forked from Imagelibrary/binutils-gdb
4e97c9dcfc
For synthesizing CFI (SCFI) for hand-written asm, the SCFI machinery in
GAS works on the generic GAS insns (ginsns). This patch adds support in
the aarch64 backend to create ginsns for the following set of machine
instructions, which are necessary to process to ensure SCFI correctness:
- Any potential register saves and unsaves. This implies the need to
process many iclasses involving str, ldr, stp, ldp.
- Any change of flow instructions, including all conditional and
unconditional branches, call (bl, blr) and return.
- Any instruction that could affect the two registers of
interest: REG_SP, REG_FP. This set includes all pre-indexed and
post-indexed memory operations, with writeback, on the stack.
SCFI is enabled for ELF targets only.
Apart from creating ginsn, we also add functionality in the backend to
detect dynamically if an instruction of interest may have been skipped.
Such a check is added with an intent to also capture changes in the ISA
which may otherwise render incorrect SCFI results.
The current SCFI machinery does not currently synthesize the PAC-related
aarch64-specific CFI directives: .cfi_b_key_frame. The support for this
is planned for near future.
gas/
* config/tc-aarch64.c (GINSN_DW2_REGNUM_R1_DUMMY):
(aarch64_scfi_callee_saved_p):
(ginsn_dw2_regnum):
(aarch64_ginsn_addsub):
(aarch64_ginsn_ldstp):
(aarch64_ginsn_ldstr):
(aarch64_ginsn_jump):
(aarch64_ginsn_jump_cond):
(aarch64_ginsn_mov):
(aarch64_ginsn_safe_to_skip_p):
(AARCH64_GINSN_UNHANDLED_NONE):
(AARCH64_GINSN_UNHANDLED_DEST_REG):
(AARCH64_GINSN_UNHANDLED_CFG):
(AARCH64_GINSN_UNHANDLED_STACKOP):
(AARCH64_GINSN_UNHANDLED_UNEXPECTED):
(aarch64_ginsn_unhandled):
(aarch64_ginsn_new):
(md_assemble):
* config/tc-aarch64.h (TARGET_USE_GINSN):
(TARGET_USE_SCFI):
(SCFI_MAX_REG_ID):
(REG_FP):
(REG_LR):
(REG_SP):
(SCFI_INIT_CFA_OFFSET):
(SCFI_CALLEE_SAVED_REG_P):
(aarch64_scfi_callee_saved_p):
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.