forked from Imagelibrary/binutils-gdb
b41c5a85a7
Recently a feature called "return address signing" has been added to GCC to prevent stack smash stack on AArch64. For details please refer: https://gcc.gnu.org/ml/gcc-patches/2017-01/msg00376.html GDB needs to be aware of this feature so it can restore the original return address which is critical for unwinding. On compiler side, whenever return address, i.e. LR register, is mangled or restored by hardware instruction, compiler is expected to generate a DW_CFA_AARCH64_negate_ra_state to toggle return address signing status. DW_CFA_AARCH64_negate_ra_state is using the same CFI number and therefore need to be multiplexed with DW_CFA_GNU_window_save which was designed for SPARC. A new gdbarch method "execute_dwarf_cfa_vendor_op" is introduced by this patch. It's parameters has been restricted to those only needed by SPARC and AArch64 for multiplexing DW_CFA_GNU_window_save which is a CFI operation takes none operand. Should any further DWARF CFI operation want to be multiplexed in the future, the parameter list can be extended. Below is the current function prototype. typedef int (gdbarch_execute_dwarf_cfa_vendor_op_ftype) (struct gdbarch *gdbarch, gdb_byte op, struct dwarf2_frame_state *fs); DW_CFA_GNU_window_save support for SPARC is migrated to this new gdbarch method by this patch. gdb/ * gdbarch.sh: New gdbarch method execute_dwarf_cfa_vendor_op. * gdbarch.c: Regenerated. * gdbarch.h: Regenerated. * dwarf2-frame.c (dwarf2_frame_state_alloc_regs): Made the visibility external. (execute_cfa_program): Call execute_dwarf_cfa_vendor_op for CFI between DW_CFA_lo_user and DW_CFA_high_user inclusive. (enum cfa_how_kind): Move to ... (struct dwarf2_frame_state_reg_info): Likewise. (struct dwarf2_frame_state): Likewise. * dwarf2-frame.h: ... here. (dwarf2_frame_state_alloc_regs): New declaration. * sparc-tdep.c (sparc_execute_dwarf_cfa_vendor_op): New function. (sparc32_gdbarch_init): Register execute_dwarf_cfa_vendor_op hook.
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.