1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright (c) 2011, Joyent, Inc. All rights reserved.
24 * Copyright (c) 2011, Robert Mustacchi, Inc. All rights reserved.
25 * Copyright 2013, Richard Lowe.
26 */
27
28#include <err.h>
29#include <fcntl.h>
30#include <gelf.h>
31#include <libctf.h>
32#include <saveargs.h>
33#include <stdarg.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <strings.h>
37#include <unistd.h>
38
39extern const char *__progname;
40
41typedef struct symtab_sym {
42	GElf_Sym ss_sym;
43	char *ss_name;
44	ctf_funcinfo_t ss_finfo;
45	uint8_t *ss_data;
46	size_t ss_size;
47} symtab_sym_t;
48
49static void
50walk_symtab(Elf *elf, char *fname, ctf_file_t *fp,
51    void (*callback)(ctf_file_t *, symtab_sym_t *))
52{
53	Elf_Scn *stab = NULL;
54	Elf_Scn *text = NULL;
55	Elf_Data *stabdata = NULL;
56	Elf_Data *textdata = NULL;
57	GElf_Ehdr ehdr;
58	GElf_Shdr stabshdr;
59	GElf_Shdr textshdr;
60	int foundtext = 0, foundstab = 0;
61	symtab_sym_t ss;
62
63	if ((gelf_getehdr(elf, &ehdr)) == NULL)
64		errx(1, "could not read ELF header from %s\n",
65		    fname);
66
67	while ((stab = elf_nextscn(elf, stab)) != NULL) {
68		(void) gelf_getshdr(stab, &stabshdr);
69
70		if (stabshdr.sh_type == SHT_SYMTAB) {
71			foundstab = 1;
72			break;
73		}
74	}
75
76	while ((text = elf_nextscn(elf, text)) != NULL) {
77		(void) gelf_getshdr(text, &textshdr);
78
79		if (strcmp(".text", elf_strptr(elf,
80		    ehdr.e_shstrndx, (size_t)textshdr.sh_name)) == 0) {
81			foundtext = 1;
82			break;
83		}
84	}
85
86	if (!foundstab || !foundtext)
87		return;
88
89	stabdata = elf_getdata(stab, NULL);
90	textdata = elf_rawdata(text,  NULL);
91	for (unsigned symdx = 0;
92	    symdx < (stabshdr.sh_size / stabshdr.sh_entsize);
93	    symdx++) {
94		(void) gelf_getsym(stabdata, symdx, &ss.ss_sym);
95
96		if ((GELF_ST_TYPE(ss.ss_sym.st_info) != STT_FUNC) ||
97		    (ss.ss_sym.st_shndx == SHN_UNDEF))
98			continue;
99
100		ss.ss_name = elf_strptr(elf, stabshdr.sh_link,
101		    ss.ss_sym.st_name);
102		ss.ss_data = ((uint8_t *)(textdata->d_buf)) +
103		    (ss.ss_sym.st_value - textshdr.sh_addr);
104
105		if (ctf_func_info(fp, symdx, &ss.ss_finfo) == CTF_ERR) {
106			fprintf(stderr, "failed to get funcinfo for: %s\n",
107			    ss.ss_name);
108			continue;
109		}
110
111		(void) callback(fp, &ss);
112	}
113}
114
115void
116check_sym(ctf_file_t *ctfp, symtab_sym_t *ss)
117{
118	int rettype = ctf_type_kind(ctfp, ss->ss_finfo.ctc_return);
119	int start_index = 0;
120
121	if (ss->ss_finfo.ctc_argc == 0) /* No arguments, no point */
122		return;
123
124	if (((rettype == CTF_K_STRUCT) || (rettype == CTF_K_UNION)) &&
125	    ctf_type_size(ctfp, ss->ss_finfo.ctc_return) > 16)
126		start_index = 1;
127
128	if (saveargs_has_args(ss->ss_data, ss->ss_sym.st_size,
129	    ss->ss_finfo.ctc_argc, start_index) != SAVEARGS_NO_ARGS)
130		printf("%s has %d saved args\n", ss->ss_name,
131		    ss->ss_finfo.ctc_argc);
132}
133
134int
135main(int argc, char **argv)
136{
137	Elf		*elf;
138	ctf_file_t	*ctfp;
139	int errp, fd;
140
141	if (ctf_version(CTF_VERSION) == -1)
142		errx(1, "mismatched libctf versions\n");
143
144	if (elf_version(EV_CURRENT) == EV_NONE)
145		errx(1, "mismatched libelf versions\n");
146
147	if (argc != 2)
148		errx(2, "usage: %s <file>\n", __progname);
149
150	if ((ctfp = ctf_open(argv[1], &errp)) == NULL)
151		errx(1, "failed to ctf_open file: %s: %s\n", argv[1],
152		    ctf_errmsg(errp));
153
154	if ((fd = open(argv[1], O_RDONLY)) == -1)
155		errx(1, "could not open %s\n", argv[1]);
156
157	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
158		errx(1, "could not interpret ELF from %s\n",
159		    argv[1]);
160
161	walk_symtab(elf, argv[1], ctfp, check_sym);
162
163	(void) elf_end(elf);
164	(void) close(fd);
165
166	return (0);
167}
168