On 17/11/2025 04:10, Ally Heev wrote: > uninitialized pointers with __free attribute can cause undefined > behavior as the memory randomly assigned to the pointer is freed > automatically when the pointer goes out of scope. > add check in checkpatch to detect such issues. > > Suggested-by: Dan Carpenter <[email protected]> > Link: > https://lore.kernel.org/all/[email protected]/ > Acked-by: Dan Williams <[email protected]> > Signed-off-by: Ally Heev <[email protected]> > --- > Testing: > ran checkpatch.pl before and after the change on > crypto/asymmetric_keys/x509_public_key.c, which has > both initialized with NULL and uninitialized pointers > --- > Changes in v4: > - fixed UNINITIALIZED_PTR_WITH_FREE description > - Link to v3: > https://lore.kernel.org/r/20251025-aheev-checkpatch-uninitialized-free-v3-1-a67f72b1c...@gmail.com > > Changes in v3: > - remove $FreeAttribute > - Link to v2: > https://lore.kernel.org/r/20251024-aheev-checkpatch-uninitialized-free-v2-0-16c0900e8...@gmail.com > > Changes in v2: > - change cover letter and title to reflect new changes > - fix regex to handle multiple declarations in a single line case > - convert WARN to ERROR for uninitialized pointers > - add a new WARN for pointers initialized with NULL > - NOTE: tried handling multiple declarations on a single line by splitting > them and matching the parts with regex, but, it turned out to be > complex and overkill. Moreover, multi-line declarations pose a threat > - Link to v1: > https://lore.kernel.org/r/20251021-aheev-checkpatch-uninitialized-free-v1-1-18fb01bc6...@gmail.com > --- > Documentation/dev-tools/checkpatch.rst | 5 +++++ > scripts/checkpatch.pl | 6 ++++++ > 2 files changed, 11 insertions(+) > > diff --git a/Documentation/dev-tools/checkpatch.rst > b/Documentation/dev-tools/checkpatch.rst > index > d5c47e560324fb2399a5b1bc99c891ed1de10535..c61a3892a60c13f7c5ba89e969e39a93a3dcd5bc > 100644 > --- a/Documentation/dev-tools/checkpatch.rst > +++ b/Documentation/dev-tools/checkpatch.rst > @@ -1009,6 +1009,11 @@ Functions and Variables > > return bar; > > + **UNINITIALIZED_PTR_WITH_FREE** > + Pointers with __free attribute should be initialized. Not doing so
I saw the other discussion and Linus re-iterated old approach/syntax preference, thus I think this should also include it, since it is de facto a coding style: "Pointers with __free attribute should be declared in the place of use and initialized (see include/linux/cleanup.h)......" Best regards, Krzysztof
