68 lines
2.2 KiB
Diff
68 lines
2.2 KiB
Diff
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# HG changeset patch
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# User Jean Guyader <jean.guyader@eu.citrix.com>
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# Date 1321002862 -3600
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# Node ID a095cf28f2b6eeb8f5873c18eb18d4d7e5544e2c
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# Parent 6534da595d695a4f2af12a64e46fb06219a0e4bc
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Hypercall continuation cancelation in compat mode for XENMEM_get/set_pod_target
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If copy_to_guest failed in the compat code after a continuation as been
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done in the native code we need to cancel it so we won't reexecute the
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hypercall but return from the hypercall with the appropriate error.
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Signed-off-by: Jean Guyader <jean.guyader@eu.citrix.com>
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Acked-by: Jan Beulich <jbeulich@suse.com>
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Acked-by: Keir Fraser <keir@xen.org>
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Committed-by: Jan Beulich <jbeulich@suse.com>
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--- a/xen/arch/x86/domain.c
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+++ b/xen/arch/x86/domain.c
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@@ -1585,6 +1585,24 @@ void sync_vcpu_execstate(struct vcpu *v)
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__arg; \
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})
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+void hypercall_cancel_continuation(void)
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+{
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+ struct cpu_user_regs *regs = guest_cpu_user_regs();
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+ struct mc_state *mcs = ¤t->mc_state;
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+
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+ if ( test_bit(_MCSF_in_multicall, &mcs->flags) )
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+ {
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+ __clear_bit(_MCSF_call_preempted, &mcs->flags);
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+ }
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+ else
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+ {
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+ if ( !is_hvm_vcpu(current) )
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+ regs->eip += 2; /* skip re-execute 'syscall' / 'int $xx' */
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+ else
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+ current->arch.hvm_vcpu.hcall_preempted = 0;
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+ }
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+}
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+
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unsigned long hypercall_create_continuation(
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unsigned int op, const char *format, ...)
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{
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--- a/xen/arch/x86/x86_64/compat/mm.c
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+++ b/xen/arch/x86/x86_64/compat/mm.c
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@@ -133,7 +133,11 @@ int compat_arch_memory_op(int op, XEN_GU
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XLAT_pod_target(&cmp, nat);
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if ( copy_to_guest(arg, &cmp, 1) )
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+ {
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+ if ( rc == __HYPERVISOR_memory_op )
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+ hypercall_cancel_continuation();
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rc = -EFAULT;
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+ }
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break;
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}
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--- a/xen/include/xen/sched.h
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+++ b/xen/include/xen/sched.h
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@@ -560,6 +560,7 @@ void startup_cpu_idle_loop(void);
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*/
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unsigned long hypercall_create_continuation(
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unsigned int op, const char *format, ...);
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+void hypercall_cancel_continuation(void);
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#define hypercall_preempt_check() (unlikely( \
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softirq_pending(smp_processor_id()) | \
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