The patch titled
Subject: mm: make mem_dump_obj() handle NULL and zero-sized pointers
has been added to the -mm tree. Its filename is
mm-make-mem_dump_obj-handle-null-and-zero-sized-pointers.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-make-mem_dump_obj-handle-null-and-zero-sized-pointers.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-make-mem_dump_obj-handle-null-and-zero-sized-pointers.patch
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 and is updated
there every 3-4 working days
------------------------------------------------------
From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Subject: mm: make mem_dump_obj() handle NULL and zero-sized pointers
This commit makes mem_dump_obj() call out NULL and zero-sized pointers
specially instead of classifying them as non-paged memory.
Link: https://lkml.kernel.org/r/20210106011750.13709-2-paulmck@xxxxxxxxxx
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Reported-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/util.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/mm/util.c~mm-make-mem_dump_obj-handle-null-and-zero-sized-pointers
+++ a/mm/util.c
@@ -997,7 +997,12 @@ int __weak memcmp_pages(struct page *pag
void mem_dump_obj(void *object)
{
if (!virt_addr_valid(object)) {
- pr_cont(" non-paged (local) memory.\n");
+ if (object == NULL)
+ pr_cont(" NULL pointer.\n");
+ else if (object == ZERO_SIZE_PTR)
+ pr_cont(" zero-size pointer.\n");
+ else
+ pr_cont(" non-paged (local) memory.\n");
return;
}
if (kmem_valid_obj(object)) {
_
Patches currently in -mm which might be from paulmck@xxxxxxxxxx are
mm-add-mem_dump_obj-to-print-source-of-memory-block.patch
mm-make-mem_dump_obj-handle-null-and-zero-sized-pointers.patch
mm-make-mem_dump_obj-handle-vmalloc-memory.patch
mm-make-mem_obj_dump-vmalloc-dumps-include-start-and-length.patch
rcu-make-call_rcu-print-mem_dump_obj-info-for-double-freed-callback.patch
percpu_ref-dump-mem_dump_obj-info-upon-reference-count-underflow.patch
