The patch titled Subject: Revert "mm/kmemleak: move the initialisation of object to __link_object" has been added to the -mm mm-hotfixes-unstable branch. Its filename is revert-mm-kmemleak-move-the-initialisation-of-object-to-__link_object.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/revert-mm-kmemleak-move-the-initialisation-of-object-to-__link_object.patch This patch will later appear in the mm-hotfixes-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: Liu Shixin <liushixin2@xxxxxxxxxx> Subject: Revert "mm/kmemleak: move the initialisation of object to __link_object" Date: Wed, 15 Nov 2023 16:21:37 +0800 Patch series "Fix invalid wait context of set_track_prepare()". Geert reported an invalid wait context[1] which is resulted by moving set_track_prepare() inside kmemleak_lock. This is not allowed because in RT mode, the spinlocks can be preempted but raw_spinlocks can not, so it is not allowd to acquire spinlocks while holding raw_spinlocks. The second patch fix same problem in kmemleak_update_trace(). This patch (of 2): Move the initialisation of object back to__alloc_object() because set_track_prepare() attempt to acquire zone->lock(spinlocks) while __link_object is holding kmemleak_lock(raw_spinlocks). This is not right for RT mode. This reverts commit 245245c2fffd00 ("mm/kmemleak: move the initialisation of object to __link_object"). Link: https://lkml.kernel.org/r/20231115082138.2649870-1-liushixin2@xxxxxxxxxx Link: https://lkml.kernel.org/r/20231115082138.2649870-2-liushixin2@xxxxxxxxxx Fixes: 245245c2fffd ("mm/kmemleak: move the initialisation of object to __link_object") Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx> Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Closes: https://lore.kernel.org/linux-mm/CAMuHMdWj0UzwNaxUvcocTfh481qRJpOWwXxsJCTJfu1oCqvgdA@xxxxxxxxxxxxxx/ [1] Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Patrick Wang <patrick.wang.shcn@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kmemleak.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) --- a/mm/kmemleak.c~revert-mm-kmemleak-move-the-initialisation-of-object-to-__link_object +++ a/mm/kmemleak.c @@ -642,32 +642,16 @@ static struct kmemleak_object *__alloc_o if (!object) { pr_warn("Cannot allocate a kmemleak_object structure\n"); kmemleak_disable(); + return NULL; } - return object; -} - -static int __link_object(struct kmemleak_object *object, unsigned long ptr, - size_t size, int min_count, bool is_phys) -{ - - struct kmemleak_object *parent; - struct rb_node **link, *rb_parent; - unsigned long untagged_ptr; - unsigned long untagged_objp; - INIT_LIST_HEAD(&object->object_list); INIT_LIST_HEAD(&object->gray_list); INIT_HLIST_HEAD(&object->area_list); raw_spin_lock_init(&object->lock); atomic_set(&object->use_count, 1); - object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0); - object->pointer = ptr; - object->size = kfence_ksize((void *)ptr) ?: size; object->excess_ref = 0; - object->min_count = min_count; object->count = 0; /* white color initially */ - object->jiffies = jiffies; object->checksum = 0; object->del_state = 0; @@ -692,6 +676,24 @@ static int __link_object(struct kmemleak /* kernel backtrace */ object->trace_handle = set_track_prepare(); + return object; +} + +static int __link_object(struct kmemleak_object *object, unsigned long ptr, + size_t size, int min_count, bool is_phys) +{ + + struct kmemleak_object *parent; + struct rb_node **link, *rb_parent; + unsigned long untagged_ptr; + unsigned long untagged_objp; + + object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0); + object->pointer = ptr; + object->size = kfence_ksize((void *)ptr) ?: size; + object->min_count = min_count; + object->jiffies = jiffies; + untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr); /* * Only update min_addr and max_addr with object _ Patches currently in -mm which might be from liushixin2@xxxxxxxxxx are revert-mm-kmemleak-move-the-initialisation-of-object-to-__link_object.patch mm-kmemleak-move-set_track_prepare-outside-raw_spinlocks.patch mm-vmscan-try-to-reclaim-swapcache-pages-if-no-swap-space.patch mm-vmscan-try-to-reclaim-swapcache-pages-if-no-swap-space-v6.patch