1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

qsimd: perform RDSEED sanity check in case if available

Browse Source 
Fixes: QTBUG-134538
Pick-to: 6.5 6.8 6.9
Change-Id: Iab51337b9b27ccf48a0e60c08cf14706112b6235
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
Mikhail Paulyshka 2025-03-11 00:35:40 +03:00
parent e67568706f
commit 1b8d085322
1 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/corelib/global/qsimd.cpp
View File

@ -260,7 +260,7 @@ static inline quint64 detectProcessorFeatures()
X86_BASELINE "," QT_FUNCTION_TARGET_STRING_RDRND X86_BASELINE "," QT_FUNCTION_TARGET_STRING_RDRND
#endif #endif
static bool checkRdrndWorks() noexcept; static bool checkRdrndWorks(quint64) noexcept;
QT_FUNCTION_TARGET_BASELINE QT_FUNCTION_TARGET_BASELINE
static int maxBasicCpuidSupported() static int maxBasicCpuidSupported()
@ -466,7 +466,7 @@ static quint64 detectProcessorFeatures()
features &= ~req.cpu_features; features &= ~req.cpu_features;
} }
if (features & CpuFeatureRDRND && !checkRdrndWorks()) if (features & CpuFeatureRDRND && !checkRdrndWorks(features))
features &= ~(CpuFeatureRDRND | CpuFeatureRDSEED); features &= ~(CpuFeatureRDRND | CpuFeatureRDSEED);
return features; return features;
@ -778,7 +778,7 @@ out:
} }
QT_FUNCTION_TARGET(BASELINE_RDRND) Q_DECL_COLD_FUNCTION QT_FUNCTION_TARGET(BASELINE_RDRND) Q_DECL_COLD_FUNCTION
static bool checkRdrndWorks() noexcept static bool checkRdrndWorks(quint64 features) noexcept
{ {
/* /*
* Some AMD CPUs (e.g. AMD A4-6250J and AMD Ryzen 3000-series) have a * Some AMD CPUs (e.g. AMD A4-6250J and AMD Ryzen 3000-series) have a
@ -800,7 +800,12 @@ static bool checkRdrndWorks() noexcept
if (_compilerCpuFeatures & CpuFeatureRDRND) if (_compilerCpuFeatures & CpuFeatureRDRND)
return true; return true;
unsigned *end = qt_random_rdrnd(testBuffer, testBuffer + TestBufferSize); unsigned *end;
if (features & CpuFeatureRDSEED)
end = qt_random_rdseed(testBuffer, testBuffer + TestBufferSize);
else
end = qt_random_rdrnd(testBuffer, testBuffer + TestBufferSize);
if (end < testBuffer + 3) { if (end < testBuffer + 3) {
// Random generation didn't produce enough data for us to make a // Random generation didn't produce enough data for us to make a
// determination whether it's working or not. Assume it isn't, but // determination whether it's working or not. Assume it isn't, but
@ -838,7 +843,7 @@ QT_FUNCTION_TARGET(RDRND) qsizetype qRandomCpu(void *buffer, qsizetype count) no
return ptr - reinterpret_cast<unsigned *>(buffer); return ptr - reinterpret_cast<unsigned *>(buffer);
} }
#elif defined(Q_PROCESSOR_X86) && !defined(Q_PROCESSOR_ARM) #elif defined(Q_PROCESSOR_X86) && !defined(Q_PROCESSOR_ARM)
static bool checkRdrndWorks() noexcept { return false; } static bool checkRdrndWorks(quint64) noexcept { return false; }
#endif // Q_PROCESSOR_X86 && RDRND #endif // Q_PROCESSOR_X86 && RDRND
#if QT_SUPPORTS_INIT_PRIORITY #if QT_SUPPORTS_INIT_PRIORITY