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It is possible to construct indirect calls to __tls_get_addr in assembly that confuse TLS optimization. (PowerPC gcc doesn't support such calls, ignoring -mlongcall for __tls_get_addr.) This patch fixes the problem by requiring a TLSLD or TLSGD marker reloc before any insn in an indirect call to __tls_get_addr will be optimized. They also need additional marker relocs defined in a later patch, so don't expect the optimization to work just yet. The point here is to prevent mis-optimization of indirect calls without any marker relocs. The presense of a marker reloc is tracked by a new bit in the tls_mask field of ppc_link_hash_entry and the corresponding lgot_masks unsigned char array for local symbols. Since the field is only 8 bits, we've run out of space. However, tracking TLS use for variables, and tracking IFUNC for functions are independent, and bits can be reused. TLS_TLS is always set for TLS usage, so can be used to select the meaning of the other bits. This patch does that even for elf32-ppc.c which hasn't yet run out of space in the field. * elf64-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL, TLS_TPRELGD, TLS_EXPLICIT): Renumber. Test TLS_TLS throughout file when other TLS flags are tested in a mask. (TLS_MARK, NON_GOT): Define. (PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well. (update_local_sym_info): Don't create got entry when NON_GOT. (ppc64_elf_check_relocs): Pass NON_GOT with PLT_IFUNC. Set TLS_MARK. (get_tls_mask): Do toc lookup if tls_mask is just TLS_MARK. (ppc64_elf_relocate_section): Likewise. (ppc64_elf_tls_optimize): Don't attempt to optimize indirect __tls_get_addr calls lacking a marker reloc. * elf32-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL, TLS_TPRELGD): Renumber. Update comment. (TLS_MARK, NON_GOT): Define. (PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well. (update_local_sym_info): Don't create got entry when NON_GOT. (ppc_elf_check_relocs): Pass NON_GOT with PLT_IFUNC. Set TLS_MARK. (ppc_elf_tls_optimize): Don't attempt to optimize indirect __tls_get_addr calls lacking a marker reloc.
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.