1 /* The kernel calls that are implemented in this file:
2 * m_type: SYS_SETMCONTEXT
3 * m_type: SYS_GETMCONTEXT
4 *
5 * The parameters for SYS_SETMCONTEXT kernel call are:
6 * m_lsys_krn_sys_setmcontext.endpt # proc endpoint doing call
7 * m_lsys_krn_sys_setmcontext.ctx_ptr # pointer to mcontext structure
8 *
9 * The parameters for SYS_GETMCONTEXT kernel call are:
10 * m_lsys_krn_sys_getmcontext.endpt # proc endpoint doing call
11 * m_lsys_krn_sys_getmcontext.ctx_ptr # pointer to mcontext structure
12 */
13
14 #include "kernel/system.h"
15 #include <string.h>
16 #include <assert.h>
17 #include <machine/mcontext.h>
18
19 #if USE_MCONTEXT
20 /*===========================================================================*
21 * do_getmcontext *
22 *===========================================================================*/
do_getmcontext(struct proc * caller,message * m_ptr)23 int do_getmcontext(struct proc * caller, message * m_ptr)
24 {
25 /* Retrieve machine context of a process */
26
27 register struct proc *rp;
28 int proc_nr, r;
29 mcontext_t mc;
30
31 if (!isokendpt(m_ptr->m_lsys_krn_sys_getmcontext.endpt, &proc_nr))
32 return(EINVAL);
33 if (iskerneln(proc_nr)) return(EPERM);
34 rp = proc_addr(proc_nr);
35
36 #if defined(__i386__)
37 if (!proc_used_fpu(rp))
38 return(OK); /* No state to copy */
39 #endif
40
41 /* Get the mcontext structure into our address space. */
42 if ((r = data_copy(m_ptr->m_lsys_krn_sys_getmcontext.endpt,
43 m_ptr->m_lsys_krn_sys_getmcontext.ctx_ptr, KERNEL,
44 (vir_bytes) &mc, (phys_bytes) sizeof(mcontext_t))) != OK)
45 return(r);
46
47 mc.mc_flags = 0;
48 #if defined(__i386__)
49 /* Copy FPU state */
50 if (proc_used_fpu(rp)) {
51 /* make sure that the FPU context is saved into proc structure first */
52 save_fpu(rp);
53 mc.mc_flags = (rp->p_misc_flags & MF_FPU_INITIALIZED) ? _MC_FPU_SAVED : 0;
54 assert(sizeof(mc.__fpregs.__fp_reg_set) == FPU_XFP_SIZE);
55 memcpy(&(mc.__fpregs.__fp_reg_set), rp->p_seg.fpu_state, FPU_XFP_SIZE);
56 }
57 #endif
58
59
60 /* Copy the mcontext structure to the user's address space. */
61 if ((r = data_copy(KERNEL, (vir_bytes) &mc,
62 m_ptr->m_lsys_krn_sys_getmcontext.endpt,
63 m_ptr->m_lsys_krn_sys_getmcontext.ctx_ptr,
64 (phys_bytes) sizeof(mcontext_t))) != OK)
65 return(r);
66
67 return(OK);
68 }
69
70
71 /*===========================================================================*
72 * do_setmcontext *
73 *===========================================================================*/
do_setmcontext(struct proc * caller,message * m_ptr)74 int do_setmcontext(struct proc * caller, message * m_ptr)
75 {
76 /* Set machine context of a process */
77
78 register struct proc *rp;
79 int proc_nr, r;
80 mcontext_t mc;
81
82 if (!isokendpt(m_ptr->m_lsys_krn_sys_setmcontext.endpt, &proc_nr)) return(EINVAL);
83 rp = proc_addr(proc_nr);
84
85 /* Get the mcontext structure into our address space. */
86 if ((r = data_copy(m_ptr->m_lsys_krn_sys_setmcontext.endpt,
87 m_ptr->m_lsys_krn_sys_setmcontext.ctx_ptr, KERNEL,
88 (vir_bytes) &mc, (phys_bytes) sizeof(mcontext_t))) != OK)
89 return(r);
90
91 #if defined(__i386__)
92 /* Copy FPU state */
93 if (mc.mc_flags & _MC_FPU_SAVED) {
94 rp->p_misc_flags |= MF_FPU_INITIALIZED;
95 assert(sizeof(mc.__fpregs.__fp_reg_set) == FPU_XFP_SIZE);
96 memcpy(rp->p_seg.fpu_state, &(mc.__fpregs.__fp_reg_set), FPU_XFP_SIZE);
97 } else
98 rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
99 /* force reloading FPU in either case */
100 release_fpu(rp);
101 #endif
102
103 return(OK);
104 }
105
106 #endif
107