xref: /qemu/system/watchpoint.c (revision b103cc6e74ac92f070a0e004bd84334e845c20b5)
1 /*
2  * CPU watchpoints
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/error-report.h"
22 #include "exec/cputlb.h"
23 #include "exec/target_page.h"
24 #include "exec/watchpoint.h"
25 #include "hw/core/cpu.h"
26 
27 /* Add a watchpoint.  */
28 int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
29                           int flags, CPUWatchpoint **watchpoint)
30 {
31     CPUWatchpoint *wp;
32     vaddr in_page;
33 
34     /* forbid ranges which are empty or run off the end of the address space */
35     if (len == 0 || (addr + len - 1) < addr) {
36         error_report("tried to set invalid watchpoint at %"
37                      VADDR_PRIx ", len=%" VADDR_PRIu, addr, len);
38         return -EINVAL;
39     }
40     wp = g_malloc(sizeof(*wp));
41 
42     wp->vaddr = addr;
43     wp->len = len;
44     wp->flags = flags;
45 
46     /* keep all GDB-injected watchpoints in front */
47     if (flags & BP_GDB) {
48         QTAILQ_INSERT_HEAD(&cpu->watchpoints, wp, entry);
49     } else {
50         QTAILQ_INSERT_TAIL(&cpu->watchpoints, wp, entry);
51     }
52 
53     in_page = -(addr | TARGET_PAGE_MASK);
54     if (len <= in_page) {
55         tlb_flush_page(cpu, addr);
56     } else {
57         tlb_flush(cpu);
58     }
59 
60     if (watchpoint) {
61         *watchpoint = wp;
62     }
63     return 0;
64 }
65 
66 /* Remove a specific watchpoint.  */
67 int cpu_watchpoint_remove(CPUState *cpu, vaddr addr, vaddr len,
68                           int flags)
69 {
70     CPUWatchpoint *wp;
71 
72     QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
73         if (addr == wp->vaddr && len == wp->len
74                 && flags == (wp->flags & ~BP_WATCHPOINT_HIT)) {
75             cpu_watchpoint_remove_by_ref(cpu, wp);
76             return 0;
77         }
78     }
79     return -ENOENT;
80 }
81 
82 /* Remove a specific watchpoint by reference.  */
83 void cpu_watchpoint_remove_by_ref(CPUState *cpu, CPUWatchpoint *watchpoint)
84 {
85     QTAILQ_REMOVE(&cpu->watchpoints, watchpoint, entry);
86 
87     tlb_flush_page(cpu, watchpoint->vaddr);
88 
89     g_free(watchpoint);
90 }
91 
92 /* Remove all matching watchpoints.  */
93 void cpu_watchpoint_remove_all(CPUState *cpu, int mask)
94 {
95     CPUWatchpoint *wp, *next;
96 
97     QTAILQ_FOREACH_SAFE(wp, &cpu->watchpoints, entry, next) {
98         if (wp->flags & mask) {
99             cpu_watchpoint_remove_by_ref(cpu, wp);
100         }
101     }
102 }
103