ChangeSet 1.1449, 2005/05/12 10:27:46+01:00, kaf24@xxxxxxxxxxxxxxxxxxxx
Fix page-faulting error path in privileged-instruction emulator.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
traps.c | 31 ++++++++++++++++---------------
1 files changed, 16 insertions(+), 15 deletions(-)
diff -Nru a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c 2005-05-12 06:04:25 -04:00
+++ b/xen/arch/x86/traps.c 2005-05-12 06:04:25 -04:00
@@ -433,10 +433,19 @@
#define outl_user(_v, _p, _d, _r) \
(admin_io_okay(_p, 4, _d, _r) ? outl(_v, _p) : ((void)0))
+/* Propagate a fault back to the guest kernel. */
+#define USER_READ_FAULT 4 /* user mode, read fault */
+#define USER_WRITE_FAULT 6 /* user mode, write fault */
+#define PAGE_FAULT(_faultaddr, _errcode) \
+({ propagate_page_fault(_faultaddr, _errcode); \
+ return EXCRET_fault_fixed; \
+})
+
+/* Isntruction fetch with error handling. */
#define insn_fetch(_type, _size, _ptr) \
({ unsigned long _x; \
if ( get_user(_x, (_type *)eip) ) \
- goto read_fault; \
+ PAGE_FAULT(eip, USER_READ_FAULT); \
eip += _size; (_type)_x; })
static int emulate_privileged_op(struct cpu_user_regs *regs)
@@ -502,17 +511,17 @@
case 1:
data = (u8)inb_user((u16)regs->edx, ed, regs);
if ( put_user((u8)data, (u8 *)regs->edi) )
- goto write_fault;
+ PAGE_FAULT(regs->edi, USER_WRITE_FAULT);
break;
case 2:
data = (u16)inw_user((u16)regs->edx, ed, regs);
if ( put_user((u16)data, (u16 *)regs->edi) )
- goto write_fault;
+ PAGE_FAULT(regs->edi, USER_WRITE_FAULT);
break;
case 4:
data = (u32)inl_user((u16)regs->edx, ed, regs);
if ( put_user((u32)data, (u32 *)regs->edi) )
- goto write_fault;
+ PAGE_FAULT(regs->edi, USER_WRITE_FAULT);
break;
}
regs->edi += (regs->eflags & EF_DF) ? -op_bytes : op_bytes;
@@ -527,17 +536,17 @@
{
case 1:
if ( get_user(data, (u8 *)regs->esi) )
- goto read_fault;
+ PAGE_FAULT(regs->esi, USER_READ_FAULT);
outb_user((u8)data, (u16)regs->edx, ed, regs);
break;
case 2:
if ( get_user(data, (u16 *)regs->esi) )
- goto read_fault;
+ PAGE_FAULT(regs->esi, USER_READ_FAULT);
outw_user((u16)data, (u16)regs->edx, ed, regs);
break;
case 4:
if ( get_user(data, (u32 *)regs->esi) )
- goto read_fault;
+ PAGE_FAULT(regs->esi, USER_READ_FAULT);
outl_user((u32)data, (u16)regs->edx, ed, regs);
break;
}
@@ -736,14 +745,6 @@
fail:
return 0;
-
- read_fault:
- propagate_page_fault(eip, 4); /* user mode, read fault */
- return EXCRET_fault_fixed;
-
- write_fault:
- propagate_page_fault(eip, 6); /* user mode, write fault */
- return EXCRET_fault_fixed;
}
asmlinkage int do_general_protection(struct cpu_user_regs *regs)
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