7384826ebf
Use a register map to describe the registers in mcontext_t as part of the signal frame as is done on several other FreeBSD arches. This permits fetching the fsbase and gsbase register values from the signal frame for both amd64 and i386 and permits fetching additional segment registers stored as 16-bit values on amd64. While signal frames on FreeBSD do contain floating point/XSAVE state, these unwinders do not attempt to supply those registers. The existing x86 signal frame uwinders do not support these registers, and the only existing functions which handle FSAVE/FXSAVE/XSAVE state all work with regcaches. In the future these unwinders could create a tempory regcache, collect floating point registers, and then supply values out of the regcache into the trad-frame.
223 lines
6.3 KiB
C
223 lines
6.3 KiB
C
/* Native-dependent code for FreeBSD/amd64.
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Copyright (C) 2003-2022 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 "inferior.h"
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#include "regcache.h"
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#include "target.h"
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#include <signal.h>
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#include <sys/types.h>
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#include <sys/ptrace.h>
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#include <sys/sysctl.h>
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#include <sys/user.h>
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#include <machine/reg.h>
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#include "fbsd-nat.h"
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#include "amd64-tdep.h"
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#include "amd64-nat.h"
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#include "amd64-bsd-nat.h"
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#include "x86-nat.h"
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#include "gdbsupport/x86-xstate.h"
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class amd64_fbsd_nat_target final
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: public amd64_bsd_nat_target<fbsd_nat_target>
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{
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public:
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/* Add some extra features to the common *BSD/amd64 target. */
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const struct target_desc *read_description () override;
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#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
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bool supports_stopped_by_hw_breakpoint () override;
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#endif
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};
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static amd64_fbsd_nat_target the_amd64_fbsd_nat_target;
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/* Offset in `struct reg' where MEMBER is stored. */
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#define REG_OFFSET(member) offsetof (struct reg, member)
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/* At amd64fbsd64_r_reg_offset[REGNUM] you'll find the offset in
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`struct reg' location where the GDB register REGNUM is stored.
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Unsupported registers are marked with `-1'. */
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static int amd64fbsd64_r_reg_offset[] =
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{
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REG_OFFSET (r_rax),
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REG_OFFSET (r_rbx),
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REG_OFFSET (r_rcx),
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REG_OFFSET (r_rdx),
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REG_OFFSET (r_rsi),
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REG_OFFSET (r_rdi),
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REG_OFFSET (r_rbp),
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REG_OFFSET (r_rsp),
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REG_OFFSET (r_r8),
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REG_OFFSET (r_r9),
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REG_OFFSET (r_r10),
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REG_OFFSET (r_r11),
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REG_OFFSET (r_r12),
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REG_OFFSET (r_r13),
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REG_OFFSET (r_r14),
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REG_OFFSET (r_r15),
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REG_OFFSET (r_rip),
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REG_OFFSET (r_rflags),
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REG_OFFSET (r_cs),
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REG_OFFSET (r_ss),
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-1,
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-1,
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-1,
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-1
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};
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/* Mapping between the general-purpose registers in FreeBSD/amd64
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`struct reg' format and GDB's register cache layout for
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FreeBSD/i386.
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Note that most FreeBSD/amd64 registers are 64-bit, while the
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FreeBSD/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 amd64fbsd32_r_reg_offset[I386_NUM_GREGS] =
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{
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14 * 8, 13 * 8, /* %eax, %ecx */
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12 * 8, 11 * 8, /* %edx, %ebx */
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20 * 8, 10 * 8, /* %esp, %ebp */
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9 * 8, 8 * 8, /* %esi, %edi */
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17 * 8, 19 * 8, /* %eip, %eflags */
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18 * 8, 21 * 8, /* %cs, %ss */
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-1, -1, -1, -1 /* %ds, %es, %fs, %gs */
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};
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/* Support for debugging kernel virtual memory images. */
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#include <machine/pcb.h>
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#include <osreldate.h>
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#include "bsd-kvm.h"
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static int
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amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
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{
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/* The following is true for FreeBSD 5.2:
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The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
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%ds, %es, %fs and %gs. This accounts for all callee-saved
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registers specified by the psABI and then some. Here %esp
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contains the stack pointer at the point just after the call to
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cpu_switch(). From this information we reconstruct the register
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state as it would like when we just returned from cpu_switch(). */
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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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pcb->pcb_rsp += 8;
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regcache->raw_supply (AMD64_RIP_REGNUM, &pcb->pcb_rip);
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regcache->raw_supply (AMD64_RBX_REGNUM, &pcb->pcb_rbx);
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regcache->raw_supply (AMD64_RSP_REGNUM, &pcb->pcb_rsp);
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regcache->raw_supply (AMD64_RBP_REGNUM, &pcb->pcb_rbp);
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regcache->raw_supply (12, &pcb->pcb_r12);
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regcache->raw_supply (13, &pcb->pcb_r13);
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regcache->raw_supply (14, &pcb->pcb_r14);
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regcache->raw_supply (15, &pcb->pcb_r15);
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#if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
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/* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
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up until __FreeBSD_version 800074: The removal of these fields
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occurred on 2009-04-01 while the __FreeBSD_version number was
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bumped to 800075 on 2009-04-06. So 800075 is the closest version
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number where we should not try to access these fields. */
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regcache->raw_supply (AMD64_DS_REGNUM, &pcb->pcb_ds);
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regcache->raw_supply (AMD64_ES_REGNUM, &pcb->pcb_es);
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regcache->raw_supply (AMD64_FS_REGNUM, &pcb->pcb_fs);
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regcache->raw_supply (AMD64_GS_REGNUM, &pcb->pcb_gs);
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#endif
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return 1;
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}
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/* Implement the read_description method. */
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const struct target_desc *
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amd64_fbsd_nat_target::read_description ()
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{
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#ifdef PT_GETXSTATE_INFO
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static int xsave_probed;
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static uint64_t xcr0;
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#endif
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struct reg regs;
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int is64;
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if (ptrace (PT_GETREGS, inferior_ptid.pid (),
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(PTRACE_TYPE_ARG3) ®s, 0) == -1)
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perror_with_name (_("Couldn't get registers"));
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is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
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#ifdef PT_GETXSTATE_INFO
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if (!xsave_probed)
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{
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struct ptrace_xstate_info info;
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if (ptrace (PT_GETXSTATE_INFO, inferior_ptid.pid (),
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(PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
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{
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x86bsd_xsave_len = info.xsave_len;
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xcr0 = info.xsave_mask;
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}
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xsave_probed = 1;
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}
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if (x86bsd_xsave_len != 0)
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{
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if (is64)
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return amd64_target_description (xcr0, true);
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else
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return i386_target_description (xcr0, true);
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}
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#endif
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if (is64)
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return amd64_target_description (X86_XSTATE_SSE_MASK, true);
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else
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return i386_target_description (X86_XSTATE_SSE_MASK, true);
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}
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#if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO)
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/* Implement the supports_stopped_by_hw_breakpoints method. */
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bool
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amd64_fbsd_nat_target::supports_stopped_by_hw_breakpoint ()
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{
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return true;
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}
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#endif
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void _initialize_amd64fbsd_nat ();
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void
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_initialize_amd64fbsd_nat ()
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{
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amd64_native_gregset32_reg_offset = amd64fbsd32_r_reg_offset;
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amd64_native_gregset64_reg_offset = amd64fbsd64_r_reg_offset;
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add_inf_child_target (&the_amd64_fbsd_nat_target);
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/* Support debugging kernel virtual memory images. */
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bsd_kvm_add_target (amd64fbsd_supply_pcb);
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}
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