Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Author: Aleksa Sarai <cyphar@cyphar.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2018-2019 SUSE LLC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #define _GNU_SOURCE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <stdbool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <syscall.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <limits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include "helpers.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) bool needs_openat2(const struct open_how *how)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 	return how->resolve != 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) int raw_openat2(int dfd, const char *path, void *how, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	int ret = syscall(__NR_openat2, dfd, path, how, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	return ret >= 0 ? ret : -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) int sys_openat2(int dfd, const char *path, struct open_how *how)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	return raw_openat2(dfd, path, how, sizeof(*how));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) int sys_openat(int dfd, const char *path, struct open_how *how)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	int ret = openat(dfd, path, how->flags, how->mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	return ret >= 0 ? ret : -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) int sys_renameat2(int olddirfd, const char *oldpath,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		  int newdirfd, const char *newpath, unsigned int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	int ret = syscall(__NR_renameat2, olddirfd, oldpath,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 					  newdirfd, newpath, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return ret >= 0 ? ret : -errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) int touchat(int dfd, const char *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	int fd = openat(dfd, path, O_CREAT, 0700);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	if (fd >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) char *fdreadlink(int fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	char *target, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	E_asprintf(&tmp, "/proc/self/fd/%d", fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	target = malloc(PATH_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	if (!target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		ksft_exit_fail_msg("fdreadlink: malloc failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	memset(target, 0, PATH_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	E_readlink(tmp, target, PATH_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	free(tmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	return target;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) bool fdequal(int fd, int dfd, const char *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	char *fdpath, *dfdpath, *other;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	bool cmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	fdpath = fdreadlink(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	dfdpath = fdreadlink(dfd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		E_asprintf(&other, "%s", dfdpath);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	else if (*path == '/')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		E_asprintf(&other, "%s", path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		E_asprintf(&other, "%s/%s", dfdpath, path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	cmp = !strcmp(fdpath, other);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	free(fdpath);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	free(dfdpath);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	free(other);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	return cmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) bool openat2_supported = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) void __attribute__((constructor)) init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	struct open_how how = {};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	/* Check openat2(2) support. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	fd = sys_openat2(AT_FDCWD, ".", &how);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	openat2_supported = (fd >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	if (fd >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		close(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }