Author: Walter Erquinigo Date: 2022-08-08T12:31:42-07:00 New Revision: ddd576ab87a16eb7fb06531da8040ac2ece0c9a3
URL: https://github.com/llvm/llvm-project/commit/ddd576ab87a16eb7fb06531da8040ac2ece0c9a3 DIFF: https://github.com/llvm/llvm-project/commit/ddd576ab87a16eb7fb06531da8040ac2ece0c9a3.diff LOG: [lldb] Prevent race condition when fetching /proc/cpuinfo @clayborg found a potential race condition when setting a static variable. The fix seems simply to use call_once. All relevant tests pass. Differential Revision: https://reviews.llvm.org/D131081 Added: Modified: lldb/source/Plugins/Process/Linux/Procfs.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/Process/Linux/Procfs.cpp b/lldb/source/Plugins/Process/Linux/Procfs.cpp index 7c0c55a4f208..f59883d1caff 100644 --- a/lldb/source/Plugins/Process/Linux/Procfs.cpp +++ b/lldb/source/Plugins/Process/Linux/Procfs.cpp @@ -7,9 +7,9 @@ //===----------------------------------------------------------------------===// #include "Procfs.h" - #include "lldb/Host/linux/Support.h" #include "llvm/Support/MemoryBuffer.h" +#include "llvm/Support/Threading.h" using namespace lldb; using namespace lldb_private; @@ -17,17 +17,14 @@ using namespace process_linux; using namespace llvm; Expected<ArrayRef<uint8_t>> lldb_private::process_linux::GetProcfsCpuInfo() { - static Optional<std::vector<uint8_t>> cpu_info; - if (!cpu_info) { - auto buffer_or_error = errorOrToExpected(getProcFile("cpuinfo")); - if (!buffer_or_error) - return buffer_or_error.takeError(); - MemoryBuffer &buffer = **buffer_or_error; - cpu_info = std::vector<uint8_t>( - reinterpret_cast<const uint8_t *>(buffer.getBufferStart()), - reinterpret_cast<const uint8_t *>(buffer.getBufferEnd())); - } - return *cpu_info; + static ErrorOr<std::unique_ptr<MemoryBuffer>> cpu_info_or_err = + getProcFile("cpuinfo"); + + if (!*cpu_info_or_err) + cpu_info_or_err.getError(); + + MemoryBuffer &buffer = **cpu_info_or_err; + return arrayRefFromStringRef(buffer.getBuffer()); } Expected<std::vector<cpu_id_t>> _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits