1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
/* Native-dependent code for FreeBSD/i386.
Copyright (C) 2001-2017 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "inferior.h"
#include "regcache.h"
#include "target.h"
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include "fbsd-nat.h"
#include "i386-tdep.h"
#include "x86-nat.h"
#include "x86-xstate.h"
#include "x86-bsd-nat.h"
#include "i386-bsd-nat.h"
/* Resume execution of the inferior process. If STEP is nonzero,
single-step it. If SIGNAL is nonzero, give it that signal. */
static void
i386fbsd_resume (struct target_ops *ops,
ptid_t ptid, int step, enum gdb_signal signal)
{
pid_t pid = ptid_get_pid (ptid);
int request = PT_STEP;
if (pid == -1)
/* Resume all threads. This only gets used in the non-threaded
case, where "resume all threads" and "resume inferior_ptid" are
the same. */
pid = ptid_get_pid (inferior_ptid);
if (!step)
{
struct regcache *regcache = get_current_regcache ();
ULONGEST eflags;
/* Workaround for a bug in FreeBSD. Make sure that the trace
flag is off when doing a continue. There is a code path
through the kernel which leaves the flag set when it should
have been cleared. If a process has a signal pending (such
as SIGALRM) and we do a PT_STEP, the process never really has
a chance to run because the kernel needs to notify the
debugger that a signal is being sent. Therefore, the process
never goes through the kernel's trap() function which would
normally clear it. */
regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM,
&eflags);
if (eflags & 0x0100)
regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM,
eflags & ~0x0100);
request = PT_CONTINUE;
}
/* An addres of (caddr_t) 1 tells ptrace to continue from where it
was. (If GDB wanted it to start some other way, we have already
written a new PC value to the child.) */
if (ptrace (request, pid, (caddr_t) 1,
gdb_signal_to_host (signal)) == -1)
perror_with_name (("ptrace"));
}
/* Support for debugging kernel virtual memory images. */
#include <machine/pcb.h>
#include "bsd-kvm.h"
static int
i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
{
/* The following is true for FreeBSD 4.7:
The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs.
This accounts for all callee-saved registers specified by the
psABI and then some. Here %esp contains the stack pointer at the
point just after the call to cpu_switch(). From this information
we reconstruct the register state as it would look when we just
returned from cpu_switch(). */
/* The stack pointer shouldn't be zero. */
if (pcb->pcb_esp == 0)
return 0;
pcb->pcb_esp += 4;
regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi);
regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi);
regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);
regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx);
regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip);
regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs);
return 1;
}
#ifdef PT_GETXSTATE_INFO
/* Implement the to_read_description method. */
static const struct target_desc *
i386fbsd_read_description (struct target_ops *ops)
{
static int xsave_probed;
static uint64_t xcr0;
if (!xsave_probed)
{
struct ptrace_xstate_info info;
if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid),
(PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
{
x86bsd_xsave_len = info.xsave_len;
xcr0 = info.xsave_mask;
}
xsave_probed = 1;
}
if (x86bsd_xsave_len == 0)
xcr0 = X86_XSTATE_SSE_MASK;
return i386_target_description (xcr0);
}
#endif
/* Prevent warning from -Wmissing-prototypes. */
void _initialize_i386fbsd_nat (void);
void
_initialize_i386fbsd_nat (void)
{
struct target_ops *t;
/* Add some extra features to the common *BSD/i386 target. */
t = i386bsd_target ();
#ifdef PT_GETXSTATE_INFO
t->to_read_description = i386fbsd_read_description;
#endif
t->to_resume = i386fbsd_resume;
fbsd_nat_add_target (t);
/* Support debugging kernel virtual memory images. */
bsd_kvm_add_target (i386fbsd_supply_pcb);
#ifdef KERN_PROC_SIGTRAMP
/* Normally signal frames are detected via i386fbsd_sigtramp_p.
However, FreeBSD 9.2 through 10.1 do not include the page holding
the signal code in core dumps. These releases do provide a
kern.proc.sigtramp.<pid> sysctl that returns the location of the
signal trampoline for a running process. We fetch the location
of the current (gdb) process and use this to identify signal
frames in core dumps from these releases. */
{
int mib[4];
struct kinfo_sigtramp kst;
size_t len;
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_SIGTRAMP;
mib[3] = getpid ();
len = sizeof (kst);
if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0)
{
i386fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start;
i386fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end;
}
}
#endif
}
|
