Hi!
This is probably a known issue, but just in case: looks like it's not
possible to use kmemleak when kfence is enabled:
[ 0.272136] kmemleak: Cannot insert 0xffff888236e02f00 into the object search tree (overlaps existing)
[ 0.272136] CPU: 0 PID: 8 Comm: kthreadd Not tainted 5.12.0-rc3+ #92
[ 0.272136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
[ 0.272136] Call Trace:
[ 0.272136] dump_stack+0x6d/0x89
[ 0.272136] create_object.isra.0.cold+0x40/0x62
[ 0.272136] ? process_one_work+0x5a0/0x5a0
[ 0.272136] ? process_one_work+0x5a0/0x5a0
[ 0.272136] kmem_cache_alloc_trace+0x110/0x2f0
[ 0.272136] ? process_one_work+0x5a0/0x5a0
[ 0.272136] kthread+0x3f/0x150
[ 0.272136] ? lockdep_hardirqs_on_prepare+0xd4/0x170
[ 0.272136] ? __kthread_bind_mask+0x60/0x60
[ 0.272136] ret_from_fork+0x22/0x30
[ 0.272136] kmemleak: Kernel memory leak detector disabled
[ 0.272136] kmemleak: Object 0xffff888236e00000 (size 2097152):
[ 0.272136] kmemleak: comm "swapper", pid 0, jiffies 4294892296
[ 0.272136] kmemleak: min_count = 0
[ 0.272136] kmemleak: count = 0
[ 0.272136] kmemleak: flags = 0x1
[ 0.272136] kmemleak: checksum = 0
[ 0.272136] kmemleak: backtrace:
[ 0.272136] memblock_alloc_internal+0x6d/0xb0
[ 0.272136] memblock_alloc_try_nid+0x6c/0x8a
[ 0.272136] kfence_alloc_pool+0x26/0x3f
[ 0.272136] start_kernel+0x242/0x548
[ 0.272136] secondary_startup_64_no_verify+0xb0/0xbb
I've tried the hack below but it didn't really helped. Obviously I don't
really understand what's going on ;-) But I think the reason for this
patch not working as (I) expected is because kfence is initialised
*before* kmemleak.
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 3b8ec938470a..b4ffd7695268 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -631,6 +631,9 @@ void __init kfence_alloc_pool(void)
if (!__kfence_pool)
pr_err("failed to allocate pool\n");
+ kmemleak_no_scan(__kfence_pool);
}
Cheers,
--
Luís
