The patch titled Subject: mm: userfaultfd: use swap() in double_pt_lock() has been added to the -mm mm-unstable branch. Its filename is mm-userfaultfd-use-swap-in-double_pt_lock.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-userfaultfd-use-swap-in-double_pt_lock.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx> Subject: mm: userfaultfd: use swap() in double_pt_lock() Date: Fri, 31 May 2024 17:16:43 +0800 Use existing swap() function rather than duplicating its implementation. ./mm/userfaultfd.c:1006:13-14: WARNING opportunity for swap() Link: https://lkml.kernel.org/r/20240531091643.67778-1-jiapeng.chong@xxxxxxxxxxxxxxxxx Signed-off-by: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx> Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9266 Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/userfaultfd.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) --- a/mm/userfaultfd.c~mm-userfaultfd-use-swap-in-double_pt_lock +++ a/mm/userfaultfd.c @@ -995,14 +995,8 @@ void double_pt_lock(spinlock_t *ptl1, __acquires(ptl1) __acquires(ptl2) { - spinlock_t *ptl_tmp; - - if (ptl1 > ptl2) { - /* exchange ptl1 and ptl2 */ - ptl_tmp = ptl1; - ptl1 = ptl2; - ptl2 = ptl_tmp; - } + if (ptl1 > ptl2) + swap(ptl1, ptl2); /* lock in virtual address order to avoid lock inversion */ spin_lock(ptl1); if (ptl1 != ptl2) _ Patches currently in -mm which might be from jiapeng.chong@xxxxxxxxxxxxxxxxx are mm-userfaultfd-use-swap-in-double_pt_lock.patch