[llvm] r175509 - Fix initialization-order bug in llvm::Support::TimeValue. TimeValue::now() is explicitly called during module initialization of lib/Support/Process.cpp. It reads the field of global object PosixZeroTime, which is not guaranteed to be initialized at this point. Found by AddressSanitizer with -fsanitize=init-order option.
David Blaikie
dblaikie at gmail.com
Tue Feb 19 09:57:30 PST 2013
On Tue, Feb 19, 2013 at 3:35 AM, Alexey Samsonov <samsonov at google.com>wrote:
> Author: samsonov
> Date: Tue Feb 19 05:35:39 2013
> New Revision: 175509
>
> URL: http://llvm.org/viewvc/llvm-project?rev=175509&view=rev
> Log:
> Fix initialization-order bug in llvm::Support::TimeValue. TimeValue::now()
> is explicitly called during module initialization of
> lib/Support/Process.cpp. It reads the field of global object PosixZeroTime,
> which is not guaranteed to be initialized at this point. Found by
> AddressSanitizer with -fsanitize=init-order option.
>
Do we have a public bot with this configuration on it?
>
> Modified:
> llvm/trunk/include/llvm/Support/TimeValue.h
> llvm/trunk/lib/Support/TimeValue.cpp
> llvm/trunk/lib/Support/Unix/TimeValue.inc
>
> Modified: llvm/trunk/include/llvm/Support/TimeValue.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/TimeValue.h?rev=175509&r1=175508&r2=175509&view=diff
>
> ==============================================================================
> --- llvm/trunk/include/llvm/Support/TimeValue.h (original)
> +++ llvm/trunk/include/llvm/Support/TimeValue.h Tue Feb 19 05:35:39 2013
> @@ -240,7 +240,7 @@ namespace sys {
> /// Posix, correcting for the difference in Posix zero time.
> /// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan
> 1,1970)
> uint64_t toPosixTime() const {
> - uint64_t result = seconds_ - PosixZeroTime.seconds_;
> + uint64_t result = seconds_ - PosixZeroTimeSeconds;
> result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
> return result;
> }
> @@ -248,14 +248,14 @@ namespace sys {
> /// Converts the TimeValue into the corresponding number of seconds
> /// since the epoch (00:00:00 Jan 1,1970).
> uint64_t toEpochTime() const {
> - return seconds_ - PosixZeroTime.seconds_;
> + return seconds_ - PosixZeroTimeSeconds;
> }
>
> /// Converts the TimeValue into the corresponding number of "ticks"
> for
> /// Win32 platforms, correcting for the difference in Win32 zero time.
> /// @brief Convert to windows time (seconds since 12:00:00a Jan 1,
> 1601)
> uint64_t toWin32Time() const {
> - uint64_t result = seconds_ - Win32ZeroTime.seconds_;
> + uint64_t result = seconds_ - Win32ZeroTimeSeconds;
> result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
> return result;
> }
> @@ -264,7 +264,7 @@ namespace sys {
> /// correction for the Posix zero time.
> /// @brief Convert to timespec time (ala POSIX.1b)
> void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
> - seconds = seconds_ - PosixZeroTime.seconds_;
> + seconds = seconds_ - PosixZeroTimeSeconds;
> nanos = nanos_;
> }
>
> @@ -331,7 +331,7 @@ namespace sys {
> /// TimeValue and assigns that value to \p this.
> /// @brief Convert seconds form PosixTime to TimeValue
> void fromEpochTime( SecondsType seconds ) {
> - seconds_ = seconds + PosixZeroTime.seconds_;
> + seconds_ = seconds + PosixZeroTimeSeconds;
> nanos_ = 0;
> this->normalize();
> }
> @@ -340,7 +340,7 @@ namespace sys {
> /// corresponding TimeValue and assigns that value to \p this.
> /// @brief Convert seconds form Windows FILETIME to TimeValue
> void fromWin32Time( uint64_t win32Time ) {
> - this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
> + this->seconds_ = win32Time / 10000000 + Win32ZeroTimeSeconds;
> this->nanos_ = NanoSecondsType(win32Time % 10000000) * 100;
> }
>
> @@ -360,6 +360,9 @@ namespace sys {
> /// Store the values as a <timeval>.
> SecondsType seconds_;///< Stores the seconds part of the TimeVal
> NanoSecondsType nanos_; ///< Stores the nanoseconds part of the
> TimeVal
> +
> + static const SecondsType PosixZeroTimeSeconds;
> + static const SecondsType Win32ZeroTimeSeconds;
> /// @}
>
> };
>
> Modified: llvm/trunk/lib/Support/TimeValue.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/TimeValue.cpp?rev=175509&r1=175508&r2=175509&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Support/TimeValue.cpp (original)
> +++ llvm/trunk/lib/Support/TimeValue.cpp Tue Feb 19 05:35:39 2013
> @@ -17,11 +17,16 @@
> namespace llvm {
> using namespace sys;
>
> +const TimeValue::SecondsType
> + TimeValue::PosixZeroTimeSeconds = -946684800;
> +const TimeValue::SecondsType
> + TimeValue::Win32ZeroTimeSeconds = -12591158400ULL;
> +
> const TimeValue TimeValue::MinTime = TimeValue ( INT64_MIN,0 );
> const TimeValue TimeValue::MaxTime = TimeValue ( INT64_MAX,0 );
> const TimeValue TimeValue::ZeroTime = TimeValue ( 0,0 );
> -const TimeValue TimeValue::PosixZeroTime = TimeValue ( -946684800,0 );
> -const TimeValue TimeValue::Win32ZeroTime = TimeValue ( -12591158400ULL,0
> );
> +const TimeValue TimeValue::PosixZeroTime = TimeValue (
> PosixZeroTimeSeconds,0 );
> +const TimeValue TimeValue::Win32ZeroTime = TimeValue (
> Win32ZeroTimeSeconds,0 );
>
> void
> TimeValue::normalize( void ) {
>
> Modified: llvm/trunk/lib/Support/Unix/TimeValue.inc
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Unix/TimeValue.inc?rev=175509&r1=175508&r2=175509&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Support/Unix/TimeValue.inc (original)
> +++ llvm/trunk/lib/Support/Unix/TimeValue.inc Tue Feb 19 05:35:39 2013
> @@ -48,7 +48,8 @@ TimeValue TimeValue::now() {
> }
>
> return TimeValue(
> - static_cast<TimeValue::SecondsType>( the_time.tv_sec +
> PosixZeroTime.seconds_ ),
> + static_cast<TimeValue::SecondsType>( the_time.tv_sec +
> + PosixZeroTimeSeconds ),
> static_cast<TimeValue::NanoSecondsType>( the_time.tv_usec *
> NANOSECONDS_PER_MICROSECOND ) );
> }
>
>
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