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- /* Native-dependent code for FreeBSD/i386.
- Copyright (C) 2001-2022 Free Software Foundation, Inc.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "inferior.h"
- #include "regcache.h"
- #include "target.h"
- #include <sys/types.h>
- #include <sys/ptrace.h>
- #include <sys/sysctl.h>
- #include <sys/user.h>
- #include "i386-tdep.h"
- #include "i386-fbsd-tdep.h"
- #include "i387-tdep.h"
- #include "x86-nat.h"
- #include "gdbsupport/x86-xstate.h"
- #include "x86-fbsd-nat.h"
- class i386_fbsd_nat_target final : public x86_fbsd_nat_target
- {
- public:
- void fetch_registers (struct regcache *, int) override;
- void store_registers (struct regcache *, int) override;
- const struct target_desc *read_description () override;
- void resume (ptid_t, int, enum gdb_signal) override;
- };
- static i386_fbsd_nat_target the_i386_fbsd_nat_target;
- #ifdef PT_GETXSTATE_INFO
- static size_t xsave_len;
- #endif
- static int have_ptrace_xmmregs;
- /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
- for all registers. */
- void
- i386_fbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
- const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- #endif
- pid_t pid = get_ptrace_pid (regcache->ptid ());
- if (fetch_register_set<struct reg> (regcache, regnum, PT_GETREGS,
- &i386_fbsd_gregset))
- {
- if (regnum != -1)
- return;
- }
- #ifdef PT_GETFSBASE
- if (regnum == -1 || regnum == I386_FSBASE_REGNUM)
- {
- register_t base;
- if (ptrace (PT_GETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
- perror_with_name (_("Couldn't get segment register fs_base"));
- regcache->raw_supply (I386_FSBASE_REGNUM, &base);
- if (regnum != -1)
- return;
- }
- #endif
- #ifdef PT_GETGSBASE
- if (regnum == -1 || regnum == I386_GSBASE_REGNUM)
- {
- register_t base;
- if (ptrace (PT_GETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
- perror_with_name (_("Couldn't get segment register gs_base"));
- regcache->raw_supply (I386_GSBASE_REGNUM, &base);
- if (regnum != -1)
- return;
- }
- #endif
- /* There is no i386_fxsave_supplies or i386_xsave_supplies.
- Instead, the earlier register sets return early if the request
- was for a specific register that was already satisified to avoid
- fetching the FPU/XSAVE state unnecessarily. */
- #ifdef PT_GETXSTATE_INFO
- if (xsave_len != 0)
- {
- void *xstateregs = alloca (xsave_len);
- if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
- perror_with_name (_("Couldn't get extended state status"));
- i387_supply_xsave (regcache, regnum, xstateregs);
- return;
- }
- #endif
- if (have_ptrace_xmmregs != 0)
- {
- char xmmregs[I387_SIZEOF_FXSAVE];
- if (ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
- perror_with_name (_("Couldn't get XMM registers"));
- i387_supply_fxsave (regcache, regnum, xmmregs);
- return;
- }
- struct fpreg fpregs;
- if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
- perror_with_name (_("Couldn't get floating point status"));
- i387_supply_fsave (regcache, regnum, &fpregs);
- }
- /* Store register REGNUM back into the inferior. If REGNUM is -1, do
- this for all registers. */
- void
- i386_fbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
- const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- #endif
- pid_t pid = get_ptrace_pid (regcache->ptid ());
- if (store_register_set<struct reg> (regcache, regnum, PT_GETREGS, PT_SETREGS,
- &i386_fbsd_gregset))
- {
- if (regnum != -1)
- return;
- }
- #ifdef PT_SETFSBASE
- if (regnum == -1 || regnum == I386_FSBASE_REGNUM)
- {
- register_t base;
- regcache->raw_collect (I386_FSBASE_REGNUM, &base);
- if (ptrace (PT_SETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
- perror_with_name (_("Couldn't write segment register fs_base"));
- if (regnum != -1)
- return;
- }
- #endif
- #ifdef PT_SETGSBASE
- if (regnum == -1 || regnum == I386_GSBASE_REGNUM)
- {
- register_t base;
- regcache->raw_collect (I386_GSBASE_REGNUM, &base);
- if (ptrace (PT_SETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
- perror_with_name (_("Couldn't write segment register gs_base"));
- if (regnum != -1)
- return;
- }
- #endif
- /* There is no i386_fxsave_supplies or i386_xsave_supplies.
- Instead, the earlier register sets return early if the request
- was for a specific register that was already satisified to avoid
- fetching the FPU/XSAVE state unnecessarily. */
- #ifdef PT_GETXSTATE_INFO
- if (xsave_len != 0)
- {
- void *xstateregs = alloca (xsave_len);
- if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
- perror_with_name (_("Couldn't get extended state status"));
- i387_collect_xsave (regcache, regnum, xstateregs, 0);
- if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, xsave_len)
- == -1)
- perror_with_name (_("Couldn't write extended state status"));
- return;
- }
- #endif
- if (have_ptrace_xmmregs != 0)
- {
- char xmmregs[I387_SIZEOF_FXSAVE];
- if (ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
- perror_with_name (_("Couldn't get XMM registers"));
- i387_collect_fxsave (regcache, regnum, xmmregs);
- if (ptrace (PT_SETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
- perror_with_name (_("Couldn't write XMM registers"));
- return;
- }
- struct fpreg fpregs;
- if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
- perror_with_name (_("Couldn't get floating point status"));
- i387_collect_fsave (regcache, regnum, &fpregs);
- if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
- perror_with_name (_("Couldn't write floating point status"));
- }
- /* Resume execution of the inferior process. If STEP is nonzero,
- single-step it. If SIGNAL is nonzero, give it that signal. */
- void
- i386_fbsd_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
- {
- pid_t pid = ptid.pid ();
- int request = PT_STEP;
- if (pid == -1)
- /* Resume all threads. This only gets used in the non-threaded
- case, where "resume all threads" and "resume inferior_ptid" are
- the same. */
- pid = inferior_ptid.pid ();
- if (!step)
- {
- struct regcache *regcache = get_current_regcache ();
- ULONGEST eflags;
- /* Workaround for a bug in FreeBSD. Make sure that the trace
- flag is off when doing a continue. There is a code path
- through the kernel which leaves the flag set when it should
- have been cleared. If a process has a signal pending (such
- as SIGALRM) and we do a PT_STEP, the process never really has
- a chance to run because the kernel needs to notify the
- debugger that a signal is being sent. Therefore, the process
- never goes through the kernel's trap() function which would
- normally clear it. */
- regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM,
- &eflags);
- if (eflags & 0x0100)
- regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM,
- eflags & ~0x0100);
- request = PT_CONTINUE;
- }
- /* An addres of (caddr_t) 1 tells ptrace to continue from where it
- was. (If GDB wanted it to start some other way, we have already
- written a new PC value to the child.) */
- if (ptrace (request, pid, (caddr_t) 1,
- gdb_signal_to_host (signal)) == -1)
- perror_with_name (("ptrace"));
- }
- /* Support for debugging kernel virtual memory images. */
- #include <machine/pcb.h>
- #include "bsd-kvm.h"
- static int
- i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
- {
- /* The following is true for FreeBSD 4.7:
- The pcb contains %eip, %ebx, %esp, %ebp, %esi, %edi and %gs.
- This accounts for all callee-saved registers specified by the
- psABI and then some. Here %esp contains the stack pointer at the
- point just after the call to cpu_switch(). From this information
- we reconstruct the register state as it would look when we just
- returned from cpu_switch(). */
- /* The stack pointer shouldn't be zero. */
- if (pcb->pcb_esp == 0)
- return 0;
- pcb->pcb_esp += 4;
- regcache->raw_supply (I386_EDI_REGNUM, &pcb->pcb_edi);
- regcache->raw_supply (I386_ESI_REGNUM, &pcb->pcb_esi);
- regcache->raw_supply (I386_EBP_REGNUM, &pcb->pcb_ebp);
- regcache->raw_supply (I386_ESP_REGNUM, &pcb->pcb_esp);
- regcache->raw_supply (I386_EBX_REGNUM, &pcb->pcb_ebx);
- regcache->raw_supply (I386_EIP_REGNUM, &pcb->pcb_eip);
- regcache->raw_supply (I386_GS_REGNUM, &pcb->pcb_gs);
- return 1;
- }
- /* Implement the read_description method. */
- const struct target_desc *
- i386_fbsd_nat_target::read_description ()
- {
- #ifdef PT_GETXSTATE_INFO
- static int xsave_probed;
- static uint64_t xcr0;
- #endif
- static int xmm_probed;
- #ifdef PT_GETXSTATE_INFO
- if (!xsave_probed)
- {
- struct ptrace_xstate_info info;
- if (ptrace (PT_GETXSTATE_INFO, inferior_ptid.pid (),
- (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
- {
- xsave_len = info.xsave_len;
- xcr0 = info.xsave_mask;
- }
- xsave_probed = 1;
- }
- if (xsave_len != 0)
- return i386_target_description (xcr0, true);
- #endif
- if (!xmm_probed)
- {
- char xmmregs[I387_SIZEOF_FXSAVE];
- if (ptrace (PT_GETXMMREGS, inferior_ptid.pid (),
- (PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
- have_ptrace_xmmregs = 1;
- xmm_probed = 1;
- }
- if (have_ptrace_xmmregs)
- return i386_target_description (X86_XSTATE_SSE_MASK, true);
- return i386_target_description (X86_XSTATE_X87_MASK, true);
- }
- void _initialize_i386fbsd_nat ();
- void
- _initialize_i386fbsd_nat ()
- {
- add_inf_child_target (&the_i386_fbsd_nat_target);
- /* Support debugging kernel virtual memory images. */
- bsd_kvm_add_target (i386fbsd_supply_pcb);
- }
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