1 files changed, 313 insertions, 0 deletions
diff --git a/common/ctf/ctf_lookup.c b/common/ctf/ctf_lookup.c
new file mode 100644
index 000000000000..f8fa72435591
--- /dev/null
+++ b/common/ctf/ctf_lookup.c
@@ -0,0 +1,313 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <sys/sysmacros.h>
+#include <ctf_impl.h>
+
+/*
+ * Compare the given input string and length against a table of known C storage
+ * qualifier keywords.  We just ignore these in ctf_lookup_by_name, below.  To
+ * do this quickly, we use a pre-computed Perfect Hash Function similar to the
+ * technique originally described in the classic paper:
+ *
+ * R.J. Cichelli, "Minimal Perfect Hash Functions Made Simple",
+ * Communications of the ACM, Volume 23, Issue 1, January 1980, pp. 17-19.
+ *
+ * For an input string S of length N, we use hash H = S[N - 1] + N - 105, which
+ * for the current set of qualifiers yields a unique H in the range [0 .. 20].
+ * The hash can be modified when the keyword set changes as necessary.  We also
+ * store the length of each keyword and check it prior to the final strcmp().
+ */
+static int
+isqualifier(const char *s, size_t len)
+{
+	static const struct qual {
+		const char *q_name;
+		size_t q_len;
+	} qhash[] = {
+		{ "static", 6 }, { "", 0 }, { "", 0 }, { "", 0 },
+		{ "volatile", 8 }, { "", 0 }, { "", 0 }, { "", 0 }, { "", 0 },
+		{ "", 0 }, { "auto", 4 }, { "extern", 6 }, { "", 0 }, { "", 0 },
+		{ "", 0 }, { "", 0 }, { "const", 5 }, { "register", 8 },
+		{ "", 0 }, { "restrict", 8 }, { "_Restrict", 9 }
+	};
+
+	int h = s[len - 1] + (int)len - 105;
+	const struct qual *qp = &qhash[h];
+
+	return (h >= 0 && h < sizeof (qhash) / sizeof (qhash[0]) &&
+	    len == qp->q_len && strncmp(qp->q_name, s, qp->q_len) == 0);
+}
+
+/*
+ * Attempt to convert the given C type name into the corresponding CTF type ID.
+ * It is not possible to do complete and proper conversion of type names
+ * without implementing a more full-fledged parser, which is necessary to
+ * handle things like types that are function pointers to functions that
+ * have arguments that are function pointers, and fun stuff like that.
+ * Instead, this function implements a very simple conversion algorithm that
+ * finds the things that we actually care about: structs, unions, enums,
+ * integers, floats, typedefs, and pointers to any of these named types.
+ */
+ctf_id_t
+ctf_lookup_by_name(ctf_file_t *fp, const char *name)
+{
+	static const char delimiters[] = " \t\n\r\v\f*";
+
+	const ctf_lookup_t *lp;
+	const ctf_helem_t *hp;
+	const char *p, *q, *end;
+	ctf_id_t type = 0;
+	ctf_id_t ntype, ptype;
+
+	if (name == NULL)
+		return (ctf_set_errno(fp, EINVAL));
+
+	for (p = name, end = name + strlen(name); *p != '\0'; p = q) {
+		while (isspace(*p))
+			p++; /* skip leading ws */
+
+		if (p == end)
+			break;
+
+		if ((q = strpbrk(p + 1, delimiters)) == NULL)
+			q = end; /* compare until end */
+
+		if (*p == '*') {
+			/*
+			 * Find a pointer to type by looking in fp->ctf_ptrtab.
+			 * If we can't find a pointer to the given type, see if
+			 * we can compute a pointer to the type resulting from
+			 * resolving the type down to its base type and use
+			 * that instead.  This helps with cases where the CTF
+			 * data includes "struct foo *" but not "foo_t *" and
+			 * the user tries to access "foo_t *" in the debugger.
+			 */
+			ntype = fp->ctf_ptrtab[CTF_TYPE_TO_INDEX(type)];
+			if (ntype == 0) {
+				ntype = ctf_type_resolve(fp, type);
+				if (ntype == CTF_ERR || (ntype = fp->ctf_ptrtab[
+				    CTF_TYPE_TO_INDEX(ntype)]) == 0) {
+					(void) ctf_set_errno(fp, ECTF_NOTYPE);
+					goto err;
+				}
+			}
+
+			type = CTF_INDEX_TO_TYPE(ntype,
+			    (fp->ctf_flags & LCTF_CHILD));
+
+			q = p + 1;
+			continue;
+		}
+
+		if (isqualifier(p, (size_t)(q - p)))
+			continue; /* skip qualifier keyword */
+
+		for (lp = fp->ctf_lookups; lp->ctl_prefix != NULL; lp++) {
+			if (lp->ctl_prefix[0] == '\0' ||
+			    strncmp(p, lp->ctl_prefix, (size_t)(q - p)) == 0) {
+				for (p += lp->ctl_len; isspace(*p); p++)
+					continue; /* skip prefix and next ws */
+
+				if ((q = strchr(p, '*')) == NULL)
+					q = end;  /* compare until end */
+
+				while (isspace(q[-1]))
+					q--;	  /* exclude trailing ws */
+
+				if ((hp = ctf_hash_lookup(lp->ctl_hash, fp, p,
+				    (size_t)(q - p))) == NULL) {
+					(void) ctf_set_errno(fp, ECTF_NOTYPE);
+					goto err;
+				}
+
+				type = hp->h_type;
+				break;
+			}
+		}
+
+		if (lp->ctl_prefix == NULL) {
+			(void) ctf_set_errno(fp, ECTF_NOTYPE);
+			goto err;
+		}
+	}
+
+	if (*p != '\0' || type == 0)
+		return (ctf_set_errno(fp, ECTF_SYNTAX));
+
+	return (type);
+
+err:
+	if (fp->ctf_parent != NULL &&
+	    (ptype = ctf_lookup_by_name(fp->ctf_parent, name)) != CTF_ERR)
+		return (ptype);
+
+	return (CTF_ERR);
+}
+
+/*
+ * Given a symbol table index, return the type of the data object described
+ * by the corresponding entry in the symbol table.
+ */
+ctf_id_t
+ctf_lookup_by_symbol(ctf_file_t *fp, ulong_t symidx)
+{
+	const ctf_sect_t *sp = &fp->ctf_symtab;
+	ctf_id_t type;
+
+	if (sp->cts_data == NULL)
+		return (ctf_set_errno(fp, ECTF_NOSYMTAB));
+
+	if (symidx >= fp->ctf_nsyms)
+		return (ctf_set_errno(fp, EINVAL));
+
+	if (sp->cts_entsize == sizeof (Elf32_Sym)) {
+		const Elf32_Sym *symp = (Elf32_Sym *)sp->cts_data + symidx;
+		if (ELF32_ST_TYPE(symp->st_info) != STT_OBJECT)
+			return (ctf_set_errno(fp, ECTF_NOTDATA));
+	} else {
+		const Elf64_Sym *symp = (Elf64_Sym *)sp->cts_data + symidx;
+		if (ELF64_ST_TYPE(symp->st_info) != STT_OBJECT)
+			return (ctf_set_errno(fp, ECTF_NOTDATA));
+	}
+
+	if (fp->ctf_sxlate[symidx] == -1u)
+		return (ctf_set_errno(fp, ECTF_NOTYPEDAT));
+
+	type = *(ushort_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]);
+	if (type == 0)
+		return (ctf_set_errno(fp, ECTF_NOTYPEDAT));
+
+	return (type);
+}
+
+/*
+ * Return the pointer to the internal CTF type data corresponding to the
+ * given type ID.  If the ID is invalid, the function returns NULL.
+ * This function is not exported outside of the library.
+ */
+const ctf_type_t *
+ctf_lookup_by_id(ctf_file_t **fpp, ctf_id_t type)
+{
+	ctf_file_t *fp = *fpp; /* caller passes in starting CTF container */
+
+	if ((fp->ctf_flags & LCTF_CHILD) && CTF_TYPE_ISPARENT(type) &&
+	    (fp = fp->ctf_parent) == NULL) {
+		(void) ctf_set_errno(*fpp, ECTF_NOPARENT);
+		return (NULL);
+	}
+
+	type = CTF_TYPE_TO_INDEX(type);
+	if (type > 0 && type <= fp->ctf_typemax) {
+		*fpp = fp; /* function returns ending CTF container */
+		return (LCTF_INDEX_TO_TYPEPTR(fp, type));
+	}
+
+	(void) ctf_set_errno(fp, ECTF_BADID);
+	return (NULL);
+}
+
+/*
+ * Given a symbol table index, return the info for the function described
+ * by the corresponding entry in the symbol table.
+ */
+int
+ctf_func_info(ctf_file_t *fp, ulong_t symidx, ctf_funcinfo_t *fip)
+{
+	const ctf_sect_t *sp = &fp->ctf_symtab;
+	const ushort_t *dp;
+	ushort_t info, kind, n;
+
+	if (sp->cts_data == NULL)
+		return (ctf_set_errno(fp, ECTF_NOSYMTAB));
+
+	if (symidx >= fp->ctf_nsyms)
+		return (ctf_set_errno(fp, EINVAL));
+
+	if (sp->cts_entsize == sizeof (Elf32_Sym)) {
+		const Elf32_Sym *symp = (Elf32_Sym *)sp->cts_data + symidx;
+		if (ELF32_ST_TYPE(symp->st_info) != STT_FUNC)
+			return (ctf_set_errno(fp, ECTF_NOTFUNC));
+	} else {
+		const Elf64_Sym *symp = (Elf64_Sym *)sp->cts_data + symidx;
+		if (ELF64_ST_TYPE(symp->st_info) != STT_FUNC)
+			return (ctf_set_errno(fp, ECTF_NOTFUNC));
+	}
+
+	if (fp->ctf_sxlate[symidx] == -1u)
+		return (ctf_set_errno(fp, ECTF_NOFUNCDAT));
+
+	dp = (ushort_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]);
+
+	info = *dp++;
+	kind = LCTF_INFO_KIND(fp, info);
+	n = LCTF_INFO_VLEN(fp, info);
+
+	if (kind == CTF_K_UNKNOWN && n == 0)
+		return (ctf_set_errno(fp, ECTF_NOFUNCDAT));
+
+	if (kind != CTF_K_FUNCTION)
+		return (ctf_set_errno(fp, ECTF_CORRUPT));
+
+	fip->ctc_return = *dp++;
+	fip->ctc_argc = n;
+	fip->ctc_flags = 0;
+
+	if (n != 0 && dp[n - 1] == 0) {
+		fip->ctc_flags |= CTF_FUNC_VARARG;
+		fip->ctc_argc--;
+	}
+
+	return (0);
+}
+
+/*
+ * Given a symbol table index, return the arguments for the function described
+ * by the corresponding entry in the symbol table.
+ */
+int
+ctf_func_args(ctf_file_t *fp, ulong_t symidx, uint_t argc, ctf_id_t *argv)
+{
+	const ushort_t *dp;
+	ctf_funcinfo_t f;
+
+	if (ctf_func_info(fp, symidx, &f) == CTF_ERR)
+		return (CTF_ERR); /* errno is set for us */
+
+	/*
+	 * The argument data is two ushort_t's past the translation table
+	 * offset: one for the function info, and one for the return type.
+	 */
+	dp = (ushort_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]) + 2;
+
+	for (argc = MIN(argc, f.ctc_argc); argc != 0; argc--)
+		*argv++ = *dp++;
+
+	return (0);
+}