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Code Issues Releases Wiki Activity

trim Mach_command from stub. [Dirty, needs cleanup!]

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changed src/p_mach.cpp
This commit is contained in:
jreiser@BitWagon.com 2016-09-13 20:20:41 -07:00 committed by Markus F.X.J. Oberhumer
parent af2fddfd6d
commit 73d1b331f1
1 changed files with 45 additions and 1 deletions
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46
src/p_mach.cpp
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@ -765,6 +765,7 @@ void PackMachAMD64::pack4(OutputFile *fo, Filter &ft) // append PackHeader
super::pack4(fo, ft);
unsigned const t = fo->getBytesWritten();
segTEXT.vmaddr = segZERO.vmaddr + segZERO.vmsize;
segTEXT.filesize = t;
segTEXT.vmsize += t; // utilize GAP + NO_LAP + sz_unc - sz_cpr
secTEXT.offset = overlay_offset - sizeof(linfo);
@ -800,14 +801,16 @@ void PackMachAMD64::pack4(OutputFile *fo, Filter &ft) // append PackHeader
unsigned cmdsize = mhdro.sizeofcmds - sizeof(segXHDR);
Mach_header const *const ptr0 = (Mach_header const *)stub_amd64_darwin_macho_upxmain_exe;
Mach_command const *ptr1 = (Mach_command const *)(1+ ptr0);
unsigned const ncmds = mhdro.ncmds;
unsigned delta = 0;
for (unsigned j = 0; j < mhdro.ncmds -1; ++j,
for (unsigned j = 0; j < ncmds -1; ++j,
(cmdsize -= ptr1->cmdsize),
ptr1 = (Mach_command const *)(ptr1->cmdsize + (char const *)ptr1))
switch (ptr1->cmd) {
case Mach_segment_command::LC_SEGMENT_64: {
Mach_segment_command const *const segptr = (Mach_segment_command const *)ptr1;
if (!strcmp("__TEXT", segptr->segname)) {
memcpy(&segTEXT, segptr, sizeof(segTEXT));
Mach_section_command const *const secptr = (Mach_section_command const *)(1+ segptr);
memcpy(&secTEXT, secptr, sizeof(secTEXT));
secTEXT.align = 0;
@ -849,6 +852,8 @@ void PackMachAMD64::pack4(OutputFile *fo, Filter &ft) // append PackHeader
if (blk.bind_off) blk.bind_off += delta;
if (blk.lazy_bind_off) blk.lazy_bind_off += delta;
if (blk.export_off) blk.export_off += delta;
blk.export_off = 0;
blk.export_size = 0;
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&blk, sizeof(blk));
} break;
@ -867,6 +872,12 @@ void PackMachAMD64::pack4(OutputFile *fo, Filter &ft) // append PackHeader
if (blk.indirectsymoff) blk.indirectsymoff += delta;
if (blk.extreloff) blk.extreloff += delta;
if (blk.locreloff) blk.locreloff += delta;
blk.ilocalsym = 0;
blk.nlocalsym = 0;
blk.iextdefsym = 0;
blk.nextdefsym = 0;
blk.iundefsym = 0;
blk.nundefsym = 0;
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&blk, sizeof(blk));
} break;
@ -876,11 +887,44 @@ void PackMachAMD64::pack4(OutputFile *fo, Filter &ft) // append PackHeader
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&blk, sizeof(blk));
} break;
case Mach_segment_command::LC_MAIN: {
// TEMPORARY: change to LC_UNIX_THREAD; known to be continusous with last
// LC_MAIN requires libSystem.B.dylib to provide the environment for main(), and CALLs the entryoff.
// LC_UNIXTHREAD does not need libSystem.B.dylib, and JMPs to the .rip with %rsp/argc and argv= 8+%rsp
threado.cmd = Mach_segment_command::LC_UNIXTHREAD;
threado.cmdsize = sizeof(threado);
threado.flavor = my_thread_flavor;
threado.count = my_thread_state_word_count;
memset(&threado.state, 0, sizeof(threado.state));
threado.state.rip = ((N_Mach::Mach_main_command const *)ptr1)->entryoff + segTEXT.vmaddr;
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&threado, sizeof(threado));
mhdro.sizeofcmds += sizeof(threado) - ((Mach_command const *)ptr1)->cmdsize;
fo->seek(0, SEEK_SET);
fo->rewrite(&mhdro, sizeof(mhdro));
} break;
case Mach_segment_command::LC_LOAD_DYLIB: {
// Temporary test: remove this command; known to be contiguous with last
N_Mach::Mach_load_dylib_command blk;
memset(&blk, 0, sizeof(blk));
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&blk, sizeof(blk));
mhdro.ncmds -= 1;
mhdro.sizeofcmds -= ((Mach_command const *)ptr1)->cmdsize;
fo->seek(0, SEEK_SET);
fo->rewrite(&mhdro, sizeof(mhdro));
} break;
case Mach_segment_command::LC_DATA_IN_CODE: {
N_Mach::Mach_data_in_code_command blk; memcpy(&blk, ptr1, sizeof(blk));
if (blk.dataoff) blk.dataoff += delta;
memset(&blk, 0, sizeof(blk));
fo->seek(sizeof(segXHDR) + ((char const *)ptr1 - (char const *)ptr0), SEEK_SET);
fo->rewrite(&blk, sizeof(blk));
// Temporary test: remove this command; known to be last
mhdro.ncmds -= 1;
mhdro.sizeofcmds -= ((Mach_command const *)ptr1)->cmdsize;
fo->seek(0, SEEK_SET);
fo->rewrite(&mhdro, sizeof(mhdro));
} break;
} // end switch
fo->seek(0, SEEK_END);