/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Konstantin Belousov <kib@freebsd.org>
 * 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. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/auxv.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/sysctl.h>

#include <machine/tls.h>

#include <link.h>
#include <stddef.h>
#include <string.h>

#include "libc_private.h"

void __pthread_map_stacks_exec(void);

int
__elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr)
{
        const Elf_Phdr *ph;
        int i;

        for (i = 0; i < phdr_info->dlpi_phnum; i++) {
                ph = &phdr_info->dlpi_phdr[i];
                if (ph->p_type != PT_LOAD)
                        continue;

                /* ELFv1 ABI for powerpc64 passes function descriptor
                 * pointers around, not function pointers.  The function
                 * descriptors live in .opd, which is a non-executable segment.
                 * The PF_X check would therefore make all address checks fail,
                 * causing a crash in some instances.  Don't skip over
                 * non-executable segments in the ELFv1 powerpc64 case.
                 */
#if !defined(__powerpc64__) || (defined(_CALL_ELF) && _CALL_ELF == 2)
                if ((ph->p_flags & PF_X) == 0)
                        continue;
#endif

                if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr &&
                    (uintptr_t)addr < phdr_info->dlpi_addr +
                    ph->p_vaddr + ph->p_memsz)
                        break;
        }
        return (i != phdr_info->dlpi_phnum);
}

void
__libc_map_stacks_exec(void)
{
        int mib[2];
        struct rlimit rlim;
        u_long usrstack, stacksz;
        size_t len;
        
        if (_elf_aux_info(AT_USRSTACKBASE, &usrstack, sizeof(usrstack)) != 0) {
                mib[0] = CTL_KERN;
                mib[1] = KERN_USRSTACK;
                len = sizeof(usrstack);
                if (sysctl(mib, nitems(mib), &usrstack, &len, NULL, 0) == -1)
                        return;
        }
        if (_elf_aux_info(AT_USRSTACKLIM, &stacksz, sizeof(stacksz)) != 0) {
                if (getrlimit(RLIMIT_STACK, &rlim) == -1)
                        return;
                stacksz = rlim.rlim_cur;
        }
        mprotect((void *)(uintptr_t)(usrstack - stacksz), stacksz,
            _rtld_get_stack_prot());
}

#pragma weak __pthread_map_stacks_exec
void
__pthread_map_stacks_exec(void)
{

        ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])();
}