Red Hat Bugzilla – Bug 589638
opcontrol accepting bogus values for --cpu-buffer-size argument
Last modified: 2016-09-19 22:06:19 EDT
Description of problem: RHEL5 oprofile did not allow the value for --cpu-buffer-size for be invalid (albeit maybe accidentally - see the additional info below). The parameter is supposed to be a number. RHEL6 oprofile accepts negative values and even a totally bogus value: opcontrol --deinit; opcontrol --start --no-vmlinux --cpu-buffer-size=GGHHGGNEE opcontrol --deinit; opcontrol --start --no-vmlinux --cpu-buffer-size=-20 Oprofile starts without any problem. When using --verbose, you can see that oprofile doesn't sanitize the value: (...) CPU_BUF_SIZE -20 (...) However, oprofile does not seem to be misbehaving with this input, so perhaps the values are sanitized (or ignored) somewhere later. But IMO it would be good to actively refuse bogus arguments. Version-Release number of selected component (if applicable): oprofile-0.9.6-4.el6 How reproducible: always Steps to Reproduce: 1. opcontrol --start --no-vmlinux --cpu-buffer-size=GGHHGGNEE Actual results: oprofile starts Expected results: oprofile refuses to start, or at least issues a warning Additional info: RHEL5 oprofile's behavior: # opcontrol --start --no-vmlinux --cpu-buffer-size=gghdgs Using default event: CPU_CLK_UNHALTED:100000:0:1:1 Using 2.6+ OProfile kernel interface. Failed to open profile device: Cannot allocate memory Couldn't start oprofiled. Check the log file "/var/lib/oprofile/samples/oprofiled.log" and kernel syslog The failure to start seems to be caused by active refusal from some internal memory allocation function which was passed wrong parameters, than some real sanity check.
Please be so kind and add a few key words to the Technical Note field of this Bugzilla entry using the following structure: Cause: Consequence: Fix: Result: For details, see: https://bugzilla.redhat.com/page.cgi?id=fields.html#cf_release_notes Thanks
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Cause: Consequence: Fix: Result:
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1,7 +1,7 @@ -Cause: +Cause: Using non-numeric arguments for opcontrol options that require numerical arguments (--buffer-size, --buffer-watershed,--cpu-buffer-size, and --callgraph) -Consequence: +Consequence: opcontrol would write bogus values to /dev/oprofile files. -Fix: +Fix: Add argument checking to opcontrol -Result:+Result: opcontrol will report illegal argument rather than blindly writing them to /dev/oprofile files.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1,7 +1,7 @@ -Cause: Using non-numeric arguments for opcontrol options that require numerical arguments (--buffer-size, --buffer-watershed,--cpu-buffer-size, and --callgraph) +Cause: Passing non-numeric arguments for opcontrol options that require numerical arguments (--buffer-size, --buffer-watershed,--cpu-buffer-size, and --callgraph) would be written to /dev/oprofile files as is. -Consequence: opcontrol would write bogus values to /dev/oprofile files. +Consequence: opcontrol would write bogus values as-is to /dev/oprofile files. -Fix: Add argument checking to opcontrol +Fix: Numeric argument checking added to opcontrol. -Result: opcontrol will report illegal argument rather than blindly writing them to /dev/oprofile files.+Result: opcontrol will report illegal non-numeric argument rather than blindly writing them to /dev/oprofile files.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2011-0566.html