blob: d3bde4b242a7bc558ae6a29b1c56b0737f6ed85d [file] [log] [blame]
//===-- sanitizer_coverage_mapping.cc -------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Mmap-based implementation of sanitizer coverage.
//
// This is part of the implementation of code coverage that does not require
// __sanitizer_cov_dump() call. Data is stored in 2 files per process.
//
// $pid.sancov.map describes process memory layout in the following text-based
// format:
// <pointer size in bits> // 1 line, 32 or 64
// <mapping start> <mapping end> <base address> <dso name> // repeated
// ...
// Mapping lines are NOT sorted. This file is updated every time memory layout
// is changed (i.e. in dlopen() and dlclose() interceptors).
//
// $pid.sancov.raw is a binary dump of PC values, sizeof(uptr) each. Again, not
// sorted. This file is extended by 64Kb at a time and mapped into memory. It
// contains one or more 0 words at the end, up to the next 64Kb aligned offset.
//
// To convert these 2 files to the usual .sancov format, run sancov.py rawunpack
// $pid.sancov.raw.
//
//===----------------------------------------------------------------------===//
#include "sanitizer_allocator_internal.h"
#include "sanitizer_libc.h"
#include "sanitizer_procmaps.h"
namespace __sanitizer {
static const uptr kMaxNumberOfModules = 1 << 14;
static const uptr kMaxTextSize = 64 * 1024;
struct CachedMapping {
public:
bool NeedsUpdate(uptr pc) {
int new_pid = internal_getpid();
if (last_pid == new_pid && pc && pc >= last_range_start &&
pc < last_range_end)
return false;
last_pid = new_pid;
return true;
}
void SetModuleRange(uptr start, uptr end) {
last_range_start = start;
last_range_end = end;
}
private:
uptr last_range_start, last_range_end;
int last_pid;
};
static CachedMapping cached_mapping;
static StaticSpinMutex mapping_mu;
void CovUpdateMapping(const char *coverage_dir, uptr caller_pc) {
if (!common_flags()->coverage_direct) return;
SpinMutexLock l(&mapping_mu);
if (!cached_mapping.NeedsUpdate(caller_pc))
return;
InternalScopedString text(kMaxTextSize);
{
InternalScopedBuffer<LoadedModule> modules(kMaxNumberOfModules);
CHECK(modules.data());
int n_modules = GetListOfModules(modules.data(), kMaxNumberOfModules,
/* filter */ 0);
text.append("%d\n", sizeof(uptr) * 8);
for (int i = 0; i < n_modules; ++i) {
const char *module_name = StripModuleName(modules[i].full_name());
uptr base = modules[i].base_address();
for (auto iter = modules[i].ranges(); iter.hasNext();) {
const auto *range = iter.next();
if (range->executable) {
uptr start = range->beg;
uptr end = range->end;
text.append("%zx %zx %zx %s\n", start, end, base, module_name);
if (caller_pc && caller_pc >= start && caller_pc < end)
cached_mapping.SetModuleRange(start, end);
}
}
modules[i].clear();
}
}
int err;
InternalScopedString tmp_path(64 + internal_strlen(coverage_dir));
uptr res = internal_snprintf((char *)tmp_path.data(), tmp_path.size(),
"%s/%zd.sancov.map.tmp", coverage_dir,
internal_getpid());
CHECK_LE(res, tmp_path.size());
uptr map_fd = OpenFile(tmp_path.data(), WrOnly);
if (internal_iserror(map_fd, &err)) {
Report(" Coverage: failed to open %s for writing: %d\n", tmp_path.data(),
err);
Die();
}
res = internal_write(map_fd, text.data(), text.length());
if (internal_iserror(res, &err)) {
Printf("sancov.map write failed: %d\n", err);
Die();
}
internal_close(map_fd);
InternalScopedString path(64 + internal_strlen(coverage_dir));
res = internal_snprintf((char *)path.data(), path.size(), "%s/%zd.sancov.map",
coverage_dir, internal_getpid());
CHECK_LE(res, path.size());
res = internal_rename(tmp_path.data(), path.data());
if (internal_iserror(res, &err)) {
Printf("sancov.map rename failed: %d\n", err);
Die();
}
}
} // namespace __sanitizer