codetag: debug: mark codetags for reserved pages as empty

To avoid debug warnings while freeing reserved pages which were not allocated with usual allocators, mark their codetags as empty before freeing. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Suren Baghdasaryan <[email protected]> Reviewed-by: Kees Cook <[email protected]> Tested-by: Kees Cook <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Alex Gaynor <[email protected]> Cc: Alice Ryhl <[email protected]> Cc: Andreas Hindborg <[email protected]> Cc: Benno Lossin <[email protected]> Cc: "Björn Roy Baron" <[email protected]> Cc: Boqun Feng <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Dennis Zhou <[email protected]> Cc: Gary Guo <[email protected]> Cc: Kent Overstreet <[email protected]> Cc: Miguel Ojeda <[email protected]> Cc: Pasha Tatashin <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Wedson Almeida Filho <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
jwrdegoede · Apr 26, 2024 · d224eb0 · d224eb0
1 parent 239d6c9
commit d224eb0
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Showing 4 changed files with 23 additions and 1 deletion.
diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
@@ -47,6 +47,7 @@ static inline void set_codetag_empty(union codetag_ref *ref)
 #else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
 
 static inline bool is_codetag_empty(union codetag_ref *ref) { return false; }
+static inline void set_codetag_empty(union codetag_ref *ref) {}
 
 #endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
 

diff --git a/include/linux/mm.h b/include/linux/mm.h
@@ -5,6 +5,7 @@
 #include <linux/errno.h>
 #include <linux/mmdebug.h>
 #include <linux/gfp.h>
+#include <linux/pgalloc_tag.h>
 #include <linux/bug.h>
 #include <linux/list.h>
 #include <linux/mmzone.h>
@@ -3134,6 +3135,14 @@ extern void reserve_bootmem_region(phys_addr_t start,
 /* Free the reserved page into the buddy system, so it gets managed. */
 static inline void free_reserved_page(struct page *page)
 {
+	if (mem_alloc_profiling_enabled()) {
+		union codetag_ref *ref = get_page_tag_ref(page);
+
+		if (ref) {
+			set_codetag_empty(ref);
+			put_page_tag_ref(ref);
+		}
+	}
 	ClearPageReserved(page);
 	init_page_count(page);
 	__free_page(page);

diff --git a/include/linux/pgalloc_tag.h b/include/linux/pgalloc_tag.h
@@ -120,6 +120,8 @@ static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr)
 
 #else /* CONFIG_MEM_ALLOC_PROFILING */
 
+static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; }
+static inline void put_page_tag_ref(union codetag_ref *ref) {}
 static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
 				   unsigned int nr) {}
 static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}

diff --git a/mm/mm_init.c b/mm/mm_init.c
@@ -2567,7 +2567,6 @@ void __init set_dma_reserve(unsigned long new_dma_reserve)
 void __init memblock_free_pages(struct page *page, unsigned long pfn,
 							unsigned int order)
 {
-
 	if (IS_ENABLED(CONFIG_DEFERRED_STRUCT_PAGE_INIT)) {
 		int nid = early_pfn_to_nid(pfn);
 
@@ -2579,6 +2578,17 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn,
 		/* KMSAN will take care of these pages. */
 		return;
 	}
+
+	/* pages were reserved and not allocated */
+	if (mem_alloc_profiling_enabled()) {
+		union codetag_ref *ref = get_page_tag_ref(page);
+
+		if (ref) {
+			set_codetag_empty(ref);
+			put_page_tag_ref(ref);
+		}
+	}
+
 	__free_pages_core(page, order);
 }