linux/arch/um/os-Linux/mem.c
Paolo 'Blaisorblade' Giarrusso 87276f721a [PATCH] uml: fix big stack user
Switch this proc from storing 4k of data (a whole path) on the stack to
keeping it on the heap.

Maybe it's not called in process context but only in early boot context (where
in UML you have a normal process stack on the host) but just to be safe, fix
it.

While at it some little readability simplifications.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:37 -07:00

140 lines
2.4 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;
int fd;
tempname = malloc(MAXPATHLEN);
find_tempdir();
if (template[0] != '/')
strcpy(tempname, tempdir);
else
tempname[0] = '\0';
strcat(tempname, template);
fd = mkstemp(tempname);
if(fd < 0){
fprintf(stderr, "open - cannot create %s: %s\n", tempname,
strerror(errno));
goto out;
}
if(do_unlink && (unlink(tempname) < 0)){
perror("unlink");
goto out;
}
if(out_tempname){
*out_tempname = tempname;
} else {
free(tempname);
}
return(fd);
out:
free(tempname);
return -1;
}
#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 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);
}
int create_mem_file(unsigned long long len)
{
int err, fd;
fd = create_tmp_file(len);
err = os_set_exec_close(fd, 1);
if(err < 0){
errno = -err;
perror("exec_close");
}
return(fd);
}