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authorZhen Lei <thunder.leizhen@huawei.com>2023-08-05 11:17:25 +0800
committerFrederic Weisbecker <frederic@kernel.org>2023-09-13 22:28:59 +0200
commit6e284c55fc0bef7d25fd34d29db11f483da60ea4 (patch)
treeae98df125e1e383ad0b4e86fa16fa28ee9d39ebb
parentb93c5fe16e4aa177cd072c1c4652cbe1b19a7812 (diff)
mm: Remove kmem_valid_obj()
Function kmem_dump_obj() will splat if passed a pointer to a non-slab object. So nothing calls it directly, instead calling kmem_valid_obj() first to determine whether the passed pointer to a valid slab object. This means that merging kmem_valid_obj() into kmem_dump_obj() will make the code more concise. Therefore, convert kmem_dump_obj() to work the same way as vmalloc_dump_obj(), removing the need for the kmem_dump_obj() caller to check kmem_valid_obj(). After this, there are no remaining calls to kmem_valid_obj() anymore, and it can be safely removed. Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
-rw-r--r--include/linux/slab.h5
-rw-r--r--mm/slab_common.c41
-rw-r--r--mm/util.c4
3 files changed, 15 insertions, 35 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 8228d1276a2f..ff56ab804bf6 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -245,8 +245,9 @@ DEFINE_FREE(kfree, void *, if (_T) kfree(_T))
size_t ksize(const void *objp);
#ifdef CONFIG_PRINTK
-bool kmem_valid_obj(void *object);
-void kmem_dump_obj(void *object);
+bool kmem_dump_obj(void *object);
+#else
+static inline bool kmem_dump_obj(void *object) { return false; }
#endif
/*
diff --git a/mm/slab_common.c b/mm/slab_common.c
index cd71f9581e67..a425bedf2103 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -528,26 +528,6 @@ bool slab_is_available(void)
}
#ifdef CONFIG_PRINTK
-/**
- * kmem_valid_obj - does the pointer reference a valid slab object?
- * @object: pointer to query.
- *
- * Return: %true if the pointer is to a not-yet-freed object from
- * kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer
- * is to an already-freed object, and %false otherwise.
- */
-bool kmem_valid_obj(void *object)
-{
- struct folio *folio;
-
- /* Some arches consider ZERO_SIZE_PTR to be a valid address. */
- if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
- return false;
- folio = virt_to_folio(object);
- return folio_test_slab(folio);
-}
-EXPORT_SYMBOL_GPL(kmem_valid_obj);
-
static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
{
if (__kfence_obj_info(kpp, object, slab))
@@ -566,11 +546,11 @@ static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *
* and, if available, the slab name, return address, and stack trace from
* the allocation and last free path of that object.
*
- * This function will splat if passed a pointer to a non-slab object.
- * If you are not sure what type of object you have, you should instead
- * use mem_dump_obj().
+ * Return: %true if the pointer is to a not-yet-freed object from
+ * kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer
+ * is to an already-freed object, and %false otherwise.
*/
-void kmem_dump_obj(void *object)
+bool kmem_dump_obj(void *object)
{
char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc";
int i;
@@ -578,13 +558,13 @@ void kmem_dump_obj(void *object)
unsigned long ptroffset;
struct kmem_obj_info kp = { };
- if (WARN_ON_ONCE(!virt_addr_valid(object)))
- return;
+ /* Some arches consider ZERO_SIZE_PTR to be a valid address. */
+ if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
+ return false;
slab = virt_to_slab(object);
- if (WARN_ON_ONCE(!slab)) {
- pr_cont(" non-slab memory.\n");
- return;
- }
+ if (!slab)
+ return false;
+
kmem_obj_info(&kp, object, slab);
if (kp.kp_slab_cache)
pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name);
@@ -621,6 +601,7 @@ void kmem_dump_obj(void *object)
pr_info(" %pS\n", kp.kp_free_stack[i]);
}
+ return true;
}
EXPORT_SYMBOL_GPL(kmem_dump_obj);
#endif
diff --git a/mm/util.c b/mm/util.c
index 8cbbfd3a3d59..6eddd891198e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -1060,10 +1060,8 @@ void mem_dump_obj(void *object)
{
const char *type;
- if (kmem_valid_obj(object)) {
- kmem_dump_obj(object);
+ if (kmem_dump_obj(object))
return;
- }
if (vmalloc_dump_obj(object))
return;