ANDROID: mm: add vendor hook in fault and read file

Add a vendor hook to notify vendor module fault and read events.

Bug: 351175506
Change-Id: I4c46e9e00aa5f5555fd42a6b0815563497658b34
Signed-off-by: Sooyong Suk <s.suk@samsung.corp-partner.google.com>

drivers/android/vendor_hooks.c

@@ -337,3 +337,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_madvise_pageout_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_pages_prepare_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_pages_ok_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_split_large_folio_bypass);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_read_fault);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_filemap_read);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_filemap_map_pages);

include/trace/hooks/mm.h

@@ -217,6 +217,16 @@ DECLARE_HOOK(android_vh_free_pages_ok_bypass,
 DECLARE_HOOK(android_vh_split_large_folio_bypass,
 	TP_PROTO(bool *bypass),
 	TP_ARGS(bypass));
+DECLARE_HOOK(android_vh_do_read_fault,
+	TP_PROTO(struct vm_fault *vmf, unsigned long fault_around_bytes),
+	TP_ARGS(vmf, fault_around_bytes));
+DECLARE_HOOK(android_vh_filemap_read,
+	TP_PROTO(struct file *file, loff_t pos, size_t size),
+	TP_ARGS(file, pos, size));
+DECLARE_HOOK(android_vh_filemap_map_pages,
+	TP_PROTO(struct file *file, pgoff_t first_pgoff,
+		pgoff_t last_pgoff, vm_fault_t ret),
+	TP_ARGS(file, first_pgoff, last_pgoff, ret));
 #endif /* _TRACE_HOOK_MM_H */
 
 /* This part must be outside protection */

mm/filemap.c

@@ -2641,6 +2641,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
 
 	iov_iter_truncate(iter, inode->i_sb->s_maxbytes - iocb->ki_pos);
 	folio_batch_init(&fbatch);
+	trace_android_vh_filemap_read(filp, iocb->ki_pos, iov_iter_count(iter));
 
 	do {
 		cond_resched();
@@ -3654,11 +3655,13 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
 	vm_fault_t ret = 0;
 	unsigned long rss = 0;
 	unsigned int nr_pages = 0, mmap_miss = 0, mmap_miss_saved, folio_type;
+	pgoff_t first_pgoff = 0;
 
 	rcu_read_lock();
 	folio = next_uptodate_folio(&xas, mapping, end_pgoff);
 	if (!folio)
 		goto out;
+	first_pgoff = xas.xa_index;
 
 	if (filemap_map_pmd(vmf, folio, start_pgoff)) {
 		ret = VM_FAULT_NOPAGE;
@@ -3709,6 +3712,7 @@ out:
 		WRITE_ONCE(file->f_ra.mmap_miss, 0);
 	else
 		WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss_saved - mmap_miss);
+	trace_android_vh_filemap_map_pages(file, first_pgoff, last_pgoff, ret);
 
 	return ret;
 }

mm/memory.c

@@ -5297,6 +5297,8 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf)
 		ret = do_fault_around(vmf);
 		if (ret)
 			return ret;
+	} else {
+		trace_android_vh_do_read_fault(vmf, fault_around_pages);
 	}
 
 	ret = vmf_can_call_fault(vmf);