ANDROID: vendor_hooks: Add hook in try_to_unmap_one()

Add hook in try_to_unmap_one() to trace this function for debug memory
swap bugs.

Bug: 198385827
Change-Id: I1fdbe60e09bb491b949e06a07133710453ecca03
Signed-off-by: Jiewen Wang <jiewen.wang@vivo.com>

drivers/android/vendor_hooks.c

@@ -382,3 +382,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_tcp_recvmsg_stat);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_pci_d3_sleep);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_kmalloc_slab);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mmap_region);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_try_to_unmap_one);

include/trace/hooks/mm.h

@@ -123,6 +123,9 @@ DECLARE_HOOK(android_vh_kmalloc_slab,
 DECLARE_HOOK(android_vh_mmap_region,
 	TP_PROTO(struct vm_area_struct *vma, unsigned long addr),
 	TP_ARGS(vma, addr));
+DECLARE_HOOK(android_vh_try_to_unmap_one,
+	TP_PROTO(struct vm_area_struct *vma, struct page *page, unsigned long addr, bool ret),
+	TP_ARGS(vma, page, addr, ret));
 /* macro versions of hooks are no longer required */
 
 #endif /* _TRACE_HOOK_MM_H */

mm/rmap.c

@@ -77,6 +77,8 @@
 
 #include <trace/events/tlb.h>
 
+#include <trace/hooks/mm.h>
+
 #include "internal.h"
 
 static struct kmem_cache *anon_vma_cachep;
@@ -1706,6 +1708,7 @@ discard:
 	}
 
 	mmu_notifier_invalidate_range_end(&range);
+	trace_android_vh_try_to_unmap_one(vma, page, address, ret);
 
 	return ret;
 }