From: Jack Lange <jarusl@cs.northwestern.edu>
Date: Sat, 15 May 2010 00:29:18 +0000 (-0500)
Subject: add more permission checks to shadow paging
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=c26a28a0070ca2aeedf58294d274be78d0991b05;p=palacios.git

add more permission checks to shadow paging
---

diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
index c0ce265..6eca4d5 100644
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
@@ -389,7 +389,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
 		PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
 		return -1;
 	    }
-	} else {
+	} else if (shdw_reg->flags.write == 1) {
 	    PrintDebug("Shadow PTE Write Error\n");
 	    shadow_pte->writable = guest_pte->writable;
 	}
diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
index c3d2964..287b14c 100644
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
@@ -500,7 +500,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
 		PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
 		return -1;
 	    }
-	} else {
+	} else if (shdw_reg->flags.write == 1) {
 	    PrintDebug("Shadow PTE Write Error\n");
 	    shadow_pte->writable = guest_pte->writable;
 	}
diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
index 91ae34e..30acc7a 100644
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
@@ -274,8 +274,6 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
 	    }
 
 
-
-	    // Write hooks trump all, and are set Read Only
 	    if (shdw_reg->flags.write == 0) {
 		shadow_pte->writable = 0;
 	    }
@@ -296,7 +294,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
 		PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
 		return -1;
 	    }
-	} else {
+	} else if (shdw_reg->flags.write == 1) {
 	    PrintDebug("Shadow PTE Write Error\n");
 	    shadow_pte->writable = guest_pte->writable;
 	}
diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
index cdbb580..df44714 100644
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
@@ -500,7 +500,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
 		PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
 		return -1;
 	    }
-	} else {
+	} else if (shdw_reg->flags.write == 1) {
 	    PrintDebug("Shadow PTE Write Error\n");
 	    shadow_pte->writable = guest_pte->writable;
 	}