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

@@ -545,3 +545,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_oom_swapmem_gather_init);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_oom_swapmem_gather_finish);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_set_gfp_zone_flags);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_set_readahead_gfp_mask);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_shmem_swapin_folio);
+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);

include/trace/hooks/mm.h

@@ -497,6 +497,22 @@ DECLARE_HOOK(android_vh_oom_swapmem_gather_init,
 DECLARE_HOOK(android_vh_oom_swapmem_gather_finish,
 	TP_PROTO(struct mm_struct *mm),
 	TP_ARGS(mm));
+DECLARE_HOOK(android_vh_do_anonymous_page,
+	TP_PROTO(struct vm_area_struct *vma, struct folio *folio),
+	TP_ARGS(vma, folio));
+DECLARE_HOOK(android_vh_do_swap_page,
+	TP_PROTO(struct folio *folio, pte_t *pte, struct vm_fault *vmf,
+		swp_entry_t entry),
+	TP_ARGS(folio, pte, vmf, entry));
+DECLARE_HOOK(android_vh_do_wp_page,
+	TP_PROTO(struct folio *folio),
+	TP_ARGS(folio));
+DECLARE_HOOK(android_vh_uprobes_replace_page,
+	TP_PROTO(struct folio *new_folio, struct folio *old_folio),
+	TP_ARGS(new_folio, old_folio));
+DECLARE_HOOK(android_vh_shmem_swapin_folio,
+	TP_PROTO(struct folio *folio),
+	TP_ARGS(folio));
 #endif /* _TRACE_HOOK_MM_H */
 
 /* This part must be outside protection */

kernel/events/uprobes.c

@@ -29,6 +29,9 @@
 
 #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
 
@@ -202,6 +205,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 		folio_get(new_folio);
 		folio_add_new_anon_rmap(new_folio, vma, addr, RMAP_EXCLUSIVE);
 		folio_add_lru_vma(new_folio, vma);
+		trace_android_vh_uprobes_replace_page(new_folio, old_folio);
 	} else
 		/* no new page, just dec_mm_counter for old_page */
 		dec_mm_counter(mm, MM_ANONPAGES);

mm/memory.c

@@ -3739,6 +3739,8 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
 		return wp_page_shared(vmf, folio);
 	}
 
+	trace_android_vh_do_wp_page(folio);
+
 	/*
 	 * Private mapping: create an exclusive anonymous page copy if reuse
 	 * is impossible. We might miss VM_WRITE for FOLL_FORCE handling.
@@ -4564,6 +4566,7 @@ check_folio:
 		pte = pte_mksoft_dirty(pte);
 	if (pte_swp_uffd_wp(vmf->orig_pte))
 		pte = pte_mkuffd_wp(pte);
+	trace_android_vh_do_swap_page(folio, &pte, vmf, entry);
 
 	/*
 	 * Same logic as in do_wp_page(); however, optimize for pages that are
@@ -4828,6 +4831,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	 */
 	__folio_mark_uptodate(folio);
 
+	trace_android_vh_do_anonymous_page(vma, folio);
 	entry = mk_pte(&folio->page, vma->vm_page_prot);
 	entry = pte_sw_mkyoung(entry);
 	if (vma->vm_flags & VM_WRITE)

mm/shmem.c

@@ -2178,6 +2178,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
 
 	/* We have to do this with folio locked to prevent races */
 	folio_lock(folio);
+	trace_android_vh_shmem_swapin_folio(folio);
 	if (!folio_test_swapcache(folio) ||
 	    folio->swap.val != swap.val ||
 	    !shmem_confirm_swap(mapping, index, swap)) {