History log of /haiku/src/system/runtime_loader/elf_symbol_lookup.cpp
Revision Date Author Comments
# 88865292 11-Mar-2019 Jérôme Duval <jerome.duval@gmail.com>

runtime_loader: treat weak symbols as strong symbols definitions.

http://www.sourceware.org/ml/libc-hacker/2000-06/msg00029.html
Change-Id: I15bf1f48dda32942e2a93610d62dabe0cabdc9a1
Reviewed-on: https://review.haiku-os.org/c/1191
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>


# 4bc43f43 30-Oct-2016 Adrien Destugues <pulkomandy@pulkomandy.tk>

style fix.


# 61987fe7 29-Oct-2016 Adrien Destugues <pulkomandy@pulkomandy.tk>

runtime_loader: allow the ABI version symbol to be local.

Some libraries buildsystems (eg. zlib) somehow prevent the symbol from
being exported. We should fix that, but binaries with missing symbols
are already out there, so we need to handle them in any case.


# 0e45e3eb 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: keep symbol DSO in SymbolLookupCache

While resolving TLS related relocations it is necessary to know the DSO
that defines the symbol. Without proper support in caching that information
is available only when the symbol is resolved first time. That works well
for TLS since TLS_DTPMOD is guaranteed to be before TLS_DTPOFF relocation.
This patch makes the newly introduced parts of the interface work in a
general case.


# df58e6a9 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: support linking TLS symbols from any DSO

Previously TLS_DTPMOD relocation blindly returned ID of the current DSO.
This patch does proper symbol lookup if there is a symbol assigned to the
relocation and uses ID of the DSO in which the symbol is defined.


# 44c0c4d3 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: add support for ELF based TLS

This patch introduces support of ELF based TLS handling with lazy allocation
and initalization of TLS block for each DSO and thread. The implementation
generally follows the official ABI except that generation counter in dtv
is in fact a pointer to Generation object that contains both generation
counter and size of the dtv. That simplified the implementation a bit, but
could be changed later. The ABI requirements regariding in memory position
of TLS block is not honoured what results in static TLS model being
unsupported. However, that should not be a problem as long as
"executables" in Haiku are in fact shared objects and optimizations which
require specific TLS block in memory layout are not possible anyway.


# e3ac2588 25-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Changed runtime_loader to use elf_* typedefs over Elf32_*.

This means that it will be using ELF64 types on x86_64 rather than
ELF32. The next step for supporting x86_64 is to implement relocations.


# b7786ebd 19-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_add_on(): Resolve non-weak symbols defined in the add-on
to themselves. This works around the problem that those symbols could be
resolved to symbols in the application, which is usually undesired. Weak
symbols have the same problem, but the the runtime loader cannot decide which
should be resolved locally and which mustn't.

The root issue is that BeOS style add-ons simply cannot be supported by a
standard-complying ELF loader.

Affects gcc 4 only, since with gcc 2 we link everything symbolically. The best
solution for the time being would be to build gcc 4 add-ons with default
hidden visibility, exporting only the symbols that should be visible.

Related ticket: #7114


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40248 a95241bf-73f2-0310-859d-f6bbb57e9c96


# cd463b4d 12-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_beos(): Forgot to return the image in the code
introduced in r40211.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40228 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ca7aa99f 11-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added SymbolLookupInfo::requestingSymbol which is passed in by
resolve_symbol().
* find_undefined_symbol_beos(): Does now check whether
SymbolLookupInfo::requestingSymbol is defined, and, if so, returns it
directly. This saves the time for the hash table lookup and also works
around broken files like SoundPlay. Fixes the runtime loader part of #7094.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40211 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 78f7f874 24-Nov-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_beos(): Look up the symbol in the requesting image
first. Fixes binary compatibility issue introduced with symbol preemption
support in the runtime loader. For unknown reasons liblayout.so, though
linked symbolically, contains a non-weak (!), preemptable BFont type info,
which was no longer resolved correctly with the new method.
Fixes #6892.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39617 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 25dc253d 22-Nov-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Merged weak-symbols branch.
* Fixed trivial merge conflict in src/system/libroot/posix/locale/nl_langinfo.cpp
* Fixed gcc 2 compilation of src/system/glue/init_term_dyn.c.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39571 a95241bf-73f2-0310-859d-f6bbb57e9c96


# be1f4fe8 08-Jul-2009 Oliver Tappe <zooey@hirschkaefer.de>

* find_symbol_breadth_first() didn't ever set _foundInImage, although
it's signature indicates that it should - the callers just never use
the value currently, so it caused no harm
* squashed a TODO in the runtime_loader about the resolving strategy
for undefined symbols in add-ons: I've implemented the breadth-first
strategy (leaving out the add-on itself), as that one made most sense to
me.
This avoids loader problems with older optional packages of Pe on gcc4, as some
add-ons (e.g. "Expand Tabs") could not be loaded due to them containing undefined
symbols that are found in second level dependencies (libstdc++.so in this case).

Ingo: please review.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31465 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c533f813 27-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

Normalized the FATAL messages. The image path is always printed, now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30878 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f15e418b 22-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

Removed remapping of the *stat() symbols for BeOS executables. We'll use
symbol versioning instead.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30829 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 94830eb2 20-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved most code of the heavy elf.cpp into several smaller source files.
* Some style cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30808 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0e45e3eb1d8a2c29e1163878bfcf29b81a6eb791 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: keep symbol DSO in SymbolLookupCache

While resolving TLS related relocations it is necessary to know the DSO
that defines the symbol. Without proper support in caching that information
is available only when the symbol is resolved first time. That works well
for TLS since TLS_DTPMOD is guaranteed to be before TLS_DTPOFF relocation.
This patch makes the newly introduced parts of the interface work in a
general case.


# df58e6a9f4fb84266cc2f78f611243171b407315 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: support linking TLS symbols from any DSO

Previously TLS_DTPMOD relocation blindly returned ID of the current DSO.
This patch does proper symbol lookup if there is a symbol assigned to the
relocation and uses ID of the DSO in which the symbol is defined.


# 44c0c4d3d0d68c3c3db23858b1089d3cf51bdf16 03-May-2014 Pawel Dziepak <pdziepak@quarnos.org>

runtime_loader: add support for ELF based TLS

This patch introduces support of ELF based TLS handling with lazy allocation
and initalization of TLS block for each DSO and thread. The implementation
generally follows the official ABI except that generation counter in dtv
is in fact a pointer to Generation object that contains both generation
counter and size of the dtv. That simplified the implementation a bit, but
could be changed later. The ABI requirements regariding in memory position
of TLS block is not honoured what results in static TLS model being
unsupported. However, that should not be a problem as long as
"executables" in Haiku are in fact shared objects and optimizations which
require specific TLS block in memory layout are not possible anyway.


# e3ac2588e64059e0c140504e9acc8e73b3c36fdc 25-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Changed runtime_loader to use elf_* typedefs over Elf32_*.

This means that it will be using ELF64 types on x86_64 rather than
ELF32. The next step for supporting x86_64 is to implement relocations.


# b7786ebd30816e9065e45cf19ce2d2a57f4b38a1 19-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_add_on(): Resolve non-weak symbols defined in the add-on
to themselves. This works around the problem that those symbols could be
resolved to symbols in the application, which is usually undesired. Weak
symbols have the same problem, but the the runtime loader cannot decide which
should be resolved locally and which mustn't.

The root issue is that BeOS style add-ons simply cannot be supported by a
standard-complying ELF loader.

Affects gcc 4 only, since with gcc 2 we link everything symbolically. The best
solution for the time being would be to build gcc 4 add-ons with default
hidden visibility, exporting only the symbols that should be visible.

Related ticket: #7114


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40248 a95241bf-73f2-0310-859d-f6bbb57e9c96


# cd463b4dd2e8b7b76d81adce694bd7aa106e056f 12-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_beos(): Forgot to return the image in the code
introduced in r40211.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40228 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ca7aa99f983390f2997f478c86819a4dc69487be 11-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added SymbolLookupInfo::requestingSymbol which is passed in by
resolve_symbol().
* find_undefined_symbol_beos(): Does now check whether
SymbolLookupInfo::requestingSymbol is defined, and, if so, returns it
directly. This saves the time for the hash table lookup and also works
around broken files like SoundPlay. Fixes the runtime loader part of #7094.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40211 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 78f7f8745e63c7a8c9e8513dd86a116c9e3834b8 24-Nov-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

find_undefined_symbol_beos(): Look up the symbol in the requesting image
first. Fixes binary compatibility issue introduced with symbol preemption
support in the runtime loader. For unknown reasons liblayout.so, though
linked symbolically, contains a non-weak (!), preemptable BFont type info,
which was no longer resolved correctly with the new method.
Fixes #6892.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39617 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 25dc253d6ab28ce204fa4de2d3e7a27d167fc817 22-Nov-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Merged weak-symbols branch.
* Fixed trivial merge conflict in src/system/libroot/posix/locale/nl_langinfo.cpp
* Fixed gcc 2 compilation of src/system/glue/init_term_dyn.c.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39571 a95241bf-73f2-0310-859d-f6bbb57e9c96


# be1f4fe8000a0e6d3e3f9c30920eef3a79f2234f 08-Jul-2009 Oliver Tappe <zooey@hirschkaefer.de>

* find_symbol_breadth_first() didn't ever set _foundInImage, although
it's signature indicates that it should - the callers just never use
the value currently, so it caused no harm
* squashed a TODO in the runtime_loader about the resolving strategy
for undefined symbols in add-ons: I've implemented the breadth-first
strategy (leaving out the add-on itself), as that one made most sense to
me.
This avoids loader problems with older optional packages of Pe on gcc4, as some
add-ons (e.g. "Expand Tabs") could not be loaded due to them containing undefined
symbols that are found in second level dependencies (libstdc++.so in this case).

Ingo: please review.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31465 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c533f813a2c1392f51f8a0f803ab41775817d530 27-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

Normalized the FATAL messages. The image path is always printed, now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30878 a95241bf-73f2-0310-859d-f6bbb57e9c96


# f15e418bab33ae70e462cc66cf9e768a0e9523b9 22-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

Removed remapping of the *stat() symbols for BeOS executables. We'll use
symbol versioning instead.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30829 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 94830eb226ce51bd1fd0143bad2538f788883e85 20-May-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved most code of the heavy elf.cpp into several smaller source files.
* Some style cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30808 a95241bf-73f2-0310-859d-f6bbb57e9c96