Subzero: Add Non-SFI support for x86-32.

pydir/szbuild.py

 #!/usr/bin/env python2
 
 import argparse
 import os
 import pipes
 import re
 import sys
 
 from utils import shellcmd
 from utils import FindBaseNaCl
@@ skipping 67 matching lines @@
     argparser.add_argument('-O', default='2', dest='optlevel',
                            choices=['m1', '-1', '0', '1', '2'],
                            help='Optimization level ' +
                                 '(m1 and -1 are equivalent).' +
                                 ' Default %(default)s.')
     argparser.add_argument('--filetype', default='iasm', dest='filetype',
                            choices=['obj', 'asm', 'iasm'],
                            help='Output file type.  Default %(default)s.')
     argparser.add_argument('--sandbox', dest='sandbox', action='store_true',
                            help='Enable sandboxing in the translator')
+    argparser.add_argument('--nonsfi', dest='nonsfi', action='store_true',
+                           help='Enable Non-SFI in the translator')
     argparser.add_argument('--enable-block-profile',
                            dest='enable_block_profile', action='store_true',
                            help='Enable basic block profiling.')
     argparser.add_argument('--target', default='x8632', dest='target',
                            choices=['arm32', 'x8632'],
                            help='Generate code for specified target.')
     argparser.add_argument('--verbose', '-v', dest='verbose',
                            action='store_true',
                            help='Display some extra debugging output')
     argparser.add_argument('--sz', dest='sz_args', action='append', default=[],
@@ skipping 78 matching lines @@
     whitelist_sz_unescaped = pexe_base_unescaped + '.wl.sz.txt'
     pnacl_sz = (
         '{root}/toolchain_build/src/subzero/pnacl-sz'
         ).format(root=nacl_root)
     llcbin = '{base}/pnacl-llc'.format(base=path_addition)
     gold = '{base}/le32-nacl-ld.gold'.format(base=path_addition)
     objcopy = '{base}/le32-nacl-objcopy'.format(base=path_addition)
     opt_level = args.optlevel
     opt_level_map = { 'm1':'0', '-1':'0', '0':'0', '1':'1', '2':'2' }
     hybrid = args.include or args.exclude
+    sb_or_nonsfi = args.sandbox or args.nonsfi
 
     if hybrid and (args.force or
                    NewerThanOrNotThere(pexe, obj_llc) or
                    NewerThanOrNotThere(llcbin, obj_llc)):
         arch = {
           'arm32': 'armv7' if args.sandbox else 'arm-nonsfi',
-          'x8632': 'x86-32' if args.sandbox else 'x86-32-linux',
+          'x8632': 'x86-32' if args.sandbox else

[John, 2015/12/22 15:44:38]

this makes me sad. can something be done about this?

[Jim Stichnoth, 2015/12/28 07:54:07]

What is your specific suggestion?  (just to avoid multiple round trips)

Are you thinking that these "target triples" should be tabularized?  to avoid
all the conditionals sprinkled around the various scripts?

+                   'x86-32-nonsfi' if args.nonsfi else 'x86-32-linux',
         }[args.target]
 
         # Only run pnacl-translate in hybrid mode.
         shellcmd(['{base}/pnacl-translate'.format(base=path_addition),
                   '-split-module=1',
                   '-ffunction-sections',
                   '-fdata-sections',
                   '-c',
                   '-arch',  arch,
                   '-O' + opt_level_map[opt_level],
                   '--pnacl-driver-append-LLC_FLAGS_EXTRA=-externalize',
                   '-o', obj_llc] +
                  (['--pnacl-driver-verbose'] if args.verbose else []) +
                  args.llc_args +
                  [pexe],
                  echo=args.verbose)
-        if not args.sandbox:
+        if not sb_or_nonsfi:
             shellcmd((
                 '{objcopy} --redefine-sym _start=_user_start {obj}'
                 ).format(objcopy=objcopy, obj=obj_llc), echo=args.verbose)
         # Generate llc syms file for consistency, even though it's not used.
         shellcmd((
             'nm {obj} | sed -n "s/.* [a-zA-Z] //p" > {sym}'
             ).format(obj=obj_llc, sym=sym_llc), echo=args.verbose)
 
     if (args.force or
         NewerThanOrNotThere(pexe, obj_sz) or
         NewerThanOrNotThere(pnacl_sz, obj_sz)):
         if not args.nosz:
             # Run pnacl-sz regardless of hybrid mode.
             shellcmd([pnacl_sz,
                       '-O' + opt_level,
                       '-bitcode-format=pnacl',
                       '-filetype=' + args.filetype,
                       '-o', obj_sz if args.filetype == 'obj' else asm_sz,
                       '-target=' + args.target] +
                      (['-externalize',
                        '-ffunction-sections',
                        '-fdata-sections'] if hybrid else []) +
                      (['-sandbox'] if args.sandbox else []) +
+                     (['-nonsfi'] if args.nonsfi else []) +
                      (['-enable-block-profile'] if
                           args.enable_block_profile and not args.sandbox
                           else []) +
                      args.sz_args +
                      [pexe],
                      echo=args.verbose)
         if args.filetype != 'obj':
             triple = {
               'arm32': 'arm-nacl' if args.sandbox else 'arm',
               'x8632': 'i686-nacl' if args.sandbox else 'i686',
             }[args.target]
 
             shellcmd((
                 '{base}/llvm-mc -triple={triple} -filetype=obj -o {obj} {asm}'
                 ).format(base=path_addition, asm=asm_sz, obj=obj_sz,
                          triple=triple),
                      echo=args.verbose)
-        if not args.sandbox:
+        if not sb_or_nonsfi:
             shellcmd((
                 '{objcopy} --redefine-sym _start=_user_start {obj}'
                 ).format(objcopy=objcopy, obj=obj_sz), echo=args.verbose)
         if hybrid:
             shellcmd((
                 'nm {obj} | sed -n "s/.* [a-zA-Z] //p" > {sym}'
                 ).format(obj=obj_sz, sym=sym_sz), echo=args.verbose)
 
     if hybrid:
         with open(sym_sz_unescaped) as f:
@@ skipping 45 matching lines @@
                      sz=obj_sz_weak, llc=obj_llc_weak),
                  echo=args.verbose)
         shellcmd((
             '{objcopy} -w --localize-symbol="*" {partial}'
             ).format(objcopy=objcopy, partial=obj_partial),
             echo=args.verbose)
         shellcmd((
             '{objcopy} --globalize-symbol={start} ' +
             '--globalize-symbol=__Sz_block_profile_info {partial}'
             ).format(objcopy=objcopy, partial=obj_partial,
-                     start='_start' if args.sandbox else '_user_start'),
+                     start='_start' if sb_or_nonsfi else '_user_start'),
                  echo=args.verbose)
 
     # Run the linker regardless of hybrid mode.
     if args.sandbox:
         assert args.target in ('x8632', 'arm32'), \
             '-sandbox is not available for %s' % args.target
         target_lib_dir = {
           'arm32': 'arm',
           'x8632': 'x86-32',
         }[args.target]
         linklib = ('{root}/toolchain/linux_x86/pnacl_newlib_raw/translator/' +
                    '{target_dir}/lib').format(root=nacl_root,
                                               target_dir=target_lib_dir)
         shellcmd((
             '{gold} -nostdlib --no-fix-cortex-a8 --eh-frame-hdr -z text ' +
             '--build-id --entry=__pnacl_start -static ' +
             '{linklib}/crtbegin.o {partial} ' +
             '{root}/toolchain_build/src/subzero/build/runtime/' +
             'szrt_sb_{target}.o ' +
             '{linklib}/libpnacl_irt_shim_dummy.a --start-group ' +
             '{linklib}/libgcc.a {linklib}/libcrt_platform.a ' +
             '--end-group {linklib}/crtend.o --undefined=_start ' +
             '--defsym=__Sz_AbsoluteZero=0 ' +
             '-o {exe}'
             ).format(gold=gold, linklib=linklib, partial=obj_partial, exe=exe,
                      root=nacl_root, target=args.target),
                  echo=args.verbose)
+    elif args.nonsfi:
+        # TODO(stichnot): args.nonsfi and args.sandbox branches are nearly
+        # identical; refactor.
+        target_lib_dir = {
+          'arm32': 'arm-nonsfi',
+          'x8632': 'x86-32-nonsfi',
+        }[args.target]
+        linklib = ('{root}/toolchain/linux_x86/pnacl_newlib_raw/translator/' +
+                   '{target_dir}/lib').format(root=nacl_root,
+                                              target_dir=target_lib_dir)
+        shellcmd((
+            '{gold} -nostdlib --no-fix-cortex-a8 --eh-frame-hdr -z text ' +
+            '-z noexecstack ' +
+            '--build-id --entry=__pnacl_start -pie ' +
+            '{linklib}/crtbegin.o {partial} ' +
+            '{root}/toolchain_build/src/subzero/build/runtime/' +
+            'szrt_nonsfi_{target}.o ' +
+            '{linklib}/libpnacl_irt_shim_dummy.a --start-group ' +
+            '{linklib}/libgcc.a {linklib}/libcrt_platform.a ' +
+            '--end-group {linklib}/crtend.o --undefined=_start ' +
+            '--defsym=__Sz_AbsoluteZero=0 ' +
+            '--defsym=_begin=0 ' +
+            '-o {exe}'
+            ).format(gold=gold, linklib=linklib, partial=obj_partial, exe=exe,
+                     root=nacl_root, target=args.target),
+                 echo=args.verbose)
     else:
         linker = {
           'arm32': '/usr/bin/arm-linux-gnueabihf-g++',
           'x8632': ('{root}/../third_party/llvm-build/Release+Asserts/bin/clang'
                    ).format(root=nacl_root)
         }[args.target]
 
         extra_linker_args = ' '.join({
           'arm32': ['-mcpu=cortex-a9'],
           'x8632': ['-m32']
@@ skipping 21 matching lines @@
 
     # Put the extra verbose printing at the end.
     if args.verbose and hybrid:
         print 'include={regex}'.format(regex=re_include_str)
         print 'exclude={regex}'.format(regex=re_exclude_str)
         print 'default_match={dm}'.format(dm=default_match)
         print 'Number of Subzero syms = {num}'.format(num=len(sz_syms))
 
 if __name__ == '__main__':
     main()