diff options
| author | Antonio Napolitano <anton@polit.no> | 2023-12-30 19:11:32 +0100 |
|---|---|---|
| committer | Antonio Napolitano <anton@polit.no> | 2024-01-30 11:06:03 +0100 |
| commit | 524d260c5c135d193e06350e48357444ddb13ddb (patch) | |
| tree | d867a9b06d0ba64c61c4d0dfd5dbc00bae534edc /src/3rdparty | |
| parent | 5d79b207c7a47ac96a32c9aff3527e052364b209 (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: 5.15 6.2 6.5 6.6 6.7
Change-Id: I6f1a8968853cc5e61561371bd2a435a686eaf0e4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Diffstat (limited to 'src/3rdparty')
| -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(); |