Messages in this thread | | | Date | Tue, 19 Mar 2013 10:21:48 -0400 | From | Prarit Bhargava <> | Subject | Re: [PATCH] hpet, allow user controlled mmap for user processes |
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On 03/19/2013 03:43 AM, Clemens Ladisch wrote: > Prarit Bhargava wrote: >> The CONFIG_HPET_MMAP Kconfig option exposes the memory map of the HPET >> registers to userspace. The Kconfig help points out that in some cases this >> can be a security risk as some systems may erroneously configure the map such >> that additional data is exposed to userspace. >> >> This is a problem for distributions -- some users want the MMAP functionality >> but it comes with a significant security risk. In an effort to mitigate this >> risk, and due to the low number of users of the MMAP functionality, I've >> introduced a kernel parameter, hpet_mmap_enable, that is required in order >> to actually have the HPET MMAP exposed. >> >> [v2]: Clemens suggested modifying the Kconfig help text and making the >> default setting configurable. >> >> Signed-off-by: Prarit Bhargava <prarit@redhat.com> >> Cc: Clemens Ladisch <clemens@ladisch.de> > >> +++ b/Documentation/kernel-parameters.txt >> + hpet_mmap_enable [X86, HPET_MMAP] option to expose HPET MMAP to >> + userspace. By default this is disabled. > > This now takes a value. > >> + int "Enable HPET MMAP access by default" >> + range 0 1 > > Shouldn't this be bool?
I'll fix those in v3.
> >> + default 0 > > This breaks backwards compatibility.
Does backwards compatibility matter for something like? I have no problem setting it to 1 but I'm more curious from a general kernel point of view.
I'll change this in v3 as well.
P.
P.
> > > Regards, > Clemens
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