From: paulmck@kernel.org
To: linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-mm@kvack.org
Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com,
iamjoonsoo.kim@lge.com, akpm@linux-foundation.org,
ming.lei@redhat.com, axboe@kernel.dk, kernel-team@fb.com,
"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH mm,percpu_ref,rcu 3/6] mm: Make mem_dump_obj() handle vmalloc() memory
Date: Tue, 5 Jan 2021 17:17:47 -0800 [thread overview]
Message-ID: <20210106011750.13709-3-paulmck@kernel.org> (raw)
In-Reply-To: <20210106011603.GA13180@paulmck-ThinkPad-P72>
From: "Paul E. McKenney" <paulmck@kernel.org>
This commit adds vmalloc() support to mem_dump_obj(). Note that the
vmalloc_dump_obj() function combines the checking and dumping, in
contrast with the split between kmem_valid_obj() and kmem_dump_obj().
The reason for the difference is that the checking in the vmalloc()
case involves acquiring a global lock, and redundant acquisitions of
global locks should be avoided, even on not-so-fast paths.
Note that this change causes on-stack variables to be reported as
vmalloc() storage from kernel_clone() or similar, depending on the degree
of inlining that your compiler does. This is likely more helpful than
the earlier "non-paged (local) memory".
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
include/linux/vmalloc.h | 6 ++++++
mm/util.c | 14 ++++++++------
mm/vmalloc.c | 12 ++++++++++++
3 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 80c0181..c18f475 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -246,4 +246,10 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
int register_vmap_purge_notifier(struct notifier_block *nb);
int unregister_vmap_purge_notifier(struct notifier_block *nb);
+#ifdef CONFIG_MMU
+bool vmalloc_dump_obj(void *object);
+#else
+static inline bool vmalloc_dump_obj(void *object) { return false; }
+#endif
+
#endif /* _LINUX_VMALLOC_H */
diff --git a/mm/util.c b/mm/util.c
index 92f23d2..5487022 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -996,18 +996,20 @@ int __weak memcmp_pages(struct page *page1, struct page *page2)
*/
void mem_dump_obj(void *object)
{
+ if (kmem_valid_obj(object)) {
+ kmem_dump_obj(object);
+ return;
+ }
+ if (vmalloc_dump_obj(object))
+ return;
if (!virt_addr_valid(object)) {
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)) {
- kmem_dump_obj(object);
+ pr_cont(" non-paged memory.\n");
return;
}
- pr_cont(" non-slab memory.\n");
+ pr_cont(" non-slab/vmalloc memory.\n");
}
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 4d88fe5..c274ea4 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3448,6 +3448,18 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
}
#endif /* CONFIG_SMP */
+bool vmalloc_dump_obj(void *object)
+{
+ struct vm_struct *vm;
+ void *objp = (void *)PAGE_ALIGN((unsigned long)object);
+
+ vm = find_vm_area(objp);
+ if (!vm)
+ return false;
+ pr_cont(" vmalloc allocated at %pS\n", vm->caller);
+ return true;
+}
+
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
__acquires(&vmap_purge_lock)
--
2.9.5
next prev parent reply other threads:[~2021-01-06 1:18 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 1:16 [PATCH v4 sl-b 0/6] Export return addresses etc. for better diagnostics Paul E. McKenney
2021-01-06 1:17 ` [PATCH mm,percpu_ref,rcu 1/6] mm: Add mem_dump_obj() to print source of memory block paulmck
2021-01-08 13:50 ` Vlastimil Babka
2021-01-08 19:01 ` Paul E. McKenney
2021-01-08 19:41 ` Vlastimil Babka
2021-01-06 1:17 ` [PATCH mm,percpu_ref,rcu 2/6] mm: Make mem_dump_obj() handle NULL and zero-sized pointers paulmck
2021-01-06 1:17 ` paulmck [this message]
2021-01-08 15:30 ` [PATCH mm,percpu_ref,rcu 3/6] mm: Make mem_dump_obj() handle vmalloc() memory Vlastimil Babka
2021-01-06 1:17 ` [PATCH mm,percpu_ref,rcu 4/6] mm: Make mem_obj_dump() vmalloc() dumps include start and length paulmck
2021-01-08 15:30 ` Vlastimil Babka
2021-01-06 1:17 ` [PATCH mm,percpu_ref,rcu 5/6] rcu: Make call_rcu() print mem_dump_obj() info for double-freed callback paulmck
2021-01-06 1:17 ` [PATCH mm,percpu_ref,rcu 6/6] percpu_ref: Dump mem_dump_obj() info upon reference-count underflow paulmck
2021-01-06 21:48 ` [PATCH v4 sl-b 0/6] Export return addresses etc. for better diagnostics Andrew Morton
2021-01-06 23:42 ` Paul E. McKenney
2021-01-08 0:26 ` Paul E. McKenney
2021-01-08 15:35 ` Vlastimil Babka
2021-01-08 17:36 ` Paul E. McKenney
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