[PATCH 1/8] malloc: implement USE_DL_PREFIX via inline functions

[Simon Goldschmidt]

Am 20.02.2020 um 04:05 schrieb Simon Glass:
> On Wed, 19 Feb 2020 at 12:39, Simon Goldschmidt
> <simon.k.r.goldschmidt at gmail.com> wrote:
>>
>> Commit cfda60f99ae2 ("sandbox: Use a prefix for all allocation functions")
>> introduced preprocessor macros for malloc/free etc.
>>
>> This is bad practice as it essentially makes 'free' a reserved keyword and
>> resulted in quite a bit of renaming to avoid that reserved keyword.
>>
>> A better solution is to define the allocation functions as 'static inline'.
>>
>> As a side effect, exports.h must not export malloc/free for sandbox.
>>
>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
>> ---
>>
>> A side-effect is that exports.h may not declare malloc/free. I'm not really
>> sure if this is correct, but for sandbox, it should probably be ok?
> 
> Is it possible to fix this? E.g. don't use inline for these two
> functions on sandbox?

Not using inline for sandbox for these two is *not* an option as these
two are exactly the ones offending globally known names.

I guess we have to know what we want here: what is exports.h meant for?
To me it looks like it is meant for "U-Boot API" applications to link
against. If so, why is it included in U-Boot sources (in over 20 files)?

I guess one solution would be to move (or copy) the DL prefix handling
into exports.h and _exports.h so that applications linking with
exports.h implicily call dlmalloc/dlfree, not malloc/free (which would
be the OS versions for sandbox).

I'll try to prepare v2 in that direction, but I'm still not unsure since
exports.h is included in internal U-Boot code.

Regards,
Simon

> 
>>
>>  include/_exports.h |  2 ++
>>  include/exports.h  |  2 ++
>>  include/malloc.h   | 44 +++++++++++++++++++++++++++++---------------
>>  3 files changed, 33 insertions(+), 15 deletions(-)
> 
> Reviewed-by: Simon Glass <sjg at chromium.org>
>