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[Qemu-devel] [PATCH 1/2] tcg-aarch64: user doesn't need R/W access to ex
From: |
Andrew Jones |
Subject: |
[Qemu-devel] [PATCH 1/2] tcg-aarch64: user doesn't need R/W access to exec |
Date: |
Tue, 13 Jan 2015 16:48:10 +0100 |
Table D4-32 shows that execute access from EL0 doesn't depend
on AP[1].
Signed-off-by: Andrew Jones <address@hidden>
---
target-arm/helper.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 3ef0f1f38eda5..7c30a2669a0f2 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -4787,7 +4787,7 @@ static int get_phys_addr_lpae(CPUARMState *env,
target_ulong address,
hwaddr descaddr, descmask;
uint32_t tableattrs;
target_ulong page_size;
- uint32_t attrs;
+ uint32_t attrs, ap;
int32_t granule_sz = 9;
int32_t va_size = 32;
int32_t tbi = 0;
@@ -4952,14 +4952,20 @@ static int get_phys_addr_lpae(CPUARMState *env,
target_ulong address,
/* Access flag */
goto do_fault;
}
+
fault_type = permission_fault;
- if (is_user && !(attrs & (1 << 4))) {
- /* Unprivileged access not enabled */
- goto do_fault;
+ ap = extract32(attrs, 4, 2); /* AP[2:1] */
+
+ *prot = 0;
+ if (!is_user || (ap & 1)) {
+ *prot |= PAGE_READ;
+ *prot |= !(ap & 2) ? PAGE_WRITE : 0;
}
- *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+
+ *prot |= PAGE_EXEC;
if ((arm_feature(env, ARM_FEATURE_V8) && is_user && (attrs & (1 << 12))) ||
(!arm_feature(env, ARM_FEATURE_V8) && (attrs & (1 << 12))) ||
+ (!arm_el_is_aa64(env, 1) && is_user && !(ap & 1)) ||
(!is_user && (attrs & (1 << 11)))) {
/* XN/UXN or PXN. Since we only implement EL0/EL1 we unconditionally
* treat XN/UXN as UXN for v8.
@@ -4969,12 +4975,11 @@ static int get_phys_addr_lpae(CPUARMState *env,
target_ulong address,
}
*prot &= ~PAGE_EXEC;
}
- if (attrs & (1 << 5)) {
- /* Write access forbidden */
- if (access_type == 1) {
- goto do_fault;
- }
- *prot &= ~PAGE_WRITE;
+
+ if ((*prot == 0)
+ || (!(*prot & PAGE_WRITE) && access_type == 1)
+ || (!(*prot & PAGE_EXEC) && access_type == 2)) {
+ goto do_fault;
}
*phys_ptr = descaddr;
--
1.9.3