fix: read base address from ELF headers and use it consistently#42
Merged
milianw merged 3 commits intoKDAB:hotspotfrom Jul 3, 2025
Merged
fix: read base address from ELF headers and use it consistently#42milianw merged 3 commits intoKDAB:hotspotfrom
milianw merged 3 commits intoKDAB:hotspotfrom
Conversation
milianw
reviewed
May 29, 2025
Contributor
milianw
left a comment
milianw
left a comment
There was a problem hiding this comment.
sorry, I'll have to test this myself before approval to ensure it doesn't regress anything and ideally we try to find some test coverage too
GitMensch
pushed a commit
to GitMensch/perfparser
that referenced
this pull request
May 29, 2025
In qt6 QHash is no longer iterator safe
==138723==ERROR: AddressSanitizer: heap-use-after-free on address 0x51b000035c68 at pc 0x5d085ec696b9 bp 0x7ffe43776e00 sp 0x7ffe43776df0
READ of size 8 at 0x51b000035c68 thread T0
#0 0x5d085ec696b8 in void qt_ptr_swap<QTypedArrayData<char> >(QTypedArrayData<char>*&, QTypedArrayData<char>*&) /usr/include/qt6/QtCore/qswap.h:31
KDAB#1 0x5d085ec67e4f in QArrayDataPointer<char>::swap(QArrayDataPointer<char>&) /usr/include/qt6/QtCore/qarraydatapointer.h:131
KDAB#2 0x5d085ec66e97 in QByteArray::swap(QByteArray&) /usr/include/qt6/QtCore/qbytearray.h:103
#3 0x5d085ec66da8 in QByteArray::operator=(QByteArray&&) /usr/include/qt6/QtCore/qbytearray.h:101
KDAB#4 0x5d085ef0ca5c in CuDieRangeMapping::dieName(Dwarf_Die*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdwarfdiecache.cpp:364
KDAB#5 0x5d085ee36e7c in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:768
KDAB#6 0x5d085ee39eea in PerfSymbolTable::lookupFrame(unsigned long, bool, bool*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:774
KDAB#7 0x5d085ed06ec5 in frameCallback /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:541
KDAB#8 0x75a7437f7b08 in dwfl_thread_getframes (/usr/lib/libdw.so.1+0x5bb08) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#9 0x75a7437f2eba (/usr/lib/libdw.so.1+0x56eba) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#10 0x75a7437f3f2b in dwfl_getthreads (/usr/lib/libdw.so.1+0x57f2b) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#11 0x75a7437f7e81 in dwfl_getthread_frames (/usr/lib/libdw.so.1+0x5be81) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#12 0x5d085ed07b21 in PerfUnwind::unwindStack() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:557
KDAB#13 0x5d085ed0d129 in PerfUnwind::analyze(PerfRecordSample const&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:744
KDAB#14 0x5d085ed1b65f in PerfUnwind::flushEventBuffer(unsigned int) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1115
KDAB#15 0x5d085ed164b1 in PerfUnwind::finishedRound() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:976
KDAB#16 0x5d085ecc2fe8 in PerfData::processEvents(QDataStream&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:243
KDAB#17 0x5d085eccbdc2 in PerfData::doRead() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:414
KDAB#18 0x5d085eccd6f3 in PerfData::read() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:431
KDAB#19 0x5d085ebfa511 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:383
KDAB#20 0x5d085ebfd5c6 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:452
KDAB#21 0x5d085ec0b9b9 in call /usr/include/qt6/QtCore/qobjectdefs_impl.h:137
KDAB#22 0x5d085ec0b121 in call<QtPrivate::List<>, void> /usr/include/qt6/QtCore/qobjectdefs_impl.h:345
KDAB#23 0x5d085ec0aa1e in impl /usr/include/qt6/QtCore/qobjectdefs_impl.h:555
KDAB#24 0x75a7429a3456 (/usr/lib/libQt6Core.so.6+0x1a3456) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#25 0x5d085ec33520 in PerfHeader::finished() /home/lieven/KDAB/hotspot/build-dev-asan-qt6/3rdparty/libhotspot-perfparser_autogen/6F7ISLN55V/moc_perfheader.cpp:234
KDAB#26 0x5d085ec5d91c in PerfHeader::read() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfheader.cpp:122
KDAB#27 0x5d085ec2f1b7 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (PerfHeader::*)()>::call(void (PerfHeader::*)(), PerfHeader*, void**) /usr/include/qt6/QtCore/qobjectdefs_impl.h:145
KDAB#28 0x5d085ec2e24a in void QtPrivate::FunctionPointer<void (PerfHeader::*)()>::call<QtPrivate::List<>, void>(void (PerfHeader::*)(), PerfHeader*, void**) /usr/include/qt6/QtCore/qobjectdefs_impl.h:182
KDAB#29 0x5d085ec2bf91 in QtPrivate::QCallableObject<void (PerfHeader::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) /usr/include/qt6/QtCore/qobjectdefs_impl.h:553
KDAB#30 0x75a74298d93e in QObject::event(QEvent*) (/usr/lib/libQt6Core.so.6+0x18d93e) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#31 0x75a742945bc2 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (/usr/lib/libQt6Core.so.6+0x145bc2) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#32 0x75a742945faa in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (/usr/lib/libQt6Core.so.6+0x145faa) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#33 0x75a742babe4b (/usr/lib/libQt6Core.so.6+0x3abe4b) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#34 0x75a740d13558 (/usr/lib/libglib-2.0.so.0+0x5d558) (BuildId: 7b781c8d1a6e2161838c5d8f3bd797797c132753)
KDAB#35 0x75a740d76156 (/usr/lib/libglib-2.0.so.0+0xc0156) (BuildId: 7b781c8d1a6e2161838c5d8f3bd797797c132753)
KDAB#36 0x75a740d12a54 in g_main_context_iteration (/usr/lib/libglib-2.0.so.0+0x5ca54) (BuildId: 7b781c8d1a6e2161838c5d8f3bd797797c132753)
KDAB#37 0x75a742ba985c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (/usr/lib/libQt6Core.so.6+0x3a985c) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#38 0x75a742950105 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (/usr/lib/libQt6Core.so.6+0x150105) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#39 0x75a74294a27c in QCoreApplication::exec() (/usr/lib/libQt6Core.so.6+0x14a27c) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#40 0x5d085ec04e44 in main /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:481
KDAB#41 0x75a741a34e07 (/usr/lib/libc.so.6+0x25e07) (BuildId: 98b3d8e0b8c534c769cb871c438b4f8f3a8e4bf3)
KDAB#42 0x75a741a34ecb in __libc_start_main (/usr/lib/libc.so.6+0x25ecb) (BuildId: 98b3d8e0b8c534c769cb871c438b4f8f3a8e4bf3)
KDAB#43 0x5d085ebf4b64 in _start (/home/lieven/KDAB/hotspot/build-dev-asan-qt6/libexec/hotspot-perfparser+0x72db64) (BuildId: 580374afdfc7f3994c76369459f6848384c3c771)
0x51b000035c68 is located 1512 bytes inside of 1536-byte region [0x51b000035680,0x51b000035c80)
freed by thread T0 here:
#0 0x75a7430ff22a in operator delete[](void*) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:155
KDAB#1 0x5d085ef2c5af in QHashPrivate::Span<QHashPrivate::Node<unsigned long, QByteArray> >::addStorage() /usr/include/qt6/QtCore/qhash.h:409
KDAB#2 0x5d085ef240f5 in QHashPrivate::Span<QHashPrivate::Node<unsigned long, QByteArray> >::insert(unsigned long) /usr/include/qt6/QtCore/qhash.h:283
#3 0x5d085ef1d324 in QHashPrivate::Data<QHashPrivate::Node<unsigned long, QByteArray> >::Bucket::insert() const /usr/include/qt6/QtCore/qhash.h:511
KDAB#4 0x5d085ef18c64 in QHashPrivate::Data<QHashPrivate::Node<unsigned long, QByteArray> >::findOrInsert(unsigned long const&) /usr/include/qt6/QtCore/qhash.h:728
KDAB#5 0x5d085ef1551a in QHash<unsigned long, QByteArray>::operator[](unsigned long const&) /usr/include/qt6/QtCore/qhash.h:1064
KDAB#6 0x5d085ef08e30 in prependScopeNames(QByteArray&, Dwarf_Die*, QHash<unsigned long, QByteArray>&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdwarfdiecache.cpp:204
KDAB#7 0x5d085ef0965b in qualifiedDieName(Dwarf_Die*, QHash<unsigned long, QByteArray>&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdwarfdiecache.cpp:229
KDAB#8 0x5d085ef0c9b8 in CuDieRangeMapping::dieName(Dwarf_Die*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdwarfdiecache.cpp:364
KDAB#9 0x5d085ee36e7c in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:768
KDAB#10 0x5d085ee39eea in PerfSymbolTable::lookupFrame(unsigned long, bool, bool*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:774
KDAB#11 0x5d085ed06ec5 in frameCallback /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:541
KDAB#12 0x75a7437f7b08 in dwfl_thread_getframes (/usr/lib/libdw.so.1+0x5bb08) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#13 0x75a7437f2eba (/usr/lib/libdw.so.1+0x56eba) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#14 0x75a7437f3f2b in dwfl_getthreads (/usr/lib/libdw.so.1+0x57f2b) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#15 0x75a7437f7e81 in dwfl_getthread_frames (/usr/lib/libdw.so.1+0x5be81) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#16 0x5d085ed07b21 in PerfUnwind::unwindStack() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:557
KDAB#17 0x5d085ed0d129 in PerfUnwind::analyze(PerfRecordSample const&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:744
KDAB#18 0x5d085ed1b65f in PerfUnwind::flushEventBuffer(unsigned int) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1115
KDAB#19 0x5d085ed164b1 in PerfUnwind::finishedRound() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:976
KDAB#20 0x5d085ecc2fe8 in PerfData::processEvents(QDataStream&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:243
KDAB#21 0x5d085eccbdc2 in PerfData::doRead() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:414
KDAB#22 0x5d085eccd6f3 in PerfData::read() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:431
KDAB#23 0x5d085ebfa511 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:383
KDAB#24 0x5d085ebfd5c6 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:452
KDAB#25 0x5d085ec0b9b9 in call /usr/include/qt6/QtCore/qobjectdefs_impl.h:137
KDAB#26 0x5d085ec0b121 in call<QtPrivate::List<>, void> /usr/include/qt6/QtCore/qobjectdefs_impl.h:345
KDAB#27 0x5d085ec0aa1e in impl /usr/include/qt6/QtCore/qobjectdefs_impl.h:555
KDAB#28 0x75a7429a3456 (/usr/lib/libQt6Core.so.6+0x1a3456) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#29 0x5d085ec33520 in PerfHeader::finished() /home/lieven/KDAB/hotspot/build-dev-asan-qt6/3rdparty/libhotspot-perfparser_autogen/6F7ISLN55V/moc_perfheader.cpp:234
previously allocated by thread T0 here:
#0 0x75a7430fe682 in operator new[](unsigned long) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:98
KDAB#1 0x5d085ef2c181 in QHashPrivate::Span<QHashPrivate::Node<unsigned long, QByteArray> >::addStorage() /usr/include/qt6/QtCore/qhash.h:394
KDAB#2 0x5d085ef240f5 in QHashPrivate::Span<QHashPrivate::Node<unsigned long, QByteArray> >::insert(unsigned long) /usr/include/qt6/QtCore/qhash.h:283
#3 0x5d085ef1d324 in QHashPrivate::Data<QHashPrivate::Node<unsigned long, QByteArray> >::Bucket::insert() const /usr/include/qt6/QtCore/qhash.h:511
KDAB#4 0x5d085ef18c64 in QHashPrivate::Data<QHashPrivate::Node<unsigned long, QByteArray> >::findOrInsert(unsigned long const&) /usr/include/qt6/QtCore/qhash.h:728
KDAB#5 0x5d085ef1551a in QHash<unsigned long, QByteArray>::operator[](unsigned long const&) /usr/include/qt6/QtCore/qhash.h:1064
KDAB#6 0x5d085ef0c883 in CuDieRangeMapping::dieName(Dwarf_Die*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdwarfdiecache.cpp:362
KDAB#7 0x5d085ee36e7c in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:768
KDAB#8 0x5d085ee39eea in PerfSymbolTable::lookupFrame(unsigned long, bool, bool*) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:774
KDAB#9 0x5d085ed06ec5 in frameCallback /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:541
KDAB#10 0x75a7437f7b08 in dwfl_thread_getframes (/usr/lib/libdw.so.1+0x5bb08) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#11 0x75a7437f2eba (/usr/lib/libdw.so.1+0x56eba) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#12 0x75a7437f3f2b in dwfl_getthreads (/usr/lib/libdw.so.1+0x57f2b) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#13 0x75a7437f7e81 in dwfl_getthread_frames (/usr/lib/libdw.so.1+0x5be81) (BuildId: 9b3f42d0dd4107f1cd947702b04157dad2a9069a)
KDAB#14 0x5d085ed07b21 in PerfUnwind::unwindStack() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:557
KDAB#15 0x5d085ed0d129 in PerfUnwind::analyze(PerfRecordSample const&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:744
KDAB#16 0x5d085ed1b65f in PerfUnwind::flushEventBuffer(unsigned int) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1115
KDAB#17 0x5d085ed164b1 in PerfUnwind::finishedRound() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfunwind.cpp:976
KDAB#18 0x5d085ecc2fe8 in PerfData::processEvents(QDataStream&) /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:243
KDAB#19 0x5d085eccbdc2 in PerfData::doRead() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:414
KDAB#20 0x5d085eccd6f3 in PerfData::read() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfdata.cpp:431
KDAB#21 0x5d085ebfa511 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:383
KDAB#22 0x5d085ebfd5c6 in operator() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/main.cpp:452
KDAB#23 0x5d085ec0b9b9 in call /usr/include/qt6/QtCore/qobjectdefs_impl.h:137
KDAB#24 0x5d085ec0b121 in call<QtPrivate::List<>, void> /usr/include/qt6/QtCore/qobjectdefs_impl.h:345
KDAB#25 0x5d085ec0aa1e in impl /usr/include/qt6/QtCore/qobjectdefs_impl.h:555
KDAB#26 0x75a7429a3456 (/usr/lib/libQt6Core.so.6+0x1a3456) (BuildId: 2dc7cac262eec1f545dffaf6727f87faf910fb09)
KDAB#27 0x5d085ec33520 in PerfHeader::finished() /home/lieven/KDAB/hotspot/build-dev-asan-qt6/3rdparty/libhotspot-perfparser_autogen/6F7ISLN55V/moc_perfheader.cpp:234
KDAB#28 0x5d085ec5d91c in PerfHeader::read() /home/lieven/KDAB/hotspot/3rdparty/perfparser/app/perfheader.cpp:122
KDAB#29 0x5d085ec2f1b7 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (PerfHeader::*)()>::call(void (PerfHeader::*)(), PerfHeader*, void**) /usr/include/qt6/QtCore/qobjectdefs_impl.h:145
SUMMARY: AddressSanitizer: heap-use-after-free /usr/include/qt6/QtCore/qswap.h:31 in void qt_ptr_swap<QTypedArrayData<char> >(QTypedArrayData<char>*&, QTypedArrayData<char>*&)
Shadow bytes around the buggy address:
0x51b000035980: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x51b000035a00: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x51b000035a80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x51b000035b00: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x51b000035b80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
=>0x51b000035c00: fd fd fd fd fd fd fd fd fd fd fd fd fd[fd]fd fd
0x51b000035c80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x51b000035d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x51b000035d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x51b000035e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x51b000035e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==138723==ABORTING
pcc
commented
Jun 1, 2025
| mod = dwfl_addrmodule(m_dwfl, baseAddr); | ||
| } | ||
|
|
||
| if (mod) { |
Contributor
Author
There was a problem hiding this comment.
I deleted this code because it was causing some tests to fail. I also tried replacing it with code that reads dwbias from dwfl_module_info but elfutils only provides that value if the file has DWARF debug info which caused some tests without DWARF to fail. I don't know how to reproduce the original problem ("many modules overlap ld.so"), and I'm not sure if it was a valid diagnosis.
Contributor
There was a problem hiding this comment.
I am pretty sure that I remember this was a real problem back then - but the situation may have changed in the last ~8years and potentially we can only reproduce this on older kernels. maybe it's time to move on, so let's see if simply removing it is good enough nowadays
Contributor
There was a problem hiding this comment.
apparently some platforms still run into this @pcc - see e.g. KDAB/hotspot#728 (comment) and I think I also saw it on some other platform the other day but forgot again where it was and I'll keep my eyes open.
but I wonder: if I would want to re-instantiate the old code, what would I need to keep from your new code? such that I could see the test failures you saw to allow me to debug those?
milianw
reviewed
Jun 4, 2025
Contributor
milianw
left a comment
milianw
left a comment
There was a problem hiding this comment.
some small nits, I can also take care of those for you if you want?
otherwise awesome work, really - thank you so much for this!
perf doesn't normally report non-executable mappings. Ignore them just in case it does, as they will confuse the logic that will be added to registerElf.
Some linkers such as lld and mold will create position-independent binaries with p_offset != p_vaddr. This causes problems for some code in hotspot which was sometimes assuming that they are the same (for example by using addr - offset as the base address) and resulted in incorrect backtraces. To fix this, make it so that we set the base address for every readable binary by reading the ELF headers to check whether the mapping fully contains a segment, and if so use the p_vaddr field to calculate the base address. Subsequent code is adjusted to use the base address instead of vaddr - offset if present.
Contributor
|
Looking forward to possibly get this and KDAB/hotspot#727 merged :-) |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Some linkers such as lld and mold will create position-independent binaries with p_offset != p_vaddr. This causes problems for some code in hotspot which was sometimes assuming that they are the same (for example by using addr - offset as the base address) and resulted in incorrect backtraces. To fix this, make it so that we set the base address for every readable binary by reading the ELF headers to check whether the mapping fully contains a segment, and if so use the p_vaddr field to calculate the base address. Subsequent code is adjusted to use the base address instead of vaddr - offset if present.