From 256a32438f736cd8ee08e24c9cc8468e911be6da Mon Sep 17 00:00:00 2001
From: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
Date: Thu, 2 Nov 2023 11:57:56 +0100
Subject: [PATCH] arch,pt: add frame finder for virtual address functionality

Signed-off-by: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
---
 arch/x86/pagetables.c        | 21 +++++++++++++++++++++
 include/arch/x86/pagetable.h |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/arch/x86/pagetables.c b/arch/x86/pagetables.c
index 3d733f43..ff2a6a39 100644
--- a/arch/x86/pagetables.c
+++ b/arch/x86/pagetables.c
@@ -422,6 +422,27 @@ int get_user_va_mfn_order(void *va, mfn_t *mfn, unsigned int *order) {
     return err;
 }
 
+static frame_t *get_va_frame(const cr3_t *cr3_ptr, const void *va) {
+    frame_t *frame = NULL;
+    unsigned int order;
+    mfn_t mfn;
+
+    spin_lock(&vmap_lock);
+    if (get_va_mfn_order(cr3_ptr, va, &mfn, &order) == 0)
+        frame = find_mfn_frame(mfn, order);
+    spin_unlock(&vmap_lock);
+
+    return frame;
+}
+
+frame_t *get_kern_va_frame(const void *va) {
+    return get_va_frame(&cr3, va);
+}
+
+frame_t *get_user_va_frame(const void *va) {
+    return get_va_frame(&user_cr3, va);
+}
+
 void init_pagetables(void) {
     init_tmp_mapping();
 
diff --git a/include/arch/x86/pagetable.h b/include/arch/x86/pagetable.h
index fb95e444..30f68680 100644
--- a/include/arch/x86/pagetable.h
+++ b/include/arch/x86/pagetable.h
@@ -304,6 +304,9 @@ extern void dump_user_pagetable_va(void *va);
 extern int get_kern_va_mfn_order(void *va, mfn_t *mfn, unsigned int *order);
 extern int get_user_va_mfn_order(void *va, mfn_t *mfn, unsigned int *order);
 
+extern frame_t *get_kern_va_frame(const void *va);
+extern frame_t *get_user_va_frame(const void *va);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* KTF_PAGETABLE_H */