From 363248e8c92c6331253e2a768884c69183805050 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Tue, 4 Feb 2014 18:21:39 +0100 Subject: [PATCH] mmu-hash64: fix Virtual Page Class Key Protection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit f80872e21c07edd06eb343eeeefc8af404b518a6 (mmu-hash64: Implement Virtual Page Class Key Protection) added a new page protection mechanism based on page keys and the AMR register to control access. The AMR register allows or prohibits reads and/or writes on a page depending on the control bits associated to the key. A store or a load is only permitted if the associate bit is 0 (Power ISA), and not 1 as the code is currently doing. This patch modifies ppc_hash64_amr_prot() to correct the protection check. This issue was unvailed by commit ccfb53ed6360cac0d5f6f7915ca9ae7eed866412 (target-ppc: fix Authority Mask Register init value) which changed the initialisation value of the AMR register to 0. Signed-off-by: Cédric Le Goater Signed-off-by: Alexander Graf --- target-ppc/mmu-hash64.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c index 67fc1b5dec..c1c33b0f9a 100644 --- a/target-ppc/mmu-hash64.c +++ b/target-ppc/mmu-hash64.c @@ -278,12 +278,12 @@ static int ppc_hash64_pte_prot(CPUPPCState *env, static int ppc_hash64_amr_prot(CPUPPCState *env, ppc_hash_pte64_t pte) { int key, amrbits; - int prot = PAGE_EXEC; + int prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC; /* Only recent MMUs implement Virtual Page Class Key Protection */ if (!(env->mmu_model & POWERPC_MMU_AMR)) { - return PAGE_READ | PAGE_WRITE | PAGE_EXEC; + return prot; } key = HPTE64_R_KEY(pte.pte1); @@ -292,11 +292,19 @@ static int ppc_hash64_amr_prot(CPUPPCState *env, ppc_hash_pte64_t pte) /* fprintf(stderr, "AMR protection: key=%d AMR=0x%" PRIx64 "\n", key, */ /* env->spr[SPR_AMR]); */ + /* + * A store is permitted if the AMR bit is 0. Remove write + * protection if it is set. + */ if (amrbits & 0x2) { - prot |= PAGE_WRITE; + prot &= ~PAGE_WRITE; } + /* + * A load is permitted if the AMR bit is 0. Remove read + * protection if it is set. + */ if (amrbits & 0x1) { - prot |= PAGE_READ; + prot &= ~PAGE_READ; } return prot;