OpenCloudOS-Kernel/arch/um/os-Linux/mem.c

162 lines
2.8 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include "kern_util.h"
#include "user.h"
#include "user_util.h"
#include "mem_user.h"
#include "init.h"
#include "os.h"
#include "tempfile.h"
#include "kern_constants.h"
#include <sys/param.h>
static char *tempdir = NULL;
static void __init find_tempdir(void)
{
char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
int i;
char *dir = NULL;
if(tempdir != NULL) return; /* We've already been called */
for(i = 0; dirs[i]; i++){
dir = getenv(dirs[i]);
if((dir != NULL) && (*dir != '\0'))
break;
}
if((dir == NULL) || (*dir == '\0'))
dir = "/tmp";
tempdir = malloc(strlen(dir) + 2);
if(tempdir == NULL){
fprintf(stderr, "Failed to malloc tempdir, "
"errno = %d\n", errno);
return;
}
strcpy(tempdir, dir);
strcat(tempdir, "/");
}
/*
* This proc still used in tt-mode
* (file: kernel/tt/ptproxy/proxy.c, proc: start_debugger).
* So it isn't 'static' yet.
*/
int make_tempfile(const char *template, char **out_tempname, int do_unlink)
{
char tempname[MAXPATHLEN];
int fd;
find_tempdir();
if (*template != '/')
strcpy(tempname, tempdir);
else
*tempname = 0;
strcat(tempname, template);
fd = mkstemp(tempname);
if(fd < 0){
fprintf(stderr, "open - cannot create %s: %s\n", tempname,
strerror(errno));
return -1;
}
if(do_unlink && (unlink(tempname) < 0)){
perror("unlink");
return -1;
}
if(out_tempname){
*out_tempname = strdup(tempname);
if(*out_tempname == NULL){
perror("strdup");
return -1;
}
}
return(fd);
}
#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"
/*
* This proc is used in start_up.c
* So it isn't 'static'.
*/
int create_tmp_file(unsigned long len)
{
int fd, err;
char zero;
fd = make_tempfile(TEMPNAME_TEMPLATE, NULL, 1);
if(fd < 0) {
exit(1);
}
err = fchmod(fd, 0777);
if(err < 0){
perror("os_mode_fd");
exit(1);
}
if (lseek64(fd, len, SEEK_SET) < 0) {
perror("os_seek_file");
exit(1);
}
zero = 0;
err = os_write_file(fd, &zero, 1);
if(err != 1){
errno = -err;
perror("os_write_file");
exit(1);
}
return(fd);
}
static int create_anon_file(unsigned long len)
{
void *addr;
int fd;
fd = open("/dev/anon", O_RDWR);
if(fd < 0) {
perror("opening /dev/anon");
exit(1);
}
addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if(addr == MAP_FAILED){
perror("mapping physmem file");
exit(1);
}
munmap(addr, len);
return(fd);
}
extern int have_devanon;
int create_mem_file(unsigned long len)
{
int err, fd;
if(have_devanon)
fd = create_anon_file(len);
else fd = create_tmp_file(len);
err = os_set_exec_close(fd, 1);
if(err < 0){
errno = -err;
perror("exec_close");
}
return(fd);
}