dart-sdk/runtime/vm/bss_relocs.h
Tess Strickland 826576dcfc [vm] Store relocated addresses for text sections in BSS.
The relocated addresses are populated during BSS::Initialize() for
natively loaded ELF snapshots, and during the non-native loader when it
is used. Putting this information in the BSS segment avoids having to
change the embedder interface, since we only need this information for
AOT snapshots. This also avoids depending on our ELF snapshot layout
to reverse-engineer the DSO base for ELF-compiled snapshots.

We now always print the DSO base for both the VM and isolate in
non-symbolic stack traces, not just for ELF-compiled snapshots. However,
we still only print the relocated addresses in individual stack frames
if we're guaranteed they match those in separately saved debugging
information.

Bug: https://github.com/dart-lang/sdk/issues/41880

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-win-release-x64-try,vm-kernel-precomp-mac-release-simarm64-try
Change-Id: I4837262f78e6e73a32eb7e24ef7a68ccb8ec2669
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148441
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
2020-05-26 08:47:30 +00:00

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1.5 KiB
C++

// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#ifndef RUNTIME_VM_BSS_RELOCS_H_
#define RUNTIME_VM_BSS_RELOCS_H_
#include "platform/allocation.h"
namespace dart {
class Thread;
class BSS : public AllStatic {
public:
// Entries found in both the VM and isolate BSS come first. Each has its own
// portion of the BSS segment, so just the indices are shared, not the values
// stored at the index.
enum class Relocation : intptr_t {
InstructionsRelocatedAddress,
// End of shared entries.
DRT_GetThreadForNativeCallback,
// End of isolate-only entries.
};
static constexpr intptr_t kVmEntryCount =
static_cast<intptr_t>(Relocation::InstructionsRelocatedAddress) + 1;
static constexpr intptr_t kIsolateEntryCount =
static_cast<intptr_t>(Relocation::DRT_GetThreadForNativeCallback) + 1;
static constexpr intptr_t RelocationIndex(Relocation reloc) {
return static_cast<intptr_t>(reloc);
}
static void Initialize(Thread* current, uword* bss, bool vm);
// Currently only used externally by LoadedElf::ResolveSymbols() to set the
// relocated address without changing the embedder interface.
static void InitializeBSSEntry(BSS::Relocation relocation,
uword new_value,
uword* bss_start);
};
} // namespace dart
#endif // RUNTIME_VM_BSS_RELOCS_H_