVirtualMemory) *GetOfferVirtualMemory(void) {
-  static bool once;
-  static typeof(OfferVirtualMemory) *OfferVirtualMemory_;
-  if (!once) {
+typedef bool32 (*__msabi OfferVirtualMemoryPtr)(void *inout_VirtualAddress,
+                                                size_t Size, int Priority);
+
+textwindows static OfferVirtualMemoryPtr GetOfferVirtualMemory(void) {
+  static OfferVirtualMemoryPtr OfferVirtualMemory_;
+  if (!OfferVirtualMemory_) {
     OfferVirtualMemory_ = /* win8.1+ */
         GetProcAddressModule("Kernel32.dll", "OfferVirtualMemory");
-    once = true;
   }
   return OfferVirtualMemory_;
 }
 
 textwindows int sys_madvise_nt(void *addr, size_t length, int advice) {
-  uint32_t rangecount;
-  struct NtMemoryRangeEntry ranges[1];
   if (advice == MADV_WILLNEED || advice == MADV_SEQUENTIAL) {
-    typeof(PrefetchVirtualMemory) *fn = GetPrefetchVirtualMemory();
+    PrefetchVirtualMemoryPtr fn = GetPrefetchVirtualMemory();
     if (fn) {
-      ranges[0].VirtualAddress = addr;
-      ranges[0].NumberOfBytes = length;
-      rangecount = ARRAYLEN(ranges);
-      if (fn(GetCurrentProcess(), &rangecount, ranges, 0)) {
+      if (fn(GetCurrentProcess(), 1, &(struct NtMemoryRangeEntry){addr, length},
+             0)) {
         return 0;
       } else {
         return __winerr();
@@ -65,7 +62,7 @@ textwindows int sys_madvise_nt(void *addr, size_t length, int advice) {
       return enosys();
     }
   } else if (advice == MADV_FREE) {
-    typeof(OfferVirtualMemory) *fn = GetOfferVirtualMemory();
+    OfferVirtualMemoryPtr fn = GetOfferVirtualMemory();
     if (fn) {
       if (fn(addr, length, kNtVmOfferPriorityNormal)) {
         return 0;

libc/calls/madvise.c

@@ -29,21 +29,21 @@
  *
  * @param advice can be MADV_WILLNEED, MADV_SEQUENTIAL, MADV_FREE, etc.
  * @return 0 on success, or -1 w/ errno
+ * @raise EINVAL if `advice` isn't valid or supported by system
+ * @raise EINVAL on Linux if addr/length isn't page size aligned with
+ *     respect to `getauxval(AT_PAGESZ)`
+ * @raise ENOMEM on Linux if addr/length overlaps unmapped regions
  * @see libc/sysv/consts.sh
  * @see fadvise()
  */
 int madvise(void *addr, size_t length, int advice) {
   int rc;
-  if (advice != 127 /* see consts.sh */) {
-    if (IsAsan() && !__asan_is_valid(addr, length)) {
-      rc = efault();
-    } else if (!IsWindows()) {
-      rc = sys_madvise(addr, length, advice);
-    } else {
-      rc = sys_madvise_nt(addr, length, advice);
-    }
+  if (IsAsan() && !__asan_is_valid(addr, length)) {
+    rc = efault();
+  } else if (!IsWindows()) {
+    rc = sys_madvise(addr, length, advice);
   } else {
-    rc = einval();
+    rc = sys_madvise_nt(addr, length, advice);
   }
   STRACE("madvise(%p, %'zu, %d) → %d% m", addr, length, advice, rc);
   return rc;

libc/calls/posix_madvise.c

@@ -23,6 +23,10 @@
  * Advises kernel about memory intentions, the POSIX way.
  *
  * @return 0 on success, or errno on error
+ * @raise EINVAL if `advice` isn't valid or supported by system
+ * @raise EINVAL on Linux if addr/length isn't page size aligned with
+ *     respect to `getauxval(AT_PAGESZ)`
+ * @raise ENOMEM on Linux if addr/length overlaps unmapped regions
  * @returnserrno
  */
 errno_t posix_madvise(void *addr, uint64_t len, int advice) {

libc/nt/memory.h

@@ -73,12 +73,6 @@ uint64_t VirtualQuery(const void *lpAddress,
 void *VirtualAllocEx(int64_t hProcess, void *lpAddress, uint64_t dwSize,
                      uint32_t flAllocationType, uint32_t flProtect);
 
-bool32 PrefetchVirtualMemory(int64_t hProcess, const uint32_t *NumberOfEntries,
-                             struct NtMemoryRangeEntry *VirtualAddresses,
-                             uint32_t reserved_Flags);
-bool32 OfferVirtualMemory(void *inout_VirtualAddress, size_t Size,
-                          int Priority);
-
 int64_t GetProcessHeap(void);
 void *HeapAlloc(int64_t hHeap, uint32_t dwFlags, size_t dwBytes) __wur;
 bool32 HeapFree(int64_t hHeap, uint32_t dwFlags, void *opt_lpMem);