Messages in this thread | | | From | Bodo Eggert <> | Subject | Re: [PATCH] capability: WARN when invalid capability is requested rather than BUG/panic | Date | Wed, 01 Oct 2008 21:36:39 +0200 |
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Eric Paris <eparis@redhat.com> wrote:
> Do we have any concern of a module being compiled against a new kernel > say with cap number 35 defined and then loaded into a kernel with only > 34 capabilities? Do we care about that forward compatibility? If we > care BUG is scary. EPERM would be the right thing since clearly on this > kernel the process can't possibly have cap #35. > > We really have 4 options (in the order I like them). > > 1) do nothing (garbage in garbage out, sometimes panic sometimes not) > 2) mask CAP_TO_INDEX (garbage in garbage out, no panic) > 3) BUG_ON(!cap_valid(flag)) (garbage in BUG out, no panic) > 4) WARN_ON/EPERM (garbage in EPERM out, no panic)
5) Use a macro or inline function to test for $cap <= $max_cap, eliminating the test in the final code.
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