Messages in this thread | | | Date | Sun, 3 Jul 2011 21:46:18 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 00/10] Enhance /dev/mem to allow read/write of arbitrary physical addresses |
| |
* Petr Tesarik <ptesarik@suse.cz> wrote:
> > Do you expect distros to enable this boot option by default? I.e. > > would SuSE be willing to ship with a restrictive /dev/mem by > > default? That's really the wider goal we want to work towards. > > I'm not really the decision-maker on this, but even though I don't > need it for crash, there are several other users which would have > to be fixed: > > 1. hwinfo (EFI, MPTABLE and ACPI table parsing, analyzing video BIOS) > 2. dmidecode (SMBIOS, DMI) > 3. possibly others
But those tables wont be in regular RAM (they will be in ROM or in RAM marked non-RAM in a special way in the e820 tables).
dmidecode certainly works on Fedora.
> > Hm, why would the ability "dirty and/or flush an arbitrary > > physical cache line for testing purposes" be a DoS? > > Effectively switching off CPU caches can slow things down quite a > bit... especially on a large SMP system. ;)
Flushing a cacheline isnt switching it off. You can already 'flush' the cache from user-space as well, by trashing it for example. So i don't see the DoS angle.
Thanks,
Ingo
| |