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authorMarco Elver <elver@google.com>2022-04-14 19:13:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-15 14:49:55 -0700
commit2dfe63e61cc31ee59ce951672b0850b5229cd5b0 (patch)
tree9194074ed5008747db7b6a0aed068751d8b50b20 /include/linux
parentb1add418d457bc30cdd6a89c2bba092cd8941fcf (diff)
mm, kfence: support kmem_dump_obj() for KFENCE objects
Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been producing garbage data due to the object not actually being maintained by SLAB or SLUB. Fix this by implementing __kfence_obj_info() that copies relevant information to struct kmem_obj_info when the object was allocated by KFENCE; this is called by a common kmem_obj_info(), which also calls the slab/slub/slob specific variant now called __kmem_obj_info(). For completeness, kmem_dump_obj() now displays if the object was allocated by KFENCE. Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/ Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com Fixes: b89fb5ef0ce6 ("mm, kfence: insert KFENCE hooks for SLUB") Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reported-by: kernel test robot <oliver.sang@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> [slab] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/kfence.h24
1 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/kfence.h b/include/linux/kfence.h
index f49e64222628..726857a4b680 100644
--- a/include/linux/kfence.h
+++ b/include/linux/kfence.h
@@ -204,6 +204,22 @@ static __always_inline __must_check bool kfence_free(void *addr)
*/
bool __must_check kfence_handle_page_fault(unsigned long addr, bool is_write, struct pt_regs *regs);
+#ifdef CONFIG_PRINTK
+struct kmem_obj_info;
+/**
+ * __kfence_obj_info() - fill kmem_obj_info struct
+ * @kpp: kmem_obj_info to be filled
+ * @object: the object
+ *
+ * Return:
+ * * false - not a KFENCE object
+ * * true - a KFENCE object, filled @kpp
+ *
+ * Copies information to @kpp for KFENCE objects.
+ */
+bool __kfence_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
+#endif
+
#else /* CONFIG_KFENCE */
static inline bool is_kfence_address(const void *addr) { return false; }
@@ -221,6 +237,14 @@ static inline bool __must_check kfence_handle_page_fault(unsigned long addr, boo
return false;
}
+#ifdef CONFIG_PRINTK
+struct kmem_obj_info;
+static inline bool __kfence_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
+{
+ return false;
+}
+#endif
+
#endif
#endif /* _LINUX_KFENCE_H */