Another day, another sanitizer.
After fixing issues reported by -fsanitize=address yesterday, I gave
-fsanitize=undefined a try. The GCC documentation points to the clang
documentation:
https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html
The issues related to cControl::player were tricky. In the end, I
figured it out after setting UBSAN_OPTIONS=print_stacktrace=1 and
setting a breakpoint on _Unwind_Backtrace(). The name of the reporting
function in my system was __ubsan_handle_dynamic_type_cache_miss(),
nothing about "vptr". Also, the diagnostics was misleadingly pointing to
the body of the constructor, and not the initializer list where a data
member was being assigned to before the base class had been initialized.
The -fsanitize=undefined in clang might report more things.
Next I may give -fsanitize=thread a try.
GCC does not implement -fsanitize=memory (checking for the use of
uninitialized memory) at all. It will require clang and libc++ (not
libstdc++) and that all libraries except libc are built with
-fsanitize=memory. If you are familiar with Valgrind's default memcheck
tool, it is roughly comparable to the combination of -fsanitize=address
and -fsanitize=memory.
Marko
>From b69ff7105d4bb8d933f0214f34b103fda8e8b155 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@xxxxxx>
Date: Sun, 4 Dec 2022 13:42:57 +0200
Subject: [PATCH] Fix GCC 8.3.0 -fsanitize=undefined
sections.c:183:30: runtime error: variable length array bound evaluates to non-positive value 0
device.c:251:31: runtime error: variable length array bound evaluates to non-positive value 0
osd.h:301:37: runtime error: signed integer overflow: -2147483648 - 2147483647 cannot be represented in type 'int'
osd.h:301:37: runtime error: signed integer overflow: -2147483647 - 2147483647 cannot be represented in type 'int'
transfer.c:71:11: runtime error: member access within address 0x020f0428 which does not point to an object of type 'cTransferControl'
dvbplayer.c:984:11: runtime error: member access within address 0x02a388d0 which does not point to an object of type 'cDvbPlayerControl'
---
device.c | 2 +-
dvbplayer.c | 3 ++-
font.c | 3 ++-
osd.h | 4 ++--
sections.c | 2 +-
transfer.c | 3 ++-
6 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/device.c b/device.c
index 4e987389..a770aa90 100644
--- a/device.c
+++ b/device.c
@@ -248,7 +248,7 @@ cDevice *cDevice::GetDevice(const cChannel *Channel, int Priority, bool LiveView
{
// Collect the current priorities of all CAM slots that can decrypt the channel:
int NumCamSlots = CamSlots.Count();
- int SlotPriority[NumCamSlots];
+ int SlotPriority[std::max(NumCamSlots, 1)];
int NumUsableSlots = 0;
bool InternalCamNeeded = false;
if (Channel->Ca() >= CA_ENCRYPTED_MIN) {
diff --git a/dvbplayer.c b/dvbplayer.c
index 2ee846b6..72bc46ad 100644
--- a/dvbplayer.c
+++ b/dvbplayer.c
@@ -981,8 +981,9 @@ bool cDvbPlayer::GetReplayMode(bool &Play, bool &Forward, int &Speed)
// --- cDvbPlayerControl -----------------------------------------------------
cDvbPlayerControl::cDvbPlayerControl(const char *FileName, bool PauseLive)
-:cControl(player = new cDvbPlayer(FileName, PauseLive))
+:cControl(new cDvbPlayer(FileName, PauseLive))
{
+ player = static_cast<cDvbPlayer*>(cControl::player);
}
cDvbPlayerControl::~cDvbPlayerControl()
diff --git a/font.c b/font.c
index 8b37798c..c78b1a15 100644
--- a/font.c
+++ b/font.c
@@ -74,7 +74,8 @@ cGlyph::cGlyph(uint CharCode, FT_GlyphSlotRec_ *GlyphData)
rows = GlyphData->bitmap.rows;
pitch = GlyphData->bitmap.pitch;
bitmap = MALLOC(uchar, rows * pitch);
- memcpy(bitmap, GlyphData->bitmap.buffer, rows * pitch);
+ if (int bytes = rows * pitch)
+ memcpy(bitmap, GlyphData->bitmap.buffer, bytes);
}
cGlyph::~cGlyph()
diff --git a/osd.h b/osd.h
index 77722662..7a293321 100644
--- a/osd.h
+++ b/osd.h
@@ -298,8 +298,8 @@ public:
struct tArea {
int x1, y1, x2, y2;
int bpp;
- int Width(void) const { return x2 - x1 + 1; }
- int Height(void) const { return y2 - y1 + 1; }
+ int Width(void) const { return x2 < 0 ? 0 : x2 - x1 + 1; }
+ int Height(void) const { return y2 < 0 ? 0 : y2 - y1 + 1; }
bool Intersects(const tArea &Area) const { return !(x2 < Area.x1 || x1 > Area.x2 || y2 < Area.y1 || y1 > Area.y2); }
};
diff --git a/sections.c b/sections.c
index 51a2823c..4d90b19c 100644
--- a/sections.c
+++ b/sections.c
@@ -180,7 +180,7 @@ void cSectionHandler::Action(void)
startFilters = false;
}
int NumFilters = filterHandles.Count();
- pollfd pfd[NumFilters];
+ pollfd pfd[std::max(NumFilters, 1)];
for (cFilterHandle *fh = filterHandles.First(); fh; fh = filterHandles.Next(fh)) {
int i = fh->Index();
pfd[i].fd = fh->handle;
diff --git a/transfer.c b/transfer.c
index 88931e58..b888910a 100644
--- a/transfer.c
+++ b/transfer.c
@@ -68,8 +68,9 @@ void cTransfer::Receive(const uchar *Data, int Length)
cDevice *cTransferControl::receiverDevice = NULL;
cTransferControl::cTransferControl(cDevice *ReceiverDevice, const cChannel *Channel)
-:cControl(transfer = new cTransfer(Channel), true)
+:cControl(new cTransfer(Channel), true)
{
+ transfer = static_cast<cTransfer*>(player);
ReceiverDevice->AttachReceiver(transfer);
receiverDevice = ReceiverDevice;
}
--
2.38.1
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