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25630444 | 1 | /* Native-dependent code for FreeBSD/i386. |
5d93ae8c | 2 | |
32d0add0 | 3 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
25630444 MK |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
25630444 MK |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
25630444 MK |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
22 | #include "regcache.h" | |
9692934b | 23 | #include "target.h" |
25630444 MK |
24 | |
25 | #include <sys/types.h> | |
26 | #include <sys/ptrace.h> | |
27 | #include <sys/sysctl.h> | |
cf424aef | 28 | #include <sys/user.h> |
25630444 | 29 | |
9692934b | 30 | #include "fbsd-nat.h" |
f0925262 | 31 | #include "i386-tdep.h" |
df7e5265 | 32 | #include "x86-nat.h" |
9692934b | 33 | #include "i386bsd-nat.h" |
f0925262 | 34 | |
9692934b MK |
35 | /* Resume execution of the inferior process. If STEP is nonzero, |
36 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
25630444 | 37 | |
9692934b | 38 | static void |
28439f5e | 39 | i386fbsd_resume (struct target_ops *ops, |
2ea28649 | 40 | ptid_t ptid, int step, enum gdb_signal signal) |
25630444 MK |
41 | { |
42 | pid_t pid = ptid_get_pid (ptid); | |
43 | int request = PT_STEP; | |
44 | ||
45 | if (pid == -1) | |
46 | /* Resume all threads. This only gets used in the non-threaded | |
47 | case, where "resume all threads" and "resume inferior_ptid" are | |
48 | the same. */ | |
49 | pid = ptid_get_pid (inferior_ptid); | |
50 | ||
51 | if (!step) | |
52 | { | |
594f7785 | 53 | struct regcache *regcache = get_current_regcache (); |
f0925262 | 54 | ULONGEST eflags; |
25630444 MK |
55 | |
56 | /* Workaround for a bug in FreeBSD. Make sure that the trace | |
57 | flag is off when doing a continue. There is a code path | |
58 | through the kernel which leaves the flag set when it should | |
59 | have been cleared. If a process has a signal pending (such | |
60 | as SIGALRM) and we do a PT_STEP, the process never really has | |
61 | a chance to run because the kernel needs to notify the | |
62 | debugger that a signal is being sent. Therefore, the process | |
63 | never goes through the kernel's trap() function which would | |
64 | normally clear it. */ | |
65 | ||
594f7785 | 66 | regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM, |
f0925262 | 67 | &eflags); |
25630444 | 68 | if (eflags & 0x0100) |
594f7785 | 69 | regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM, |
f0925262 | 70 | eflags & ~0x0100); |
25630444 MK |
71 | |
72 | request = PT_CONTINUE; | |
73 | } | |
74 | ||
75 | /* An addres of (caddr_t) 1 tells ptrace to continue from where it | |
76 | was. (If GDB wanted it to start some other way, we have already | |
77 | written a new PC value to the child.) */ | |
78 | if (ptrace (request, pid, (caddr_t) 1, | |
2ea28649 | 79 | gdb_signal_to_host (signal)) == -1) |
e2e0b3e5 | 80 | perror_with_name (("ptrace")); |
25630444 MK |
81 | } |
82 | \f | |
2e0c3539 MK |
83 | |
84 | /* Support for debugging kernel virtual memory images. */ | |
85 | ||
2e0c3539 MK |
86 | #include <machine/pcb.h> |
87 | ||
88 | #include "bsd-kvm.h" | |
89 | ||
90 | static int | |
91 | i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) | |
92 | { | |
93 | /* The following is true for FreeBSD 4.7: | |
94 | ||
95 | The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs. | |
96 | This accounts for all callee-saved registers specified by the | |
97 | psABI and then some. Here %esp contains the stack pointer at the | |
98 | point just after the call to cpu_switch(). From this information | |
99 | we reconstruct the register state as it would look when we just | |
100 | returned from cpu_switch(). */ | |
101 | ||
102 | /* The stack pointer shouldn't be zero. */ | |
103 | if (pcb->pcb_esp == 0) | |
104 | return 0; | |
105 | ||
106 | pcb->pcb_esp += 4; | |
107 | regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi); | |
108 | regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi); | |
109 | regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp); | |
110 | regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp); | |
111 | regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx); | |
112 | regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip); | |
113 | regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs); | |
114 | ||
115 | return 1; | |
116 | } | |
117 | \f | |
118 | ||
97de3545 JB |
119 | #ifdef PT_GETXSTATE_INFO |
120 | /* Implement the to_read_description method. */ | |
121 | ||
122 | static const struct target_desc * | |
123 | i386fbsd_read_description (struct target_ops *ops) | |
124 | { | |
125 | static int xsave_probed; | |
126 | static uint64_t xcr0; | |
127 | ||
128 | if (!xsave_probed) | |
129 | { | |
130 | struct ptrace_xstate_info info; | |
131 | ||
132 | if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid), | |
133 | (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0) | |
134 | { | |
135 | i386bsd_xsave_len = info.xsave_len; | |
136 | xcr0 = info.xsave_mask; | |
137 | } | |
138 | xsave_probed = 1; | |
139 | } | |
140 | ||
141 | if (i386bsd_xsave_len != 0) | |
142 | { | |
143 | return i386_target_description (xcr0); | |
144 | } | |
145 | else | |
146 | return tdesc_i386; | |
147 | } | |
148 | #endif | |
149 | ||
2e0c3539 MK |
150 | /* Prevent warning from -Wmissing-prototypes. */ |
151 | void _initialize_i386fbsd_nat (void); | |
152 | ||
25630444 MK |
153 | void |
154 | _initialize_i386fbsd_nat (void) | |
155 | { | |
9692934b MK |
156 | struct target_ops *t; |
157 | ||
158 | /* Add some extra features to the common *BSD/i386 target. */ | |
159 | t = i386bsd_target (); | |
9bb9e8ad PM |
160 | |
161 | #ifdef HAVE_PT_GETDBREGS | |
162 | ||
df7e5265 | 163 | x86_use_watchpoints (t); |
9bb9e8ad | 164 | |
df7e5265 GB |
165 | x86_dr_low.set_control = i386bsd_dr_set_control; |
166 | x86_dr_low.set_addr = i386bsd_dr_set_addr; | |
167 | x86_dr_low.get_addr = i386bsd_dr_get_addr; | |
168 | x86_dr_low.get_status = i386bsd_dr_get_status; | |
169 | x86_dr_low.get_control = i386bsd_dr_get_control; | |
170 | x86_set_debug_register_length (4); | |
9bb9e8ad PM |
171 | |
172 | #endif /* HAVE_PT_GETDBREGS */ | |
173 | ||
97de3545 JB |
174 | #ifdef PT_GETXSTATE_INFO |
175 | t->to_read_description = i386fbsd_read_description; | |
176 | #endif | |
9bb9e8ad | 177 | |
9692934b | 178 | t->to_resume = i386fbsd_resume; |
8f60fe01 | 179 | fbsd_nat_add_target (t); |
9692934b | 180 | |
771e236c MK |
181 | /* Support debugging kernel virtual memory images. */ |
182 | bsd_kvm_add_target (i386fbsd_supply_pcb); | |
183 | ||
cf424aef JB |
184 | #ifdef KERN_PROC_SIGTRAMP |
185 | /* Normally signal frames are detected via i386fbsd_sigtramp_p. | |
186 | However, FreeBSD 9.2 through 10.1 do not include the page holding | |
187 | the signal code in core dumps. These releases do provide a | |
188 | kern.proc.sigtramp.<pid> sysctl that returns the location of the | |
189 | signal trampoline for a running process. We fetch the location | |
190 | of the current (gdb) process and use this to identify signal | |
191 | frames in core dumps from these releases. */ | |
25630444 | 192 | { |
cf424aef JB |
193 | int mib[4]; |
194 | struct kinfo_sigtramp kst; | |
25630444 MK |
195 | size_t len; |
196 | ||
197 | mib[0] = CTL_KERN; | |
cf424aef JB |
198 | mib[1] = KERN_PROC; |
199 | mib[2] = KERN_PROC_SIGTRAMP; | |
200 | mib[3] = getpid (); | |
201 | len = sizeof (kst); | |
202 | if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0) | |
25630444 | 203 | { |
cf424aef JB |
204 | i386fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start; |
205 | i386fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end; | |
25630444 MK |
206 | } |
207 | } | |
208 | #endif | |
209 | } |