ANDROID: vendor_hooks: add hooks to modify pageflags

These hooks are designed to set or clear OEM reserved pageflags when the
memory state may change.

Bug: 336964184

Change-Id: I9cb288ef6eef7a719d4f4748d6b71010645b7d50
Signed-off-by: Xiaofeng Yuan <yuanxiaofeng@vivo.com>

drivers/android/vendor_hooks.c

@@ -543,6 +543,11 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_blk_mq_all_tag_iter);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_blk_mq_queue_tag_busy_iter);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_blk_mq_free_tags);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_blk_mq_sched_insert_request);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_shmem_swapin_page);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_wp_page);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_swap_page);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_anonymous_page);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_uprobes_replace_page);
 /*
  * For type visibility
  */

include/trace/hooks/mm.h

@@ -370,6 +370,22 @@ DECLARE_HOOK(android_vh_do_swap_page_spf,
 DECLARE_HOOK(android_vh_tune_fault_around_bytes,
 	TP_PROTO(unsigned long *fault_around_bytes),
 	TP_ARGS(fault_around_bytes));
+DECLARE_HOOK(android_vh_do_anonymous_page,
+	TP_PROTO(struct vm_area_struct *vma, struct page *page),
+	TP_ARGS(vma, page));
+DECLARE_HOOK(android_vh_do_swap_page,
+	TP_PROTO(struct page *page, pte_t *pte, struct vm_fault *vmf,
+		swp_entry_t entry),
+	TP_ARGS(page, pte, vmf, entry));
+DECLARE_HOOK(android_vh_do_wp_page,
+	TP_PROTO(struct page *page),
+	TP_ARGS(page));
+DECLARE_HOOK(android_vh_uprobes_replace_page,
+	TP_PROTO(struct page *new_page, struct page *old_page),
+	TP_ARGS(new_page, old_page));
+DECLARE_HOOK(android_vh_shmem_swapin_page,
+	TP_PROTO(struct page *page),
+	TP_ARGS(page));
 #endif /* _TRACE_HOOK_MM_H */
 
 /* This part must be outside protection */

kernel/events/uprobes.c

@@ -30,6 +30,9 @@
 
 #include <linux/uprobes.h>
 
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/mm.h>
+
 #define UINSNS_PER_PAGE			(PAGE_SIZE/UPROBE_XOL_SLOT_BYTES)
 #define MAX_UPROBE_XOL_SLOTS		UINSNS_PER_PAGE
 
@@ -185,6 +188,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 		get_page(new_page);
 		page_add_new_anon_rmap(new_page, vma, addr, false);
 		lru_cache_add_inactive_or_unevictable(new_page, vma);
+		trace_android_vh_uprobes_replace_page(new_page, old_page);
 	} else
 		/* no new page, just dec_mm_counter for old_page */
 		dec_mm_counter(mm, MM_ANONPAGES);

mm/memory.c

@@ -78,6 +78,9 @@
 
 #include <trace/events/kmem.h>
 
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/mm.h>
+
 #include <asm/io.h>
 #include <asm/mmu_context.h>
 #include <asm/pgalloc.h>
@@ -3444,6 +3447,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
 	 * Take out anonymous pages first, anonymous shared vmas are
 	 * not dirty accountable.
 	 */
+	trace_android_vh_do_wp_page(vmf->page);
 	if (PageAnon(vmf->page)) {
 		struct page *page = vmf->page;
 
@@ -3815,6 +3819,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 	inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
 	dec_mm_counter_fast(vma->vm_mm, MM_SWAPENTS);
 	pte = mk_pte(page, vmf->vma_page_prot);
+	trace_android_vh_do_swap_page(page, &pte, vmf, entry);
 	if ((vmf->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) {
 		pte = maybe_mkwrite(pte_mkdirty(pte), vmf->vma_flags);
 		vmf->flags &= ~FAULT_FLAG_WRITE;
@@ -3971,6 +3976,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	 */
 	__SetPageUptodate(page);
 
+	trace_android_vh_do_anonymous_page(vma, page);
 	entry = mk_pte(page, vmf->vma_page_prot);
 	entry = pte_sw_mkyoung(entry);
 	if (vmf->vma_flags & VM_WRITE)

mm/shmem.c

@@ -1742,6 +1742,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index,
 
 	/* We have to do this with page locked to prevent races */
 	lock_page(page);
+	trace_android_vh_shmem_swapin_page(page);
 	if (!PageSwapCache(page) || page_private(page) != swap.val ||
 	    !shmem_confirm_swap(mapping, index, swap)) {
 		error = -EEXIST;