Till now pool-os used to contain a mapping from pool_{alloc,free}_area()
to pool_{alloc,free}_area_uaf() in case of DEBUG_UAF, or the regular
malloc-based function. And the *_uaf() functions were in pool.c. But
since 2.4 with the first cleanup of the pools, there has been no more
calls to pool_{alloc,free}_area() from anywhere but pool.c, from exactly
one place each. As such, there's no more need to keep *_uaf() apart in
pool.c, we can inline it into pool-os.h and leave all the OS stuff there,
with pool.c calling either based on DEBUG_UAF. This is cleaner with less
round trips between both files and easier to find.
Right now the free() call is not intercepted since all this is done
using macros and that would break a lot of stuff. Instead a __free()
macro was provided but never used. In addition it used to only report
a zero size, which is not very convenient.
With this patch comes a better solution. Instead it provides a new
will_free() macro that can be prepended before a call to free(). It
only keeps the counters up to date, and also supports being passed a
size. The pool_free_area() command now uses it, which finally allows
the stats to look correct:
pool-os.h:38 MALLOC size: 5802127832 calls: 3868044 size/call: 1500
pool-os.h:47 FREE size: 5800041576 calls: 3867444 size/call: 1499
The few other places directly calling free() could now be instrumented to
use this and to pass the correct sizeof() when known.
pool-os.h relies on a number of includes solely because the
pool_alloc_area() function was inlined, and this only because we want
the normal version to be inlined so that we can track the calling
places for the memory profiler. It's worth noting that it already
does not work at -O0, and that when UAF is enabled we don't care a
dime about profiling.
This patch does two things at once:
- force-inline the functions so that pool_alloc_area() is still
inlined at -O0 to help track malloc() users ;
- uninline the UAF version of these (that rely on mmap/munmap)
and move them to pools.c so that we can remove all unneeded
includes.
Doing so reduces by ~270kB or 0.15% the total build size.
The memory.h file is particularly complex due to the combination of
debugging options. This patch extracts the OS-level interface and
places it into a new file: pool-os.h.
Doing this also moves pool_alloc_area() and pool_free_area() out of
the #ifndef CONFIG_HAP_LOCKLESS_POOLS, making them usable from
__pool_refill_alloc(), pool_free(), pool_flush() and pool_gc() instead
of having direct calls to malloc/free there that are hard to wrap for
debugging purposes.
