Head

GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	lib/libc/dlfcn/init.c	Lines:	41	53	77.4 %
Date:	2017-11-13	Branches:	19	37	51.4 %


/*	$OpenBSD: init.c,v 1.5 2016/09/06 18:49:34 guenther Exp $ */
/*
 * Copyright (c) 2014,2015 Philip Guenther <guenther@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */


#define _DYN_LOADER

#include <sys/types.h>
#include <sys/syscall.h>

#ifndef PIC
#include <sys/mman.h>
#endif

#include <tib.h>
#include <limits.h>		/* NAME_MAX */
#include <link.h>
#include <stdlib.h>		/* atexit */
#include <string.h>
#include <unistd.h>

#include "init.h"

/* XXX should be in an include file shared with csu */
char	***_csu_finish(char **_argv, char **_envp, void (*_cleanup)(void));

/* provide definition for this */
int	_pagesize = 0;

/*
 * In dynamicly linked binaries environ and __progname are overriden by
 * the definitions in ld.so.
 */
char	**environ __attribute__((weak)) = NULL;
char	*__progname __attribute__((weak)) = NULL;


#ifndef PIC
struct dl_phdr_info	_static_phdr_info = { .dlpi_name = "a.out" };

static inline void early_static_init(char **_argv, char **_envp);
static inline void setup_static_tib(Elf_Phdr *_phdr, int _phnum);
#endif /* PIC */


/*
 * extract useful bits from the auxiliary vector and either
 * a) register ld.so's cleanup in dynamic links, or
 * b) init __progname, environ, and the TIB in static links.
 */
char ***
_csu_finish(char **argv, char **envp, void (*cleanup)(void))
{
	AuxInfo	*aux;
#ifndef PIC
	Elf_Phdr *phdr = NULL;
	int phnum = 0;

	/* static libc in a static link? */
	if (cleanup == NULL)
		early_static_init(argv, envp);
#endif /* !PIC */

	/* Extract useful bits from the auxiliary vector */
	while (*envp++ != NULL)
		;
	for (aux = (void *)envp; aux->au_id != AUX_null; aux++) {
		switch (aux->au_id) {
		case AUX_pagesz:
			_pagesize = aux->au_v;
			break;
#ifndef PIC
		case AUX_base:
			_static_phdr_info.dlpi_addr = aux->au_v;
			break;
		case AUX_phdr:
			phdr = (void *)aux->au_v;
			_static_phdr_info.dlpi_phdr = phdr;
			break;
		case AUX_phnum:
			phnum = aux->au_v;
			_static_phdr_info.dlpi_phnum = phnum;
			break;
#endif /* !PIC */
		}
	}

#ifndef PIC
	/* static libc in a static link? */
	if (cleanup == NULL)
		setup_static_tib(phdr, phnum);
#endif /* !PIC */

	if (cleanup != NULL)
		atexit(cleanup);

	return &environ;
}

#ifndef PIC
/*
 * static libc in a static link?  Then disable kbind and set up
 * __progname and environ
 */
static inline void
early_static_init(char **argv, char **envp)
{
	static char progname_storage[NAME_MAX+1];

	/* disable kbind */
	syscall(SYS_kbind, (void *)NULL, (size_t)0, (long long)0);

	environ = envp;

	/* set up __progname */
	if (*argv != NULL) {		/* NULL ptr if argc = 0 */
		const char *p = strrchr(*argv, '/');

		if (p == NULL)
			p = *argv;
		else
			p++;
		strlcpy(progname_storage, p, sizeof(progname_storage));
	}
	__progname = progname_storage;
}

/*
 * static TLS handling
 */
#define ELF_ROUND(x,malign)	(((x) + (malign)-1) & ~((malign)-1))

/* for static binaries, the location and size of the TLS image */
static void		*static_tls;
static size_t		static_tls_fsize;

size_t			_static_tls_size = 0;

static inline void
setup_static_tib(Elf_Phdr *phdr, int phnum)
{
	struct tib *tib;
	char *base;
	int i;

	if (phdr != NULL) {
		for (i = 0; i < phnum; i++) {
			if (phdr[i].p_type != PT_TLS)
				continue;
			if (phdr[i].p_memsz == 0)
				break;
			if (phdr[i].p_memsz < phdr[i].p_filesz)
				break;		/* invalid */
#if TLS_VARIANT == 1
			_static_tls_size = phdr[i].p_memsz;
#elif TLS_VARIANT == 2
			/*
			 * variant 2 places the data before the TIB
			 * so we need to round up to the alignment
			 */
			_static_tls_size = ELF_ROUND(phdr[i].p_memsz,
			    phdr[i].p_align);
#endif
			if (phdr[i].p_vaddr != 0 && phdr[i].p_filesz != 0) {
				static_tls = (void *)phdr[i].p_vaddr;
				static_tls_fsize = phdr[i].p_filesz;
			}
			break;
		}
	}

	/*
	 * We call getpagesize() here instead of using _pagesize because
	 * there's no aux-vector in non-PIE static links, so _pagesize
	 * might not be set yet.  If so getpagesize() will get the value.
	 */
	base = mmap(NULL, ELF_ROUND(_static_tls_size + sizeof *tib,
	    getpagesize()), PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
# if TLS_VARIANT == 1
	tib = (struct tib *)base;
# elif TLS_VARIANT == 2
	tib = (struct tib *)(base + _static_tls_size);
# endif

	_static_tls_init(base);
	TIB_INIT(tib, NULL, NULL);
	tib->tib_tid = getthrid();
	TCB_SET(TIB_TO_TCB(tib));
#if ! TCB_HAVE_MD_GET
	_libc_single_tcb = TIB_TO_TCB(tib);
#endif
}

void
_static_tls_init(char *base)
{
	if (_static_tls_size) {
#if TLS_VARIANT == 1
		base += sizeof(struct tib);
#endif
		if (static_tls != NULL)
			memcpy(base, static_tls, static_tls_fsize);
		memset(base + static_tls_fsize, 0,
		    _static_tls_size - static_tls_fsize);
	}
}
#endif /* !PIC */


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: init.c,v 1.5 2016/09/06 18:49:34 guenther Exp $ */
2			/*
3			* Copyright (c) 2014,2015 Philip Guenther <guenther@openbsd.org>
4			*
5			* Permission to use, copy, modify, and distribute this software for any
6			* purpose with or without fee is hereby granted, provided that the above
7			* copyright notice and this permission notice appear in all copies.
8			*
9			* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10			* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11			* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12			* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13			* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14			* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15			* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16			*/
17
18
19			#define _DYN_LOADER
20
21			#include <sys/types.h>
22			#include <sys/syscall.h>
23
24			#ifndef PIC
25			#include <sys/mman.h>
26			#endif
27
28			#include <tib.h>
29			#include <limits.h> /* NAME_MAX */
30			#include <link.h>
31			#include <stdlib.h> /* atexit */
32			#include <string.h>
33			#include <unistd.h>
34
35			#include "init.h"
36
37			/* XXX should be in an include file shared with csu */
38			char *_csu_finish(char _argv, char *_envp, void (_cleanup)(void));
39
40			/* provide definition for this */
41			int _pagesize = 0;
42
43			/*
44			* In dynamicly linked binaries environ and __progname are overriden by
45			* the definitions in ld.so.
46			*/
47			char **environ __attribute__((weak)) = NULL;
48			char *__progname __attribute__((weak)) = NULL;
49
50
51			#ifndef PIC
52			struct dl_phdr_info _static_phdr_info = { .dlpi_name = "a.out" };
53
54			static inline void early_static_init(char _argv, char _envp);
55			static inline void setup_static_tib(Elf_Phdr *_phdr, int _phnum);
56			#endif /* PIC */
57
58
59			/*
60			* extract useful bits from the auxiliary vector and either
61			* a) register ld.so's cleanup in dynamic links, or
62			* b) init __progname, environ, and the TIB in static links.
63			*/
64			char ***
65			_csu_finish(char argv, char envp, void (*cleanup)(void))
66			{
67			AuxInfo *aux;
68			#ifndef PIC
69			Elf_Phdr *phdr = NULL;
70			int phnum = 0;
71
72			/* static libc in a static link? */
73	✓✗	30	if (cleanup == NULL)
74		15	early_static_init(argv, envp);
75			#endif /* !PIC */
76
77			/* Extract useful bits from the auxiliary vector */
78	✓✓	750	while (*envp++ != NULL)
79			;
80	✓✓	240	for (aux = (void *)envp; aux->au_id != AUX_null; aux++) {
81	✓✓✓✓ ✓	165	switch (aux->au_id) {
82			case AUX_pagesz:
83		15	_pagesize = aux->au_v;
84		15	break;
85			#ifndef PIC
86			case AUX_base:
87		15	_static_phdr_info.dlpi_addr = aux->au_v;
88		15	break;
89			case AUX_phdr:
90		15	phdr = (void *)aux->au_v;
91		15	_static_phdr_info.dlpi_phdr = phdr;
92		15	break;
93			case AUX_phnum:
94		15	phnum = aux->au_v;
95		15	_static_phdr_info.dlpi_phnum = phnum;
96		15	break;
97			#endif /* !PIC */
98			}
99			}
100
101			#ifndef PIC
102			/* static libc in a static link? */
103	✓✗	15	if (cleanup == NULL)
104		15	setup_static_tib(phdr, phnum);
105			#endif /* !PIC */
106
107	✗✓	15	if (cleanup != NULL)
108			atexit(cleanup);
109
110		15	return &environ;
111			}
112
113			#ifndef PIC
114			/*
115			* static libc in a static link? Then disable kbind and set up
116			* __progname and environ
117			*/
118			static inline void
119			early_static_init(char argv, char envp)
120			{
121			static char progname_storage[NAME_MAX+1];
122
123			/* disable kbind */
124		30	syscall(SYS_kbind, (void *)NULL, (size_t)0, (long long)0);
125
126		15	environ = envp;
127
128			/* set up __progname */
129	✓✗	15	if (argv != NULL) { / NULL ptr if argc = 0 */
130		15	const char p = strrchr(argv, '/');
131
132	✗✓	15	if (p == NULL)
133			p = *argv;
134			else
135		15	p++;
136		15	strlcpy(progname_storage, p, sizeof(progname_storage));
137		15	}
138		15	__progname = progname_storage;
139		15	}
140
141			/*
142			* static TLS handling
143			*/
144			#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
145
146			/* for static binaries, the location and size of the TLS image */
147			static void *static_tls;
148			static size_t static_tls_fsize;
149
150			size_t _static_tls_size = 0;
151
152			static inline void
153			setup_static_tib(Elf_Phdr *phdr, int phnum)
154			{
155			struct tib *tib;
156			char *base;
157			int i;
158
159	✓✗	30	if (phdr != NULL) {
160	✓✓	300	for (i = 0; i < phnum; i++) {
161	✗✓	135	if (phdr[i].p_type != PT_TLS)
162			continue;
163			if (phdr[i].p_memsz == 0)
164			break;
165			if (phdr[i].p_memsz < phdr[i].p_filesz)
166			break; /* invalid */
167			#if TLS_VARIANT == 1
168			_static_tls_size = phdr[i].p_memsz;
169			#elif TLS_VARIANT == 2
170			/*
171			* variant 2 places the data before the TIB
172			* so we need to round up to the alignment
173			*/
174			_static_tls_size = ELF_ROUND(phdr[i].p_memsz,
175			phdr[i].p_align);
176			#endif
177			if (phdr[i].p_vaddr != 0 && phdr[i].p_filesz != 0) {
178			static_tls = (void *)phdr[i].p_vaddr;
179			static_tls_fsize = phdr[i].p_filesz;
180			}
181			break;
182			}
183			}
184
185			/*
186			* We call getpagesize() here instead of using _pagesize because
187			* there's no aux-vector in non-PIE static links, so _pagesize
188			* might not be set yet. If so getpagesize() will get the value.
189			*/
190		15	base = mmap(NULL, ELF_ROUND(_static_tls_size + sizeof *tib,
191			getpagesize()), PROT_READ\|PROT_WRITE, MAP_ANON\|MAP_PRIVATE, -1, 0);
192			# if TLS_VARIANT == 1
193			tib = (struct tib *)base;
194			# elif TLS_VARIANT == 2
195		15	tib = (struct tib *)(base + _static_tls_size);
196			# endif
197
198		15	_static_tls_init(base);
199		15	TIB_INIT(tib, NULL, NULL);
200		15	tib->tib_tid = getthrid();
201		15	TCB_SET(TIB_TO_TCB(tib));
202			#if ! TCB_HAVE_MD_GET
203			_libc_single_tcb = TIB_TO_TCB(tib);
204			#endif
205		15	}
206
207			void
208			_static_tls_init(char *base)
209			{
210	✗✓	30	if (_static_tls_size) {
211			#if TLS_VARIANT == 1
212			base += sizeof(struct tib);
213			#endif
214			if (static_tls != NULL)
215			memcpy(base, static_tls, static_tls_fsize);
216			memset(base + static_tls_fsize, 0,
217			_static_tls_size - static_tls_fsize);
218			}
219		15	}
220			#endif /* !PIC */