Orange Pi5 kernel

^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) 2015 Thomas Meyer (thomas@m3y3r.de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^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) #include <stdio.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 <signal.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/resource.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <as-layout.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <kern_util.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <um_malloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #define PGD_BOUND (4 * 1024 * 1024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #define STACKSIZE (8 * 1024 * 1024)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #define THREAD_NAME_LEN (256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) long elf_aux_hwcap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) static void set_stklim(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct rlimit lim;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	if (getrlimit(RLIMIT_STACK, &lim) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 		perror("getrlimit");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 		lim.rlim_cur = STACKSIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 		if (setrlimit(RLIMIT_STACK, &lim) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 			perror("setrlimit");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 			exit(1);
^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) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) static void last_ditch_exit(int sig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	uml_cleanup();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) static void install_fatal_handler(int sig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	struct sigaction action;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	/* All signals are enabled in this handler ... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	sigemptyset(&action.sa_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	 * ... including the signal being handled, plus we want the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	 * handler reset to the default behavior, so that if an exit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	 * handler is hanging for some reason, the UML will just die
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	 * after this signal is sent a second time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	action.sa_flags = SA_RESETHAND | SA_NODEFER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	action.sa_restorer = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	action.sa_handler = last_ditch_exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (sigaction(sig, &action, NULL) < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		os_warn("failed to install handler for signal %d "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 			"- errno = %d\n", sig, errno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		exit(1);
^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) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) #define UML_LIB_PATH	":" OS_LIB_PATH "/uml"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) static void setup_env_path(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	char *new_path = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	char *old_path = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	int path_len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	old_path = getenv("PATH");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	 * if no PATH variable is set or it has an empty value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	 * just use the default + /usr/lib/uml
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	if (!old_path || (path_len = strlen(old_path)) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			perror("couldn't putenv");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		return;
^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) 	/* append /usr/lib/uml to the existing path */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	path_len += strlen("PATH=" UML_LIB_PATH) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	new_path = malloc(path_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	if (!new_path) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		perror("couldn't malloc to set a new PATH");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	if (putenv(new_path)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		perror("couldn't putenv to set a new PATH");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		free(new_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) extern void scan_elf_aux( char **envp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) int __init main(int argc, char **argv, char **envp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	char **new_argv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	int ret, i, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	set_stklim();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	setup_env_path();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	setsid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	new_argv = malloc((argc + 1) * sizeof(char *));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	if (new_argv == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 		perror("Mallocing argv");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	for (i = 0; i < argc; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 		new_argv[i] = strdup(argv[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		if (new_argv[i] == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 			perror("Mallocing an arg");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 			exit(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	new_argv[argc] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	 * Allow these signals to bring down a UML if all other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	 * methods of control fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	install_fatal_handler(SIGINT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	install_fatal_handler(SIGTERM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	scan_elf_aux(envp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	change_sig(SIGPIPE, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	ret = linux_main(argc, argv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	 * Disable SIGPROF - I have no idea why libc doesn't do this or turn
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	 * off the profiling time, but UML dies with a SIGPROF just before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	 * exiting when profiling is active.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	change_sig(SIGPROF, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	 * This signal stuff used to be in the reboot case.  However,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	 * sometimes a timer signal can come in when we're halting (reproducably
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	 * when writing out gcov information, presumably because that takes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	 * some time) and cause a segfault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	/* stop timers and set timer signal to be ignored */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	os_timer_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	/* disable SIGIO for the fds and set SIGIO to be ignored */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	err = deactivate_all_fds();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		os_warn("deactivate_all_fds failed, errno = %d\n", -err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	 * Let any pending signals fire now.  This ensures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	 * that they won't be delivered after the exec, when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	 * they are definitely not expected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	unblock_signals();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	os_info("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	/* Reboot */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		execvp(new_argv[0], new_argv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		perror("Failed to exec kernel");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	return uml_exitcode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) extern void *__real_malloc(int);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) void *__wrap_malloc(int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	void *ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	if (!kmalloc_ok)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		return __real_malloc(size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	else if (size <= UM_KERN_PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		/* finding contiguous pages can be hard*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		ret = uml_kmalloc(size, UM_GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	else ret = vmalloc(size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	 * glibc people insist that if malloc fails, errno should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	 * set by malloc as well. So we do.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	if (ret == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		errno = ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) void *__wrap_calloc(int n, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	void *ptr = __wrap_malloc(n * size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	if (ptr == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	memset(ptr, 0, n * size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	return ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) extern void __real_free(void *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) extern unsigned long high_physmem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) void __wrap_free(void *ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	unsigned long addr = (unsigned long) ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	 * We need to know how the allocation happened, so it can be correctly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	 * freed.  This is done by seeing what region of memory the pointer is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	 * in -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	 * 	physical memory - kmalloc/kfree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	 *	kernel virtual memory - vmalloc/vfree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	 * 	anywhere else - malloc/free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	 * If kmalloc is not yet possible, then either high_physmem and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	 * end_vm are still 0 (as at startup), in which case we call free, or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	 * we have set them, but anyway addr has not been allocated from those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	 * areas. So, in both cases __real_free is called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	 * CAN_KMALLOC is checked because it would be bad to free a buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	 * with kmalloc/vmalloc after they have been turned off during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	 * shutdown.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	 * there is a possibility for memory leaks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	if ((addr >= uml_physmem) && (addr < high_physmem)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		if (kmalloc_ok)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 			kfree(ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	else if ((addr >= start_vm) && (addr < end_vm)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		if (kmalloc_ok)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 			vfree(ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	else __real_free(ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) }