debuggers.hg

view xen/common/multicall.c @ 22906:700ac6445812

Now add KDB to the non-kdb tree
author Mukesh Rathor
date Thu Feb 03 15:42:41 2011 -0800 (2011-02-03)
parents 894d10d315c2
children
line source
1 /******************************************************************************
2 * multicall.c
3 */
5 #include <xen/config.h>
6 #include <xen/types.h>
7 #include <xen/lib.h>
8 #include <xen/mm.h>
9 #include <xen/sched.h>
10 #include <xen/event.h>
11 #include <xen/multicall.h>
12 #include <xen/guest_access.h>
13 #include <xen/perfc.h>
14 #include <asm/current.h>
15 #include <asm/hardirq.h>
17 #ifndef COMPAT
18 typedef long ret_t;
19 #define xlat_multicall_entry(mcs)
20 #endif
22 ret_t
23 do_multicall(
24 XEN_GUEST_HANDLE(multicall_entry_t) call_list, unsigned int nr_calls)
25 {
26 struct mc_state *mcs = &current->mc_state;
27 unsigned int i;
29 if ( unlikely(__test_and_set_bit(_MCSF_in_multicall, &mcs->flags)) )
30 {
31 gdprintk(XENLOG_INFO, "Multicall reentry is disallowed.\n");
32 return -EINVAL;
33 }
35 if ( unlikely(!guest_handle_okay(call_list, nr_calls)) )
36 goto fault;
38 for ( i = 0; i < nr_calls; i++ )
39 {
40 if ( hypercall_preempt_check() )
41 goto preempted;
43 if ( unlikely(__copy_from_guest(&mcs->call, call_list, 1)) )
44 goto fault;
46 do_multicall_call(&mcs->call);
48 #ifndef NDEBUG
49 {
50 /*
51 * Deliberately corrupt the contents of the multicall structure.
52 * The caller must depend only on the 'result' field on return.
53 */
54 struct multicall_entry corrupt;
55 memset(&corrupt, 0xAA, sizeof(corrupt));
56 (void)__copy_to_guest(call_list, &corrupt, 1);
57 }
58 #endif
60 if ( unlikely(__copy_field_to_guest(call_list, &mcs->call, result)) )
61 goto fault;
63 if ( test_bit(_MCSF_call_preempted, &mcs->flags) )
64 {
65 /* Translate sub-call continuation to guest layout */
66 xlat_multicall_entry(mcs);
68 /* Copy the sub-call continuation. */
69 (void)__copy_to_guest(call_list, &mcs->call, 1);
70 goto preempted;
71 }
73 guest_handle_add_offset(call_list, 1);
74 }
76 perfc_incr(calls_to_multicall);
77 perfc_add(calls_from_multicall, nr_calls);
78 mcs->flags = 0;
79 return 0;
81 fault:
82 perfc_incr(calls_to_multicall);
83 mcs->flags = 0;
84 return -EFAULT;
86 preempted:
87 perfc_add(calls_from_multicall, i);
88 mcs->flags = 0;
89 return hypercall_create_continuation(
90 __HYPERVISOR_multicall, "hi", call_list, nr_calls-i);
91 }
93 /*
94 * Local variables:
95 * mode: C
96 * c-set-style: "BSD"
97 * c-basic-offset: 4
98 * tab-width: 4
99 * indent-tabs-mode: nil
100 * End:
101 */