From: Marco Elver elver@google.com
This reverts commit 07313a2b29ed1079eaa7722624544b97b3ead84b.
Commit 0c24e061196c21d5 ("mm: kmemleak: add rbtree and store physical address for objects allocated with PA") is not yet in 5.19 (but appears in 6.0). Without 0c24e061196c21d5, kmemleak still stores phys objects and non-phys objects in the same tree, and ignoring (instead of freeing) will cause insertions into the kmemleak object tree by the slab post-alloc hook to conflict with the pool object (see comment).
Reports such as the following would appear on boot, and effectively disable kmemleak:
| kmemleak: Cannot insert 0xffffff806e24f000 into the object search tree (overlaps existing) | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-v8-0815+ #5 | Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) | Call trace: | dump_backtrace.part.0+0x1dc/0x1ec | show_stack+0x24/0x80 | dump_stack_lvl+0x8c/0xb8 | dump_stack+0x1c/0x38 | create_object.isra.0+0x490/0x4b0 | kmemleak_alloc+0x3c/0x50 | kmem_cache_alloc+0x2f8/0x450 | __proc_create+0x18c/0x400 | proc_create_reg+0x54/0xd0 | proc_create_seq_private+0x94/0x120 | init_mm_internals+0x1d8/0x248 | kernel_init_freeable+0x188/0x388 | kernel_init+0x30/0x150 | ret_from_fork+0x10/0x20 | kmemleak: Kernel memory leak detector disabled | kmemleak: Object 0xffffff806e24d000 (size 2097152): | kmemleak: comm "swapper", pid 0, jiffies 4294892296 | kmemleak: min_count = -1 | kmemleak: count = 0 | kmemleak: flags = 0x5 | kmemleak: checksum = 0 | kmemleak: backtrace: | kmemleak_alloc_phys+0x94/0xb0 | memblock_alloc_range_nid+0x1c0/0x20c | memblock_alloc_internal+0x88/0x100 | memblock_alloc_try_nid+0x148/0x1ac | kfence_alloc_pool+0x44/0x6c | mm_init+0x28/0x98 | start_kernel+0x178/0x3e8 | __primary_switched+0xc4/0xcc
Reported-by: Max Schulze max.schulze@online.de Signed-off-by: Marco Elver elver@google.com Link: https://lore.kernel.org/all/b33b33bc-2d06-1bcd-2df7-43678962b728@online.de/ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/kfence/core.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
--- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -603,6 +603,14 @@ static unsigned long kfence_init_pool(vo addr += 2 * PAGE_SIZE; }
+ /* + * The pool is live and will never be deallocated from this point on. + * Remove the pool object from the kmemleak object tree, as it would + * otherwise overlap with allocations returned by kfence_alloc(), which + * are registered with kmemleak through the slab post-alloc hook. + */ + kmemleak_free(__kfence_pool); + return 0; }
@@ -615,16 +623,8 @@ static bool __init kfence_init_pool_earl
addr = kfence_init_pool();
- if (!addr) { - /* - * The pool is live and will never be deallocated from this point on. - * Ignore the pool object from the kmemleak phys object tree, as it would - * otherwise overlap with allocations returned by kfence_alloc(), which - * are registered with kmemleak through the slab post-alloc hook. - */ - kmemleak_ignore_phys(__pa(__kfence_pool)); + if (!addr) return true; - }
/* * Only release unprotected pages, and do not try to go back and change