cvs commit: src/sys/netipsec ipsec_mbuf.c

Sam Leffler sam at
Mon Sep 26 13:58:13 PDT 2005

Andre Oppermann wrote:
> Sam Leffler wrote:
>>Andre Oppermann wrote:
>>>andre       2005-09-26 20:35:45 UTC
>>>  FreeBSD src repository
>>>  Modified files:
>>>    sys/netipsec         ipsec_mbuf.c
>>>  Log:
>>>  Replace custom mbuf writeability test with generic M_WRITABLE() test
>>>  covering all edge cases too.
>>I vaguely recall that M_WRITEABLE did exist when I wrote that code but
>>it did not do the right thing.  I'm not sure why you needed to make this
>>change but beware of unexpected side effects.
> The test in question tries to determine whether to copy the mbuf to make
> to safe for modification.  The old did not respect the M_RDONLY for example.
> M_WRITABLE() correctly tests for all cases.

And as I said; I did it for a reason that I cannot recall now.  I'm 
certain that it was pre-mbufs-over-uma so maybe this is now safe but 
such are the ways that subtle bugs are introduced into code...


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