RE: Linux audit performance impact
by Viswanath, Logeswari P (MCOU OSTL)
Hi all,
We did profiling of the kernel (using perf tool) during our performance test and below were the top 4 functions for the overhead.
11.33% loader1 [kernel.kallsyms] [k] format_decode
10.40% loader1 [kernel.kallsyms] [k] memcpy
7.46% loader1 [kernel.kallsyms] [k] number.isra.1
6.99% loader1 [kernel.kallsyms] [k] vsnprintf
I was unable to attach the entire profiling data of the kernel because it exceeds the limit of 80KB.
>From the perf data, we believed the overhead is because of invoking audit_log_format function multiple times.
We changed the code to reduce the number of times this function is called.
With this change the performance degradation is 20% now compared to the performance without auditing.
Without this change the performance degradation is 200% compared to the performance without auditing.
We can publish the code change done tomorrow.
Please let me know your feedback on this idea.
Regards,
Logeswari.
-----Original Message-----
From: Richard Guy Briggs [mailto:rgb@redhat.com]
Sent: Wednesday, February 11, 2015 10:21 PM
To: Viswanath, Logeswari P (MCOU OSTL)
Cc: linux-audit(a)redhat.com
Subject: Re: Linux audit performance impact
On 15/02/06, Viswanath, Logeswari P (MCOU OSTL) wrote:
> Hi all,
>
> Please find the below the details of the performance test we ran.
> It would be great if we get help to identify the reason behind the degradation and the ways of improving it.
>
> Kernel Version:
> root > uname -r
> 3.13.0-36-generic
>
> OS Version:
> Ubuntu 14.04.1
>
> No. of CPUs:
> root > nproc
> 24
>
> Audit Status:
> root > auditctl -s
> AUDIT_STATUS: enabled=1 flag=1 pid=0 rate_limit=0 backlog_limit=320
> lost=57190353 backlog=0
>
> Rules Configured:
> root > auditctl -l
> LIST_RULES: exit,always arch=3221225534 (0xc000003e) syscall=all
>
> Attached is the program used to load the system.
>
> Results:
>
> Without enabling audit 12.29
> With auditing enabled and no rules configured 12.31
> With auditing enabled, 1 rule configured but auditd not running - kauditd logs audit records to syslog via printk 41.02
This would be more meaningful if you hacked the kernel to drain the queue figuratively to /dev/nul to eliminate the effect of auditd draining it, or syslog covering for a missing auditd. This stat doesn't tell us that much since the I/O act can vary significantly per installation. That one rule you chose is pretty unnaturally abusive and needs to be carefully thought out to avoid self-measurement.
> The degradation is around 200%
>
> Regards,
> Logeswari.
>
> -----Original Message-----
> From: Richard Guy Briggs [mailto:rgb@redhat.com]
> Sent: Wednesday, February 04, 2015 9:46 PM
> To: Viswanath, Logeswari P (MCOU OSTL)
> Cc: Satish Chandra Kilaru; Steve Grubb; linux-audit(a)redhat.com
> Subject: Re: Linux audit performance impact
>
> On 15/02/04, Viswanath, Logeswari P (MCOU OSTL) wrote:
> > The intent is to calculate the performance impact by the auditing
> > components such as
> >
> > 1) impact because of kauditd without auditd - but kauditd writes to syslog, so we are unable to determine the impact just because of kauditd - It is fine even if the audit record is dropped by kauditd. Is there any way to do this?
>
> Not yet. That is a mode that has not been useful to anyone yet. You are welcome to hack a custom kernel to disable klog for doing testing instrumentation.
>
> > 2) impact because of running auditd - log format NOLOG
> > 3) impact because of running audispd - small plugin is written which will just read the audit records and doesn't processes it.
> >
> > -----Original Message-----
> > From: Richard Guy Briggs [mailto:rgb@redhat.com]
> > Sent: Tuesday, February 03, 2015 10:33 PM
> > To: Satish Chandra Kilaru
> > Cc: Viswanath, Logeswari P (MCOU OSTL); Steve Grubb;
> > linux-audit(a)redhat.com
> > Subject: Re: Linux audit performance impact
> >
> > On 15/02/03, Satish Chandra Kilaru wrote:
> > > Thanks for The info. But my question was rhetorical... I meant to
> > > say that it would not be much... She is trying to bombard the
> > > system with open calls ... So lots and lots of events will be
> > > generated and kernel has to write down the events some where or discard them...
> >
> > Exactly. It is of little practical use. You have to do I/O at some point, either to the same disk or another, or to a network interface or serial port, otherwise, just chuck it out. You could do a performance measurement on a short burst, then drain the queue, but what will that actually tell us?
> >
> > > On Tuesday, February 3, 2015, Richard Guy Briggs <rgb(a)redhat.com> wrote:
> > >
> > > > On 15/02/03, Satish Chandra Kilaru wrote:
> > > > > How many events can kernel accumulate without I/o ?
> > > >
> > > > The kernel default is 64 *buffers*, but I think Fedora and RHEL
> > > > set it to 320. It is now possible to set it to "0" which means
> > > > limited only by system resources. See "man auditctl", "-b"
> > > > option. An event can be made up of several buffers.
> > > >
> > > > Of course, how long a system lasts before the queue blows up
> > > > depends on your rule set...
> > > >
> > > > However, at the moment, it will still write out to klog if
> > > > auditd isn't running.
> > > >
> > > > > On Tuesday, February 3, 2015, Viswanath, Logeswari P (MCOU
> > > > > OSTL) < logeswari.pv(a)hp.com <javascript:;>> wrote:
> > > > >
> > > > > > I don't want to disable auditing (i.e. disable audit record
> > > > collection),
> > > > > > but just do not want the records to delivered to user space
> > > > > > since I
> > > > want to
> > > > > > remove the I/O overhead while running the performance test.
> > > > > > Is there any option for this?
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Richard Guy Briggs [mailto:rgb@redhat.com
> > > > > > <javascript:;>
> > > > <javascript:;>]
> > > > > > Sent: Thursday, January 29, 2015 10:23 PM
> > > > > > To: Viswanath, Logeswari P (MCOU OSTL)
> > > > > > Cc: Satish Chandra Kilaru; Steve Grubb;
> > > > > > linux-audit(a)redhat.com
> > > > <javascript:;>
> > > > > > <javascript:;>
> > > > > > Subject: Re: Linux audit performance impact
> > > > > >
> > > > > > On 15/01/29, Viswanath, Logeswari P (MCOU OSTL) wrote:
> > > > > > > Please read my question as “Is there any option to
> > > > > > > configure kaudit not to log audit records to syslog? when auditd not running.”
> > > > > >
> > > > > > Yeah, remove audit=1 from the kernel command line, or set
> > > > > > audit=0 in
> > > > its
> > > > > > place. This will stop all but AVCs and if auditd has ever
> > > > > > run since
> > > > boot.
> > > > > > If audit=0 is on the kernel boot line, it will be impossible
> > > > > > to run
> > > > auditd.
> > > > > >
> > > > > > There is a feature request that is likely coming soon that
> > > > > > could be
> > > > > > useful:
> > > > > >
> > > > > > https://bugzilla.redhat.com/show_bug.cgi?id=1160046
> > > > > > "If no audit daemon is running, but an audit multicast
> > > > > > subscriber is around, then the kernel shouldn't forward audit data to kmsg"
> > > > > >
> > > > > > > From: Viswanath, Logeswari P (MCOU OSTL)
> > > > > > > Sent: Thursday, January 29, 2015 11:49 AM
> > > > > > > To: 'Satish Chandra Kilaru'; Steve Grubb
> > > > > > > Cc: linux-audit(a)redhat.com <javascript:;> <javascript:;>
> > > > > > > Subject: RE: Linux audit performance impact
> > > > > > >
> > > > > > > Is there any option to configure kaudit not to log audit
> > > > > > > records to
> > > > > > syslog when auditd is running?
> > > > > > > This way we can assess the impact of enabling audit
> > > > > > > without involving
> > > > > > disk I/o overhead.
> > > > > > >
> > > > > > > From: Satish Chandra Kilaru [mailto:iam.kilaru@gmail.com
> > > > <javascript:;> <javascript:;>]
> > > > > > > Sent: Thursday, January 29, 2015 9:12 AM
> > > > > > > To: Steve Grubb
> > > > > > > Cc: linux-audit(a)redhat.com <javascript:;> <javascript:;><mailto:
> > > > linux-audit(a)redhat.com <javascript:;>
> > > > > > <javascript:;>>; Viswanath,
> > > > > > > Logeswari P (MCOU OSTL)
> > > > > > > Subject: Re: Linux audit performance impact
> > > > > > >
> > > > > > > I agree with you... but writing to disk can trigger
> > > > > > > further events
> > > > > > leading spiralling of events...
> > > > > > > I brought down my server few times with stupid rules...
> > > > > > >
> > > > > > > On Wed, Jan 28, 2015 at 10:39 PM, Steve Grubb
> > > > > > > <sgrubb(a)redhat.com
> > > > <javascript:;>
> > > > > > <javascript:;><mailto:sgrubb@redhat.com <javascript:;>
> > > > <javascript:;>>> wrote:
> > > > > > > On Wednesday, January 28, 2015 10:18:47 AM Satish Chandra
> > > > > > > Kilaru
> > > > wrote:
> > > > > > > > Write your own program to receive audit events directly
> > > > > > > > without using auditd...
> > > > > > > > That should be faster ....
> > > > > > > > Auditd will log the events to disk causing more I/o than u need...
> > > > > > >
> > > > > > > But even that is configurable in many ways. You can decide
> > > > > > > if you
> > > > want
> > > > > > > logging to disk or not and what kind of assurance that it
> > > > > > > made it to disk and the priority of that audit daemon.
> > > > > > > Then you also have all
> > > > the
> > > > > > > normal tuning knobs for disk throughput that you would use
> > > > > > > for any disk performance critical system.
> > > > > > >
> > > > > > > -Steve
> > > > > > >
> > > > > > > > On Wednesday, January 28, 2015, Viswanath, Logeswari P
> > > > > > > > (MCOU
> > > > > > > > OSTL)
> > > > <
> > > > > > > >
> > > > > > > > logeswari.pv(a)hp.com <javascript:;> <javascript:;><mailto:
> > > > logeswari.pv(a)hp.com <javascript:;>
> > > > > > <javascript:;>>> wrote:
> > > > > > > > > Hi Steve,
> > > > > > > > >
> > > > > > > > > I am Logeswari working for HP.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > We want to know audit performance impact on RHEL and
> > > > > > > > > Suse linux
> > > > to
> > > > > > > > > help us evaluate linux audit as data source for our
> > > > > > > > > host based
> > > > IDS.
> > > > > > > > >
> > > > > > > > > When we ran our own performance test with a test
> > > > > > > > > audispd plugin, we found if a system can perform
> > > > > > > > > 200000 open/close system calls per second without
> > > > > > > > > auditing, system can perform only 3000 open/close
> > > > > > > > > system calls auditing is enabled for open/close system
> > > > > > > > > call which is a HUGE impact on the system performance.
> > > > > > > > > It would
> > > > be
> > > > > > > > > great if anyone can help us answering the following questions.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > 1) Is this performance impact expected? If yes, what is the
> > > > > > reason
> > > > > > > > > behind it and can we fix it?
> > > > > > > > >
> > > > > > > > > 2) Have anyone done any benchmarking for performance
> > > > impact? If
> > > > > > yes,
> > > > > > > > > can you please share the numbers and also the
> > > > > > > > > steps/programs used the run the same.
> > > > > > > > >
> > > > > > > > > 3) Help us validating the performance test we have done in
> > > > our
> > > > > > test
> > > > > > > > > setup using the steps mentioned along with the results attached.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Attached test program (loader.c) to invoke open and
> > > > > > > > > close system
> > > > > > calls.
> > > > > > > > >
> > > > > > > > > Attached idskerndsp is the audispd plugin program.
> > > > > > > > >
> > > > > > > > > We used time command to determine how much time the
> > > > > > > > > system took
> > > > to
> > > > > > > > > complete 50000 open/close system calls without
> > > > > > > > > (results attached
> > > > > > > > > Without-auditing) and with auditing enabled on the
> > > > > > > > > system (With-auditing-NOLOG-audispd-plugin and
> > > > > > > > > With-auditing-RAW)
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > System details:
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > 1 CPU machine
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > *OS Version*
> > > > > > > > >
> > > > > > > > > RHEL 6.5
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > *Kernel Version*
> > > > > > > > >
> > > > > > > > > uname –r
> > > > > > > > >
> > > > > > > > > 2.6.32-431.el6.x86_64
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Note: auditd was occupying 35% of CPU and was sleeping
> > > > > > > > > for most
> > > > of
> > > > > > > > > the time whereas kauditd was occupying 20% of the CPU.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Thanks & Regards,
> > > > > > > > >
> > > > > > > > > Logeswari.
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > Please Donate to
> > > > > > > www.wikipedia.org<http://www.wikipedia.org>
> > > > > >
> > > > > > > --
> > > > > > > Linux-audit mailing list
> > > > > > > Linux-audit(a)redhat.com <javascript:;> <javascript:;>
> > > > > > > https://www.redhat.com/mailman/listinfo/linux-audit
> > > > > >
> > > > > >
> > > > > > - RGB
> > > > > >
> > > > > > --
> > > > > > Richard Guy Briggs <rbriggs(a)redhat.com <javascript:;>
> > > > > > <javascript:;>> Senior Software Engineer, Kernel Security,
> > > > > > AMER ENG Base Operating Systems, Red Hat Remote, Ottawa,
> > > > > > Canada
> > > > > > Voice: +1.647.777.2635, Internal: (81) 32635, Alt:
> > > > > > +1.613.693.0684x3545
> > > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Please Donate to www.wikipedia.org
> > > >
> > > > - RGB
> > > >
> > > > --
> > > > Richard Guy Briggs <rbriggs(a)redhat.com <javascript:;>> Senior
> > > > Software Engineer, Kernel Security, AMER ENG Base Operating
> > > > Systems, Red Hat Remote, Ottawa, Canada
> > > > Voice: +1.647.777.2635, Internal: (81) 32635, Alt:
> > > > +1.613.693.0684x3545
> > > >
> > >
> > >
> > > --
> > > Please Donate to www.wikipedia.org
> >
> > - RGB
> >
> > --
> > Richard Guy Briggs <rbriggs(a)redhat.com> Senior Software Engineer,
> > Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote,
> > Ottawa, Canada
> > Voice: +1.647.777.2635, Internal: (81) 32635, Alt:
> > +1.613.693.0684x3545
>
> - RGB
>
> --
> Richard Guy Briggs <rbriggs(a)redhat.com> Senior Software Engineer,
> Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote,
> Ottawa, Canada
> Voice: +1.647.777.2635, Internal: (81) 32635, Alt:
> +1.613.693.0684x3545
> #include <stdio.h>
> #include <stdlib.h>
> #include <sys/stat.h>
> #include <fcntl.h>
> #include <unistd.h>
> #include <errno.h>
>
> void create_load(int iters);
> void cleanup();
>
> int high_rate = 0;
> int num_iters = 100000;
> int fd1;
> char file1[50];
> char file2[50];
> char dir1[50];
> char symlink1[50];
>
> /* Purpose: To create system load by invoking system calls used by templates.
> *
> * Note: The unlink(2) of a file can be an expensive operation (i.e., event
> * rate goes way down).
> */
>
> main(int argc, char **argv) {
>
> int num_children=1;
> int iters;
> int i;
> char c;
>
> while ((c = getopt(argc, argv, "hi:")) != -1) {
> switch (c) {
> case 'h':
> /*
> * Desire "high" event rate
> */
> high_rate = 1;
> argc--;
> break;
> case 'i':
> /*
> * Desire a specified number of iterations
> */
> num_iters = atoi(optarg);
> argc--;
> break;
> default:
> fprintf(stderr,"Unknown option: %c\n",optarg);
> exit(1);
> }
> }
>
>
> /*if(argv[optind] != NULL) {
> num_children = atoi(argv[optind]);
> } else {
> num_children = 0;
> }
> Register cleanup routine */
> fprintf(stderr,"Registering cleanup routine...\n");
> if (atexit(cleanup) == -1) {
> fprintf(stderr,"Error calling atexit(), errno=%d(%s)\n",
> errno,strerror(errno));
> exit(1);
> }
>
>
> /* fork child processes, if any requested */
> for(i=1; i < num_children; i++) {
> if(fork() == 0) {
>
> printf("child pid: %d\n",getpid());
>
> /* Setup file names based on child's pid */
> sprintf(file1,"./file1_%d",getpid());
> sprintf(file2,"./file2_%d",getpid());
> sprintf(dir1,"./dir1_%d",getpid());
> sprintf(symlink1,"./file1symlink_%d",getpid());
>
> /* each child creates load */
> iters=0;
> if (num_iters == -1) {
> while(1) {
> create_load(iters);
> iters++;
> if( (iters % 1000) == 0) {
> printf("pid %d iteration %d\n",getpid(),iters);
> }
> }
> } else {
> while(iters < num_iters) {
> create_load(iters);
> iters++;
> if( (iters % 1000) == 0) {
> printf("pid %d iteration %d\n",getpid(),iters);
> }
> }
> }
> }
> }
>
> /* Parent creates load also */
> printf("parent pid: %d\n",getpid());
>
> /* Setup file names based on parent's pid */
> sprintf(file1,"./file1_%d",getpid());
> sprintf(file2,"./file2_%d",getpid());
> sprintf(dir1,"./dir1_%d",getpid());
> sprintf(symlink1,"./file1symlink_%d",getpid());
>
> iters=0;
> if (num_iters == -1) {
> while(1) {
> create_load(iters);
> iters++;
> if( (iters % 1000) == 0) {
> printf("pid %d iteration %d\n",getpid(),iters);
> }
> }
> } else {
> while(iters < num_iters) {
> create_load(iters);
> iters++;
> if( (iters % 1000) == 0) {
> printf("pid %d iteration %d\n",getpid(),iters);
> }
> }
> }
>
> } /* main */
>
>
> void create_load(int iters) {
>
> int pid;
> char *args[2];
> struct stat stat_buf;
>
> fd1 = creat(file1,0x644);
> if (fd1 == -1) {
> fprintf(stderr,"pid %d: creat() returned error for file %s, errno=%d(%s)\n",
> getpid(),file1,errno,strerror(errno));
> exit(1);
> }
> if (close(fd1) == -1) {
> fprintf(stderr,"pid %d: close() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> fd1 = open(file1, O_RDWR, 0777);
> if (fd1 == -1) {
> fprintf(stderr,"pid %d: open() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
>
> /* Chown this file to root instead of user ids so that we don't generate a
> * non-owned alert when the file is truncated when invoking creat() again
> * as root on an existing file owned by another user.
> */
> if (chown(file1,0,0) == -1) {
> fprintf(stderr,"pid %d: chown(%d,%d) returned error, errno=%d(%s)\n",
> getpid(),0,0,errno,strerror(errno));
> exit(1);
> }
>
> if (fchown(fd1,0,0) == -1) {
> fprintf(stderr,"pid %d: fchown(%d,%d) returned error, errno=%d(%s)\n",
> getpid(),0,0,errno,strerror(errno));
> exit(1);
> }
>
> if (chmod(file1, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) == -1) {
> fprintf(stderr,"pid %d: chmod(S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> if (fchmod(fd1, S_IXUSR|S_IXGRP|S_IXOTH) == -1) {
> fprintf(stderr,"pid %d: fchmod(S_IXUSR|S_IXGRP|S_IXOTH) returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
>
>
> if (write(fd1,"Some stuff",strlen("Some stuff")) == -1) {
> fprintf(stderr,"pid %d: write() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> if (ftruncate(fd1,7) == -1) {
> fprintf(stderr,"pid %d: ftruncate() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> if (close(fd1) == -1) {
> fprintf(stderr,"pid %d: close() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
>
> if (truncate(file1,3) == -1) {
> fprintf(stderr,"pid %d: truncate() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> if (rename(file1,file2) == -1) {
> fprintf(stderr,"pid %d: rename(%s,%s) returned error, errno=%d(%s)\n",
> getpid(),file1,file2,errno,strerror(errno));
> exit(1);
> }
> if (rename(file2,file1) == -1) {
> fprintf(stderr,"pid %d: rename(%s,%s) returned error, errno=%d(%s)\n",
> getpid(),file2,file1,errno,strerror(errno));
> exit(1);
> }
> if (link(file1,file2) == -1) {
> fprintf(stderr,"pid %d: link(%s,%s) returned error, errno=%d(%s)\n",
> getpid(),file1,file2,errno,strerror(errno));
> exit(1);
> }
> if (symlink(file1,symlink1) == -1) {
> fprintf(stderr,"pid %d: symlink(%s,%s) returned error, errno=%d(%s)\n",
> getpid(),file1,symlink1,errno,strerror(errno));
> exit(1);
> }
> if (lchown(symlink1,0,0) == -1) {
> fprintf(stderr,"pid %d: lchown(%s,%d,%d) returned error, errno=%d(%s)\n",
> getpid(),symlink1,0,0,errno,strerror(errno));
> exit(1);
> }
>
> if (lstat(symlink1,&stat_buf) == -1) {
> fprintf(stderr,"pid %d: lstat(%s) returned error, errno=%d(%s)\n",
> getpid(),symlink1,errno,strerror(errno));
> exit(1);
> }
> if (stat(file1,&stat_buf) == -1) {
> fprintf(stderr,"pid %d: stat(%s) returned error, errno=%d(%s)\n",
> getpid(),file1,errno,strerror(errno));
> exit(1);
> }
> if (unlink(file1) == -1) {
> fprintf(stderr,"pid %d: unlink(%s) returned error, errno=%d(%s)\n",
> getpid(),file1,errno,strerror(errno));
> exit(1);
> }
> if (unlink(file2) == -1) {
> fprintf(stderr,"pid %d: unlink(%s) returned error, errno=%d(%s)\n",
> getpid(),file2,errno,strerror(errno));
> exit(1);
> }
> if (unlink(symlink1) == -1) {
> fprintf(stderr,"pid %d: unlink(%s) returned error, errno=%d(%s)\n",
> getpid(),symlink1,errno,strerror(errno));
> exit(1);
> }
> if (mkdir(dir1,S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP) == -1) {
> fprintf(stderr,"pid %d: mkdir() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> if (rmdir(dir1) == -1) {
> fprintf(stderr,"pid %d: rmdir() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
>
> /* Fork every 10000 iterations to not use up process resources too quickly */
> if ( (iters % 10000) == 0) {
> pid = fork();
> if(pid == 0) {
> fprintf(stderr,"child pid %d: fork!\n",getpid());
> // child
> args[0] = "/bin/ls";
> args[1] = NULL;
> close(1);
> close(2);
> execve(args[0], args, NULL);
> fprintf(stderr,"pid %d: execve(%s) returned error, errno=%d(%s)\n",
> getpid(),args[0],errno,strerror(errno));
> _exit(1);
> } else if (pid < 0) {
> fprintf(stderr,"pid %d: fork() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> } else {
> fprintf(stderr,"parent pid %d, child pid: %d: fork!\n",getpid(),pid);
> }
>
> pid = vfork();
> if(pid == 0) {
> args[0] = "/bin/pwd";
> args[1] = NULL;
> close(1);
> close(2);
> execv(args[0], args);
> fprintf(stderr,"pid %d: execve(%s) returned error, errno=%d(%s)\n",
> getpid(),args[0],errno,strerror(errno));
> _exit(1);
> } else if (pid < 0) {
> fprintf(stderr,"pid %d: vfork() returned error, errno=%d(%s)\n",
> getpid(),errno,strerror(errno));
> exit(1);
> }
> }
>
> /* Make sure everything is cleaned up and deleted before returning */
> cleanup();
>
> } /* create_load() */
>
> void cleanup() {
> close(fd1);
> unlink(file1);
> unlink(file2);
> unlink(symlink1);
> unlink(dir1);
> return;
> }
> --
> Linux-audit mailing list
> Linux-audit(a)redhat.com
> https://www.redhat.com/mailman/listinfo/linux-audit
- RGB
--
Richard Guy Briggs <rbriggs(a)redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
