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25630444 | 1 | /* Native-dependent code for FreeBSD/i386. |
5d93ae8c MK |
2 | |
3 | Copyright 2001, 2002, 2003, 2004 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 | |
9 | the Free Software Foundation; either version 2 of the License, or | |
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 | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "defs.h" | |
23 | #include "inferior.h" | |
24 | #include "regcache.h" | |
25 | ||
26 | #include <sys/types.h> | |
27 | #include <sys/ptrace.h> | |
28 | #include <sys/sysctl.h> | |
29 | ||
f0925262 MK |
30 | #include "i386-tdep.h" |
31 | ||
25630444 MK |
32 | /* Resume execution of the inferior process. |
33 | If STEP is nonzero, single-step it. | |
34 | If SIGNAL is nonzero, give it that signal. */ | |
35 | ||
36 | void | |
37 | child_resume (ptid_t ptid, int step, enum target_signal signal) | |
38 | { | |
39 | pid_t pid = ptid_get_pid (ptid); | |
40 | int request = PT_STEP; | |
41 | ||
42 | if (pid == -1) | |
43 | /* Resume all threads. This only gets used in the non-threaded | |
44 | case, where "resume all threads" and "resume inferior_ptid" are | |
45 | the same. */ | |
46 | pid = ptid_get_pid (inferior_ptid); | |
47 | ||
48 | if (!step) | |
49 | { | |
f0925262 | 50 | ULONGEST eflags; |
25630444 MK |
51 | |
52 | /* Workaround for a bug in FreeBSD. Make sure that the trace | |
53 | flag is off when doing a continue. There is a code path | |
54 | through the kernel which leaves the flag set when it should | |
55 | have been cleared. If a process has a signal pending (such | |
56 | as SIGALRM) and we do a PT_STEP, the process never really has | |
57 | a chance to run because the kernel needs to notify the | |
58 | debugger that a signal is being sent. Therefore, the process | |
59 | never goes through the kernel's trap() function which would | |
60 | normally clear it. */ | |
61 | ||
f0925262 MK |
62 | regcache_cooked_read_unsigned (current_regcache, I386_EFLAGS_REGNUM, |
63 | &eflags); | |
25630444 | 64 | if (eflags & 0x0100) |
f0925262 MK |
65 | regcache_cooked_write_unsigned (current_regcache, I386_EFLAGS_REGNUM, |
66 | eflags & ~0x0100); | |
25630444 MK |
67 | |
68 | request = PT_CONTINUE; | |
69 | } | |
70 | ||
71 | /* An addres of (caddr_t) 1 tells ptrace to continue from where it | |
72 | was. (If GDB wanted it to start some other way, we have already | |
73 | written a new PC value to the child.) */ | |
74 | if (ptrace (request, pid, (caddr_t) 1, | |
75 | target_signal_to_host (signal)) == -1) | |
76 | perror_with_name ("ptrace"); | |
77 | } | |
78 | \f | |
2e0c3539 MK |
79 | |
80 | /* Support for debugging kernel virtual memory images. */ | |
81 | ||
82 | #include <sys/types.h> | |
83 | #include <machine/pcb.h> | |
84 | ||
85 | #include "bsd-kvm.h" | |
86 | ||
87 | static int | |
88 | i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) | |
89 | { | |
90 | /* The following is true for FreeBSD 4.7: | |
91 | ||
92 | The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs. | |
93 | This accounts for all callee-saved registers specified by the | |
94 | psABI and then some. Here %esp contains the stack pointer at the | |
95 | point just after the call to cpu_switch(). From this information | |
96 | we reconstruct the register state as it would look when we just | |
97 | returned from cpu_switch(). */ | |
98 | ||
99 | /* The stack pointer shouldn't be zero. */ | |
100 | if (pcb->pcb_esp == 0) | |
101 | return 0; | |
102 | ||
103 | pcb->pcb_esp += 4; | |
104 | regcache_raw_supply (regcache, I386_EDI_REGNUM, &pcb->pcb_edi); | |
105 | regcache_raw_supply (regcache, I386_ESI_REGNUM, &pcb->pcb_esi); | |
106 | regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp); | |
107 | regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp); | |
108 | regcache_raw_supply (regcache, I386_EBX_REGNUM, &pcb->pcb_ebx); | |
109 | regcache_raw_supply (regcache, I386_EIP_REGNUM, &pcb->pcb_eip); | |
110 | regcache_raw_supply (regcache, I386_GS_REGNUM, &pcb->pcb_gs); | |
111 | ||
112 | return 1; | |
113 | } | |
114 | \f | |
115 | ||
116 | /* Prevent warning from -Wmissing-prototypes. */ | |
117 | void _initialize_i386fbsd_nat (void); | |
118 | ||
25630444 MK |
119 | void |
120 | _initialize_i386fbsd_nat (void) | |
121 | { | |
122 | /* FreeBSD provides a kern.ps_strings sysctl that we can use to | |
123 | locate the sigtramp. That way we can still recognize a sigtramp | |
8201327c | 124 | if its location is changed in a new kernel. Of course this is |
25630444 MK |
125 | still based on the assumption that the sigtramp is placed |
126 | directly under the location where the program arguments and | |
127 | environment can be found. */ | |
128 | #ifdef KERN_PS_STRINGS | |
129 | { | |
130 | int mib[2]; | |
131 | int ps_strings; | |
132 | size_t len; | |
133 | ||
134 | mib[0] = CTL_KERN; | |
135 | mib[1] = KERN_PS_STRINGS; | |
136 | len = sizeof (ps_strings); | |
137 | if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0) | |
138 | { | |
5d93ae8c MK |
139 | i386fbsd_sigtramp_start_addr = ps_strings - 128; |
140 | i386fbsd_sigtramp_end_addr = ps_strings; | |
25630444 MK |
141 | } |
142 | } | |
143 | #endif | |
2e0c3539 MK |
144 | |
145 | /* Support debugging kernel virtual memory images. */ | |
146 | bsd_kvm_add_target (i386fbsd_supply_pcb); | |
25630444 | 147 | } |