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25630444 | 1 | /* Native-dependent code for FreeBSD/i386. |
5d93ae8c | 2 | |
61baf725 | 3 | Copyright (C) 2001-2017 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" |
26562e73 | 33 | #include "x86-xstate.h" |
03b62bbb SM |
34 | #include "x86-bsd-nat.h" |
35 | #include "i386-bsd-nat.h" | |
f0925262 | 36 | |
9692934b MK |
37 | /* Resume execution of the inferior process. If STEP is nonzero, |
38 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
25630444 | 39 | |
9692934b | 40 | static void |
28439f5e | 41 | i386fbsd_resume (struct target_ops *ops, |
2ea28649 | 42 | ptid_t ptid, int step, enum gdb_signal signal) |
25630444 MK |
43 | { |
44 | pid_t pid = ptid_get_pid (ptid); | |
45 | int request = PT_STEP; | |
46 | ||
47 | if (pid == -1) | |
48 | /* Resume all threads. This only gets used in the non-threaded | |
49 | case, where "resume all threads" and "resume inferior_ptid" are | |
50 | the same. */ | |
51 | pid = ptid_get_pid (inferior_ptid); | |
52 | ||
53 | if (!step) | |
54 | { | |
594f7785 | 55 | struct regcache *regcache = get_current_regcache (); |
f0925262 | 56 | ULONGEST eflags; |
25630444 MK |
57 | |
58 | /* Workaround for a bug in FreeBSD. Make sure that the trace | |
59 | flag is off when doing a continue. There is a code path | |
60 | through the kernel which leaves the flag set when it should | |
61 | have been cleared. If a process has a signal pending (such | |
62 | as SIGALRM) and we do a PT_STEP, the process never really has | |
63 | a chance to run because the kernel needs to notify the | |
64 | debugger that a signal is being sent. Therefore, the process | |
65 | never goes through the kernel's trap() function which would | |
66 | normally clear it. */ | |
67 | ||
594f7785 | 68 | regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM, |
f0925262 | 69 | &eflags); |
25630444 | 70 | if (eflags & 0x0100) |
594f7785 | 71 | regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM, |
f0925262 | 72 | eflags & ~0x0100); |
25630444 MK |
73 | |
74 | request = PT_CONTINUE; | |
75 | } | |
76 | ||
77 | /* An addres of (caddr_t) 1 tells ptrace to continue from where it | |
78 | was. (If GDB wanted it to start some other way, we have already | |
79 | written a new PC value to the child.) */ | |
80 | if (ptrace (request, pid, (caddr_t) 1, | |
2ea28649 | 81 | gdb_signal_to_host (signal)) == -1) |
e2e0b3e5 | 82 | perror_with_name (("ptrace")); |
25630444 MK |
83 | } |
84 | \f | |
2e0c3539 MK |
85 | |
86 | /* Support for debugging kernel virtual memory images. */ | |
87 | ||
2e0c3539 MK |
88 | #include <machine/pcb.h> |
89 | ||
90 | #include "bsd-kvm.h" | |
91 | ||
92 | static int | |
93 | i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) | |
94 | { | |
95 | /* The following is true for FreeBSD 4.7: | |
96 | ||
97 | The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs. | |
98 | This accounts for all callee-saved registers specified by the | |
99 | psABI and then some. Here %esp contains the stack pointer at the | |
100 | point just after the call to cpu_switch(). From this information | |
101 | we reconstruct the register state as it would look when we just | |
102 | returned from cpu_switch(). */ | |
103 | ||
104 | /* The stack pointer shouldn't be zero. */ | |
105 | if (pcb->pcb_esp == 0) | |
106 | return 0; | |
107 | ||
108 | pcb->pcb_esp += 4; | |
109 | regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi); | |
110 | regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi); | |
111 | regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp); | |
112 | regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp); | |
113 | regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx); | |
114 | regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip); | |
115 | regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs); | |
116 | ||
117 | return 1; | |
118 | } | |
119 | \f | |
120 | ||
97de3545 JB |
121 | #ifdef PT_GETXSTATE_INFO |
122 | /* Implement the to_read_description method. */ | |
123 | ||
124 | static const struct target_desc * | |
125 | i386fbsd_read_description (struct target_ops *ops) | |
126 | { | |
127 | static int xsave_probed; | |
128 | static uint64_t xcr0; | |
129 | ||
130 | if (!xsave_probed) | |
131 | { | |
132 | struct ptrace_xstate_info info; | |
133 | ||
134 | if (ptrace (PT_GETXSTATE_INFO, ptid_get_pid (inferior_ptid), | |
135 | (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0) | |
136 | { | |
a3405d12 | 137 | x86bsd_xsave_len = info.xsave_len; |
97de3545 JB |
138 | xcr0 = info.xsave_mask; |
139 | } | |
140 | xsave_probed = 1; | |
141 | } | |
142 | ||
ca1fa5ee YQ |
143 | if (x86bsd_xsave_len == 0) |
144 | xcr0 = X86_XSTATE_SSE_MASK; | |
145 | ||
146 | return i386_target_description (xcr0); | |
97de3545 JB |
147 | } |
148 | #endif | |
149 | ||
25630444 MK |
150 | void |
151 | _initialize_i386fbsd_nat (void) | |
152 | { | |
9692934b MK |
153 | struct target_ops *t; |
154 | ||
155 | /* Add some extra features to the common *BSD/i386 target. */ | |
156 | t = i386bsd_target (); | |
9bb9e8ad | 157 | |
97de3545 JB |
158 | #ifdef PT_GETXSTATE_INFO |
159 | t->to_read_description = i386fbsd_read_description; | |
160 | #endif | |
9bb9e8ad | 161 | |
9692934b | 162 | t->to_resume = i386fbsd_resume; |
8f60fe01 | 163 | fbsd_nat_add_target (t); |
9692934b | 164 | |
771e236c MK |
165 | /* Support debugging kernel virtual memory images. */ |
166 | bsd_kvm_add_target (i386fbsd_supply_pcb); | |
167 | ||
cf424aef JB |
168 | #ifdef KERN_PROC_SIGTRAMP |
169 | /* Normally signal frames are detected via i386fbsd_sigtramp_p. | |
170 | However, FreeBSD 9.2 through 10.1 do not include the page holding | |
171 | the signal code in core dumps. These releases do provide a | |
172 | kern.proc.sigtramp.<pid> sysctl that returns the location of the | |
173 | signal trampoline for a running process. We fetch the location | |
174 | of the current (gdb) process and use this to identify signal | |
175 | frames in core dumps from these releases. */ | |
25630444 | 176 | { |
cf424aef JB |
177 | int mib[4]; |
178 | struct kinfo_sigtramp kst; | |
25630444 MK |
179 | size_t len; |
180 | ||
181 | mib[0] = CTL_KERN; | |
cf424aef JB |
182 | mib[1] = KERN_PROC; |
183 | mib[2] = KERN_PROC_SIGTRAMP; | |
184 | mib[3] = getpid (); | |
185 | len = sizeof (kst); | |
186 | if (sysctl (mib, 4, &kst, &len, NULL, 0) == 0) | |
25630444 | 187 | { |
cf424aef JB |
188 | i386fbsd_sigtramp_start_addr = (uintptr_t) kst.ksigtramp_start; |
189 | i386fbsd_sigtramp_end_addr = (uintptr_t) kst.ksigtramp_end; | |
25630444 MK |
190 | } |
191 | } | |
192 | #endif | |
193 | } |