Public bug reported:
I have just upgraded my Kubuntu system from 11.10 to 12.04, and then
installed virtualbox. I have gotten far enough to install
Oracle_VM_VirtualBox_Extension_Pack, so that I can use USB 2.0, and to
add myself to the vboxusers group. I have not yet started installing
Windows XP inside my new virtualbox.
I am seeing the following error on both version 4.1.12 (in the 12.04
release) and in the latest downloadable version from Oracle 4.1.16.
Everytime I start up virtualbox, I get the error:
[CODE]Error opening file for reading: Permission denied[/CODE]
Running strace on this process (well, seems I have to run it on the
shell within which I start virtualbox) I can see the following:
[CODE]
15128 open("/proc/self/auxv", O_RDONLY) = -1 EACCES (Permission denied)
15128 dup(2) = 19
15128 fcntl(19, F_GETFL) = 0x8002 (flags O_RDWR|O_LARGEFILE)
15128 fstat(19, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 0), ...}) = 0
15128 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
= 0x7fe3d6b13000
15128 lseek(19, 0, SEEK_CUR) = -1 ESPIPE (Illegal seek)
15128 write(19, "Error opening file for reading: "..., 50) = 50
15128 close(19) = 0
[/CODE]
This error does not seem to cause a problem, and the virtualbox session
proceeds without further problems.
Looking about the web, I see that virtualbox is apparently trying to
open /proc/self/auxv in order to determine some system capabilities, and
that it is realized that this is not a reliable method -- auxv may or
may not be readable.
In my situation, auxv is reliably NOT readable .
The following shell command reliably shows the contents of what is, I
suspect, the desired auxv information:
[CODE]LD_SHOW_AUXV=1 /bin/true[/CODE]
For example on my Kubuntu 12.04 amd64 system, it shows:
[CODE]
AT_SYSINFO_EHDR: 0x7fffcd7c4000
AT_HWCAP: bfebfbff
AT_PAGESZ: 4096
AT_CLKTCK: 100
AT_PHDR: 0x400040
AT_PHENT: 56
AT_PHNUM: 9
AT_BASE: 0x7ffc2640c000
AT_FLAGS: 0x0
AT_ENTRY: 0x401134
AT_UID: 1000
AT_EUID: 1000
AT_GID: 1000
AT_EGID: 1000
AT_SECURE: 0
AT_RANDOM: 0x7fffcd772489
AT_EXECFN: /bin/true
AT_PLATFORM: x86_64
[/CODE]
The following code might provide a useful and reliable means of parsing
this auxv information:
[CODE]
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/*
* The following flgets() and examine_auxv() routines are Copyright
* 2006 and 2012 respectively by Paul Jackson <p...@usa.net>.
*
* These routines are free software; you can redistribute them and/or
* modify them under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You may obtain a copy of this license from: <http://www.gnu.org/licenses/>.
*/
/*
* char *flgets(char *buf, int buflen, FILE *fp)
*
* Obtain one line from input file fp. Copy up to first
* buflen-1 chars of line into buffer buf, discarding rest
* of line. Stop reading at newline, discarding newline.
* Nul terminate result and return pointer to buffer buf
* on success, or NULL if nothing more to read or failure.
*
* Paul Jackson
* p...@usa.net
* 20 Feb 2006
*/
static char *flgets(char *buf, int buflen, FILE * fp)
{
int c = -1;
char *bp;
bp = buf;
while ((--buflen > 0) && ((c = getc(fp)) >= 0)) {
if (c == '\n')
goto newline;
*bp++ = c;
}
if ((c < 0) && (bp == buf))
return NULL;
if (c > 0) {
while ((c = getc(fp)) >= 0) {
if (c == '\n')
break;
}
}
newline:
*bp++ = '\0';
return buf;
}
/*
* int examine_auxv(const char *pattern, char *buf, int buflen)
*
* Examine /proc/self/auxv, as formatted in the manner
* seen by running the command:
* LD_SHOW_AUXV=1 /bin/true
* Return the first line that has some substring matching
* the input "pattern". Return up to the first (buflen-1)
* characters of that line, nul-terminated, in the provided
* buffer "buf".
*
* Only the first buflen-1 characters of each line are examined
* for the input pattern. If that pattern is not entirely
* contained within those buflen-1 characters, it will not
* found on that line.
*
* Return zero if a match is found and placed in buf, else
* return -1 and (in most cases - see popen(3) man page)
* set errno appropriately. If no match is found, the
* buffer buf is overwritten with the last line of input
* from the above command.
*
* Paul Jackson
* p...@usa.net
* 17 June 2012
*/
int examine_auxv(const char *pattern, char *buf, int buflen)
{
char *bp;
FILE *fp;
fp = popen("LD_SHOW_AUXV=1 /bin/true", "r");
while ((bp = flgets(buf, buflen, fp)) != NULL) {
if (strstr(bp, pattern) != NULL) {
pclose(fp);
return 0;
}
}
pclose(fp);
return -1;
}
/*
* Test case for above:
*/
#define BUFLEN 256
char buf[BUFLEN];
int main(int argc, char *argv[])
{
int i;
for (i = 1; i < argc; i++) {
if (examine_auxv(argv[i], buf, BUFLEN) == 0)
printf ("%s ==> %s\n", argv[i], buf);
}
exit(0);
}
[/CODE]
** Affects: virtualbox (Ubuntu)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/1014487
Title:
virtualbox: Error opening file for reading
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