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#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "memprof_rawprofile.h"
#include "profile/MemProfData.inc"
#include "sanitizer_common/sanitizer_allocator_internal.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_linux.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_stackdepotbase.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "sanitizer_common/sanitizer_vector.h"
namespace __memprof {
using ::__sanitizer::Vector;
using ::llvm::memprof::MemInfoBlock;
using SegmentEntry = ::llvm::memprof::SegmentEntry;
using Header = ::llvm::memprof::Header;
namespace {
template <class T> char *WriteBytes(T Pod, char *&Buffer) {
*(T *)Buffer = Pod;
return Buffer + sizeof(T);
}
void RecordStackId(const uptr Key, UNUSED LockedMemInfoBlock *const &MIB,
void *Arg) {
// No need to touch the MIB value here since we are only recording the key.
auto *StackIds = reinterpret_cast<Vector<u64> *>(Arg);
StackIds->PushBack(Key);
}
} // namespace
u64 SegmentSizeBytes(MemoryMappingLayoutBase &Layout) {
u64 NumSegmentsToRecord = 0;
MemoryMappedSegment segment;
for (Layout.Reset(); Layout.Next(&segment);)
if (segment.IsReadable() && segment.IsExecutable())
NumSegmentsToRecord++;
return sizeof(u64) // A header which stores the number of records.
+ sizeof(SegmentEntry) * NumSegmentsToRecord;
}
// The segment section uses the following format:
// ---------- Segment Info
// Num Entries
// ---------- Segment Entry
// Start
// End
// Offset
// BuildID 32B
// ----------
// ...
void SerializeSegmentsToBuffer(MemoryMappingLayoutBase &Layout,
const u64 ExpectedNumBytes, char *&Buffer) {
char *Ptr = Buffer;
// Reserve space for the final count.
Ptr += sizeof(u64);
u64 NumSegmentsRecorded = 0;
MemoryMappedSegment segment;
for (Layout.Reset(); Layout.Next(&segment);) {
if (segment.IsReadable() && segment.IsExecutable()) {
// TODO: Record segment.uuid when it is implemented for Linux-Elf.
SegmentEntry Entry(segment.start, segment.end, segment.offset);
memcpy(Ptr, &Entry, sizeof(SegmentEntry));
Ptr += sizeof(SegmentEntry);
NumSegmentsRecorded++;
}
}
// Store the number of segments we recorded in the space we reserved.
*((u64 *)Buffer) = NumSegmentsRecorded;
CHECK(ExpectedNumBytes >= static_cast<u64>(Ptr - Buffer) &&
"Expected num bytes != actual bytes written");
}
u64 StackSizeBytes(const Vector<u64> &StackIds) {
u64 NumBytesToWrite = sizeof(u64);
const u64 NumIds = StackIds.Size();
for (unsigned k = 0; k < NumIds; ++k) {
const u64 Id = StackIds[k];
// One entry for the id and then one more for the number of stack pcs.
NumBytesToWrite += 2 * sizeof(u64);
const StackTrace St = StackDepotGet(Id);
CHECK(St.trace != nullptr && St.size > 0 && "Empty stack trace");
for (uptr i = 0; i < St.size && St.trace[i] != 0; i++) {
NumBytesToWrite += sizeof(u64);
}
}
return NumBytesToWrite;
}
// The stack info section uses the following format:
//
// ---------- Stack Info
// Num Entries
// ---------- Stack Entry
// Num Stacks
// PC1
// PC2
// ...
// ----------
void SerializeStackToBuffer(const Vector<u64> &StackIds,
const u64 ExpectedNumBytes, char *&Buffer) {
const u64 NumIds = StackIds.Size();
char *Ptr = Buffer;
Ptr = WriteBytes(static_cast<u64>(NumIds), Ptr);
for (unsigned k = 0; k < NumIds; ++k) {
const u64 Id = StackIds[k];
Ptr = WriteBytes(Id, Ptr);
Ptr += sizeof(u64); // Bump it by u64, we will fill this in later.
u64 Count = 0;
const StackTrace St = StackDepotGet(Id);
for (uptr i = 0; i < St.size && St.trace[i] != 0; i++) {
// PCs in stack traces are actually the return addresses, that is,
// addresses of the next instructions after the call.
uptr pc = StackTrace::GetPreviousInstructionPc(St.trace[i]);
Ptr = WriteBytes(static_cast<u64>(pc), Ptr);
++Count;
}
// Store the count in the space we reserved earlier.
*(u64 *)(Ptr - (Count + 1) * sizeof(u64)) = Count;
}
CHECK(ExpectedNumBytes >= static_cast<u64>(Ptr - Buffer) &&
"Expected num bytes != actual bytes written");
}
// The MIB section has the following format:
// ---------- MIB Info
// Num Entries
// ---------- MIB Entry 0
// Alloc Count
// ...
// ---------- MIB Entry 1
// Alloc Count
// ...
// ----------
void SerializeMIBInfoToBuffer(MIBMapTy &MIBMap, const Vector<u64> &StackIds,
const u64 ExpectedNumBytes, char *&Buffer) {
char *Ptr = Buffer;
const u64 NumEntries = StackIds.Size();
Ptr = WriteBytes(NumEntries, Ptr);
for (u64 i = 0; i < NumEntries; i++) {
const u64 Key = StackIds[i];
MIBMapTy::Handle h(&MIBMap, Key, /*remove=*/true, /*create=*/false);
CHECK(h.exists());
Ptr = WriteBytes(Key, Ptr);
Ptr = WriteBytes((*h)->mib, Ptr);
}
CHECK(ExpectedNumBytes >= static_cast<u64>(Ptr - Buffer) &&
"Expected num bytes != actual bytes written");
}
// Format
// ---------- Header
// Magic
// Version
// Total Size
// Segment Offset
// MIB Info Offset
// Stack Offset
// ---------- Segment Info
// Num Entries
// ---------- Segment Entry
// Start
// End
// Offset
// BuildID 32B
// ----------
// ...
// ----------
// Optional Padding Bytes
// ---------- MIB Info
// Num Entries
// ---------- MIB Entry
// Alloc Count
// ...
// ----------
// Optional Padding Bytes
// ---------- Stack Info
// Num Entries
// ---------- Stack Entry
// Num Stacks
// PC1
// PC2
// ...
// ----------
// Optional Padding Bytes
// ...
u64 SerializeToRawProfile(MIBMapTy &MIBMap, MemoryMappingLayoutBase &Layout,
char *&Buffer) {
// Each section size is rounded up to 8b since the first entry in each section
// is a u64 which holds the number of entries in the section by convention.
const u64 NumSegmentBytes = RoundUpTo(SegmentSizeBytes(Layout), 8);
Vector<u64> StackIds;
MIBMap.ForEach(RecordStackId, reinterpret_cast<void *>(&StackIds));
// The first 8b are for the total number of MIB records. Each MIB record is
// preceded by a 8b stack id which is associated with stack frames in the next
// section.
const u64 NumMIBInfoBytes = RoundUpTo(
sizeof(u64) + StackIds.Size() * (sizeof(u64) + sizeof(MemInfoBlock)), 8);
const u64 NumStackBytes = RoundUpTo(StackSizeBytes(StackIds), 8);
// Ensure that the profile is 8b aligned. We allow for some optional padding
// at the end so that any subsequent profile serialized to the same file does
// not incur unaligned accesses.
const u64 TotalSizeBytes = RoundUpTo(
sizeof(Header) + NumSegmentBytes + NumStackBytes + NumMIBInfoBytes, 8);
// Allocate the memory for the entire buffer incl. info blocks.
Buffer = (char *)InternalAlloc(TotalSizeBytes);
char *Ptr = Buffer;
Header header{MEMPROF_RAW_MAGIC_64,
MEMPROF_RAW_VERSION,
static_cast<u64>(TotalSizeBytes),
sizeof(Header),
sizeof(Header) + NumSegmentBytes,
sizeof(Header) + NumSegmentBytes + NumMIBInfoBytes};
Ptr = WriteBytes(header, Ptr);
SerializeSegmentsToBuffer(Layout, NumSegmentBytes, Ptr);
Ptr += NumSegmentBytes;
SerializeMIBInfoToBuffer(MIBMap, StackIds, NumMIBInfoBytes, Ptr);
Ptr += NumMIBInfoBytes;
SerializeStackToBuffer(StackIds, NumStackBytes, Ptr);
return TotalSizeBytes;
}
} // namespace __memprof
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