146 lines
4.3 KiB
C
146 lines
4.3 KiB
C
/* Native-dependent code for OpenBSD/amd64.
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Copyright (C) 2003-2013 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "regcache.h"
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#include "target.h"
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#include "gdb_assert.h"
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#include "amd64-tdep.h"
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#include "amd64-nat.h"
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/* Mapping between the general-purpose registers in OpenBSD/amd64
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`struct reg' format and GDB's register cache layout for
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OpenBSD/i386.
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Note that most (if not all) OpenBSD/amd64 registers are 64-bit,
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while the OpenBSD/i386 registers are all 32-bit, but since we're
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little-endian we get away with that. */
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/* From <machine/reg.h>. */
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static int amd64obsd32_r_reg_offset[] =
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{
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14 * 8, /* %eax */
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3 * 8, /* %ecx */
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2 * 8, /* %edx */
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13 * 8, /* %ebx */
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15 * 8, /* %esp */
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12 * 8, /* %ebp */
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1 * 8, /* %esi */
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0 * 8, /* %edi */
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16 * 8, /* %eip */
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17 * 8, /* %eflags */
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18 * 8, /* %cs */
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19 * 8, /* %ss */
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20 * 8, /* %ds */
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21 * 8, /* %es */
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22 * 8, /* %fs */
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23 * 8 /* %gs */
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};
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/* Support for debugging kernel virtual memory images. */
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#include <sys/types.h>
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#include <machine/frame.h>
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#include <machine/pcb.h>
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#include "bsd-kvm.h"
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static int
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amd64obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
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{
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struct switchframe sf;
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int regnum;
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/* The following is true for OpenBSD 3.5:
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The pcb contains the stack pointer at the point of the context
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switch in cpu_switch(). At that point we have a stack frame as
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described by `struct switchframe', which for OpenBSD 3.5 has the
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following layout:
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interrupt level
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%r15
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%r14
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%r13
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%r12
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%rbp
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%rbx
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return address
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Together with %rsp in the pcb, this accounts for all callee-saved
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registers specified by the psABI. From this information we
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reconstruct the register state as it would look when we just
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returned from cpu_switch().
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For core dumps the pcb is saved by savectx(). In that case the
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stack frame only contains the return address, and there is no way
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to recover the other registers. */
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/* The stack pointer shouldn't be zero. */
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if (pcb->pcb_rsp == 0)
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return 0;
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/* Read the stack frame, and check its validity. */
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read_memory (pcb->pcb_rsp, (gdb_byte *) &sf, sizeof sf);
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if (sf.sf_rbp == pcb->pcb_rbp)
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{
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/* Yes, we have a frame that matches cpu_switch(). */
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pcb->pcb_rsp += sizeof (struct switchframe);
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regcache_raw_supply (regcache, 12, &sf.sf_r12);
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regcache_raw_supply (regcache, 13, &sf.sf_r13);
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regcache_raw_supply (regcache, 14, &sf.sf_r14);
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regcache_raw_supply (regcache, 15, &sf.sf_r15);
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regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx);
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regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip);
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}
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else
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{
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/* No, the pcb must have been last updated by savectx(). */
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pcb->pcb_rsp += 8;
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regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf);
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}
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regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
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regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
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return 1;
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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void _initialize_amd64obsd_nat (void);
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void
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_initialize_amd64obsd_nat (void)
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{
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amd64_native_gregset32_reg_offset = amd64obsd32_r_reg_offset;
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amd64_native_gregset32_num_regs = ARRAY_SIZE (amd64obsd32_r_reg_offset);
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amd64_native_gregset64_reg_offset = amd64obsd_r_reg_offset;
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/* We've got nothing to add to the common *BSD/amd64 target. */
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add_target (amd64bsd_target ());
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/* Support debugging kernel virtual memory images. */
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bsd_kvm_add_target (amd64obsd_supply_pcb);
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}
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