Messages in this thread | | | Subject | Re: Two fixes for 2.4.19-pre5-ac3 | From | (Eric W. Biederman) | Date | 08 Apr 2002 11:53:38 -0600 |
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"Philippe Elie" <phil.el@wanadoo.fr> writes:
> From: "Bill Davidsen" <davidsen@tmr.com> > Sent: Monday, April 08, 2002 4:48 PM >
> > For legitimate use, if any, a compile-time optional system call could be > > added requiring a capability to use, and programs which are currently > > doing that (AFS?) can be converted to use another f/s interface. I have > > seen a few mentions of software which DO use that capability, I'm not sure > > I've seen one which can be done no other way. > > As stated oprofile needs it, there is no other efficient way to track exec, > mmap and other sys call needed for profiler. I hope a consensus can > be reach : explain than unloading module wich patch the sys call table > are unsafe on SMP, discourage the use of sys call table patch, but do > not forbid that.
In times past when people were working on the vm86 system call you needed a modified version of insmod, that could read System.map.
If you are going to be doing strange things I don't see why that shouldn't still be required.
Though I am wondering if the sane approach for a profiler might not to be have a kernel conditional compilation directive that simply patches the syscall path. The overhead is probably less as well.
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