whitespace fixes

allow clearing less than allocated and document freezero(3) better

Introducing freezero(3) a version of free that guarantees the process
no longer has access to the content of a memmory object. It does
this by either clearing (if the object memory remains cached) or

Introducing freezero(3) a version of free that guarantees the process
no longer has access to the content of a memmory object. It does
this by either clearing (if the object memory remains cached) or
by calling munmap(2). ok millert@, deraadt@, guenther@

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first print size in meta-data then supplied arg size when an inconsistency is
detected wrt recallocarray()

small cleanup & optimization; ok deraadt@ millert@

add a helper function to print all pools #ifdef MALLOC_STATS
from David CARLIER

move recallocarray to malloc.c and
- use internal meta-data to do more consistency checking (especially with
option C)
- use cheap free if possible
ok deraadt@

Add a NULL test to wrterror() to avoid a NULL deref when called from a
free() error path.

ok otto@

fix a comment and rm some dead code as a result of the previous diff

Let realloc handle and produce moved pointers for allocations between
half a page and a page. ok jmatthew@ tb@

1. When shrinking a chunk allocation, compare the size of the current
allocation to the size of the new allocation (instead of the requested size).
2. Previously realloc takes the easy way and always

1. When shrinking a chunk allocation, compare the size of the current
allocation to the size of the new allocation (instead of the requested size).
2. Previously realloc takes the easy way and always reallocates if C is
active. This commit fixes by carefully updating the recorded requested
size in all cases, and writing the canary bytes in the proper location
after reallocating.
3. Introduce defines to test if MALLOC_MOVE should be done and to
compute the new value.

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MALLOC_STATS tweaks, by default not compiled in

small tweak to also check canaries if F is in effect

remove some old option letters and also make P non-settable. It has
been the default for ages, and I see no valid reason to be able to
disable it. ok natano@

Pages in the malloc cache are either reused quickly or unmapped
quickly. In both cases it does not make sense to set hints on them.
So remove that option, which is just a remainder of old times when

Pages in the malloc cache are either reused quickly or unmapped
quickly. In both cases it does not make sense to set hints on them.
So remove that option, which is just a remainder of old times when
malloc used to hold on to pages. ok stefan@

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- fix MALLOC_STATS compile
- redundant cast is redundant

fix some void * arithmetic by casting

and recommit with fixed GC

backout for now; flag combination GC is not ok

Also place canaries in > page sized objects (if C is in effect); ok tb@

Wrap _malloc_init() so internal calls go directly

prodded by otto@
ok kettenis@ otto@

0xd0 -> 0xdb; ok deraadt@ millert@ tedu@

optimize canary code a bit by storing offset of sizes table instead of
recomputing it all the time

stray tab

Beter implementation of chunk canaries: store size in chunk meta data
instead of chunk itself; does not change actual allocated size; ok tedu@