From e6b1e918e12df25a359fbb87ae26f584d46df823 Mon Sep 17 00:00:00 2001
From: Edward Welbourne <edward.welbourne@theqtcompany.com>
Date: Mon, 2 May 2016 11:02:09 +0200
Subject: [PATCH] QLinuxFbScreen: fix uninitialized member warnings
Prompted by Coverity CID 11720 (allegedly recently new in dev but
long-standing in 5.6). Even assuming the class is used correctly -
test initialize() and only use if that succeeded - the destructor
would have passed uninitialized arguments to munmap() and ioctl().
Noticed a double close along the way: it's been fixed on dev but
should have been fixed in 5.6, too. Documented why ioctl() failure in
switchToGraphicsMode() should at least do no harm.
Change-Id: Ie26a9eefa435b5ff5b1a02e03e29469b8db72d3c
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
---
.../platforms/linuxfb/qlinuxfbscreen.cpp | 30 ++++++++-----------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp b/src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp
index 91708c0a476..8c3e73fd808 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp
+++ b/src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp
@@ -256,15 +256,15 @@ static int openTtyDevice(const QString &device)
return fd;
}
-static bool switchToGraphicsMode(int ttyfd, int *oldMode)
+static void switchToGraphicsMode(int ttyfd, bool doSwitch, int *oldMode)
{
- ioctl(ttyfd, KDGETMODE, oldMode);
- if (*oldMode != KD_GRAPHICS) {
- if (ioctl(ttyfd, KDSETMODE, KD_GRAPHICS) != 0)
- return false;
+ // Do not warn if the switch fails: the ioctl fails when launching from a
+ // remote console and there is nothing we can do about it. The matching
+ // call in resetTty should at least fail then, too, so we do no harm.
+ if (ioctl(ttyfd, KDGETMODE, oldMode) == 0) {
+ if (doSwitch && *oldMode != KD_GRAPHICS)
+ ioctl(ttyfd, KDSETMODE, KD_GRAPHICS);
}
-
- return true;
}
static void resetTty(int ttyfd, int oldMode)
@@ -280,21 +280,21 @@ static void blankScreen(int fd, bool on)
}
QLinuxFbScreen::QLinuxFbScreen(const QStringList &args)
- : mArgs(args), mFbFd(-1), mBlitter(0)
+ : mArgs(args), mFbFd(-1), mTtyFd(-1), mBlitter(0)
{
+ mMmap.data = 0;
}
QLinuxFbScreen::~QLinuxFbScreen()
{
if (mFbFd != -1) {
- munmap(mMmap.data - mMmap.offset, mMmap.size);
+ if (mMmap.data)
+ munmap(mMmap.data - mMmap.offset, mMmap.size);
close(mFbFd);
}
- if (mTtyFd != -1) {
+ if (mTtyFd != -1)
resetTty(mTtyFd, mOldTtyMode);
- close(mTtyFd);
- }
delete mBlitter;
}
@@ -389,11 +389,7 @@ bool QLinuxFbScreen::initialize()
if (mTtyFd == -1)
qErrnoWarning(errno, "Failed to open tty");
- if (doSwitchToGraphicsMode)
- switchToGraphicsMode(mTtyFd, &mOldTtyMode);
- // Do not warn if the switch fails: the ioctl fails when launching from
- // a remote console and there is nothing we can do about it.
-
+ switchToGraphicsMode(mTtyFd, doSwitchToGraphicsMode, &mOldTtyMode);
blankScreen(mFbFd, false);
return true;
--
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