text: /* $NetBSD: t_mlock.c,v 1.6 2016/08/09 12:02:44 kre Exp $ */
  
  /*-
   * Copyright (c) 2012 The NetBSD Foundation, Inc.
   * All rights reserved.
   *
   * This code is derived from software contributed to The NetBSD Foundation
   * by Jukka Ruohonen.
   *
   * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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/cdefs.h>
  __RCSID("$NetBSD: t_mlock.c,v 1.6 2016/08/09 12:02:44 kre Exp $");
  
  #ifdef __FreeBSD__
  #include <sys/param.h> /* NetBSD requires sys/param.h for sysctl(3), unlike FreeBSD */
  #endif
  #include <sys/mman.h>
  #include <sys/resource.h>
  #include <sys/sysctl.h>
  #include <sys/wait.h>
  
  #include <errno.h>
  #include <atf-c.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  
  #ifdef __FreeBSD__
  #include <limits.h>
  #define _KMEMUSER
  #include <machine/vmparam.h>
  #endif
  
  static long page = 0;
  
  #ifdef __FreeBSD__
  #define	VM_MAX_WIRED "vm.max_wired"
  
  static void
  vm_max_wired_sysctl(int *old_value, int *new_value)
  {
  	size_t old_len;
  	size_t new_len = (new_value == NULL ? 0 : sizeof(int));
  
  	if (old_value == NULL)
  		printf("Setting the new value to %d\n", *new_value);
  	else {
  		ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, NULL, &old_len,
  		    new_value, new_len) == 0,
  		    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
  	}
  
  	ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, old_value, &old_len,
  	    new_value, new_len) == 0,
  	    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
  
  	if (old_value != NULL)
  		printf("Saved the old value (%d)\n", *old_value);
  }
  
  static void
  set_vm_max_wired(int new_value)
  {
  	FILE *fp;
  	int old_value;
  
  	fp = fopen(VM_MAX_WIRED, "w");
  	if (fp == NULL) {
  		atf_tc_skip("could not open %s for writing: %s",
  		    VM_MAX_WIRED, strerror(errno));
  		return;
  	}
  
  	vm_max_wired_sysctl(&old_value, NULL);
  
  	ATF_REQUIRE_MSG(fprintf(fp, "%d", old_value) > 0,
  	    "saving %s failed", VM_MAX_WIRED);
  
  	fclose(fp);
  
  	vm_max_wired_sysctl(NULL, &new_value);
  }
  
  static void
  restore_vm_max_wired(void)
  {
  	FILE *fp;
  	int saved_max_wired;
  
  	fp = fopen(VM_MAX_WIRED, "r");
  	if (fp == NULL) {
  		perror("fopen failed\n");
  		return;
  	}
  
  	if (fscanf(fp, "%d", &saved_max_wired) != 1) {
  		perror("fscanf failed\n");
  		fclose(fp);
  		return;
  	}
  
  	fclose(fp);
  	printf("old value in %s: %d\n", VM_MAX_WIRED, saved_max_wired);
  
  	if (saved_max_wired == 0) /* This will cripple the test host */
  		return;
  
  	vm_max_wired_sysctl(NULL, &saved_max_wired);
  }
  #endif
  
  ATF_TC(mlock_clip);
  ATF_TC_HEAD(mlock_clip, tc)
  {
  	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
  	    "clips if the clip address is within the entry (PR kern/44788)");
  }
  
  ATF_TC_BODY(mlock_clip, tc)
  {
  	void *buf;
  
  	buf = malloc(page);
  	ATF_REQUIRE(buf != NULL);
  
  	if (page < 1024)
  		atf_tc_skip("page size too small");
  
  	for (size_t i = page; i >= 1; i = i - 1024) {
  		(void)mlock(buf, page - i);
  		(void)munlock(buf, page - i);
  	}
  
  	free(buf);
  }
  
  #ifdef __FreeBSD__
  ATF_TC_WITH_CLEANUP(mlock_err);
  #else
  ATF_TC(mlock_err);
  #endif
  ATF_TC_HEAD(mlock_err, tc)
  {
  	atf_tc_set_md_var(tc, "descr",
  	    "Test error conditions in mlock(2) and munlock(2)");
  #ifdef __FreeBSD__
  	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
  	atf_tc_set_md_var(tc, "require.user", "root");
  #endif
  }
  
  ATF_TC_BODY(mlock_err, tc)
  {
  #ifdef __NetBSD__
  	unsigned long vmin = 0;
  	size_t len = sizeof(vmin);
  #endif
  #if !defined(__aarch64__) && !defined(__riscv__)
  	void *invalid_ptr;
  #endif
  	int null_errno = ENOMEM;	/* error expected for NULL */
  	void *buf;
  
  #ifdef __FreeBSD__
  #ifdef VM_MIN_ADDRESS
  	if ((uintptr_t)VM_MIN_ADDRESS > 0)
  		null_errno = EINVAL;	/* NULL is not inside user VM */
  #endif
  	/* Set max_wired really really high to avoid EAGAIN */
  	set_vm_max_wired(INT_MAX);
  #else
  	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
  		atf_tc_fail("failed to read vm.minaddress");
  	/*
  	 * Any bad address must return ENOMEM (for lock & unlock)
  	 */
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
  
  	if (vmin > 0)
  		null_errno = EINVAL;	/* NULL is not inside user VM */
  #endif
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
  
  	buf = malloc(page);
  	ATF_REQUIRE(buf != NULL);
  
  	/*
  	 * unlocking memory that is not locked is an error...
  	 */
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
  
  /* There is no sbrk on AArch64 and RISC-V */
  #if !defined(__aarch64__) && !defined(__riscv__)
  	/*
  	 * These are permitted to fail (EINVAL) but do not on NetBSD
  	 */
  	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
  	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
  
  	(void)free(buf);
  
  	/*
  	 * Try to create a pointer to an unmapped page - first after current
  	 * brk will likely do.
  	 */
  	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
  	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
  
  	errno = 0;
  	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
  #endif
  }
  
  #ifdef __FreeBSD__
  ATF_TC_CLEANUP(mlock_err, tc)
  {
  
  	restore_vm_max_wired();
  }
  #endif
  
  ATF_TC(mlock_limits);
  ATF_TC_HEAD(mlock_limits, tc)
  {
  	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
  }
  
  ATF_TC_BODY(mlock_limits, tc)
  {
  	struct rlimit res;
  	void *buf;
  	pid_t pid;
  	int sta;
  
  	buf = malloc(page);
  	ATF_REQUIRE(buf != NULL);
  
  	pid = fork();
  	ATF_REQUIRE(pid >= 0);
  
  	if (pid == 0) {
  
  		for (ssize_t i = page; i >= 2; i -= 100) {
  
  			res.rlim_cur = i - 1;
  			res.rlim_max = i - 1;
  
  			(void)fprintf(stderr, "trying to lock %zd bytes "
  			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
  
  			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
  				_exit(EXIT_FAILURE);
  
  			errno = 0;
  
  #ifdef __FreeBSD__
  			/*
  			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
  			 * FreeBSD does.
  			 *
  			 * See: NetBSD PR # kern/48962 for more details.
  			 */
  			if (mlock(buf, i) != -1 || errno != ENOMEM) {
  #else
  			if (mlock(buf, i) != -1 || errno != EAGAIN) {
  #endif
  				(void)munlock(buf, i);
  				_exit(EXIT_FAILURE);
  			}
  		}
  
  		_exit(EXIT_SUCCESS);
  	}
  
  	(void)wait(&sta);
  
  	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
  		atf_tc_fail("mlock(2) locked beyond system limits");
  
  	free(buf);
  }
  
  #ifdef __FreeBSD__
  ATF_TC_WITH_CLEANUP(mlock_mmap);
  #else
  ATF_TC(mlock_mmap);
  #endif
  ATF_TC_HEAD(mlock_mmap, tc)
  {
  	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
  #ifdef __FreeBSD__
  	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
  	atf_tc_set_md_var(tc, "require.user", "root");
  #endif
  }
  
  ATF_TC_BODY(mlock_mmap, tc)
  {
  #ifdef __NetBSD__
  	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
  #else
  	static const int flags = MAP_ANON | MAP_PRIVATE;
  #endif
  	void *buf;
  
  #ifdef __FreeBSD__
  	/* Set max_wired really really high to avoid EAGAIN */
  	set_vm_max_wired(INT_MAX);
  #endif
  
  	/*
  	 * Make a wired RW mapping and check that mlock(2)
  	 * does not fail for the (already locked) mapping.
  	 */
  	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
  
  	ATF_REQUIRE(buf != MAP_FAILED);
  #ifdef __FreeBSD__
  	/*
  	 * The duplicate mlock call is added to ensure that the call works
  	 * as described above without MAP_WIRED support.
  	 */
  	ATF_REQUIRE(mlock(buf, page) == 0);
  #endif
  	ATF_REQUIRE(mlock(buf, page) == 0);
  	ATF_REQUIRE(munlock(buf, page) == 0);
  	ATF_REQUIRE(munmap(buf, page) == 0);
  	ATF_REQUIRE(munlock(buf, page) != 0);
  
  	/*
  	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
  	 */
  	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
  
  	ATF_REQUIRE(buf != MAP_FAILED);
  #ifdef __FreeBSD__
  	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
  #else
  	ATF_REQUIRE(mlock(buf, page) != 0);
  #endif
  	ATF_REQUIRE(munmap(buf, page) == 0);
  }
  
  #ifdef __FreeBSD__
  ATF_TC_CLEANUP(mlock_mmap, tc)
  {
  
  	restore_vm_max_wired();
  }
  #endif
  
  #ifdef __FreeBSD__
  ATF_TC_WITH_CLEANUP(mlock_nested);
  #else
  ATF_TC(mlock_nested);
  #endif
  ATF_TC_HEAD(mlock_nested, tc)
  {
  	atf_tc_set_md_var(tc, "descr",
  	    "Test that consecutive mlock(2) calls succeed");
  #ifdef __FreeBSD__
  	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
  	atf_tc_set_md_var(tc, "require.user", "root");
  #endif
  }
  
  ATF_TC_BODY(mlock_nested, tc)
  {
  	const size_t maxiter = 100;
  	void *buf;
  
  #ifdef __FreeBSD__
  	/* Set max_wired really really high to avoid EAGAIN */
  	set_vm_max_wired(INT_MAX);
  #endif
  
  	buf = malloc(page);
  	ATF_REQUIRE(buf != NULL);
  
  	for (size_t i = 0; i < maxiter; i++)
  		ATF_REQUIRE(mlock(buf, page) == 0);
  
  	ATF_REQUIRE(munlock(buf, page) == 0);
  	free(buf);
  }
  
  #ifdef __FreeBSD__
  ATF_TC_CLEANUP(mlock_nested, tc)
  {
  
  	restore_vm_max_wired();
  }
  #endif
  
  ATF_TP_ADD_TCS(tp)
  {
  
  	page = sysconf(_SC_PAGESIZE);
  	ATF_REQUIRE(page >= 0);
  
  	ATF_TP_ADD_TC(tp, mlock_clip);
  	ATF_TP_ADD_TC(tp, mlock_err);
  	ATF_TP_ADD_TC(tp, mlock_limits);
  	ATF_TP_ADD_TC(tp, mlock_mmap);
  	ATF_TP_ADD_TC(tp, mlock_nested);
  
  	return atf_no_error();
  }
  