mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-11-30 21:44:19 +08:00
d3a8dfdef0
Input sections are grouped together that can use the same stub area (within reach) and these groups have a stable id. Stubs have a name generated from the stub group id and target symbol. When a relocation requires a stub with a name that already exists, the stub is reused instead of adding a new one. For an indirect branch stub another BTI stub may be inserted near the target to provide a BTI landing pad. The BTI stub can end up with the same stub group id and thus the same name as the indirect stub. This happens if the target symbol is within reach of the indirect branch stub. Then, due to the name collision, only a single stub was emmitted which branched to itself causing an infinite loop at runtime. A possible solution is to just name the BTI stubs differently, but since in the problematic case the indirect and BTI stub are in the same stub area, a better solution is to emit a single stub with a direct branch. The stub is still needed since the caller cannot reach the target directly and we also want a BTI landing pad in the stub in case other indirect stubs target the same symbol and thus need a BTI stub. In short we convert an indirect branch stub into a BTI stub when the target is within reach and has no BTI. It is a hassle to change the symbol of the stub so a BTI stub may end up with *_veneer instead of *_bti_veneer after the conversion, but this should not matter much. (Refactoring some of _bfd_aarch64_add_call_stub_entries would be useful but too much for this bug fix patch.) The same conversion to direct branch could be done even if the target did not need a BTI. The stub groups are fixed in the current logic so linking can fail if too many stubs are inserted and the section layout is changed too much, but this only happens in extreme cases that can be reasonably ignored. Because of this the target cannot go out of reach during stub insertion so the optimization is valid, but not implemented by this patch for the non-BTI case. Fixes bug 30930. |
||
---|---|---|
bfd | ||
binutils | ||
config | ||
contrib | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gdbserver | ||
gdbsupport | ||
gnulib | ||
gold | ||
gprof | ||
gprofng | ||
include | ||
intl | ||
ld | ||
libbacktrace | ||
libctf | ||
libdecnumber | ||
libiberty | ||
libsframe | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
.cvsignore | ||
.editorconfig | ||
.gitattributes | ||
.gitignore | ||
ar-lib | ||
ChangeLog | ||
compile | ||
config-ml.in | ||
config.guess | ||
config.rpath | ||
config.sub | ||
configure | ||
configure.ac | ||
COPYING | ||
COPYING3 | ||
COPYING3.LIB | ||
COPYING.LIB | ||
COPYING.LIBGLOSS | ||
COPYING.NEWLIB | ||
depcomp | ||
djunpack.bat | ||
install-sh | ||
libtool.m4 | ||
lt~obsolete.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
MAINTAINERS | ||
Makefile.def | ||
Makefile.in | ||
Makefile.tpl | ||
makefile.vms | ||
missing | ||
mkdep | ||
mkinstalldirs | ||
move-if-change | ||
multilib.am | ||
README | ||
README-maintainer-mode | ||
SECURITY.txt | ||
setup.com | ||
src-release.sh | ||
symlink-tree | ||
test-driver | ||
ylwrap |
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.