add .8 support to libmach_amd64 [sic].

add code to handle 32-bit Mach-O and ELF binaries.

R=r
DELTA=452  (365 added, 29 deleted, 58 changed)
OCL=26696
CL=26712

src/libmach_amd64/8.c

@@ -98,7 +98,7 @@ Mach mi386 =
 	0x1000,		/* page size */
 	0x80100000ULL,	/* kernel base */
 	0xF0000000ULL,	/* kernel text mask */
-	0x7FFFFFFFULL,	/* user stack top */
+	0xFFFFFFFFULL,	/* user stack top */
 	1,		/* quantization of pc */
 	4,		/* szaddr */
 	4,		/* szreg */

src/libmach_amd64/8obj.c

@@ -0,0 +1,172 @@
+// Inferno libmach/8obj.c
+// http://code.google.com/p/inferno-os/source/browse/utils/libmach/8obj.c
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.
+//	Power PC support Copyright © 1995-2004 C H Forsyth (forsyth@terzarima.net).
+//	Portions Copyright © 1997-1999 Vita Nuova Limited.
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com).
+//	Revisions Copyright © 2000-2004 Lucent Technologies Inc. and others.
+//	Portions Copyright © 2009 The Go Authors.  All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+/*
+ * 8obj.c - identify and parse a 386 object file
+ */
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <mach_amd64.h>
+#include "../cmd/8l/8.out.h"
+#include "obj.h"
+
+typedef struct Addr	Addr;
+struct Addr
+{
+	char	sym;
+	char	flags;
+};
+static	Addr	addr(Biobuf*);
+static	char	type2char(int);
+static	void	skip(Biobuf*, int);
+
+int
+_is8(char *t)
+{
+	uchar *s = (uchar*)t;
+
+	return  s[0] == (ANAME&0xff)			/* aslo = ANAME */
+		&& s[1] == ((ANAME>>8)&0xff)
+		&& s[2] == D_FILE			/* type */
+		&& s[3] == 1				/* sym */
+		&& s[4] == '<';				/* name of file */
+}
+
+int
+_read8(Biobuf *bp, Prog* p)
+{
+	int as, n, c;
+	Addr a;
+
+	as = Bgetc(bp);		/* as(low) */
+	if(as < 0)
+		return 0;
+	c = Bgetc(bp);		/* as(high) */
+	if(c < 0)
+		return 0;
+	as |= ((c & 0xff) << 8);
+	p->kind = aNone;
+	p->sig = 0;
+	if(as == ANAME || as == ASIGNAME){
+		if(as == ASIGNAME){
+			Bread(bp, &p->sig, 4);
+			p->sig = leswal(p->sig);
+		}
+		p->kind = aName;
+		p->type = type2char(Bgetc(bp));		/* type */
+		p->sym = Bgetc(bp);			/* sym */
+		n = 0;
+		for(;;) {
+			as = Bgetc(bp);
+			if(as < 0)
+				return 0;
+			n++;
+			if(as == 0)
+				break;
+		}
+		p->id = malloc(n);
+		if(p->id == 0)
+			return 0;
+		Bseek(bp, -n, 1);
+		if(Bread(bp, p->id, n) != n)
+			return 0;
+		return 1;
+	}
+	if(as == ATEXT)
+		p->kind = aText;
+	if(as == AGLOBL)
+		p->kind = aData;
+	skip(bp, 4);		/* lineno(4) */
+	a = addr(bp);
+	addr(bp);
+	if(!(a.flags & T_SYM))
+		p->kind = aNone;
+	p->sym = a.sym;
+	return 1;
+}
+
+static Addr
+addr(Biobuf *bp)
+{
+	Addr a;
+	int t;
+	long off;
+
+	off = 0;
+	a.sym = -1;
+	a.flags = Bgetc(bp);			/* flags */
+	if(a.flags & T_INDEX)
+		skip(bp, 2);
+	if(a.flags & T_OFFSET){
+		off = Bgetc(bp);
+		off |= Bgetc(bp) << 8;
+		off |= Bgetc(bp) << 16;
+		off |= Bgetc(bp) << 24;
+		if(off < 0)
+			off = -off;
+	}
+	if(a.flags & T_OFFSET2){
+		Bgetc(bp);
+		Bgetc(bp);
+		Bgetc(bp);
+		Bgetc(bp);
+	}
+	if(a.flags & T_SYM)
+		a.sym = Bgetc(bp);
+	if(a.flags & T_FCONST)
+		skip(bp, 8);
+	else
+	if(a.flags & T_SCONST)
+		skip(bp, NSNAME);
+	if(a.flags & T_TYPE) {
+		t = Bgetc(bp);
+		if(a.sym > 0 && (t==D_PARAM || t==D_AUTO))
+			_offset(a.sym, off);
+	}
+	return a;
+}
+
+static char
+type2char(int t)
+{
+	switch(t){
+	case D_EXTERN:		return 'U';
+	case D_STATIC:		return 'b';
+	case D_AUTO:		return 'a';
+	case D_PARAM:		return 'p';
+	default:		return UNKNOWN;
+	}
+}
+
+static void
+skip(Biobuf *bp, int n)
+{
+	while (n-- > 0)
+		Bgetc(bp);
+}

src/libmach_amd64/Makefile

@@ -43,6 +43,7 @@ OFILES=\
 	8.$O\
 	8db.$O\
 	6obj.$O\
+	8obj.$O\
 	$(GOOS).$O\
 #	v.$O\
 #	k.$O\
@@ -66,7 +67,6 @@ OFILES=\
 #	2obj.$O\
 #	5obj.$O\
 #	7obj.$O\
-#	8obj.$O\
 #	9obj.$O\
 #	qobj.$O\
 #	vcodas.$O\

src/libmach_amd64/executable.c

@@ -259,13 +259,22 @@ ExecTable exectab[] =
 		sizeof(Ehdr64),
 		nil,
 		elfdotout },
-	{ MACH_MAG,			/* 64-bit MACH (apple mac) */
+	{ MACH64_MAG,			/* 64-bit MACH (apple mac) */
 		"mach executable",
 		nil,
 		FAMD64,
 		0,
+		&mamd64,
+		sizeof(Machhdr),
+		nil,
+		machdotout },
+	{ MACH32_MAG,			/* 64-bit MACH (apple mac) */
+		"mach executable",
+		nil,
+		FI386,
+		0,
 		&mi386,
-		sizeof(Ehdr64),
+		sizeof(Machhdr),
 		nil,
 		machdotout },
 	{ E_MAGIC,			/* Arm 5.out and boot image */
@@ -680,30 +689,10 @@ elf64dotout(int fd, Fhdr *fp, ExecHdr *hp)
 	fp->magic = ELF_MAG;
 	fp->hdrsz = (ep->ehsize+ep->phnum*ep->phentsize+16)&~15;
 	switch(ep->machine) {
-	case I386:
-		mach = &mi386;
-		fp->type = FI386;
-		break;
-	case MIPS:
-		mach = &mmips;
-		fp->type = FMIPS;
-		break;
-	case SPARC64:
-		mach = &msparc64;
-		fp->type = FSPARC64;
-		break;
-	case POWER:
-		mach = &mpower;
-		fp->type = FPOWER;
-		break;
 	case AMD64:
 		mach = &mamd64;
 		fp->type = FAMD64;
 		break;
-	case ARM:
-		mach = &marm;
-		fp->type = FARM;
-		break;
 	default:
 		return 0;
 	}
@@ -731,7 +720,7 @@ elf64dotout(int fd, Fhdr *fp, ExecHdr *hp)
 			free(sh);
 			sh = 0;
 		} else
-			hswal(ph, phsz/sizeof(uint32), swal);
+			hswal(sh, shsz/sizeof(uint32), swal);
 	}
 
 	/* find text, data and symbols and install them */
@@ -781,7 +770,7 @@ error:
 	setdata(fp, ph[id].vaddr, ph[id].filesz, ph[id].offset, ph[id].memsz - ph[id].filesz);
 	if(is != -1)
 		setsym(fp, ph[is].filesz, 0, ph[is].memsz, ph[is].offset);
-	else if(ep->machine == AMD64 && sh != 0){
+	else if(sh != 0){
 		char *buf;
 		uvlong symsize = 0;
 		uvlong symoff = 0;
@@ -826,7 +815,8 @@ elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
 	ushort (*swab)(ushort);
 	Ehdr32 *ep;
 	Phdr32 *ph;
-	int i, it, id, is, phsz;
+	int i, it, id, is, phsz, shsz;
+	Shdr32 *sh;
 
 	/* bitswap the header according to the DATA format */
 	ep = &hp->e.elfhdr32;
@@ -880,10 +870,6 @@ elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
 		mach = &mpower;
 		fp->type = FPOWER;
 		break;
-	case AMD64:
-		mach = &mamd64;
-		fp->type = FAMD64;
-		break;
 	case ARM:
 		mach = &marm;
 		fp->type = FARM;
@@ -907,6 +893,17 @@ elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
 	}
 	hswal(ph, phsz/sizeof(uint32), swal);
 
+	shsz = sizeof(Shdr32)*ep->shnum;
+	sh = malloc(shsz);
+	if(sh) {
+		seek(fd, ep->shoff, 0);
+		if(read(fd, sh, shsz) < 0) {
+			free(sh);
+			sh = 0;
+		} else
+			hswal(sh, shsz/sizeof(uint32), swal);
+	}
+
 	/* find text, data and symbols and install them */
 	it = id = is = -1;
 	for(i = 0; i < ep->phnum; i++) {
@@ -944,6 +941,8 @@ elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
 		}
 
 		werrstr("No TEXT or DATA sections");
+error:
+		free(sh);
 		free(ph);
 		return 0;
 	}
@@ -952,6 +951,39 @@ elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
 	setdata(fp, ph[id].vaddr, ph[id].filesz, ph[id].offset, ph[id].memsz - ph[id].filesz);
 	if(is != -1)
 		setsym(fp, ph[is].filesz, 0, ph[is].memsz, ph[is].offset);
+	else if(sh != 0){
+		char *buf;
+		uvlong symsize = 0;
+		uvlong symoff = 0;
+		uvlong pclnsz = 0;
+
+		/* load shstrtab names */
+		buf = malloc(sh[ep->shstrndx].size);
+		if (buf == 0)
+			goto done;
+		memset(buf, 0, sizeof buf);
+		seek(fd, sh[ep->shstrndx].offset, 0);
+		read(fd, buf, sh[ep->shstrndx].size);
+
+		for(i = 0; i < ep->shnum; i++) {
+			if (strcmp(&buf[sh[i].name], ".gosymtab") == 0) {
+				symsize = sh[i].size;
+				symoff = sh[i].offset;
+			}
+			if (strcmp(&buf[sh[i].name], ".gopclntab") == 0) {
+				if (sh[i].offset != symoff+symsize) {
+					werrstr("pc line table not contiguous with symbol table");
+					free(buf);
+					goto error;
+				}
+				pclnsz = sh[i].size;
+			}
+		}
+		setsym(fp, symsize, 0, pclnsz, symoff);
+		free(buf);
+	}
+done:
+	free(sh);
 	free(ph);
 	return 1;
 }
@@ -964,23 +996,24 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 	ushort (*swab)(ushort);
 	Machhdr *mp;
 	MachCmd **cmd;
-	MachSeg64 *text;
-	MachSeg64 *data;
 	MachSymSeg *symtab;
 	MachSymSeg *pclntab;
 	MachSeg64 *seg;
 	MachSect64 *sect;
+	MachSeg32 *seg32;
+	MachSect32 *sect32;
 	uvlong textsize, datasize, bsssize;
 	uchar *cmdbuf;
 	uchar *cmdp;
-	int i;
+	int i, hdrsize;
+	uint32 textva, textoff, datava, dataoff;
 
-	/* bitswap the header according to the DATA format */
 	mp = &hp->e.machhdr;
-	if (mp->cputype != leswal(MACH_CPU_TYPE_X86_64)) {
-		werrstr("bad MACH cpu type - not amd64");
+	if (leswal(mp->filetype) != MACH_EXECUTABLE_TYPE) {
+		werrstr("bad MACH executable type %#ux", leswal(mp->filetype));
 		return 0;
 	}
+
 	swab = leswab;
 	swal = leswal;
 	swav = leswav;
@@ -993,27 +1026,59 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 	mp->sizeofcmds = swal(mp->sizeofcmds);
 	mp->flags = swal(mp->flags);
 	mp->reserved = swal(mp->reserved);
-	if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86) {
-		werrstr("bad MACH cpu subtype - not amd64");
+	hdrsize = 0;
+
+	switch(mp->magic) {
+	case 0xFEEDFACE:	// 32-bit mach
+		if (mp->cputype != MACH_CPU_TYPE_X86) {
+			werrstr("bad MACH cpu type - not 386");
+			return 0;
+		}
+		if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86) {
+			werrstr("bad MACH cpu subtype - not 386");
+			return 0;
+		}
+		if (mp->filetype != MACH_EXECUTABLE_TYPE) {
+			werrstr("bad MACH executable type");
+			return 0;
+		}
+		mach = &mi386;
+		fp->type = FI386;
+		hdrsize = 28;
+		break;
+
+	case 0xFEEDFACF:	// 64-bit mach
+		if (mp->cputype != MACH_CPU_TYPE_X86_64) {
+			werrstr("bad MACH cpu type - not amd64");
+			return 0;
+		}
+
+		if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86) {
+			werrstr("bad MACH cpu subtype - not amd64");
+			return 0;
+		}
+		mach = &mamd64;
+		fp->type = FAMD64;
+		hdrsize = 32;
+		break;
+
+	default:
+		werrstr("not mach %#ux", mp->magic);
 		return 0;
 	}
-	if (mp->filetype != MACH_EXECUTABLE_TYPE) {
-		werrstr("bad MACH cpu subtype - not amd64");
-		return 0;
-	}
-	mach = &mamd64;
-	fp->type = FAMD64;
 
 	cmdbuf = malloc(mp->sizeofcmds);
-	seek(fd, sizeof(Machhdr), 0);
+	seek(fd, hdrsize, 0);
 	if(read(fd, cmdbuf, mp->sizeofcmds) != mp->sizeofcmds) {
 		free(cmdbuf);
 		return 0;
 	}
 	cmd = malloc(mp->ncmds * sizeof(MachCmd*));
 	cmdp = cmdbuf;
-	text = 0;
-	data = 0;
+	textva = 0;
+	textoff = 0;
+	dataoff = 0;
+	datava = 0;
 	symtab = 0;
 	pclntab = 0;
 	textsize = datasize = bsssize = 0;
@@ -1025,7 +1090,56 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 		c->type = swal(c->type);
 		c->size = swal(c->size);
 		switch(c->type) {
+		case MACH_SEGMENT_32:
+			if(mp->magic != 0xFEEDFACE) {
+				werrstr("segment 32 in mach 64");
+				goto bad;
+			}
+			seg32 = (MachSeg32*)c;
+			seg32->vmaddr = swav(seg32->vmaddr);
+			seg32->vmsize = swav(seg32->vmsize);
+			seg32->fileoff = swav(seg32->fileoff);
+			seg32->filesize = swav(seg32->filesize);
+			seg32->maxprot = swal(seg32->maxprot);
+			seg32->initprot = swal(seg32->initprot);
+			seg32->nsects = swal(seg32->nsects);
+			seg32->flags = swal(seg32->flags);
+			if (strcmp(seg32->segname, "__TEXT") == 0) {
+				textva = seg32->vmaddr;
+				textoff = seg32->fileoff;
+				sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32));
+				if (strcmp(sect32->sectname, "__text") == 0) {
+					textsize = swal(sect32->size);
+				} else {
+					werrstr("no text section");
+					goto bad;
+				}
+			}
+			if (strcmp(seg32->segname, "__DATA") == 0) {
+				datava = seg32->vmaddr;
+				dataoff = seg32->fileoff;
+				sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32));
+				if (strcmp(sect32->sectname, "__data") == 0) {
+					datasize = swal(sect32->size);
+				} else {
+					werrstr("no data section");
+					goto bad;
+				}
+				sect32++;
+				if (strcmp(sect32->sectname, "__bss") == 0) {
+					bsssize = swal(sect32->size);
+				} else {
+					werrstr("no bss section");
+					goto bad;
+				}
+			}
+			break;
+
 		case MACH_SEGMENT_64:
+			if(mp->magic != 0xFEEDFACF) {
+				werrstr("segment 32 in mach 64");
+				goto bad;
+			}
 			seg = (MachSeg64*)c;
 			seg->vmaddr = swav(seg->vmaddr);
 			seg->vmsize = swav(seg->vmsize);
@@ -1036,7 +1150,8 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 			seg->nsects = swal(seg->nsects);
 			seg->flags = swal(seg->flags);
 			if (strcmp(seg->segname, "__TEXT") == 0) {
-				text = seg;
+				textva = seg->vmaddr;
+				textoff = seg->fileoff;
 				sect = (MachSect64*)(cmdp + sizeof(MachSeg64));
 				if (strcmp(sect->sectname, "__text") == 0) {
 					textsize = swav(sect->size);
@@ -1046,7 +1161,8 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 				}
 			}
 			if (strcmp(seg->segname, "__DATA") == 0) {
-				data = seg;
+				datava = seg->vmaddr;
+				dataoff = seg->fileoff;
 				sect = (MachSect64*)(cmdp + sizeof(MachSeg64));
 				if (strcmp(sect->sectname, "__data") == 0) {
 					datasize = swav(sect->size);
@@ -1074,14 +1190,14 @@ machdotout(int fd, Fhdr *fp, ExecHdr *hp)
 		}
 		cmdp += c->size;
 	}
-	if (text == 0 || data == 0) {
+	if (textva == 0 || datava == 0) {
 		free(cmd);
 		free(cmdbuf);
 		return 0;
 	}
 	/* compute entry by taking address after header - weird - BUG? */
-	settext(fp, text->vmaddr+sizeof(Machhdr) + mp->sizeofcmds, text->vmaddr, textsize, text->fileoff);
-	setdata(fp, data->vmaddr, datasize, data->fileoff, bsssize);
+	settext(fp, textva+sizeof(Machhdr) + mp->sizeofcmds, textva, textsize, textoff);
+	setdata(fp, datava, datasize, dataoff, bsssize);
 	if(symtab != 0)
 		setsym(fp, symtab->filesize, 0, pclntab? pclntab->filesize : 0, symtab->fileoff);
 	free(cmd);

src/libmach_amd64/fakeobj.c

@@ -16,7 +16,6 @@
 int _is2(char* x) { return 0; }
 int _is5(char* x) { return 0; }
 int _is7(char* x) { return 0; }
-int _is8(char* x) { return 0; }
 int _is9(char* x) { return 0; }
 int _isk(char* x) { return 0; }
 int _isq(char* x) { return 0; }
@@ -25,7 +24,6 @@ int _isu(char* x) { return 0; }
 int _read2(Biobuf* b, Prog* p) { return 0; }
 int _read5(Biobuf* b, Prog* p) { return 0; }
 int _read7(Biobuf* b, Prog* p) { return 0; }
-int _read8(Biobuf* b, Prog* p) { return 0; }
 int _read9(Biobuf* b, Prog* p) { return 0; }
 int _readk(Biobuf* b, Prog* p) { return 0; }
 int _readq(Biobuf* b, Prog* p) { return 0; }

src/libmach_amd64/linux.c

@@ -38,7 +38,12 @@
 #include <libc.h>
 #include <bio.h>
 #include <mach_amd64.h>
+#define Ureg Ureg32
+#include <ureg_x86.h>
+#undef Ureg
+#define Ureg Ureg64
 #include <ureg_amd64.h>
+#undef Ureg
 #undef waitpid
 
 // The old glibc used with crosstool compilers on thresher
@@ -66,7 +71,7 @@
 #define PTRACE_EVENT_EXIT 0x6
 #endif
 
-typedef struct Ureg Ureg;
+typedef struct Ureg64 Ureg64;
 
 static Maprw ptracesegrw;
 static Maprw ptraceregrw;
@@ -787,57 +792,100 @@ ptracesegrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr)
 		isr, map->pid, addr, v, n);
 }
 
+// If the debugger is compiled as an x86-64 program,
+// then all the ptrace register read/writes are done on
+// a 64-bit register set.  If the target program
+// is a 32-bit program, the debugger is expected to
+// read the bottom half of the relevant registers
+// out of the 64-bit set.
+
+// Linux 32-bit is
+//	BX CX DX SI DI BP AX DS ES FS GS OrigAX IP CS EFLAGS SP SS
+
+// Linux 64-bit is
+//	R15 R14 R13 R12 BP BX R11 R10 R9 R8 AX CX DX SI DI OrigAX IP CS EFLAGS SP SS FSBase GSBase DS ES FS GS
+
+// Go 32-bit is
+//	DI SI BP NSP BX DX CX AX GS FS ES DS TRAP ECODE PC CS EFLAGS SP SS
+
+// uint go32tolinux32tab[] = {
+//	4, 3, 5, 15, 0, 2, 1, 6, 10, 9, 8, 7, -1, -1, 12, 13, 14, 15, 16
+// };
+uint go32tolinux64tab[] = {
+	14, 13, 4, 19, 5, 12, 11, 10, 26, 25, 24, 23, -1, -1, 16, 17, 18, 19, 20
+};
+static int
+go32tolinux64(uvlong addr)
+{
+	int r;
+
+	if(addr%4 || addr/4 >= nelem(go32tolinux64tab))
+		return -1;
+	r = go32tolinux64tab[addr/4];
+	if(r < 0)
+		return -1;
+	return r*8;
+}
+
+extern Mach mi386;
+
 static int
 go2linux(uvlong addr)
 {
+	// TODO(rsc): If this file is being compiled in 32-bit mode,
+	// need to use the go32tolinux32 table instead.
+
+	if(mach == &mi386)
+		return go32tolinux64(addr);
+
 	switch(addr){
-	case offsetof(Ureg, ax):
+	case offsetof(Ureg64, ax):
 		return offsetof(struct user_regs_struct, rax);
-	case offsetof(Ureg, bx):
+	case offsetof(Ureg64, bx):
 		return offsetof(struct user_regs_struct, rbx);
-	case offsetof(Ureg, cx):
+	case offsetof(Ureg64, cx):
 		return offsetof(struct user_regs_struct, rcx);
-	case offsetof(Ureg, dx):
+	case offsetof(Ureg64, dx):
 		return offsetof(struct user_regs_struct, rdx);
-	case offsetof(Ureg, si):
+	case offsetof(Ureg64, si):
 		return offsetof(struct user_regs_struct, rsi);
-	case offsetof(Ureg, di):
+	case offsetof(Ureg64, di):
 		return offsetof(struct user_regs_struct, rdi);
-	case offsetof(Ureg, bp):
+	case offsetof(Ureg64, bp):
 		return offsetof(struct user_regs_struct, rbp);
-	case offsetof(Ureg, r8):
+	case offsetof(Ureg64, r8):
 		return offsetof(struct user_regs_struct, r8);
-	case offsetof(Ureg, r9):
+	case offsetof(Ureg64, r9):
 		return offsetof(struct user_regs_struct, r9);
-	case offsetof(Ureg, r10):
+	case offsetof(Ureg64, r10):
 		return offsetof(struct user_regs_struct, r10);
-	case offsetof(Ureg, r11):
+	case offsetof(Ureg64, r11):
 		return offsetof(struct user_regs_struct, r11);
-	case offsetof(Ureg, r12):
+	case offsetof(Ureg64, r12):
 		return offsetof(struct user_regs_struct, r12);
-	case offsetof(Ureg, r13):
+	case offsetof(Ureg64, r13):
 		return offsetof(struct user_regs_struct, r13);
-	case offsetof(Ureg, r14):
+	case offsetof(Ureg64, r14):
 		return offsetof(struct user_regs_struct, r14);
-	case offsetof(Ureg, r15):
+	case offsetof(Ureg64, r15):
 		return offsetof(struct user_regs_struct, r15);
-	case offsetof(Ureg, ds):
+	case offsetof(Ureg64, ds):
 		return offsetof(struct user_regs_struct, ds);
-	case offsetof(Ureg, es):
+	case offsetof(Ureg64, es):
 		return offsetof(struct user_regs_struct, es);
-	case offsetof(Ureg, fs):
+	case offsetof(Ureg64, fs):
 		return offsetof(struct user_regs_struct, fs);
-	case offsetof(Ureg, gs):
+	case offsetof(Ureg64, gs):
 		return offsetof(struct user_regs_struct, gs);
-	case offsetof(Ureg, ip):
+	case offsetof(Ureg64, ip):
 		return offsetof(struct user_regs_struct, rip);
-	case offsetof(Ureg, cs):
+	case offsetof(Ureg64, cs):
 		return offsetof(struct user_regs_struct, cs);
-	case offsetof(Ureg, flags):
+	case offsetof(Ureg64, flags):
 		return offsetof(struct user_regs_struct, eflags);
-	case offsetof(Ureg, sp):
+	case offsetof(Ureg64, sp):
 		return offsetof(struct user_regs_struct, rsp);
-	case offsetof(Ureg, ss):
+	case offsetof(Ureg64, ss):
 		return offsetof(struct user_regs_struct, ss);
 	}
 	return -1;
@@ -904,7 +952,7 @@ ptraceregrw(Map *map, Seg *seg, uvlong addr, void *v, uint n, int isr)
 	return 0;
 
 ptraceerr:
-	werrstr("ptrace %s register laddr=%d pid=%d: %r", isr ? "read" : "write", laddr, map->pid);
+	werrstr("ptrace %s register laddr=%d pid=%d n=%d: %r", isr ? "read" : "write", laddr, map->pid, n);
 	return -1;
 }
 

src/libmach_amd64/macho.h

@@ -22,6 +22,19 @@ typedef struct {
 	uint32	size;	/* total size in bytes */
 } MachCmd;
 
+typedef struct  {
+	MachCmd	cmd;
+	char		segname[16];	/* segment name */
+	uint32	vmaddr;		/* memory address of this segment */
+	uint32	vmsize;		/* memory size of this segment */
+	uint32	fileoff;	/* file offset of this segment */
+	uint32	filesize;	/* amount to map from the file */
+	uint32	maxprot;	/* maximum VM protection */
+	uint32	initprot;	/* initial VM protection */
+	uint32	nsects;		/* number of sections in segment */
+	uint32	flags;		/* flags */
+} MachSeg32; /* for 32-bit architectures */
+
 typedef struct  {
 	MachCmd	cmd;
 	char		segname[16];	/* segment name */
@@ -41,6 +54,20 @@ typedef struct  {
 	uint32	filesize;	/* amount to map from the file */
 } MachSymSeg;
 
+typedef struct  {
+	char		sectname[16];	/* name of this section */
+	char		segname[16];	/* segment this section goes in */
+	uint32	addr;		/* memory address of this section */
+	uint32	size;		/* size in bytes of this section */
+	uint32	offset;		/* file offset of this section */
+	uint32	align;		/* section alignment (power of 2) */
+	uint32	reloff;		/* file offset of relocation entries */
+	uint32	nreloc;		/* number of relocation entries */
+	uint32	flags;		/* flags (section type and attributes)*/
+	uint32	reserved1;	/* reserved (for offset or index) */
+	uint32	reserved2;	/* reserved (for count or sizeof) */
+} MachSect32; /* for 32-bit architectures */
+
 typedef struct  {
 	char		sectname[16];	/* name of this section */
 	char		segname[16];	/* segment this section goes in */
@@ -58,12 +85,15 @@ typedef struct  {
 
 enum {
 	MACH_CPU_TYPE_X86_64 = (1<<24)|7,
+	MACH_CPU_TYPE_X86 = 7,
 	MACH_CPU_SUBTYPE_X86 = 3,
 	MACH_EXECUTABLE_TYPE = 2,
+	MACH_SEGMENT_32 = 1,	/* 32-bit mapped segment */
 	MACH_SEGMENT_64 = 0x19,	/* 64-bit mapped segment */
 	MACH_SYMSEG = 3,	/* obsolete gdb symtab, reused by go */
 	MACH_UNIXTHREAD = 0x5,	/* thread (for stack) */
 };
 
 
-#define	MACH_MAG		((0xcf<<24) | (0xfa<<16) | (0xed<<8) | 0xfe)
+#define	MACH64_MAG		((0xcf<<24) | (0xfa<<16) | (0xed<<8) | 0xfe)
+#define	MACH32_MAG		((0xce<<24) | (0xfa<<16) | (0xed<<8) | 0xfe)