From e1a40783da8668a8bbb1a6840eefa15e15da7b83 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Wed, 8 Jun 2022 20:21:05 -0700
Subject: [PATCH] Fix fadvise() on Windows

---
 libc/calls/fadvise-nt.c      | 15 ++++++++++++++-
 libc/calls/state.internal.h  |  3 ++-
 libc/intrin/g_fds.c          |  4 ----
 libc/log/backtrace2.c        |  4 ++--
 libc/runtime/memtrack.greg.c |  6 ++++++
 5 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/libc/calls/fadvise-nt.c b/libc/calls/fadvise-nt.c
index 2c0ec8c28..6646c7a18 100644
--- a/libc/calls/fadvise-nt.c
+++ b/libc/calls/fadvise-nt.c
@@ -21,6 +21,7 @@
 #include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/intrin/spinlock.h"
 #include "libc/nt/createfile.h"
+#include "libc/nt/enum/fileflagandattributes.h"
 #include "libc/nt/files.h"
 #include "libc/nt/runtime.h"
 #include "libc/sysv/consts/madv.h"
@@ -32,11 +33,13 @@ textwindows int sys_fadvise_nt(int fd, uint64_t offset, uint64_t len,
   int64_t h1, h2;
   int rc, flags, mode;
   uint32_t perm, share, attr;
+
   if (!__isfdkind(fd, kFdFile)) return ebadf();
   h1 = g_fds.p[fd].handle;
   mode = g_fds.p[fd].mode;
   flags = g_fds.p[fd].flags;
   flags &= ~(O_SEQUENTIAL | O_RANDOM);
+
   switch (advice) {
     case MADV_NORMAL:
       break;
@@ -50,7 +53,17 @@ textwindows int sys_fadvise_nt(int fd, uint64_t offset, uint64_t len,
     default:
       return einval();
   }
-  if (GetNtOpenFlags(flags, mode, &perm, &share, 0, &attr) == -1) return -1;
+
+  if (GetNtOpenFlags(flags, mode, &perm, &share, 0, &attr) == -1) {
+    return -1;
+  }
+
+  // MSDN says only these are allowed, otherwise it returns EINVAL.
+  attr &= kNtFileFlagBackupSemantics | kNtFileFlagDeleteOnClose |
+          kNtFileFlagNoBuffering | kNtFileFlagOpenNoRecall |
+          kNtFileFlagOpenReparsePoint | kNtFileFlagOverlapped |
+          kNtFileFlagPosixSemantics | kNtFileFlagRandomAccess |
+          kNtFileFlagSequentialScan | kNtFileFlagWriteThrough;
 
   __fds_lock();
   if ((h2 = ReOpenFile(h1, perm, share, attr)) != -1) {
diff --git a/libc/calls/state.internal.h b/libc/calls/state.internal.h
index ed8ef1437..6996ebbd2 100644
--- a/libc/calls/state.internal.h
+++ b/libc/calls/state.internal.h
@@ -1,5 +1,6 @@
 #ifndef COSMOPOLITAN_LIBC_CALLS_STATE_INTERNAL_H_
 #define COSMOPOLITAN_LIBC_CALLS_STATE_INTERNAL_H_
+#include "libc/intrin/spinlock.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
 
@@ -12,7 +13,7 @@ hidden extern unsigned __sighandflags[NSIG];
 hidden extern const struct NtSecurityAttributes kNtIsInheritable;
 
 void __fds_lock(void);
-void __fds_unlock(void);
+#define __fds_unlock() _spunlock(&__fds_lock_obj)
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
diff --git a/libc/intrin/g_fds.c b/libc/intrin/g_fds.c
index c0bb4e73f..e0ccecab2 100644
--- a/libc/intrin/g_fds.c
+++ b/libc/intrin/g_fds.c
@@ -32,10 +32,6 @@ void __fds_lock(void) {
   _spinlock(&__fds_lock_obj);
 }
 
-void __fds_unlock(void) {
-  _spunlock(&__fds_lock_obj);
-}
-
 textstartup void InitializeFileDescriptors(void) {
   struct Fds *fds;
   fds = VEIL("r", &g_fds);
diff --git a/libc/log/backtrace2.c b/libc/log/backtrace2.c
index 42606fc8b..618a8f569 100644
--- a/libc/log/backtrace2.c
+++ b/libc/log/backtrace2.c
@@ -80,13 +80,13 @@ static int PrintBacktraceUsingAddr2line(int fd, const struct StackFrame *bp) {
     return -1;
   }
 
+  // backtrace_test.com failing on windows for some reason via runitd
   if (IsWindows()) {
-    // TODO: We need a way to *not* pass //?/C:/... paths to mingw
     return -1;
   }
 
+  // doesn't work on rhel5
   if (IsLinux() && !__is_linux_2_6_23()) {
-    // we need the `addr2line -a` option
     return -1;
   }
 
diff --git a/libc/runtime/memtrack.greg.c b/libc/runtime/memtrack.greg.c
index 9ea60d1e1..b2ca98cce 100644
--- a/libc/runtime/memtrack.greg.c
+++ b/libc/runtime/memtrack.greg.c
@@ -95,7 +95,9 @@ static bool ExtendMemoryIntervals(struct MemoryIntervals *mm) {
     if (!dm.addr) return false;
     mm->n = (size + gran) / sizeof(*mm->p);
   }
+#if IsModeDbg()
   assert(AreMemoryIntervalsOk(mm));
+#endif
   return true;
 }
 
@@ -123,8 +125,10 @@ static int PunchHole(struct MemoryIntervals *mm, int x, int y, int i) {
 int ReleaseMemoryIntervals(struct MemoryIntervals *mm, int x, int y,
                            void wf(struct MemoryIntervals *, int, int)) {
   unsigned l, r;
+#if IsModeDbg()
   assert(y >= x);
   assert(AreMemoryIntervalsOk(mm));
+#endif
   if (!mm->i) return 0;
 
   // binary search for the lefthand side
@@ -194,8 +198,10 @@ int TrackMemoryInterval(struct MemoryIntervals *mm, int x, int y, long h,
                         long offset, long size) {
   // asan runtime depends on this function
   unsigned i;
+#if IsModeDbg()
   assert(y >= x);
   assert(AreMemoryIntervalsOk(mm));
+#endif
 
   i = FindMemoryInterval(mm, x);