On Fri, Jul 11, 2014 at 01:38:23AM -0600, Theo de Raadt wrote: > I am a bit concerned. The description is trying too hard to be overly > precise, and may be cumbersome for the typical reader of this page.
indeed, and I also dislike putting too much implementation details into a man page. Things might change and if you are really interested, read the code. -Otto > > > Index: lib/libc/stdlib/malloc.3 > > =================================================================== > > RCS file: /cvs/src/lib/libc/stdlib/malloc.3,v > > retrieving revision 1.78 > > diff -u -p -d -r1.78 malloc.3 > > --- lib/libc/stdlib/malloc.3 1 May 2014 18:41:59 -0000 1.78 > > +++ lib/libc/stdlib/malloc.3 11 Jul 2014 07:19:27 -0000 > > @@ -220,10 +220,23 @@ Malloc will first look for a symbolic li > > .Pa /etc/malloc.conf > > and next check the environment for a variable called > > .Ev MALLOC_OPTIONS > > +(if not > > +.Xr issetugid 2 ) > > and finally for the global variable > > .Va malloc_options > > and scan them for flags in that order. > > Flags are single letters, uppercase means on, lowercase means off. > > +.Pp > > +The default flags are > > +.Cm A > > +and > > +.Cm P , > > +small chunks are always junked, and the first > > +part of the pages is junked after free. > > +The default junk behavior does not correspond to > > +.Cm j > > +or > > +.Cm J . > > .Bl -tag -width indent > > .It Cm A > > .Dq Abort . > > @@ -271,6 +284,7 @@ Currently junk is bytes of 0xd0 when all > > .Dq Duh . > > \&:-) > > Freed chunks are filled with 0xdf. > > +This performs more junking than by default. > > .It Cm j > > .Dq Don't Junk . > > By default, small chunks are always junked, and the first part of pages > > @@ -297,6 +311,11 @@ This can substantially aid in compacting > > .\"Consult the source for this one. > > .It Cm S > > Enable all options suitable for security auditing. > > +This currently enables flags > > +.Cm U , > > +.Cm J , > > +.Cm G > > +and sets the free cache page size to 0. > > .It Cm U > > .Dq Free unmap . > > Enable use after free protection for larger allocations. > >