From a4d26cf522b966056e47e47a004b7e4d668e3a2d Mon Sep 17 00:00:00 2001
From: Alex Trotsenko <alex1973tr@gmail.com>
Date: Fri, 8 Apr 2016 16:55:39 +0300
Subject: QWindowsPipeWriter: ensure validity of the write buffer

QWindowsPipeWriter uses asynchronous API to perform writing. Once a cycle
has been started, the write buffer must remain valid until the write
operation is completed.

To avoid data corruption and possibly undefined behavior, this patch
makes QWindowsPipeWriter::write() take a QByteArray, which it keeps alive
for the duration of the write cycle.

Autotest-by: Thomas Hartmann
Task-number: QTBUG-52401
Change-Id: Ia35faee735c4e684267daa1f6bd689512b670cd2
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>
---
 src/corelib/io/qwindowspipewriter.cpp | 41 +++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 16 deletions(-)

(limited to 'src/corelib/io/qwindowspipewriter.cpp')

diff --git a/src/corelib/io/qwindowspipewriter.cpp b/src/corelib/io/qwindowspipewriter.cpp
index ff92ca763e..05a4aa484a 100644
--- a/src/corelib/io/qwindowspipewriter.cpp
+++ b/src/corelib/io/qwindowspipewriter.cpp
@@ -73,21 +73,19 @@ QWindowsPipeWriter::~QWindowsPipeWriter()
 
 bool QWindowsPipeWriter::waitForWrite(int msecs)
 {
-    if (!writeSequenceStarted)
-        return false;
-
     if (bytesWrittenPending) {
-        if (!inBytesWritten)
-            emitPendingBytesWrittenValue();
+        emitPendingBytesWrittenValue();
         return true;
     }
 
+    if (!writeSequenceStarted)
+        return false;
+
     if (!waitForNotification(msecs))
         return false;
 
     if (bytesWrittenPending) {
-        if (!inBytesWritten)
-            emitPendingBytesWrittenValue();
+        emitPendingBytesWrittenValue();
         return true;
     }
 
@@ -96,20 +94,24 @@ bool QWindowsPipeWriter::waitForWrite(int msecs)
 
 qint64 QWindowsPipeWriter::bytesToWrite() const
 {
-    return numberOfBytesToWrite;
+    return numberOfBytesToWrite + pendingBytesWrittenValue;
 }
 
 void QWindowsPipeWriter::emitPendingBytesWrittenValue()
 {
     if (bytesWrittenPending) {
+        // Reset the state even if we don't emit bytesWritten().
+        // It's a defined behavior to not re-emit this signal recursively.
         bytesWrittenPending = false;
         const qint64 bytes = pendingBytesWrittenValue;
         pendingBytesWrittenValue = 0;
 
-        inBytesWritten = true;
-        emit bytesWritten(bytes);
-        inBytesWritten = false;
         emit canWrite();
+        if (!inBytesWritten) {
+            inBytesWritten = true;
+            emit bytesWritten(bytes);
+            inBytesWritten = false;
+        }
     }
 }
 
@@ -129,6 +131,8 @@ void QWindowsPipeWriter::notified(DWORD errorCode, DWORD numberOfBytesWritten)
     notifiedCalled = true;
     writeSequenceStarted = false;
     numberOfBytesToWrite = 0;
+    Q_ASSERT(errorCode != ERROR_SUCCESS || numberOfBytesWritten == buffer.size());
+    buffer.clear();
 
     switch (errorCode) {
     case ERROR_SUCCESS:
@@ -173,21 +177,26 @@ bool QWindowsPipeWriter::waitForNotification(int timeout)
     return notifiedCalled;
 }
 
-qint64 QWindowsPipeWriter::write(const char *ptr, qint64 maxlen)
+bool QWindowsPipeWriter::write(const QByteArray &ba)
 {
     if (writeSequenceStarted)
-        return 0;
+        return false;
 
     overlapped.clear();
-    numberOfBytesToWrite = maxlen;
+    buffer = ba;
+    numberOfBytesToWrite = buffer.size();
     stopped = false;
     writeSequenceStarted = true;
-    if (!WriteFileEx(handle, ptr, maxlen, &overlapped, &writeFileCompleted)) {
+    if (!WriteFileEx(handle, buffer.constData(), numberOfBytesToWrite,
+                     &overlapped, &writeFileCompleted)) {
         writeSequenceStarted = false;
+        numberOfBytesToWrite = 0;
+        buffer.clear();
         qErrnoWarning("QWindowsPipeWriter::write failed.");
+        return false;
     }
 
-    return maxlen;
+    return true;
 }
 
 void QWindowsPipeWriter::stop()
-- 
cgit v1.2.3


From c09008d27ca1456fb53a3fc9c71d5f88b1081221 Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Mon, 2 May 2016 11:34:44 +0200
Subject: QWindowsPipeWriter: Fix developer build with MinGW.

Fix signedness in comparion:
io\qwindowspipewriter.cpp: In member function 'void QWindowsPipeWriter::notified(DWORD, DWORD)':
io\qwindowspipewriter.cpp:134:65: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     Q_ASSERT(errorCode != ERROR_SUCCESS || numberOfBytesWritten == buffer.size());

Amends change a4d26cf522b966056e47e47a004b7e4d668e3a2d.

Task-number: QTBUG-52401
Change-Id: If0c0e2107342408675fa00b93f28c9de339080f6
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>
---
 src/corelib/io/qwindowspipewriter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/corelib/io/qwindowspipewriter.cpp')

diff --git a/src/corelib/io/qwindowspipewriter.cpp b/src/corelib/io/qwindowspipewriter.cpp
index 05a4aa484a..839dc8a19c 100644
--- a/src/corelib/io/qwindowspipewriter.cpp
+++ b/src/corelib/io/qwindowspipewriter.cpp
@@ -131,7 +131,7 @@ void QWindowsPipeWriter::notified(DWORD errorCode, DWORD numberOfBytesWritten)
     notifiedCalled = true;
     writeSequenceStarted = false;
     numberOfBytesToWrite = 0;
-    Q_ASSERT(errorCode != ERROR_SUCCESS || numberOfBytesWritten == buffer.size());
+    Q_ASSERT(errorCode != ERROR_SUCCESS || numberOfBytesWritten == DWORD(buffer.size()));
     buffer.clear();
 
     switch (errorCode) {
-- 
cgit v1.2.3