diff options
Diffstat (limited to 'dev-qt/qtcore/files/qtcore-5.15.2-fix-stack-smashing.patch')
| -rw-r--r-- | dev-qt/qtcore/files/qtcore-5.15.2-fix-stack-smashing.patch | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/dev-qt/qtcore/files/qtcore-5.15.2-fix-stack-smashing.patch b/dev-qt/qtcore/files/qtcore-5.15.2-fix-stack-smashing.patch new file mode 100644 index 000000000000..cfc187251ccb --- /dev/null +++ b/dev-qt/qtcore/files/qtcore-5.15.2-fix-stack-smashing.patch @@ -0,0 +1,105 @@ +From 463c338b09710609e0dc82f67e03c829a7b83788 Mon Sep 17 00:00:00 2001 +From: Allan Sandfeld Jensen <allan.jensen@qt.io> +Date: Fri, 14 May 2021 10:43:11 +0200 +Subject: [PATCH] Avoid mixing atomic futex changes and QAtomic +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Either the mix of futex and atomic, or the mix of 32-bit futex and +64-bit atomic doesn't work. In any case, the existing code leads to +bad behavior. + +* asturm 2021-11-19: Also threw the typo fix from 587e3bb0 into the mix. + +Pick-to: 6.1 5.15 +Fixes: QTBUG-92188 +Change-Id: Icc6ba28d6e2465c373d00e84f4da2b92c037e797 +Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org> +Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io> +(cherry picked from commit 2d9cc639a4a7a5e97979a6034364bd67dfa10c23) +--- + src/corelib/thread/qsemaphore.cpp | 46 ++++++++++++------------------- + 1 file changed, 17 insertions(+), 29 deletions(-) + +diff --git a/src/corelib/thread/qsemaphore.cpp b/src/corelib/thread/qsemaphore.cpp +index d4fb756b94..1d01fc1b28 100644 +--- a/src/corelib/thread/qsemaphore.cpp ++++ b/src/corelib/thread/qsemaphore.cpp +@@ -357,47 +357,31 @@ void QSemaphore::release(int n) + quintptr prevValue = u.fetchAndAddRelease(nn); + if (futexNeedsWake(prevValue)) { + #ifdef FUTEX_OP +- if (!futexHasWaiterCount) { +- /* +- On 32-bit systems, all waiters are waiting on the same address, +- so we'll wake them all and ask the kernel to clear the high bit. +- +- atomic { +- int oldval = u; +- u = oldval & ~(1 << 31); +- futexWake(u, INT_MAX); +- if (oldval == 0) // impossible condition +- futexWake(u, INT_MAX); +- } +- */ +- quint32 op = FUTEX_OP_ANDN | FUTEX_OP_OPARG_SHIFT; +- quint32 oparg = 31; +- quint32 cmp = FUTEX_OP_CMP_EQ; +- quint32 cmparg = 0; +- futexWakeOp(u, INT_MAX, INT_MAX, u, FUTEX_OP(op, oparg, cmp, cmparg)); +- } else { ++ if (futexHasWaiterCount) { + /* + On 64-bit systems, the single-token waiters wait on the low half + and the multi-token waiters wait on the upper half. So we ask + the kernel to wake up n single-token waiters and all multi-token +- waiters (if any), then clear the multi-token wait bit. ++ waiters (if any), and clear the multi-token wait bit. + + atomic { + int oldval = *upper; +- *upper = oldval & ~(1 << 31); ++ *upper = oldval | 0; + futexWake(lower, n); +- if (oldval < 0) // sign bit set ++ if (oldval != 0) // always true + futexWake(upper, INT_MAX); + } + */ +- quint32 op = FUTEX_OP_ANDN | FUTEX_OP_OPARG_SHIFT; +- quint32 oparg = 31; +- quint32 cmp = FUTEX_OP_CMP_LT; ++ quint32 op = FUTEX_OP_OR; ++ quint32 oparg = 0; ++ quint32 cmp = FUTEX_OP_CMP_NE; + quint32 cmparg = 0; ++ u.fetchAndAndRelease(futexNeedsWakeAllBit - 1); + futexWakeOp(*futexLow32(&u), n, INT_MAX, *futexHigh32(&u), FUTEX_OP(op, oparg, cmp, cmparg)); ++ return; + } +-#else +- // Unset the bit and wake everyone. There are two possibibilies ++#endif ++ // Unset the bit and wake everyone. There are two possibilities + // under which a thread can set the bit between the AND and the + // futexWake: + // 1) it did see the new counter value, but it wasn't enough for +@@ -405,8 +389,12 @@ void QSemaphore::release(int n) + // 2) it did not see the new counter value, in which case its + // futexWait will fail. + u.fetchAndAndRelease(futexNeedsWakeAllBit - 1); +- futexWakeAll(u); +-#endif ++ if (futexHasWaiterCount) { ++ futexWakeAll(*futexLow32(&u)); ++ futexWakeAll(*futexHigh32(&u)); ++ } else { ++ futexWakeAll(u); ++ } + } + return; + } +-- +2.34.0 + |