Maintain target's byte order for multi-byte fields in CTF structures.

CTF format is not cross-platform by design, e.g. it is not guaranteed
that data generated by ctfconvert/ctfmerge on one architecture will
be successfuly read on another. CTF structures are saved/restored
using naive approach. Roughly it looks like:
	write(fd, &ctf_struct, sizeof(ctf_struct))
	read(fd, &ctf_struct, sizeof(ctf_struct))

By sheer luck memory layout of all type-related CTF structures is the same
on amd64/i386/mips32/mips64. It's different on ARM though. sparc, ia64,
powerpc, and powerpc64 were not tested. So in order to get file compatible
with dtrace on ARM it should be compiled on ARM. Alternative solution would
be to have "signatures" for every platform and ctfmerge should convert host's
reperesentation of CTF structure to target's one using "signature" as template.

This patch checks byte order of ELF files used for generating CTF record
and makes sure that byte order of data written to resulting files is the same
as target's byte order.

cddl/contrib/opensolaris/tools/ctf/cvt/ctf.c

@@ -62,6 +62,18 @@ struct ctf_buf {
 	int ntholes;		/* number of type holes */
 };
 
+/*
+ * Macros to reverse byte order
+ */
+#define	BSWAP_8(x)	((x) & 0xff)
+#define	BSWAP_16(x)	((BSWAP_8(x) << 8) | BSWAP_8((x) >> 8))
+#define	BSWAP_32(x)	((BSWAP_16(x) << 16) | BSWAP_16((x) >> 16))
+
+#define	SWAP_16(x)	(x) = BSWAP_16(x)
+#define	SWAP_32(x)	(x) = BSWAP_32(x)
+
+static int target_requires_swap;
+
 /*PRINTFLIKE1*/
 static void
 parseterminate(const char *fmt, ...)
@@ -140,6 +152,11 @@ write_label(void *arg1, void *arg2)
 	ctl.ctl_label = strtab_insert(&b->ctb_strtab, le->le_name);
 	ctl.ctl_typeidx = le->le_idx;
 
+	if (target_requires_swap) {
+		SWAP_32(ctl.ctl_label);
+		SWAP_32(ctl.ctl_typeidx);
+	}
+
 	ctf_buf_write(b, &ctl, sizeof (ctl));
 
 	return (1);
@@ -152,6 +169,10 @@ write_objects(iidesc_t *idp, ctf_buf_t *b)
 
 	ctf_buf_write(b, &id, sizeof (id));
 
+	if (target_requires_swap) {
+		SWAP_16(id);
+	}
+
 	debug(3, "Wrote object %s (%d)\n", (idp ? idp->ii_name : "(null)"), id);
 }
 
@@ -180,10 +201,21 @@ write_functions(iidesc_t *idp, ctf_buf_t *b)
 
 	fdata[0] = CTF_TYPE_INFO(CTF_K_FUNCTION, 1, nargs);
 	fdata[1] = idp->ii_dtype->t_id;
+
+	if (target_requires_swap) {
+		SWAP_16(fdata[0]);
+		SWAP_16(fdata[1]);
+	}
+
 	ctf_buf_write(b, fdata, sizeof (fdata));
 
 	for (i = 0; i < idp->ii_nargs; i++) {
 		id = idp->ii_args[i]->t_id;
+
+		if (target_requires_swap) {
+			SWAP_16(id);
+		}
+
 		ctf_buf_write(b, &id, sizeof (id));
 	}
 
@@ -208,11 +240,25 @@ write_sized_type_rec(ctf_buf_t *b, ctf_type_t *ctt, size_t size)
 		ctt->ctt_size = CTF_LSIZE_SENT;
 		ctt->ctt_lsizehi = CTF_SIZE_TO_LSIZE_HI(size);
 		ctt->ctt_lsizelo = CTF_SIZE_TO_LSIZE_LO(size);
+		if (target_requires_swap) {
+			SWAP_32(ctt->ctt_name);
+			SWAP_16(ctt->ctt_info);
+			SWAP_16(ctt->ctt_size);
+			SWAP_32(ctt->ctt_lsizehi);
+			SWAP_32(ctt->ctt_lsizelo);
+		}
 		ctf_buf_write(b, ctt, sizeof (*ctt));
 	} else {
 		ctf_stype_t *cts = (ctf_stype_t *)ctt;
 
 		cts->ctt_size = (ushort_t)size;
+
+		if (target_requires_swap) {
+			SWAP_32(cts->ctt_name);
+			SWAP_16(cts->ctt_info);
+			SWAP_16(cts->ctt_size);
+		}
+
 		ctf_buf_write(b, cts, sizeof (*cts));
 	}
 }
@@ -222,6 +268,12 @@ write_unsized_type_rec(ctf_buf_t *b, ctf_type_t *ctt)
 {
 	ctf_stype_t *cts = (ctf_stype_t *)ctt;
 
+	if (target_requires_swap) {
+		SWAP_32(cts->ctt_name);
+		SWAP_16(cts->ctt_info);
+		SWAP_16(cts->ctt_size);
+	}
+
 	ctf_buf_write(b, cts, sizeof (*cts));
 }
 
@@ -296,6 +348,9 @@ write_type(void *arg1, void *arg2)
 			encoding = ip->intr_fformat;
 
 		data = CTF_INT_DATA(encoding, ip->intr_offset, ip->intr_nbits);
+		if (target_requires_swap) {
+			SWAP_32(data);
+		}
 		ctf_buf_write(b, &data, sizeof (data));
 		break;
 
@@ -312,6 +367,11 @@ write_type(void *arg1, void *arg2)
 		cta.cta_contents = tp->t_ardef->ad_contents->t_id;
 		cta.cta_index = tp->t_ardef->ad_idxtype->t_id;
 		cta.cta_nelems = tp->t_ardef->ad_nelems;
+		if (target_requires_swap) {
+			SWAP_16(cta.cta_contents);
+			SWAP_16(cta.cta_index);
+			SWAP_32(cta.cta_nelems);
+		}
 		ctf_buf_write(b, &cta, sizeof (cta));
 		break;
 
@@ -341,6 +401,11 @@ write_type(void *arg1, void *arg2)
 				    offset);
 				ctm.ctm_type = mp->ml_type->t_id;
 				ctm.ctm_offset = mp->ml_offset;
+				if (target_requires_swap) {
+					SWAP_32(ctm.ctm_name);
+					SWAP_16(ctm.ctm_type);
+					SWAP_16(ctm.ctm_offset);
+				}
 				ctf_buf_write(b, &ctm, sizeof (ctm));
 			}
 		} else {
@@ -355,6 +420,14 @@ write_type(void *arg1, void *arg2)
 				    CTF_OFFSET_TO_LMEMHI(mp->ml_offset);
 				ctlm.ctlm_offsetlo =
 				    CTF_OFFSET_TO_LMEMLO(mp->ml_offset);
+
+				if (target_requires_swap) {
+					SWAP_32(ctlm.ctlm_name);
+					SWAP_16(ctlm.ctlm_type);
+					SWAP_32(ctlm.ctlm_offsethi);
+					SWAP_32(ctlm.ctlm_offsetlo);
+				}
+
 				ctf_buf_write(b, &ctlm, sizeof (ctlm));
 			}
 		}
@@ -377,6 +450,12 @@ write_type(void *arg1, void *arg2)
 			offset = strtab_insert(&b->ctb_strtab, ep->el_name);
 			cte.cte_name = CTF_TYPE_NAME(CTF_STRTAB_0, offset);
 			cte.cte_value = ep->el_number;
+
+			if (target_requires_swap) {
+				SWAP_32(cte.cte_name);
+				SWAP_32(cte.cte_value);
+			}
+
 			ctf_buf_write(b, &cte, sizeof (cte));
 			i--;
 		}
@@ -420,6 +499,11 @@ write_type(void *arg1, void *arg2)
 
 		for (i = 0; i < (int) tp->t_fndef->fn_nargs; i++) {
 			id = tp->t_fndef->fn_args[i]->t_id;
+
+			if (target_requires_swap) {
+				SWAP_16(id);
+			}
+
 			ctf_buf_write(b, &id, sizeof (id));
 		}
 
@@ -613,6 +697,9 @@ ctf_gen(iiburst_t *iiburst, size_t *resszp, int do_compress)
 
 	int i;
 
+	target_requires_swap = do_compress & CTF_SWAP_BYTES;
+	do_compress &= ~CTF_SWAP_BYTES;
+
 	/*
 	 * Prepare the header, and create the CTF output buffers.  The data
 	 * object section and function section are both lists of 2-byte
@@ -649,6 +736,18 @@ ctf_gen(iiburst_t *iiburst, size_t *resszp, int do_compress)
 	h.cth_stroff = ctf_buf_cur(buf);
 	h.cth_strlen = strtab_size(&buf->ctb_strtab);
 
+	if (target_requires_swap) {
+		SWAP_16(h.cth_preamble.ctp_magic);
+		SWAP_32(h.cth_parlabel);
+		SWAP_32(h.cth_parname);
+		SWAP_32(h.cth_lbloff);
+		SWAP_32(h.cth_objtoff);
+		SWAP_32(h.cth_funcoff);
+		SWAP_32(h.cth_typeoff);
+		SWAP_32(h.cth_stroff);
+		SWAP_32(h.cth_strlen);
+	}
+
 	/*
 	 * We only do compression for ctfmerge, as ctfconvert is only
 	 * supposed to be used on intermediary build objects. This is

cddl/contrib/opensolaris/tools/ctf/cvt/ctfmerge.c

@@ -620,7 +620,7 @@ copy_ctf_data(char *srcfile, char *destfile, int keep_stabs)
 		terminate("No CTF data found in source file %s\n", srcfile);
 
 	tmpname = mktmpname(destfile, ".ctf");
-	write_ctf(srctd, destfile, tmpname, CTF_COMPRESS | keep_stabs);
+	write_ctf(srctd, destfile, tmpname, CTF_COMPRESS | CTF_SWAP_BYTES | keep_stabs);
 	if (rename(tmpname, destfile) != 0) {
 		terminate("Couldn't rename temp file %s to %s", tmpname,
 		    destfile);
@@ -1015,7 +1015,7 @@ main(int argc, char **argv)
 
 	tmpname = mktmpname(outfile, ".ctf");
 	write_ctf(savetd, outfile, tmpname,
-	    CTF_COMPRESS | write_fuzzy_match | dynsym | keep_stabs);
+	    CTF_COMPRESS | CTF_SWAP_BYTES | write_fuzzy_match | dynsym | keep_stabs);
 	if (rename(tmpname, outfile) != 0)
 		terminate("Couldn't rename output temp file %s", tmpname);
 	free(tmpname);

cddl/contrib/opensolaris/tools/ctf/cvt/ctftools.h

@@ -391,6 +391,7 @@ void merge_into_master(tdata_t *, tdata_t *, tdata_t *, int);
 #define	CTF_USE_DYNSYM	0x2 /* use .dynsym not .symtab */
 #define	CTF_COMPRESS	0x4 /* compress CTF output */
 #define	CTF_KEEP_STABS	0x8 /* keep .stabs sections */
+#define	CTF_SWAP_BYTES	0x10 /* target byte order is different from host */
 
 void write_ctf(tdata_t *, const char *, const char *, int);
 

cddl/contrib/opensolaris/tools/ctf/cvt/output.c

@@ -717,7 +717,7 @@ make_ctf_data(tdata_t *td, Elf *elf, const char *file, size_t *lenp, int flags)
 
 	iiburst = sort_iidescs(elf, file, td, flags & CTF_FUZZY_MATCH,
 	    flags & CTF_USE_DYNSYM);
-	data = ctf_gen(iiburst, lenp, flags & CTF_COMPRESS);
+	data = ctf_gen(iiburst, lenp, flags & (CTF_COMPRESS |  CTF_SWAP_BYTES));
 
 	iiburst_free(iiburst);
 
@@ -730,10 +730,12 @@ write_ctf(tdata_t *td, const char *curname, const char *newname, int flags)
 	struct stat st;
 	Elf *elf = NULL;
 	Elf *telf = NULL;
+	GElf_Ehdr ehdr;
 	caddr_t data;
 	size_t len;
 	int fd = -1;
 	int tfd = -1;
+	int byteorder;
 
 	(void) elf_version(EV_CURRENT);
 	if ((fd = open(curname, O_RDONLY)) < 0 || fstat(fd, &st) < 0)
@@ -746,6 +748,22 @@ write_ctf(tdata_t *td, const char *curname, const char *newname, int flags)
 	if ((telf = elf_begin(tfd, ELF_C_WRITE, NULL)) == NULL)
 		elfterminate(curname, "Cannot write");
 
+	if (gelf_getehdr(elf, &ehdr)) {
+#if BYTE_ORDER == _BIG_ENDIAN
+		byteorder = ELFDATA2MSB;
+#else
+		byteorder = ELFDATA2LSB;
+#endif
+		/*
+		 * If target and host has the same byte order
+		 * clear byte swapping request
+		 */
+		if  (ehdr.e_ident[EI_DATA] == byteorder)
+			flags &= ~CTF_SWAP_BYTES;
+	}
+	else 
+		elfterminate(curname, "Failed to get EHDR");
+
 	data = make_ctf_data(td, elf, curname, &len, flags);
 	write_file(elf, curname, telf, newname, data, len, flags);
 	free(data);