__sigtramp2.S revision 1.8 1 /* $NetBSD: __sigtramp2.S,v 1.8 2021/11/20 19:26:20 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
5 * All rights reserved.
6 *
7 * Author: Chris G. Demetriou
8 *
9 * Permission to use, copy, modify and distribute this software and
10 * its documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 *
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 *
19 * Carnegie Mellon requests users of this software to return to
20 *
21 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU
22 * School of Computer Science
23 * Carnegie Mellon University
24 * Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie the
27 * rights to redistribute these changes.
28 */
29
30 #include "SYS.h"
31 #include "assym.h"
32
33 /*
34 * The Alpha signal trampoline is invoked only to return from
35 * the signal; the kernel calls the signal handler directly.
36 *
37 * On entry, the stack looks like:
38 *
39 * ucontext structure [128] == sp + sizeof(siginfo_t)]
40 * sp-> siginfo structure [0]
41 *
42 * The DWARF register numbers for the general purpose registers are the
43 * same as the architected register numbers. For Alpha, there is a DWARF
44 * pseudo-register for signal handler return addresses.
45 */
46
47 #if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
48 #define DWARF_SIGRETURN_REG __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
49 #else
50 #define DWARF_SIGRETURN_REG 64
51 #endif
52
53 #define CFI_OFFSET_DWARF_REG(d, r) .cfi_offset d, r*8
54 #define CFI_OFFSET(r) CFI_OFFSET_DWARF_REG(r, r)
55
56 .cfi_startproc simple
57 .cfi_signal_frame
58 .cfi_def_cfa _REG_SP, SIZEOF_SIGINFO + UC_GREGS
59 CFI_OFFSET(_REG_V0)
60 CFI_OFFSET(_REG_T0)
61 CFI_OFFSET(_REG_T1)
62 CFI_OFFSET(_REG_T2)
63 CFI_OFFSET(_REG_T3)
64 CFI_OFFSET(_REG_T4)
65 CFI_OFFSET(_REG_T5)
66 CFI_OFFSET(_REG_T6)
67 CFI_OFFSET(_REG_T7)
68 CFI_OFFSET(_REG_S0)
69 CFI_OFFSET(_REG_S1)
70 CFI_OFFSET(_REG_S2)
71 CFI_OFFSET(_REG_S3)
72 CFI_OFFSET(_REG_S4)
73 CFI_OFFSET(_REG_S5)
74 CFI_OFFSET(_REG_S6)
75 CFI_OFFSET(_REG_A0)
76 CFI_OFFSET(_REG_A1)
77 CFI_OFFSET(_REG_A2)
78 CFI_OFFSET(_REG_A3)
79 CFI_OFFSET(_REG_A4)
80 CFI_OFFSET(_REG_A5)
81 CFI_OFFSET(_REG_T8)
82 CFI_OFFSET(_REG_T9)
83 CFI_OFFSET(_REG_T10)
84 CFI_OFFSET(_REG_T11)
85 CFI_OFFSET(_REG_RA)
86 CFI_OFFSET(_REG_T12) /* a.k.a. _REG_PV */
87 CFI_OFFSET(_REG_AT)
88 CFI_OFFSET(_REG_GP)
89 CFI_OFFSET(_REG_SP)
90 .cfi_return_column DWARF_SIGRETURN_REG
91 CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
92
93 /*
94 * The unwind entry includes one instruction slot prior to the trampoline
95 * because the unwinder will look up to (return PC - 1 insn) while unwinding.
96 * Normally this would be the jump / branch, but since there isn't one in
97 * this case, we place an explicit nop there instead.
98 */
99 nop
100
101 NESTED_NOPROFILE(__sigtramp_siginfo_2,0,0,ra,0,0)
102 ldgp gp,0(ra)
103 lda a0,(SIZEOF_SIGINFO)(sp) /* get pointer to ucontext */
104 CALLSYS_NOERROR(setcontext) /* and call setcontext() with it */
105 ldiq a0,-1 /* if that failed, set an exit code */
106 CALLSYS_NOERROR(exit) /* and call exit() */
107 .cfi_endproc
108 END(__sigtramp_siginfo_2)
109