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authorDavid Gibson <david@gibson.dropbear.id.au>2013-03-12 00:31:38 +0000
committerAlexander Graf <agraf@suse.de>2013-03-22 15:28:52 +0100
commit87dc3fd13e9c573fc435678973d8eb9726d50c3b (patch)
treece8cd9f7db1faababf5278f927778a0bc1b3f14f /target-ppc
parent59acbe28552eb7bd7be75b22b3f3de93d7d40556 (diff)
mmu-hash*: Don't update PTE flags when permission is denied
BEHAVIOUR CHANGE Currently if ppc_hash{32,64}_translate() finds a PTE matching the given virtual address, it will always update the PTE's R & C (Referenced and Changed) bits. This happens even if the PTE's permissions mean we are about to deny the translation. This is clearly a bug, although we get away with it because: a) It will only incorrectly set, never reset the bits, which should not cause guest correctness problems. b) Linux guests never use the R & C bits anyway. This patch fixes the behaviour, only updating R & C when access is granted by the PTE. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'target-ppc')
-rw-r--r--target-ppc/mmu-hash32.c12
-rw-r--r--target-ppc/mmu-hash64.c12
2 files changed, 14 insertions, 10 deletions
diff --git a/target-ppc/mmu-hash32.c b/target-ppc/mmu-hash32.c
index 348809244d..ae606fdedc 100644
--- a/target-ppc/mmu-hash32.c
+++ b/target-ppc/mmu-hash32.c
@@ -439,15 +439,17 @@ static int ppc_hash32_translate(CPUPPCState *env, struct mmu_ctx_hash32 *ctx,
ctx->raddr = pte.pte1;
ctx->prot = access;
ret = ppc_hash32_check_prot(ctx->prot, rwx);
- if (ret == 0) {
- /* Access granted */
- LOG_MMU("PTE access granted !\n");
- } else {
+
+ if (ret) {
/* Access right violation */
LOG_MMU("PTE access rejected\n");
+ return ret;
}
- /* Update page flags */
+ LOG_MMU("PTE access granted !\n");
+
+ /* 8. Update PTE referenced and changed bits if necessary */
+
if (ppc_hash32_pte_update_flags(ctx, &pte.pte1, ret, rwx) == 1) {
ppc_hash32_store_hpte1(env, pte_offset, pte.pte1);
}
diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 2e109f4896..f7aa352a9b 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -460,15 +460,17 @@ static int ppc_hash64_translate(CPUPPCState *env, struct mmu_ctx_hash64 *ctx,
ctx->raddr = pte.pte1;
ctx->prot = access;
ret = ppc_hash64_check_prot(ctx->prot, rwx);
- if (ret == 0) {
- /* Access granted */
- LOG_MMU("PTE access granted !\n");
- } else {
+
+ if (ret) {
/* Access right violation */
LOG_MMU("PTE access rejected\n");
+ return ret;
}
- /* Update page flags */
+ LOG_MMU("PTE access granted !\n");
+
+ /* 6. Update PTE referenced and changed bits if necessary */
+
if (ppc_hash64_pte_update_flags(ctx, &pte.pte1, ret, rwx) == 1) {
ppc_hash64_store_hpte1(env, pte_offset, pte.pte1);
}