xref: /openbmc/qemu/disas/disas-target.c (revision f2202be2)
1 /*
2  * Routines for target instruction disassembly.
3  * SPDX-License-Identifier: GPL-2.0-or-later
4  */
5 
6 #include "qemu/osdep.h"
7 #include "disas/disas.h"
8 #include "disas/capstone.h"
9 #include "exec/translator.h"
10 #include "disas-internal.h"
11 
12 
13 static int translator_read_memory(bfd_vma memaddr, bfd_byte *myaddr,
14                                   int length, struct disassemble_info *info)
15 {
16     const DisasContextBase *db = info->application_data;
17     return translator_st(db, myaddr, memaddr, length) ? 0 : EIO;
18 }
19 
20 void target_disas(FILE *out, CPUState *cpu, const struct DisasContextBase *db)
21 {
22     uint64_t code = db->pc_first;
23     size_t size = translator_st_len(db);
24     uint64_t pc;
25     int count;
26     CPUDebug s;
27 
28     disas_initialize_debug_target(&s, cpu);
29     s.info.read_memory_func = translator_read_memory;
30     s.info.application_data = (void *)db;
31     s.info.fprintf_func = fprintf;
32     s.info.stream = out;
33     s.info.buffer_vma = code;
34     s.info.buffer_length = size;
35     s.info.show_opcodes = true;
36 
37     if (s.info.cap_arch >= 0 && cap_disas_target(&s.info, code, size)) {
38         return;
39     }
40 
41     if (s.info.print_insn == NULL) {
42         s.info.print_insn = print_insn_od_target;
43     }
44 
45     for (pc = code; size > 0; pc += count, size -= count) {
46         fprintf(out, "0x%08" PRIx64 ":  ", pc);
47         count = s.info.print_insn(pc, &s.info);
48         fprintf(out, "\n");
49         if (count < 0) {
50             break;
51         }
52         if (size < count) {
53             fprintf(out,
54                     "Disassembler disagrees with translator over instruction "
55                     "decoding\n"
56                     "Please report this to qemu-devel@nongnu.org\n");
57             break;
58         }
59     }
60 }
61 
62 #ifdef CONFIG_PLUGIN
63 static void plugin_print_address(bfd_vma addr, struct disassemble_info *info)
64 {
65     /* does nothing */
66 }
67 
68 /*
69  * We should only be dissembling one instruction at a time here. If
70  * there is left over it usually indicates the front end has read more
71  * bytes than it needed.
72  */
73 char *plugin_disas(CPUState *cpu, const DisasContextBase *db,
74                    uint64_t addr, size_t size)
75 {
76     CPUDebug s;
77     GString *ds = g_string_new(NULL);
78 
79     disas_initialize_debug_target(&s, cpu);
80     s.info.read_memory_func = translator_read_memory;
81     s.info.application_data = (void *)db;
82     s.info.fprintf_func = disas_gstring_printf;
83     s.info.stream = (FILE *)ds;  /* abuse this slot */
84     s.info.buffer_vma = addr;
85     s.info.buffer_length = size;
86     s.info.print_address_func = plugin_print_address;
87 
88     if (s.info.cap_arch >= 0 && cap_disas_plugin(&s.info, addr, size)) {
89         ; /* done */
90     } else if (s.info.print_insn) {
91         s.info.print_insn(addr, &s.info);
92     } else {
93         ; /* cannot disassemble -- return empty string */
94     }
95 
96     /* Return the buffer, freeing the GString container.  */
97     return g_string_free(ds, false);
98 }
99 #endif /* CONFIG_PLUGIN */
100