d10f3e900b
This new feature causes the compiler to zero a subset of all call-used registers at function return. This is used to increase program security by either mitigating Return-Oriented Programming (ROP) attacks or preventing information leakage through registers. gcc/ChangeLog: 2020-10-30 Qing Zhao <qing.zhao@oracle.com> H.J.Lu <hjl.tools@gmail.com> * common.opt: Add new option -fzero-call-used-regs * config/i386/i386.c (zero_call_used_regno_p): New function. (zero_call_used_regno_mode): Likewise. (zero_all_vector_registers): Likewise. (zero_all_st_registers): Likewise. (zero_all_mm_registers): Likewise. (ix86_zero_call_used_regs): Likewise. (TARGET_ZERO_CALL_USED_REGS): Define. * df-scan.c (df_epilogue_uses_p): New function. (df_get_exit_block_use_set): Replace EPILOGUE_USES with df_epilogue_uses_p. * df.h (df_epilogue_uses_p): Declare. * doc/extend.texi: Document the new zero_call_used_regs attribute. * doc/invoke.texi: Document the new -fzero-call-used-regs option. * doc/tm.texi: Regenerate. * doc/tm.texi.in (TARGET_ZERO_CALL_USED_REGS): New hook. * emit-rtl.h (struct rtl_data): New field must_be_zero_on_return. * flag-types.h (namespace zero_regs_flags): New namespace. * function.c (gen_call_used_regs_seq): New function. (class pass_zero_call_used_regs): New class. (pass_zero_call_used_regs::execute): New function. (make_pass_zero_call_used_regs): New function. * optabs.c (expand_asm_reg_clobber_mem_blockage): New function. * optabs.h (expand_asm_reg_clobber_mem_blockage): Declare. * opts.c (zero_call_used_regs_opts): New structure array initialization. (parse_zero_call_used_regs_options): New function. (common_handle_option): Handle -fzero-call-used-regs. * opts.h (zero_call_used_regs_opts): New structure array. * passes.def: Add new pass pass_zero_call_used_regs. * recog.c (valid_insn_p): New function. * recog.h (valid_insn_p): Declare. * resource.c (init_resource_info): Replace EPILOGUE_USES with df_epilogue_uses_p. * target.def (zero_call_used_regs): New hook. * targhooks.c (default_zero_call_used_regs): New function. * targhooks.h (default_zero_call_used_regs): Declare. * tree-pass.h (make_pass_zero_call_used_regs): Declare. gcc/c-family/ChangeLog: 2020-10-30 Qing Zhao <qing.zhao@oracle.com> H.J.Lu <hjl.tools@gmail.com> * c-attribs.c (c_common_attribute_table): Add new attribute zero_call_used_regs. (handle_zero_call_used_regs_attribute): New function. gcc/testsuite/ChangeLog: 2020-10-30 Qing Zhao <qing.zhao@oracle.com> H.J.Lu <hjl.tools@gmail.com> * c-c++-common/zero-scratch-regs-1.c: New test. * c-c++-common/zero-scratch-regs-10.c: New test. * c-c++-common/zero-scratch-regs-11.c: New test. * c-c++-common/zero-scratch-regs-2.c: New test. * c-c++-common/zero-scratch-regs-3.c: New test. * c-c++-common/zero-scratch-regs-4.c: New test. * c-c++-common/zero-scratch-regs-5.c: New test. * c-c++-common/zero-scratch-regs-6.c: New test. * c-c++-common/zero-scratch-regs-7.c: New test. * c-c++-common/zero-scratch-regs-8.c: New test. * c-c++-common/zero-scratch-regs-9.c: New test. * c-c++-common/zero-scratch-regs-attr-usages.c: New test. * gcc.target/i386/zero-scratch-regs-1.c: New test. * gcc.target/i386/zero-scratch-regs-10.c: New test. * gcc.target/i386/zero-scratch-regs-11.c: New test. * gcc.target/i386/zero-scratch-regs-12.c: New test. * gcc.target/i386/zero-scratch-regs-13.c: New test. * gcc.target/i386/zero-scratch-regs-14.c: New test. * gcc.target/i386/zero-scratch-regs-15.c: New test. * gcc.target/i386/zero-scratch-regs-16.c: New test. * gcc.target/i386/zero-scratch-regs-17.c: New test. * gcc.target/i386/zero-scratch-regs-18.c: New test. * gcc.target/i386/zero-scratch-regs-19.c: New test. * gcc.target/i386/zero-scratch-regs-2.c: New test. * gcc.target/i386/zero-scratch-regs-20.c: New test. * gcc.target/i386/zero-scratch-regs-21.c: New test. * gcc.target/i386/zero-scratch-regs-22.c: New test. * gcc.target/i386/zero-scratch-regs-23.c: New test. * gcc.target/i386/zero-scratch-regs-24.c: New test. * gcc.target/i386/zero-scratch-regs-25.c: New test. * gcc.target/i386/zero-scratch-regs-26.c: New test. * gcc.target/i386/zero-scratch-regs-27.c: New test. * gcc.target/i386/zero-scratch-regs-28.c: New test. * gcc.target/i386/zero-scratch-regs-29.c: New test. * gcc.target/i386/zero-scratch-regs-30.c: New test. * gcc.target/i386/zero-scratch-regs-31.c: New test. * gcc.target/i386/zero-scratch-regs-3.c: New test. * gcc.target/i386/zero-scratch-regs-4.c: New test. * gcc.target/i386/zero-scratch-regs-5.c: New test. * gcc.target/i386/zero-scratch-regs-6.c: New test. * gcc.target/i386/zero-scratch-regs-7.c: New test. * gcc.target/i386/zero-scratch-regs-8.c: New test. * gcc.target/i386/zero-scratch-regs-9.c: New test. |
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| config | ||
| contrib | ||
| fixincludes | ||
| gcc | ||
| gnattools | ||
| gotools | ||
| include | ||
| INSTALL | ||
| intl | ||
| libada | ||
| libatomic | ||
| libbacktrace | ||
| libcc1 | ||
| libcpp | ||
| libdecnumber | ||
| libffi | ||
| libgcc | ||
| libgfortran | ||
| libgo | ||
| libgomp | ||
| libhsail-rt | ||
| libiberty | ||
| libitm | ||
| libobjc | ||
| liboffloadmic | ||
| libphobos | ||
| libquadmath | ||
| libsanitizer | ||
| libssp | ||
| libstdc++-v3 | ||
| libvtv | ||
| lto-plugin | ||
| maintainer-scripts | ||
| zlib | ||
| .dir-locals.el | ||
| .gitattributes | ||
| .gitignore | ||
| ABOUT-NLS | ||
| ar-lib | ||
| ChangeLog | ||
| ChangeLog.jit | ||
| ChangeLog.tree-ssa | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.RUNTIME | ||
| depcomp | ||
| install-sh | ||
| libtool-ldflags | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| multilib.am | ||
| README | ||
| symlink-tree | ||
| test-driver | ||
| ylwrap | ||
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.