From 3f162d119ef52fda714ebb498fcb4f4b7c354d38 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Wed, 25 Jan 2012 16:27:26 +0100
Subject: PPC: booke206: Check for TLB overrun

Our internal helpers to fetch TLB entries were not able to tell us
that an entry doesn't even exist. Pass an error out if we hit such
a case to not accidently pass beyond the TLB array.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 target-ppc/cpu.h       |  4 ++++
 target-ppc/helper.c    |  3 +++
 target-ppc/op_helper.c | 22 +++++++++++++++++++++-
 target-ppc/translate.c |  1 +
 4 files changed, 29 insertions(+), 1 deletion(-)

(limited to 'target-ppc')

diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 102625460..668ddf34c 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -2112,6 +2112,10 @@ static inline ppcmas_tlb_t *booke206_get_tlbm(CPUState *env, const int tlbn,
     ea &= (1 << (tlb_bits - ways_bits)) - 1;
     r = (ea << ways_bits) | way;
 
+    if (r >= booke206_tlb_size(env, tlbn)) {
+        return NULL;
+    }
+
     /* bump up to tlbn index */
     for (i = 0; i < tlbn; i++) {
         r += booke206_tlb_size(env, i);
diff --git a/target-ppc/helper.c b/target-ppc/helper.c
index 2ce2d9238..672494c59 100644
--- a/target-ppc/helper.c
+++ b/target-ppc/helper.c
@@ -1448,6 +1448,9 @@ static int mmubooke206_get_physical_address(CPUState *env, mmu_ctx_t *ctx,
 
         for (j = 0; j < ways; j++) {
             tlb = booke206_get_tlbm(env, i, address, j);
+            if (!tlb) {
+                continue;
+            }
             ret = mmubooke206_check_tlb(env, tlb, &raddr, &ctx->prot, address,
                                         rw, access_type);
             if (ret != -1) {
diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
index 1f1fa0936..be4e539c2 100644
--- a/target-ppc/op_helper.c
+++ b/target-ppc/op_helper.c
@@ -4260,6 +4260,12 @@ void helper_booke206_tlbwe(void)
 
     tlb = booke206_cur_tlb(env);
 
+    if (!tlb) {
+        helper_raise_exception_err(POWERPC_EXCP_PROGRAM,
+                                   POWERPC_EXCP_INVAL |
+                                   POWERPC_EXCP_INVAL_INVAL);
+    }
+
     /* check that we support the targeted size */
     size_tlb = (env->spr[SPR_BOOKE_MAS1] & MAS1_TSIZE_MASK) >> MAS1_TSIZE_SHIFT;
     size_ps = booke206_tlbnps(env, tlbn);
@@ -4311,7 +4317,11 @@ void helper_booke206_tlbre(void)
     ppcmas_tlb_t *tlb = NULL;
 
     tlb = booke206_cur_tlb(env);
-    booke206_tlb_to_mas(env, tlb);
+    if (!tlb) {
+        env->spr[SPR_BOOKE_MAS1] = 0;
+    } else {
+        booke206_tlb_to_mas(env, tlb);
+    }
 }
 
 void helper_booke206_tlbsx(target_ulong address)
@@ -4330,6 +4340,10 @@ void helper_booke206_tlbsx(target_ulong address)
         for (j = 0; j < ways; j++) {
             tlb = booke206_get_tlbm(env, i, address, j);
 
+            if (!tlb) {
+                continue;
+            }
+
             if (ppcmas_tlb_check(env, tlb, &raddr, address, spid)) {
                 continue;
             }
@@ -4373,6 +4387,9 @@ static inline void booke206_invalidate_ea_tlb(CPUState *env, int tlbn,
 
     for (i = 0; i < ways; i++) {
         ppcmas_tlb_t *tlb = booke206_get_tlbm(env, tlbn, ea, i);
+        if (!tlb) {
+            continue;
+        }
         mask = ~(booke206_tlb_to_page_size(env, tlb) - 1);
         if (((tlb->mas2 & MAS2_EPN_MASK) == (ea & mask)) &&
             !(tlb->mas1 & MAS1_IPROT)) {
@@ -4453,6 +4470,9 @@ void helper_booke206_tlbilx3(target_ulong address)
 
         for (j = 0; j < ways; j++) {
             tlb = booke206_get_tlbm(env, i, address, j);
+            if (!tlb) {
+                continue;
+            }
             if ((ppcmas_tlb_check(env, tlb, NULL, address, pid) != 0) ||
                 (tlb->mas1 & MAS1_IPROT) ||
                 ((tlb->mas1 & MAS1_IND) != ind) ||
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index d8ef7196b..58a4853a0 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -6088,6 +6088,7 @@ static void gen_tlbwe_booke206(DisasContext *ctx)
         gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
         return;
     }
+    gen_update_nip(ctx, ctx->nip - 4);
     gen_helper_booke206_tlbwe();
 #endif
 }
-- 
cgit v1.2.3