staging: rtl8712: remove unnecessary alignment of pxmitpriv->pxmitbuf

Browse source

This driver wants pxmitpriv->pxmitbuf to be 4-byte aligned. This is ensured
by allocating 4 more bytes than required with kmalloc(), then do the
p = p + 4 - (p & 3) trick to make sure the pointer is 4-byte aligned.

This is unnecessary. Pointers from kmalloc() are already at least
8-byte-aligned.

Remove this alignment trick to simplify the code, and also to stop wasting
4 extra bytes of dynamic memory allocator.

This also gets rid of a (false) warning from kmemleak. This 4-byte-aligned
buffer is used to store pointers from kmalloc(). For 64-bit platforms,
pointer size is 8 bytes and kmemleak only scans for pointers in 8-byte
blocks, thus it misses the pointers stored in this 4-byte-aligned buffer
and thinks that these pointers have been leaked. This is just a false
warning, not a real problem. But still, it would be nice to get rid of
these warnings.

Reported-and-tested-by: syzbot+83763e624cfec6b462cb@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-staging/000000000000809328060a8a4c1c@google.com
Signed-off-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20240525073229.4144612-1-namcao@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Nam Cao 2024-05-25 09:32:29 +02:00 • committed by Greg Kroah-Hartman

parent 8bcb9afc5d

commit 9ed3e0a0e1

2 changed files with 5 additions and 9 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

13

drivers/staging/rtl8712/rtl871x_xmit.c

View file

1

drivers/staging/rtl8712/rtl871x_xmit.h

View file