forked from OSchip/llvm-project
68 lines
2.3 KiB
C++
68 lines
2.3 KiB
C++
//===-- xray_init.cc --------------------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of XRay, a dynamic runtime instrumentation system.
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//
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// XRay initialisation logic.
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//===----------------------------------------------------------------------===//
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#include <fcntl.h>
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#include <strings.h>
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#include <unistd.h>
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#include "sanitizer_common/sanitizer_common.h"
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#include "xray_defs.h"
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#include "xray_flags.h"
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#include "xray_interface_internal.h"
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extern "C" {
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void __xray_init();
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extern const XRaySledEntry __start_xray_instr_map[] __attribute__((weak));
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extern const XRaySledEntry __stop_xray_instr_map[] __attribute__((weak));
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}
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using namespace __xray;
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// When set to 'true' this means the XRay runtime has been initialised. We use
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// the weak symbols defined above (__start_xray_inst_map and
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// __stop_xray_instr_map) to initialise the instrumentation map that XRay uses
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// for runtime patching/unpatching of instrumentation points.
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//
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// FIXME: Support DSO instrumentation maps too. The current solution only works
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// for statically linked executables.
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__sanitizer::atomic_uint8_t XRayInitialized{0};
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// This should always be updated before XRayInitialized is updated.
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__sanitizer::SpinMutex XRayInstrMapMutex;
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XRaySledMap XRayInstrMap;
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// __xray_init() will do the actual loading of the current process' memory map
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// and then proceed to look for the .xray_instr_map section/segment.
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void __xray_init() XRAY_NEVER_INSTRUMENT {
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initializeFlags();
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if (__start_xray_instr_map == nullptr) {
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Report("XRay instrumentation map missing. Not initializing XRay.\n");
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return;
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}
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{
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__sanitizer::SpinMutexLock Guard(&XRayInstrMapMutex);
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XRayInstrMap.Sleds = __start_xray_instr_map;
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XRayInstrMap.Entries = __stop_xray_instr_map - __start_xray_instr_map;
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}
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__sanitizer::atomic_store(&XRayInitialized, true,
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__sanitizer::memory_order_release);
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if (flags()->patch_premain)
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__xray_patch();
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}
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__attribute__((section(".preinit_array"),
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used)) void (*__local_xray_preinit)(void) = __xray_init;
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