^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <stddef.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <sys/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <sys/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <sys/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/magic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /* Set by make_tempfile() during early boot. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static char *tempdir = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /* Check if dir is on tmpfs. Return 0 if yes, -1 if no or error. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) static int __init check_tmpfs(const char *dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct statfs st;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) os_info("Checking if %s is on tmpfs...", dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) if (statfs(dir, &st) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) os_info("%s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) } else if (st.f_type != TMPFS_MAGIC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) os_info("no\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) os_info("OK\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * Choose the tempdir to use. We want something on tmpfs so that our memory is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * not subject to the host's vm.dirty_ratio. If a tempdir is specified in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * environment, we use that even if it's not on tmpfs, but we warn the user.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * Otherwise, we try common tmpfs locations, and if no tmpfs directory is found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * then we fall back to /tmp.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static char * __init choose_tempdir(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) static const char * const vars[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) "TMPDIR",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) "TMP",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) "TEMP",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static const char fallback_dir[] = "/tmp";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static const char * const tmpfs_dirs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) "/dev/shm",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) fallback_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) const char *dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) os_info("Checking environment variables for a tempdir...");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) for (i = 0; vars[i]; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) dir = getenv(vars[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if ((dir != NULL) && (*dir != '\0')) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) os_info("%s\n", dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) if (check_tmpfs(dir) >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) goto warn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) os_info("none found\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) for (i = 0; tmpfs_dirs[i]; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) dir = tmpfs_dirs[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (check_tmpfs(dir) >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) goto done;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) dir = fallback_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) warn:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) os_warn("Warning: tempdir %s is not on tmpfs\n", dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) done:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /* Make a copy since getenv results may not remain valid forever. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) return strdup(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * Create an unlinked tempfile in a suitable tempdir. template must be the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * basename part of the template with a leading '/'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) static int __init make_tempfile(const char *template)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) char *tempname;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) if (tempdir == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) tempdir = choose_tempdir();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (tempdir == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) os_warn("Failed to choose tempdir: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) #ifdef O_TMPFILE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) fd = open(tempdir, O_CLOEXEC | O_RDWR | O_EXCL | O_TMPFILE, 0700);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * If the running system does not support O_TMPFILE flag then retry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * without it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (fd != -1 || (errno != EINVAL && errno != EISDIR &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) errno != EOPNOTSUPP))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) tempname = malloc(strlen(tempdir) + strlen(template) + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) if (tempname == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) strcpy(tempname, tempdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) strcat(tempname, template);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) fd = mkstemp(tempname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) if (fd < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) os_warn("open - cannot create %s: %s\n", tempname,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) if (unlink(tempname) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) perror("unlink");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) goto close;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) free(tempname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) close:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) free(tempname);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) #define TEMPNAME_TEMPLATE "/vm_file-XXXXXX"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static int __init create_tmp_file(unsigned long long len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) int fd, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) char zero;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) fd = make_tempfile(TEMPNAME_TEMPLATE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) if (fd < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * Seek to len - 1 because writing a character there will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * increase the file size by one byte, to the desired length.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) if (lseek64(fd, len - 1, SEEK_SET) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) perror("lseek64");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) zero = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) err = write(fd, &zero, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) if (err != 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) perror("write");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) int __init create_mem_file(unsigned long long len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) int err, fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) fd = create_tmp_file(len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) err = os_set_exec_close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) errno = -err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) perror("exec_close");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) void __init check_tmpexec(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) void *addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) addr = mmap(NULL, UM_KERN_PAGE_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) os_info("Checking PROT_EXEC mmap in %s...", tempdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) if (addr == MAP_FAILED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) err = errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) os_warn("%s\n", strerror(err));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) if (err == EPERM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) os_warn("%s must be not mounted noexec\n", tempdir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) os_info("OK\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) munmap(addr, UM_KERN_PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags