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//===-- sanitizer_coverage_libcdep_new.cpp --------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Sanitizer Coverage Controller for Trace PC Guard.
#include "sanitizer_platform.h"
#if !SANITIZER_FUCHSIA
#include "sancov_flags.h"
#include "sanitizer_allocator_internal.h"
#include "sanitizer_atomic.h"
#include "sanitizer_common.h"
#include "sanitizer_file.h"
using namespace __sanitizer;
using AddressRange = LoadedModule::AddressRange;
namespace __sancov {
namespace {
static const u64 Magic64 = 0xC0BFFFFFFFFFFF64ULL;
static const u64 Magic32 = 0xC0BFFFFFFFFFFF32ULL;
static const u64 Magic = SANITIZER_WORDSIZE == 64 ? Magic64 : Magic32;
static fd_t OpenFile(const char* path) {
error_t err;
fd_t fd = OpenFile(path, WrOnly, &err);
if (fd == kInvalidFd)
Report("SanitizerCoverage: failed to open %s for writing (reason: %d)\n",
path, err);
return fd;
}
static void GetCoverageFilename(char* path, const char* name,
const char* extension) {
CHECK(name);
internal_snprintf(path, kMaxPathLength, "%s/%s.%zd.%s",
common_flags()->coverage_dir, name, internal_getpid(),
extension);
}
static void WriteModuleCoverage(char* file_path, const char* module_name,
const uptr* pcs, uptr len) {
GetCoverageFilename(file_path, StripModuleName(module_name), "sancov");
fd_t fd = OpenFile(file_path);
WriteToFile(fd, &Magic, sizeof(Magic));
WriteToFile(fd, pcs, len * sizeof(*pcs));
CloseFile(fd);
Printf("SanitizerCoverage: %s: %zd PCs written\n", file_path, len);
}
static void SanitizerDumpCoverage(const uptr* unsorted_pcs, uptr len) {
if (!len) return;
char* file_path = static_cast<char*>(InternalAlloc(kMaxPathLength));
char* module_name = static_cast<char*>(InternalAlloc(kMaxPathLength));
uptr* pcs = static_cast<uptr*>(InternalAlloc(len * sizeof(uptr)));
internal_memcpy(pcs, unsorted_pcs, len * sizeof(uptr));
Sort(pcs, len);
bool module_found = false;
uptr last_base = 0;
uptr module_start_idx = 0;
for (uptr i = 0; i < len; ++i) {
const uptr pc = pcs[i];
if (!pc) continue;
if (!__sanitizer_get_module_and_offset_for_pc(pc, nullptr, 0, &pcs[i])) {
Printf("ERROR: unknown pc 0x%zx (may happen if dlclose is used)\n", pc);
continue;
}
uptr module_base = pc - pcs[i];
if (module_base != last_base || !module_found) {
if (module_found) {
WriteModuleCoverage(file_path, module_name, &pcs[module_start_idx],
i - module_start_idx);
}
last_base = module_base;
module_start_idx = i;
module_found = true;
__sanitizer_get_module_and_offset_for_pc(pc, module_name, kMaxPathLength,
&pcs[i]);
}
}
if (module_found) {
WriteModuleCoverage(file_path, module_name, &pcs[module_start_idx],
len - module_start_idx);
}
InternalFree(file_path);
InternalFree(module_name);
InternalFree(pcs);
}
// Collects trace-pc guard coverage.
// This class relies on zero-initialization.
class TracePcGuardController {
public:
void Initialize() {
CHECK(!initialized);
initialized = true;
InitializeSancovFlags();
pc_vector.Initialize(0);
}
void InitTracePcGuard(u32* start, u32* end) {
if (!initialized) Initialize();
CHECK(!*start);
CHECK_NE(start, end);
u32 i = pc_vector.size();
for (u32* p = start; p < end; p++) *p = ++i;
pc_vector.resize(i);
}
void TracePcGuard(u32* guard, uptr pc) {
u32 idx = *guard;
if (!idx) return;
// we start indices from 1.
atomic_uintptr_t* pc_ptr =
reinterpret_cast<atomic_uintptr_t*>(&pc_vector[idx - 1]);
if (atomic_load(pc_ptr, memory_order_relaxed) == 0)
atomic_store(pc_ptr, pc, memory_order_relaxed);
}
void Reset() {
internal_memset(&pc_vector[0], 0, sizeof(pc_vector[0]) * pc_vector.size());
}
void Dump() {
if (!initialized || !common_flags()->coverage) return;
__sanitizer_dump_coverage(pc_vector.data(), pc_vector.size());
}
private:
bool initialized;
InternalMmapVectorNoCtor<uptr> pc_vector;
};
static TracePcGuardController pc_guard_controller;
// A basic default implementation of callbacks for
// -fsanitize-coverage=inline-8bit-counters,pc-table.
// Use TOOL_OPTIONS (UBSAN_OPTIONS, etc) to dump the coverage data:
// * cov_8bit_counters_out=PATH to dump the 8bit counters.
// * cov_pcs_out=PATH to dump the pc table.
//
// Most users will still need to define their own callbacks for greater
// flexibility.
namespace SingletonCounterCoverage {
static char *counters_beg, *counters_end;
static const uptr *pcs_beg, *pcs_end;
static void DumpCoverage() {
const char* file_path = common_flags()->cov_8bit_counters_out;
if (file_path && internal_strlen(file_path)) {
fd_t fd = OpenFile(file_path);
FileCloser file_closer(fd);
uptr size = counters_end - counters_beg;
WriteToFile(fd, counters_beg, size);
if (common_flags()->verbosity)
__sanitizer::Printf("cov_8bit_counters_out: written %zd bytes to %s\n",
size, file_path);
}
file_path = common_flags()->cov_pcs_out;
if (file_path && internal_strlen(file_path)) {
fd_t fd = OpenFile(file_path);
FileCloser file_closer(fd);
uptr size = (pcs_end - pcs_beg) * sizeof(uptr);
WriteToFile(fd, pcs_beg, size);
if (common_flags()->verbosity)
__sanitizer::Printf("cov_pcs_out: written %zd bytes to %s\n", size,
file_path);
}
}
static void Cov8bitCountersInit(char* beg, char* end) {
counters_beg = beg;
counters_end = end;
Atexit(DumpCoverage);
}
static void CovPcsInit(const uptr* beg, const uptr* end) {
pcs_beg = beg;
pcs_end = end;
}
} // namespace SingletonCounterCoverage
} // namespace
} // namespace __sancov
namespace __sanitizer {
void InitializeCoverage(bool enabled, const char *dir) {
static bool coverage_enabled = false;
if (coverage_enabled)
return; // May happen if two sanitizer enable coverage in the same process.
coverage_enabled = enabled;
Atexit(__sanitizer_cov_dump);
AddDieCallback(__sanitizer_cov_dump);
}
} // namespace __sanitizer
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(const uptr* pcs,
uptr len) {
return __sancov::SanitizerDumpCoverage(pcs, len);
}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32* guard) {
if (!*guard) return;
__sancov::pc_guard_controller.TracePcGuard(guard, GET_CALLER_PC() - 1);
}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init,
u32* start, u32* end) {
if (start == end || *start) return;
__sancov::pc_guard_controller.InitTracePcGuard(start, end);
}
SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_trace_pc_guard_coverage() {
__sancov::pc_guard_controller.Dump();
}
SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() {
__sanitizer_dump_trace_pc_guard_coverage();
}
SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_reset() {
__sancov::pc_guard_controller.Reset();
}
// Default implementations (weak).
// Either empty or very simple.
// Most users should redefine them.
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp1, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp2, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp4, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp8, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp1, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp2, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp4, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp8, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_switch, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div4, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div8, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_gep, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_8bit_counters_init,
char* start, char* end) {
__sancov::SingletonCounterCoverage::Cov8bitCountersInit(start, end);
}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_bool_flag_init, void) {}
SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, const uptr* beg,
const uptr* end) {
__sancov::SingletonCounterCoverage::CovPcsInit(beg, end);
}
} // extern "C"
// Weak definition for code instrumented with -fsanitize-coverage=stack-depth
// and later linked with code containing a strong definition.
// E.g., -fsanitize=fuzzer-no-link
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE uptr __sancov_lowest_stack;
#endif // !SANITIZER_FUCHSIA
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