1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu-common.h"
22 #include "qemu.h"
23 #include "user-internals.h"
24 #include "cpu_loop-common.h"
25 #include "signal-common.h"
26 #include "qemu/guest-random.h"
27 #include "semihosting/common-semi.h"
28 #include "target/arm/syndrome.h"
29 
30 #define get_user_code_u32(x, gaddr, env)                \
31     ({ abi_long __r = get_user_u32((x), (gaddr));       \
32         if (!__r && bswap_code(arm_sctlr_b(env))) {     \
33             (x) = bswap32(x);                           \
34         }                                               \
35         __r;                                            \
36     })
37 
38 #define get_user_code_u16(x, gaddr, env)                \
39     ({ abi_long __r = get_user_u16((x), (gaddr));       \
40         if (!__r && bswap_code(arm_sctlr_b(env))) {     \
41             (x) = bswap16(x);                           \
42         }                                               \
43         __r;                                            \
44     })
45 
46 #define get_user_data_u32(x, gaddr, env)                \
47     ({ abi_long __r = get_user_u32((x), (gaddr));       \
48         if (!__r && arm_cpu_bswap_data(env)) {          \
49             (x) = bswap32(x);                           \
50         }                                               \
51         __r;                                            \
52     })
53 
54 #define get_user_data_u16(x, gaddr, env)                \
55     ({ abi_long __r = get_user_u16((x), (gaddr));       \
56         if (!__r && arm_cpu_bswap_data(env)) {          \
57             (x) = bswap16(x);                           \
58         }                                               \
59         __r;                                            \
60     })
61 
62 #define put_user_data_u32(x, gaddr, env)                \
63     ({ typeof(x) __x = (x);                             \
64         if (arm_cpu_bswap_data(env)) {                  \
65             __x = bswap32(__x);                         \
66         }                                               \
67         put_user_u32(__x, (gaddr));                     \
68     })
69 
70 #define put_user_data_u16(x, gaddr, env)                \
71     ({ typeof(x) __x = (x);                             \
72         if (arm_cpu_bswap_data(env)) {                  \
73             __x = bswap16(__x);                         \
74         }                                               \
75         put_user_u16(__x, (gaddr));                     \
76     })
77 
78 /* AArch64 main loop */
cpu_loop(CPUARMState * env)79 void cpu_loop(CPUARMState *env)
80 {
81     CPUState *cs = env_cpu(env);
82     int trapnr, ec, fsc, si_code;
83     abi_long ret;
84 
85     for (;;) {
86         cpu_exec_start(cs);
87         trapnr = cpu_exec(cs);
88         cpu_exec_end(cs);
89         process_queued_cpu_work(cs);
90 
91         switch (trapnr) {
92         case EXCP_SWI:
93             ret = do_syscall(env,
94                              env->xregs[8],
95                              env->xregs[0],
96                              env->xregs[1],
97                              env->xregs[2],
98                              env->xregs[3],
99                              env->xregs[4],
100                              env->xregs[5],
101                              0, 0);
102             if (ret == -TARGET_ERESTARTSYS) {
103                 env->pc -= 4;
104             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
105                 env->xregs[0] = ret;
106             }
107             break;
108         case EXCP_INTERRUPT:
109             /* just indicate that signals should be handled asap */
110             break;
111         case EXCP_UDEF:
112             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPN, env->pc);
113             break;
114         case EXCP_PREFETCH_ABORT:
115         case EXCP_DATA_ABORT:
116             /* We should only arrive here with EC in {DATAABORT, INSNABORT}. */
117             ec = syn_get_ec(env->exception.syndrome);
118             assert(ec == EC_DATAABORT || ec == EC_INSNABORT);
119 
120             /* Both EC have the same format for FSC, or close enough. */
121             fsc = extract32(env->exception.syndrome, 0, 6);
122             switch (fsc) {
123             case 0x04 ... 0x07: /* Translation fault, level {0-3} */
124                 si_code = TARGET_SEGV_MAPERR;
125                 break;
126             case 0x09 ... 0x0b: /* Access flag fault, level {1-3} */
127             case 0x0d ... 0x0f: /* Permission fault, level {1-3} */
128                 si_code = TARGET_SEGV_ACCERR;
129                 break;
130             case 0x11: /* Synchronous Tag Check Fault */
131                 si_code = TARGET_SEGV_MTESERR;
132                 break;
133             default:
134                 g_assert_not_reached();
135             }
136 
137             force_sig_fault(TARGET_SIGSEGV, si_code, env->exception.vaddress);
138             break;
139         case EXCP_DEBUG:
140         case EXCP_BKPT:
141             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
142             break;
143         case EXCP_SEMIHOST:
144             env->xregs[0] = do_common_semihosting(cs);
145             env->pc += 4;
146             break;
147         case EXCP_YIELD:
148             /* nothing to do here for user-mode, just resume guest code */
149             break;
150         case EXCP_ATOMIC:
151             cpu_exec_step_atomic(cs);
152             break;
153         default:
154             EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr);
155             abort();
156         }
157 
158         /* Check for MTE asynchronous faults */
159         if (unlikely(env->cp15.tfsr_el[0])) {
160             env->cp15.tfsr_el[0] = 0;
161             force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MTEAERR, 0);
162         }
163 
164         process_pending_signals(env);
165         /* Exception return on AArch64 always clears the exclusive monitor,
166          * so any return to running guest code implies this.
167          */
168         env->exclusive_addr = -1;
169     }
170 }
171 
target_cpu_copy_regs(CPUArchState * env,struct target_pt_regs * regs)172 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
173 {
174     ARMCPU *cpu = env_archcpu(env);
175     CPUState *cs = env_cpu(env);
176     TaskState *ts = cs->opaque;
177     struct image_info *info = ts->info;
178     int i;
179 
180     if (!(arm_feature(env, ARM_FEATURE_AARCH64))) {
181         fprintf(stderr,
182                 "The selected ARM CPU does not support 64 bit mode\n");
183         exit(EXIT_FAILURE);
184     }
185 
186     for (i = 0; i < 31; i++) {
187         env->xregs[i] = regs->regs[i];
188     }
189     env->pc = regs->pc;
190     env->xregs[31] = regs->sp;
191 #ifdef TARGET_WORDS_BIGENDIAN
192     env->cp15.sctlr_el[1] |= SCTLR_E0E;
193     for (i = 1; i < 4; ++i) {
194         env->cp15.sctlr_el[i] |= SCTLR_EE;
195     }
196     arm_rebuild_hflags(env);
197 #endif
198 
199     if (cpu_isar_feature(aa64_pauth, cpu)) {
200         qemu_guest_getrandom_nofail(&env->keys, sizeof(env->keys));
201     }
202 
203     ts->stack_base = info->start_stack;
204     ts->heap_base = info->brk;
205     /* This will be filled in on the first SYS_HEAPINFO call.  */
206     ts->heap_limit = 0;
207 }
208