1 files changed, 375 insertions, 0 deletions
diff --git a/lib/libc/gen/dlfcn.c b/lib/libc/gen/dlfcn.c
new file mode 100644
index 000000000000..ae1c8d83df19
--- /dev/null
+++ b/lib/libc/gen/dlfcn.c
@@ -0,0 +1,375 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 1998 John D. Polstra
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if !defined(IN_LIBDL) || defined(PIC)
+
+/*
+ * Linkage to services provided by the dynamic linker.
+ */
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <machine/atomic.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <link.h>
+#include <stddef.h>
+#include <string.h>
+#include "namespace.h"
+#include <pthread.h>
+#include "un-namespace.h"
+#include "rtld.h"
+#include "libc_private.h"
+#include "reentrant.h"
+
+static const char sorry[] = "Service unavailable";
+
+void _rtld_thread_init(void *);
+void _rtld_atfork_pre(int *);
+void _rtld_atfork_post(int *);
+
+/*
+ * For ELF, the dynamic linker directly resolves references to its
+ * services to functions inside the dynamic linker itself.  These
+ * weak-symbol stubs are necessary so that "ld" won't complain about
+ * undefined symbols.  The stubs are executed only when the program is
+ * linked statically, or when a given service isn't implemented in the
+ * dynamic linker.  They must return an error if called, and they must
+ * be weak symbols so that the dynamic linker can override them.
+ */
+
+#pragma weak _rtld_error
+void
+_rtld_error(const char *fmt __unused, ...)
+{
+}
+
+#pragma weak dladdr
+int
+dladdr(const void *addr __unused, Dl_info *dlip __unused)
+{
+
+	_rtld_error(sorry);
+	return (0);
+}
+
+#pragma weak dlclose
+int
+dlclose(void *handle __unused)
+{
+
+	_rtld_error(sorry);
+	return (-1);
+}
+
+#pragma weak dlerror
+char *
+dlerror(void)
+{
+
+	return (__DECONST(char *, sorry));
+}
+
+#pragma weak dllockinit
+void
+dllockinit(void *context,
+    void *(*lock_create)(void *context) __unused,
+    void (*rlock_acquire)(void *lock) __unused,
+    void (*wlock_acquire)(void *lock) __unused,
+    void (*lock_release)(void *lock) __unused,
+    void (*lock_destroy)(void *lock) __unused,
+    void (*context_destroy)(void *context) __unused)
+{
+
+	if (context_destroy != NULL)
+		context_destroy(context);
+}
+
+#pragma weak dlopen
+void *
+dlopen(const char *name __unused, int mode __unused)
+{
+
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak dlsym
+void *
+dlsym(void * __restrict handle __unused, const char * __restrict name __unused)
+{
+
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak dlfunc
+dlfunc_t
+dlfunc(void * __restrict handle __unused, const char * __restrict name __unused)
+{
+
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak dlvsym
+void *
+dlvsym(void * __restrict handle __unused, const char * __restrict name __unused,
+    const char * __restrict version __unused)
+{
+
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak dlinfo
+int
+dlinfo(void * __restrict handle __unused, int request __unused,
+    void * __restrict p __unused)
+{
+
+	_rtld_error(sorry);
+	return (0);
+}
+
+#pragma weak _rtld_thread_init
+void
+_rtld_thread_init(void *li __unused)
+{
+
+	_rtld_error(sorry);
+}
+
+#ifndef IN_LIBDL
+static pthread_once_t dl_phdr_info_once = PTHREAD_ONCE_INIT;
+static struct dl_phdr_info phdr_info;
+#ifndef PIC
+static mutex_t dl_phdr_info_lock = MUTEX_INITIALIZER;
+#endif
+
+static void
+dl_init_phdr_info(void)
+{
+	Elf_Auxinfo *auxp;
+	unsigned int i;
+
+	for (auxp = __elf_aux_vector; auxp->a_type != AT_NULL; auxp++) {
+		switch (auxp->a_type) {
+		case AT_BASE:
+			phdr_info.dlpi_addr = (Elf_Addr)auxp->a_un.a_ptr;
+			break;
+		case AT_EXECPATH:
+			phdr_info.dlpi_name = (const char *)auxp->a_un.a_ptr;
+			break;
+		case AT_PHDR:
+			phdr_info.dlpi_phdr =
+			    (const Elf_Phdr *)auxp->a_un.a_ptr;
+			break;
+		case AT_PHNUM:
+			phdr_info.dlpi_phnum = (Elf_Half)auxp->a_un.a_val;
+			break;
+		}
+	}
+	for (i = 0; i < phdr_info.dlpi_phnum; i++) {
+		if (phdr_info.dlpi_phdr[i].p_type == PT_TLS) {
+			phdr_info.dlpi_tls_modid = 1;
+		}
+	}
+	phdr_info.dlpi_adds = 1;
+}
+#endif
+
+#pragma weak _dl_iterate_phdr_locked
+int _dl_iterate_phdr_locked(int (*callback)(struct dl_phdr_info *,
+    size_t, void *), void *data);
+int
+_dl_iterate_phdr_locked(
+    int (*callback)(struct dl_phdr_info *, size_t, void *) __unused,
+    void *data __unused)
+{
+#if defined IN_LIBDL
+	return (0);
+#elif defined PIC
+	int (*r)(int (*)(struct dl_phdr_info *, size_t, void *), void *);
+
+	r = dlsym(RTLD_DEFAULT, "dl_iterate_phdr");
+	if (r == NULL)
+		return (0);
+	return (r(callback, data));
+#else
+	tls_index ti;
+	int ret;
+
+	__init_elf_aux_vector();
+	if (__elf_aux_vector == NULL)
+		return (1);
+	_once(&dl_phdr_info_once, dl_init_phdr_info);
+	ti.ti_module = 1;
+	ti.ti_offset = -TLS_DTV_OFFSET;
+	phdr_info.dlpi_tls_data = __tls_get_addr(&ti);
+	ret = callback(&phdr_info, sizeof(phdr_info), data);
+	return (ret);
+#endif
+}
+
+#pragma weak dl_iterate_phdr
+int
+dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *) __unused,
+    void *data __unused)
+{
+	int error;
+
+#if !defined(IN_LIBDL) && !defined(PIC)
+	mutex_lock(&dl_phdr_info_lock);
+#endif
+	error = _dl_iterate_phdr_locked(callback, data);
+#if !defined(IN_LIBDL) && !defined(PIC)
+	mutex_unlock(&dl_phdr_info_lock);
+#endif
+	return (error);
+}
+
+#pragma weak fdlopen
+void *
+fdlopen(int fd __unused, int mode __unused)
+{
+
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak _rtld_atfork_pre
+void
+_rtld_atfork_pre(int *locks __unused)
+{
+}
+
+#pragma weak _rtld_atfork_post
+void
+_rtld_atfork_post(int *locks __unused)
+{
+}
+
+#ifndef IN_LIBDL
+struct _rtld_addr_phdr_cb_data {
+	const void *addr;
+	struct dl_phdr_info *dli;
+};
+
+static int
+_rtld_addr_phdr_cb(struct dl_phdr_info *dli, size_t sz, void *arg)
+{
+	struct _rtld_addr_phdr_cb_data *rd;
+	const Elf_Phdr *ph;
+	unsigned i;
+
+	rd = arg;
+	for (i = 0; i < dli->dlpi_phnum; i++) {
+		ph = &dli->dlpi_phdr[i];
+		if (ph->p_type == PT_LOAD &&
+		    dli->dlpi_addr + ph->p_vaddr <= (uintptr_t)rd->addr &&
+		    (uintptr_t)rd->addr < dli->dlpi_addr + ph->p_vaddr +
+		    ph->p_memsz) {
+			memcpy(rd->dli, dli, sz);
+			return (1);
+		}
+	}
+	return (0);
+}
+#endif
+
+#pragma weak _rtld_addr_phdr
+int
+_rtld_addr_phdr(const void *addr __unused,
+    struct dl_phdr_info *phdr_info_a __unused)
+{
+#ifndef IN_LIBDL
+	struct _rtld_addr_phdr_cb_data rd;
+
+	rd.addr = addr;
+	rd.dli = phdr_info_a;
+	return (dl_iterate_phdr(_rtld_addr_phdr_cb, &rd));
+#else
+	return (0);
+#endif
+}
+
+#pragma weak _rtld_get_stack_prot
+int
+_rtld_get_stack_prot(void)
+{
+#ifndef IN_LIBDL
+	unsigned i;
+	int r;
+	static int ret;
+
+	r = atomic_load_int(&ret);
+	if (r != 0)
+		return (r);
+
+	_once(&dl_phdr_info_once, dl_init_phdr_info);
+	r = PROT_EXEC | PROT_READ | PROT_WRITE;
+	for (i = 0; i < phdr_info.dlpi_phnum; i++) {
+		if (phdr_info.dlpi_phdr[i].p_type != PT_GNU_STACK)
+			continue;
+		r = PROT_READ | PROT_WRITE;
+		if ((phdr_info.dlpi_phdr[i].p_flags & PF_X) != 0)
+			r |= PROT_EXEC;
+		break;
+	}
+	atomic_store_int(&ret, r);
+	return (r);
+#else
+	return (0);
+#endif
+}
+
+#pragma weak _rtld_is_dlopened
+int
+_rtld_is_dlopened(void *arg __unused)
+{
+
+	return (0);
+}
+
+#pragma weak rtld_get_var
+const char *
+rtld_get_var(const char *name __unused)
+{
+	_rtld_error(sorry);
+	return (NULL);
+}
+
+#pragma weak rtld_set_var
+int
+rtld_set_var(const char *name __unused, const char *val __unused)
+{
+	_rtld_error(sorry);
+	return (EINVAL);
+}
+
+#endif /* !defined(IN_LIBDL) || defined(PIC) */