diff options
| author | Antonio Napolitano <anton@polit.no> | 2023-12-30 19:11:32 +0100 |
|---|---|---|
| committer | Qt Cherry-pick Bot <cherrypick_bot@qt-project.org> | 2024-01-31 18:19:31 +0000 |
| commit | 5c42f57e88681be521e3d59f9e527d3bcd4d5732 (patch) | |
| tree | f4f07d9618a77a9326e01342c3a0779842adf97a | |
| parent | e52edaf1ba9c31491d7fe7e650dd5668bb313695 (diff) | |
masm: Don't crash on failed MADV_DONTNEED on Linux
The application could call mlockall(MCL_CURRENT|MCL_FUTURE) to lock all
its memory for performance reasons, causing the madvise call to fail.
There's no need to crash. Instead, manually zero-out the memory when
decommitting.
Fixes: QTBUG-120450
Pick-to: 6.2 5.15
Change-Id: I6f1a8968853cc5e61561371bd2a435a686eaf0e4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit 524d260c5c135d193e06350e48357444ddb13ddb)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 1ead022dfea5a6b3bed8ca80de85c20cea6c809f)
(cherry picked from commit a2e0061317954fdab6f9af1ab0490944bca33873)
| -rw-r--r-- | src/3rdparty/masm/wtf/OSAllocatorPosix.cpp | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/src/3rdparty/masm/wtf/OSAllocatorPosix.cpp b/src/3rdparty/masm/wtf/OSAllocatorPosix.cpp index a8990a92b4..e183d434bd 100644 --- a/src/3rdparty/masm/wtf/OSAllocatorPosix.cpp +++ b/src/3rdparty/masm/wtf/OSAllocatorPosix.cpp @@ -114,10 +114,7 @@ void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, if (result == MAP_FAILED) CRASH(); - while (madvise(result, bytes, MADV_DONTNEED)) { - if (errno != EAGAIN) - CRASH(); - } + while (madvise(result, bytes, MADV_DONTNEED) == -1 && errno == EAGAIN) { } if (fd != -1) close(fd); @@ -250,8 +247,10 @@ void OSAllocator::decommit(void* address, size_t bytes) mmap(address, bytes, PROT_NONE, MAP_FIXED | MAP_LAZY | MAP_PRIVATE | MAP_ANON, -1, 0); #elif OS(LINUX) while (madvise(address, bytes, MADV_DONTNEED)) { - if (errno != EAGAIN) - CRASH(); + if (errno != EAGAIN) { + memset(address, 0, bytes); // We rely on madvise to zero-out the memory + break; + } } if (mprotect(address, bytes, PROT_NONE)) CRASH(); |