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The TOC pointer register, r2, on powerpc64 is generally not mentioned in debug info. It is saved and restored by call linkage code, and set to the callee value either by call stub code (ELFv1) or in the callee global entry point code (ELFv2). A call stub uses the caller TOC pointer to access the PLT. So for gdb to read the correct PLT entry in order to determine the destination of the trampoline, gdb needs to know the caller r2. When skipping over trampolines in the normal forward direction, the caller r2 is simply the current value of r2 (at the start of the trampoline). However, when reversing over trampolines the current value of r2 is that for the callee. Using that value results in wild reads of memory rather than the correct PLT entry. This patch corrects the value of r2 by using the value saved on the stack for reverse execution. Note that in reverse execution mode it isn't really necessary for skip_trampoline_code to return the actual destination, so we're doing a little more work than needed here. Any non-zero return value would do (and it would be nicer if the interface was changed to return the start of the stub). PR tdep/22576 * ppc64-tdep.c (ppc64_plt_entry_point): Rewrite to take TOC-relative PLT offset, and retrieve r2 from stack when executing in reverse. (ppc64_standard_linkage1_target): Drop pc param. Calculate offset rather than PLT address. (ppc64_standard_linkage2_target): Likewise. (ppc64_standard_linkage3_target): Likewise. (ppc64_standard_linkage4_target): Likewise. (ppc64_skip_trampoline_code_1): Adjust to suit. |
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bfd | ||
binutils | ||
config | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gold | ||
gprof | ||
include | ||
intl | ||
ld | ||
libdecnumber | ||
libiberty | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
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.gitattributes | ||
.gitignore | ||
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 | ||
README | ||
README-maintainer-mode | ||
setup.com | ||
src-release.sh | ||
symlink-tree | ||
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.