aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJan Kiszka <jan.kiszka@siemens.com>2012-03-06 15:22:02 +0100
committerBlue Swirl <blauwirbel@gmail.com>2012-03-11 11:22:39 +0000
commit3f2cbf0d1a1340bed4a63e05b044c46df93f4768 (patch)
treec6ef216ba1164a3649444af31d266dd53a73c1b1
parentdac6b1b22cbad29ca34735a1e56c9feb9586e3c0 (diff)
target-i386: Mask NX bit from cpu_get_phys_page_debug result
This was a long pending bug, now revealed by the assert in phys_page_find that stumbled over the large page index returned by cpu_get_phys_page_debug for NX-marked pages: We need to mask out NX and all user-definable bits 52..62 from PDEs and the final PTE to avoid corrupting physical addresses. Reviewed-by: Avi Kivity <avi@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
-rw-r--r--target-i386/cpu.h1
-rw-r--r--target-i386/helper.c13
2 files changed, 8 insertions, 6 deletions
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 196b0c5c40..36e3d29ea0 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -241,6 +241,7 @@
#define PG_DIRTY_MASK (1 << PG_DIRTY_BIT)
#define PG_PSE_MASK (1 << PG_PSE_BIT)
#define PG_GLOBAL_MASK (1 << PG_GLOBAL_BIT)
+#define PG_HI_USER_MASK 0x7ff0000000000000LL
#define PG_NX_MASK (1LL << PG_NX_BIT)
#define PG_ERROR_W_BIT 1
diff --git a/target-i386/helper.c b/target-i386/helper.c
index af6bba2680..f4f3c2726a 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -885,8 +885,8 @@ target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
if (!(pml4e & PG_PRESENT_MASK))
return -1;
- pdpe_addr = ((pml4e & ~0xfff) + (((addr >> 30) & 0x1ff) << 3)) &
- env->a20_mask;
+ pdpe_addr = ((pml4e & ~0xfff & ~(PG_NX_MASK | PG_HI_USER_MASK)) +
+ (((addr >> 30) & 0x1ff) << 3)) & env->a20_mask;
pdpe = ldq_phys(pdpe_addr);
if (!(pdpe & PG_PRESENT_MASK))
return -1;
@@ -900,8 +900,8 @@ target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
return -1;
}
- pde_addr = ((pdpe & ~0xfff) + (((addr >> 21) & 0x1ff) << 3)) &
- env->a20_mask;
+ pde_addr = ((pdpe & ~0xfff & ~(PG_NX_MASK | PG_HI_USER_MASK)) +
+ (((addr >> 21) & 0x1ff) << 3)) & env->a20_mask;
pde = ldq_phys(pde_addr);
if (!(pde & PG_PRESENT_MASK)) {
return -1;
@@ -912,11 +912,12 @@ target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
pte = pde & ~( (page_size - 1) & ~0xfff); /* align to page_size */
} else {
/* 4 KB page */
- pte_addr = ((pde & ~0xfff) + (((addr >> 12) & 0x1ff) << 3)) &
- env->a20_mask;
+ pte_addr = ((pde & ~0xfff & ~(PG_NX_MASK | PG_HI_USER_MASK)) +
+ (((addr >> 12) & 0x1ff) << 3)) & env->a20_mask;
page_size = 4096;
pte = ldq_phys(pte_addr);
}
+ pte &= ~(PG_NX_MASK | PG_HI_USER_MASK);
if (!(pte & PG_PRESENT_MASK))
return -1;
} else {