This is the mail archive of the systemtap@sourceware.org mailing list for the systemtap project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH v3 2.6.39-rc1-tip 7/26] 7: x86: analyze instruction and determine fixups.


* Steven Rostedt <rostedt@goodmis.org> [2011-04-19 09:29:11]:

> On Fri, 2011-04-01 at 20:03 +0530, Srikar Dronamraju wrote:
> 
> > +
> > +static void report_bad_prefix(void)
> > +{
> > +	printk(KERN_ERR "uprobes does not currently support probing "
> > +		"instructions with any of the following prefixes: "
> > +		"cs:, ds:, es:, ss:, lock:\n");
> > +}
> > +
> > +static void report_bad_1byte_opcode(int mode, uprobe_opcode_t op)
> > +{
> > +	printk(KERN_ERR "In %d-bit apps, "
> > +		"uprobes does not currently support probing "
> > +		"instructions whose first byte is 0x%2.2x\n", mode, op);
> > +}
> > +
> > +static void report_bad_2byte_opcode(uprobe_opcode_t op)
> > +{
> > +	printk(KERN_ERR "uprobes does not currently support probing "
> > +		"instructions with the 2-byte opcode 0x0f 0x%2.2x\n", op);
> > +}
> 
> Should these really be KERN_ERR, or is KERN_WARNING a better fit?
> 
> Also, can a non-privileged user cause these printks to spam the console
> and cause a DoS to the system?
> 

Sometimes, the user might try registering a probe at a valid file +
valid offset + valid consumer; but an instruction that we cant probe.
Then trying to figure why its failing would be very hard.

how about pr_warn_ratelimited()?

-- 
Thanks and Regards
Srikar


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]