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| author | Suraj Jitindar Singh <sjitindarsingh@gmail.com> | 2017-03-01 18:12:54 +1100 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2017-03-03 11:30:59 +1100 |
| commit | 07a68f990785a8574c78a36b21cf5165e46f1113 (patch) | |
| tree | ec2a208ab06040a3b57845b492a1bb4eca3a1f98 /target/ppc/mmu-hash64.c | |
| parent | 347a5c73bafd1b5872c9d3192a4d08f8aa1d5f5a (diff) | |
| download | qemu-07a68f990785a8574c78a36b21cf5165e46f1113.zip | |
target/ppc: Move no-execute and guarded page checking into new function
A pte entry has bit fields which can be used to make a page no-execute or
guarded, if either of these bits are set then an instruction access to this
page will fail. Currently these bits are checked with the pp_prot function
however the ISA specifies that the access authority controlled by the
key-pp value pair should only be checked on an instruction access after
the no-execute and guard bits have already been verified to permit the
access.
Move the no-execute and guard bit checking into a new separate function.
Note that we can remove the check for the no-execute bit in the slb entry
since this check was already performed above when we obtained the slb
entry.
In the event that the no-execute or guard bits are set, an ISI should be
generated with the SRR1_NOEXEC_GUARD (0x10000000) bit set in srr1. Add a
define for this for clarity.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
[dwg: Move constants to cpu.h since they're not MMUv3 specific]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target/ppc/mmu-hash64.c')
| -rw-r--r-- | target/ppc/mmu-hash64.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c index 99f936ddbe..d985617068 100644 --- a/target/ppc/mmu-hash64.c +++ b/target/ppc/mmu-hash64.c @@ -290,6 +290,16 @@ target_ulong helper_load_slb_vsid(CPUPPCState *env, target_ulong rb) return rt; } +/* Check No-Execute or Guarded Storage */ +static inline int ppc_hash64_pte_noexec_guard(PowerPCCPU *cpu, + ppc_hash_pte64_t pte) +{ + /* Exec permissions CANNOT take away read or write permissions */ + return (pte.pte1 & HPTE64_R_N) || (pte.pte1 & HPTE64_R_G) ? + PAGE_READ | PAGE_WRITE : PAGE_READ | PAGE_WRITE | PAGE_EXEC; +} + +/* Check Basic Storage Protection */ static int ppc_hash64_pte_prot(PowerPCCPU *cpu, ppc_slb_t *slb, ppc_hash_pte64_t pte) { @@ -333,12 +343,6 @@ static int ppc_hash64_pte_prot(PowerPCCPU *cpu, } } - /* No execute if either noexec or guarded bits set */ - if (!(pte.pte1 & HPTE64_R_N) || (pte.pte1 & HPTE64_R_G) - || (slb->vsid & SLB_VSID_N)) { - prot |= PAGE_EXEC; - } - return prot; } @@ -696,7 +700,7 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, unsigned apshift; hwaddr ptex; ppc_hash_pte64_t pte; - int pp_prot, amr_prot, prot; + int exec_prot, pp_prot, amr_prot, prot; uint64_t new_pte1, dsisr; const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC}; hwaddr raddr; @@ -803,16 +807,19 @@ skip_slb_search: /* 5. Check access permissions */ + exec_prot = ppc_hash64_pte_noexec_guard(cpu, pte); pp_prot = ppc_hash64_pte_prot(cpu, slb, pte); amr_prot = ppc_hash64_amr_prot(cpu, pte); - prot = pp_prot & amr_prot; + prot = exec_prot & pp_prot & amr_prot; if ((need_prot[rwx] & ~prot) != 0) { /* Access right violation */ qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n"); if (rwx == 2) { int srr1 = 0; - if (PAGE_EXEC & ~pp_prot) { + if (PAGE_EXEC & ~exec_prot) { + srr1 |= SRR1_NOEXEC_GUARD; /* Access violates noexec or guard */ + } else if (PAGE_EXEC & ~pp_prot) { srr1 |= SRR1_PROTFAULT; /* Access violates access authority */ } if (PAGE_EXEC & ~amr_prot) { |