On Thu, May 24, 2018 at 06:44:20AM +0200, Mateusz Guzik wrote: M> I fundamentally disagree with this part. M> M> If a known value of a given field is needed for assertion purposes, you M> can add (possibly conditional) code setting this specific value. It M> probably should not be zero if it can be helped. M> M> Conditional zeroing of the *whole* struct depending on invariants will M> *hide* uninitialized memory read bugs - production kernel will have M> whatever it happens to find, while *debug* kernel will guarantee to M> have all the values zeroed. In fact the flag actively combats redzoning. M> if the resulting allocation is zeroed, poisoning is actively neutered. M> But only if debug is enabled. M> M> That said, I find the change harmful.
+1 on fundamentally disagree with M_ZERO_INVARIANTS. It makes the INVARIANTS-enabled kernels to crash _later_ than production kernels, since instead of uma_junk it places clean zeroes. May be changes like that deserve more than a 30 minute time frame for review? -- Gleb Smirnoff _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
