1 /* DWARF2 EH unwinding support for IA64 Linux.
2 Copyright (C) 2004-2023 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published
8 by the Free Software Foundation; either version 3, or (at your
9 option) any later version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
15
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
24
25 /* Do code reading to identify a signal frame, and set the frame
26 state data appropriately. See unwind-ia64.c for the structs. */
27
28 /* This works only for glibc-2.3 and later, because sigcontext is different
29 in glibc-2.2.4. */
30
31 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)
32 #include <signal.h>
33 #include <sys/ucontext.h>
34
35 #define IA64_GATE_AREA_START 0xa000000000000100LL
36 #define IA64_GATE_AREA_END 0xa000000000030000LL
37
38 #define MD_FALLBACK_FRAME_STATE_FOR ia64_fallback_frame_state
39
40 static _Unwind_Reason_Code
41 ia64_fallback_frame_state (struct _Unwind_Context *context,
42 _Unwind_FrameState *fs)
43 {
44 if (context->rp >= IA64_GATE_AREA_START
45 && context->rp < IA64_GATE_AREA_END)
46 {
47 struct sigframe {
48 char scratch[16];
49 unsigned long sig_number;
50 siginfo_t *info;
51 struct sigcontext *sc;
52 } *frame_ = (struct sigframe *)context->psp;
53 struct sigcontext *sc = frame_->sc;
54
55 /* Restore scratch registers in case the unwinder needs to
56 refer to a value stored in one of them. */
57 {
58 int i;
59
60 for (i = 2; i < 4; i++)
61 context->ireg[i - 2].loc = &sc->sc_gr[i];
62 for (i = 8; i < 12; i++)
63 context->ireg[i - 2].loc = &sc->sc_gr[i];
64 for (i = 14; i < 32; i++)
65 context->ireg[i - 2].loc = &sc->sc_gr[i];
66 }
67
68 context->fpsr_loc = &(sc->sc_ar_fpsr);
69 context->signal_pfs_loc = &(sc->sc_ar_pfs);
70 context->lc_loc = &(sc->sc_ar_lc);
71 context->unat_loc = &(sc->sc_ar_unat);
72 context->br_loc[0] = &(sc->sc_br[0]);
73 context->br_loc[6] = &(sc->sc_br[6]);
74 context->br_loc[7] = &(sc->sc_br[7]);
75 context->pr = sc->sc_pr;
76 context->psp = sc->sc_gr[12];
77 context->gp = sc->sc_gr[1];
78 /* Signal frame doesn't have an associated reg. stack frame
79 other than what we adjust for below. */
80 fs -> no_reg_stack_frame = 1;
81
82 if (sc->sc_rbs_base)
83 {
84 /* Need to switch from alternate register backing store. */
85 long ndirty, loadrs = sc->sc_loadrs >> 16;
86 unsigned long alt_bspstore = context->bsp - loadrs;
87 unsigned long bspstore;
88 unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
89
90 ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
91 (unsigned long *) context->bsp);
92 bspstore = (unsigned long)
93 ia64_rse_skip_regs (ar_bsp, -ndirty);
94 ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
95 sc->sc_ar_rnat);
96 }
97
98 /* Don't touch the branch registers o.t. b0, b6 and b7.
99 The kernel doesn't pass the preserved branch registers
100 in the sigcontext but leaves them intact, so there's no
101 need to do anything with them here. */
102 {
103 unsigned long sof = sc->sc_cfm & 0x7f;
104 context->bsp = (unsigned long)
105 ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
106 }
107
108 /* Account for use of br.ret to resume execution of user code. */
109 fs->curr.reg[UNW_REG_RP].where = UNW_WHERE_SPREL;
110 fs->curr.reg[UNW_REG_RP].val
111 = (unsigned long)&(sc->sc_ip) - context->psp;
112 fs->curr.reg[UNW_REG_RP].when = -1;
113
114 fs->curr.reg[UNW_REG_PFS].where = UNW_WHERE_SPREL;
115 fs->curr.reg[UNW_REG_PFS].val
116 = (unsigned long)&(sc->sc_cfm) - context->psp;
117 fs ->curr.reg[UNW_REG_PFS].when = -1;
118
119 return _URC_NO_REASON;
120 }
121 return _URC_END_OF_STACK;
122 }
123
124 #define MD_HANDLE_UNWABI ia64_handle_unwabi
125
126 #define ABI_MARKER_OLD_LINUX_SIGTRAMP ((0 << 8) | 's')
127 #define ABI_MARKER_OLD_LINUX_INTERRUPT ((0 << 8) | 'i')
128 #define ABI_MARKER_LINUX_SIGTRAMP ((3 << 8) | 's')
129 #define ABI_MARKER_LINUX_INTERRUPT ((3 << 8) | 'i')
130
131 static void
132 ia64_handle_unwabi (struct _Unwind_Context *context, _Unwind_FrameState *fs)
133 {
134 if (fs->unwabi == ABI_MARKER_LINUX_SIGTRAMP
135 || fs->unwabi == ABI_MARKER_OLD_LINUX_SIGTRAMP)
136 {
137 struct sigframe {
138 char scratch[16];
139 unsigned long sig_number;
140 siginfo_t *info;
141 struct sigcontext *sc;
142 } *frame = (struct sigframe *)context->psp;
143 struct sigcontext *sc = frame->sc;
144
145 /* Restore scratch registers in case the unwinder needs to
146 refer to a value stored in one of them. */
147 {
148 int i;
149
150 for (i = 2; i < 4; i++)
151 context->ireg[i - 2].loc = &sc->sc_gr[i];
152 for (i = 8; i < 12; i++)
153 context->ireg[i - 2].loc = &sc->sc_gr[i];
154 for (i = 14; i < 32; i++)
155 context->ireg[i - 2].loc = &sc->sc_gr[i];
156 }
157
158 context->signal_pfs_loc = &(sc->sc_ar_pfs);
159 context->lc_loc = &(sc->sc_ar_lc);
160 context->unat_loc = &(sc->sc_ar_unat);
161 context->br_loc[0] = &(sc->sc_br[0]);
162 context->br_loc[6] = &(sc->sc_br[6]);
163 context->br_loc[7] = &(sc->sc_br[7]);
164 context->pr = sc->sc_pr;
165 context->gp = sc->sc_gr[1];
166 /* Signal frame doesn't have an associated reg. stack frame
167 other than what we adjust for below. */
168 fs -> no_reg_stack_frame = 1;
169
170 if (sc->sc_rbs_base)
171 {
172 /* Need to switch from alternate register backing store. */
173 long ndirty, loadrs = sc->sc_loadrs >> 16;
174 unsigned long alt_bspstore = context->bsp - loadrs;
175 unsigned long bspstore;
176 unsigned long *ar_bsp = (unsigned long *)(sc->sc_ar_bsp);
177
178 ndirty = ia64_rse_num_regs ((unsigned long *) alt_bspstore,
179 (unsigned long *) context->bsp);
180 bspstore = (unsigned long) ia64_rse_skip_regs (ar_bsp, -ndirty);
181 ia64_copy_rbs (context, bspstore, alt_bspstore, loadrs,
182 sc->sc_ar_rnat);
183 }
184
185 /* Don't touch the branch registers o.t. b0, b6 and b7.
186 The kernel doesn't pass the preserved branch registers
187 in the sigcontext but leaves them intact, so there's no
188 need to do anything with them here. */
189 {
190 unsigned long sof = sc->sc_cfm & 0x7f;
191 context->bsp = (unsigned long)
192 ia64_rse_skip_regs ((unsigned long *)(sc->sc_ar_bsp), -sof);
193 }
194
195 /* The use of br.ret to resume execution of user code is already
196 accounted for in the unwind ABI. */
197 }
198 }
199 #endif /* glibc-2.3 or better */