[PATCH 30/57][Arm][GAS] Add support for MVE instructions: vqmovnt, vqmovnb, vqmovunt...
[binutils-gdb.git] / gdb / i386-obsd-nat.c
blobe0eb9573753cecf14aa13329bcd524e889abe314
1 /* Native-dependent code for OpenBSD/i386.
3 Copyright (C) 2002-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
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 3 of the License, or
10 (at your option) any later version.
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.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "defs.h"
21 #include "gdbcore.h"
22 #include "regcache.h"
23 #include "target.h"
25 #include <sys/sysctl.h>
26 #include <machine/frame.h>
27 #include <machine/pcb.h>
29 #include "i386-tdep.h"
30 #include "i386-bsd-nat.h"
31 #include "obsd-nat.h"
32 #include "bsd-kvm.h"
34 static int
35 i386obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
37 struct gdbarch *gdbarch = regcache->arch ();
38 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
39 struct switchframe sf;
41 /* The following is true for OpenBSD 3.6:
43 The pcb contains %esp and %ebp at the point of the context switch
44 in cpu_switch(). At that point we have a stack frame as
45 described by `struct switchframe', which for OpenBSD 3.6 has the
46 following layout:
48 interrupt level
49 %edi
50 %esi
51 %ebx
52 %eip
54 we reconstruct the register state as it would look when we just
55 returned from cpu_switch(). */
57 /* The stack pointer shouldn't be zero. */
58 if (pcb->pcb_esp == 0)
59 return 0;
61 /* Read the stack frame, and check its validity. We do this by
62 checking if the saved interrupt priority level in the stack frame
63 looks reasonable.. */
64 #ifdef PCB_SAVECTX
65 if ((pcb->pcb_flags & PCB_SAVECTX) == 0)
67 /* Yes, we have a frame that matches cpu_switch(). */
68 read_memory (pcb->pcb_esp, (gdb_byte *) &sf, sizeof sf);
69 pcb->pcb_esp += sizeof (struct switchframe);
70 regcache->raw_supply (I386_EDI_REGNUM, &sf.sf_edi);
71 regcache->raw_supply (I386_ESI_REGNUM, &sf.sf_esi);
72 regcache->raw_supply (I386_EBX_REGNUM, &sf.sf_ebx);
73 regcache->raw_supply (I386_EIP_REGNUM, &sf.sf_eip);
75 else
76 #endif
78 /* No, the pcb must have been last updated by savectx(). */
79 pcb->pcb_esp = pcb->pcb_ebp;
80 pcb->pcb_ebp = read_memory_integer(pcb->pcb_esp, 4, byte_order);
81 sf.sf_eip = read_memory_integer(pcb->pcb_esp + 4, 4, byte_order);
82 regcache->raw_supply (I386_EIP_REGNUM, &sf.sf_eip);
85 regcache->raw_supply (I386_EBP_REGNUM, &pcb->pcb_ebp);
86 regcache->raw_supply (I386_ESP_REGNUM, &pcb->pcb_esp);
88 return 1;
91 static i386_bsd_nat_target<obsd_nat_target> the_i386_obsd_nat_target;
93 void
94 _initialize_i386obsd_nat (void)
96 add_inf_child_target (&i386_obsd_nat_target);
98 /* Support debugging kernel virtual memory images. */
99 bsd_kvm_add_target (i386obsd_supply_pcb);
101 /* OpenBSD provides a vm.psstrings sysctl that we can use to locate
102 the sigtramp. That way we can still recognize a sigtramp if its
103 location is changed in a new kernel. This is especially
104 important for OpenBSD, since it uses a different memory layout
105 than NetBSD, yet we cannot distinguish between the two.
107 Of course this is still based on the assumption that the sigtramp
108 is placed directly under the location where the program arguments
109 and environment can be found. */
110 #ifdef VM_PSSTRINGS
112 struct _ps_strings _ps;
113 int mib[2];
114 size_t len;
116 mib[0] = CTL_VM;
117 mib[1] = VM_PSSTRINGS;
118 len = sizeof (_ps);
119 if (sysctl (mib, 2, &_ps, &len, NULL, 0) == 0)
121 i386obsd_sigtramp_start_addr = (u_long) _ps.val - 128;
122 i386obsd_sigtramp_end_addr = (u_long) _ps.val;
125 #endif