1 /* Native-dependent code for OpenBSD/amd64.
3 Copyright (C) 2003-2024 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/>. */
25 #include "amd64-tdep.h"
26 #include "amd64-bsd-nat.h"
27 #include "amd64-nat.h"
30 /* Mapping between the general-purpose registers in OpenBSD/amd64
31 `struct reg' format and GDB's register cache layout for
34 Note that most (if not all) OpenBSD/amd64 registers are 64-bit,
35 while the OpenBSD/i386 registers are all 32-bit, but since we're
36 little-endian we get away with that. */
38 /* From <machine/reg.h>. */
39 static int amd64obsd32_r_reg_offset
[] =
60 /* Support for debugging kernel virtual memory images. */
62 #include <sys/types.h>
63 #include <machine/frame.h>
64 #include <machine/pcb.h>
69 amd64obsd_supply_pcb (struct regcache
*regcache
, struct pcb
*pcb
)
71 struct switchframe sf
;
74 /* The following is true for OpenBSD 3.5:
76 The pcb contains the stack pointer at the point of the context
77 switch in cpu_switch(). At that point we have a stack frame as
78 described by `struct switchframe', which for OpenBSD 3.5 has the
90 Together with %rsp in the pcb, this accounts for all callee-saved
91 registers specified by the psABI. From this information we
92 reconstruct the register state as it would look when we just
93 returned from cpu_switch().
95 For core dumps the pcb is saved by savectx(). In that case the
96 stack frame only contains the return address, and there is no way
97 to recover the other registers. */
99 /* The stack pointer shouldn't be zero. */
100 if (pcb
->pcb_rsp
== 0)
103 /* Read the stack frame, and check its validity. */
104 read_memory (pcb
->pcb_rsp
, (gdb_byte
*) &sf
, sizeof sf
);
105 if (sf
.sf_rbp
== pcb
->pcb_rbp
)
107 /* Yes, we have a frame that matches cpu_switch(). */
108 pcb
->pcb_rsp
+= sizeof (struct switchframe
);
109 regcache
->raw_supply (12, &sf
.sf_r12
);
110 regcache
->raw_supply (13, &sf
.sf_r13
);
111 regcache
->raw_supply (14, &sf
.sf_r14
);
112 regcache
->raw_supply (15, &sf
.sf_r15
);
113 regcache
->raw_supply (AMD64_RBX_REGNUM
, &sf
.sf_rbx
);
114 regcache
->raw_supply (AMD64_RIP_REGNUM
, &sf
.sf_rip
);
118 /* No, the pcb must have been last updated by savectx(). */
120 regcache
->raw_supply (AMD64_RIP_REGNUM
, &sf
);
123 regcache
->raw_supply (AMD64_RSP_REGNUM
, &pcb
->pcb_rsp
);
124 regcache
->raw_supply (AMD64_RBP_REGNUM
, &pcb
->pcb_rbp
);
129 static amd64_bsd_nat_target
<obsd_nat_target
> the_amd64_obsd_nat_target
;
131 void _initialize_amd64obsd_nat ();
133 _initialize_amd64obsd_nat ()
135 amd64_native_gregset32_reg_offset
= amd64obsd32_r_reg_offset
;
136 amd64_native_gregset32_num_regs
= ARRAY_SIZE (amd64obsd32_r_reg_offset
);
137 amd64_native_gregset64_reg_offset
= amd64obsd_r_reg_offset
;
139 add_inf_child_target (&the_amd64_obsd_nat_target
);
141 /* Support debugging kernel virtual memory images. */
142 bsd_kvm_add_target (amd64obsd_supply_pcb
);