#include <fcntl.h>
#include <sys/types.h>
#include <sys/mman.h>
+#include <sys/statfs.h>
#include "kern_util.h"
#include "user.h"
#include "user_util.h"
#include <sys/param.h>
+static char *default_tmpdir = "/tmp";
static char *tempdir = NULL;
static void __init find_tempdir(void)
break;
}
if((dir == NULL) || (*dir == '\0'))
- dir = "/tmp";
+ dir = default_tmpdir;
tempdir = malloc(strlen(dir) + 2);
if(tempdir == NULL){
strcat(tempdir, "/");
}
+/* This will return 1, with the first character in buf being the
+ * character following the next instance of c in the file. This will
+ * read the file as needed. If there's an error, -errno is returned;
+ * if the end of the file is reached, 0 is returned.
+ */
+static int next(int fd, char *buf, int size, char c)
+{
+ int n, len;
+ char *ptr;
+
+ while((ptr = strchr(buf, c)) == NULL){
+ n = read(fd, buf, size - 1);
+ if(n == 0)
+ return 0;
+ else if(n < 0)
+ return -errno;
+
+ buf[n] = '\0';
+ }
+
+ ptr++;
+ len = strlen(ptr);
+ memmove(buf, ptr, len + 1);
+
+ /* Refill the buffer so that if there's a partial string that we care
+ * about, it will be completed, and we can recognize it.
+ */
+ n = read(fd, &buf[len], size - len - 1);
+ if(n < 0)
+ return -errno;
+
+ buf[len + n] = '\0';
+ return 1;
+}
+
+static int checked_tmpdir = 0;
+
+/* Look for a tmpfs mounted at /dev/shm. I couldn't find a cleaner
+ * way to do this than to parse /proc/mounts. statfs will return the
+ * same filesystem magic number and fs id for both /dev and /dev/shm
+ * when they are both tmpfs, so you can't tell if they are different
+ * filesystems. Also, there seems to be no other way of finding the
+ * mount point of a filesystem from within it.
+ *
+ * If a /dev/shm tmpfs entry is found, then we switch to using it.
+ * Otherwise, we stay with the default /tmp.
+ */
+static void which_tmpdir(void)
+{
+ int fd, found;
+ char buf[128] = { '\0' };
+
+ if(checked_tmpdir)
+ return;
+
+ checked_tmpdir = 1;
+
+ printf("Checking for tmpfs mount on /dev/shm...");
+
+ fd = open("/proc/mounts", O_RDONLY);
+ if(fd < 0){
+ printf("failed to open /proc/mounts, errno = %d\n", errno);
+ return;
+ }
+
+ while(1){
+ found = next(fd, buf, ARRAY_SIZE(buf), ' ');
+ if(found != 1)
+ break;
+
+ if(!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
+ goto found;
+
+ found = next(fd, buf, ARRAY_SIZE(buf), '\n');
+ if(found != 1)
+ break;
+ }
+
+err:
+ if(found == 0)
+ printf("nothing mounted on /dev/shm\n");
+ else if(found < 0)
+ printf("read returned errno %d\n", -found);
+
+out:
+ close(fd);
+
+ return;
+
+found:
+ found = next(fd, buf, ARRAY_SIZE(buf), ' ');
+ if(found != 1)
+ goto err;
+
+ if(strncmp(buf, "tmpfs", strlen("tmpfs"))){
+ printf("not tmpfs\n");
+ goto out;
+ }
+
+ printf("OK\n");
+ default_tmpdir = "/dev/shm";
+ goto out;
+}
+
/*
* This proc still used in tt-mode
* (file: kernel/tt/ptproxy/proxy.c, proc: start_debugger).
*/
int make_tempfile(const char *template, char **out_tempname, int do_unlink)
{
- char tempname[MAXPATHLEN];
+ char *tempname;
int fd;
+ which_tmpdir();
+ tempname = malloc(MAXPATHLEN);
+
find_tempdir();
- if (*template != '/')
+ if (template[0] != '/')
strcpy(tempname, tempdir);
else
- *tempname = 0;
+ tempname[0] = '\0';
strcat(tempname, template);
fd = mkstemp(tempname);
if(fd < 0){
fprintf(stderr, "open - cannot create %s: %s\n", tempname,
strerror(errno));
- return -1;
+ goto out;
}
if(do_unlink && (unlink(tempname) < 0)){
perror("unlink");
- return -1;
+ goto out;
}
if(out_tempname){
- *out_tempname = strdup(tempname);
- if(*out_tempname == NULL){
- perror("strdup");
- return -1;
- }
+ *out_tempname = tempname;
+ } else {
+ free(tempname);
}
return(fd);
+out:
+ free(tempname);
+ return -1;
}
#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"
exit(1);
}
- if (lseek64(fd, len, SEEK_SET) < 0) {
- perror("os_seek_file");
+ /* Seek to len - 1 because writing a character there will
+ * increase the file size by one byte, to the desired length.
+ */
+ if (lseek64(fd, len - 1, SEEK_SET) < 0) {
+ perror("os_seek_file");
exit(1);
}
return(fd);
}
-static int create_anon_file(unsigned long 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 long len)
{
int err, fd;
- if(have_devanon)
- fd = create_anon_file(len);
- else fd = create_tmp_file(len);
+ fd = create_tmp_file(len);
err = os_set_exec_close(fd, 1);
if(err < 0){
}
return(fd);
}
+
+
+void check_tmpexec(void)
+{
+ void *addr;
+ int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
+
+ addr = mmap(NULL, UM_KERN_PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
+ printf("Checking PROT_EXEC mmap in %s...",tempdir);
+ fflush(stdout);
+ if(addr == MAP_FAILED){
+ err = errno;
+ perror("failed");
+ if(err == EPERM)
+ printf("%s must be not mounted noexec\n",tempdir);
+ exit(1);
+ }
+ printf("OK\n");
+ munmap(addr, UM_KERN_PAGE_SIZE);
+
+ close(fd);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff