From ae581a19fbe896a797450b9d9573fb66f2735227 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 16:37:38 +0200 Subject: Adding upstream version 1.9.13p3. Signed-off-by: Daniel Baumann --- lib/util/mmap_alloc.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 lib/util/mmap_alloc.c (limited to 'lib/util/mmap_alloc.c') diff --git a/lib/util/mmap_alloc.c b/lib/util/mmap_alloc.c new file mode 100644 index 0000000..cd678a0 --- /dev/null +++ b/lib/util/mmap_alloc.c @@ -0,0 +1,160 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2008 Otto Moerbeek + * Copyright (c) 2022 Todd C. Miller + * + * 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. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include + +#include +#include + +#include +#include +#include +#if defined(HAVE_STDINT_H) +# include +#elif defined(HAVE_INTTYPES_H) +# include +#endif + +#include "sudo_compat.h" +#include "sudo_util.h" + +#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS) +# define MAP_ANON MAP_ANONYMOUS +#endif + +#ifndef MAP_FAILED +# define MAP_FAILED ((void *)-1) +#endif + +/* + * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX + * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW + */ +#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) + +/* + * Allocate "size" bytes via mmap(). + * Space is allocated to store the size for later unmapping. + */ +void * +sudo_mmap_alloc_v1(size_t size) +{ + void *ptr; + unsigned long *ulp; +#ifndef MAP_ANON + int fd; + + /* SunOS-style mmap allocation using /dev/zero. */ + if ((fd = open("/dev/zero", O_RDWR)) == -1) + return NULL; + size += sizeof(unsigned long); + ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + close(fd); +#else + size += sizeof(unsigned long); + ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); +#endif + if (ptr == MAP_FAILED) { + errno = ENOMEM; + return NULL; + } + + /* Store size before the actual data. */ + ulp = (unsigned long *)ptr; + ulp[0] = size; + return (void *)&ulp[1]; +} + +/* + * Allocate "nmemb" elements of "size" bytes via mmap(). + * If overflow would occur, errno is set to ENOMEM and + * NULL is returned. + */ +void * +sudo_mmap_allocarray_v1(size_t nmemb, size_t size) +{ + if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && + nmemb > 0 && SIZE_MAX / nmemb < size) { + errno = ENOMEM; + return NULL; + } + return sudo_mmap_alloc_v1(nmemb * size); +} + +/* + * Make a copy of "str" via mmap() and return it. + */ +char * +sudo_mmap_strdup_v1(const char *str) +{ + size_t len = strlen(str); + char *newstr; + + if (len == SIZE_MAX) { + errno = ENOMEM; + return NULL; + } + newstr = sudo_mmap_alloc_v1(len + 1); + if (newstr != NULL) { + memcpy(newstr, str, len); + newstr[len] = '\0'; + } + + return newstr; +} + +/* + * Set the page permissions for the allocation represented by "ptr" to + * read-only. Returns 0 on success, -1 on failure. + */ +int +sudo_mmap_protect_v1(void *ptr) +{ + if (ptr != NULL) { + unsigned long *ulp = ptr; + const unsigned long size = ulp[-1]; + return mprotect((void *)&ulp[-1], size, PROT_READ); + } + + /* Can't protect NULL. */ + errno = EINVAL; + return -1; +} + +/* + * Free "ptr" allocated by sudo_mmap_alloc(). + * The allocated size is stored (as unsigned long) in ptr[-1]. + */ +void +sudo_mmap_free_v1(void *ptr) +{ + if (ptr != NULL) { + unsigned long *ulp = (unsigned long *)ptr - 1; + const unsigned long size = ulp[0]; + int saved_errno = errno; + + (void)munmap((void *)ulp, size); + errno = saved_errno; + } +} -- cgit v1.2.3