1 /* Native-dependent code for GNU/Linux i386.
3 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
4 2009, 2010, 2011 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "linux-nat.h"
30 #include "gdb_assert.h"
31 #include "gdb_string.h"
32 #include "elf/common.h"
34 #include <sys/ptrace.h>
36 #include <sys/procfs.h>
46 #ifdef HAVE_SYS_DEBUGREG_H
47 #include <sys/debugreg.h>
51 #define DR_FIRSTADDR 0
66 /* Prototypes for supply_gregset etc. */
69 #include "i387-tdep.h"
70 #include "i386-tdep.h"
71 #include "i386-linux-tdep.h"
73 /* Defines ps_err_e, struct ps_prochandle. */
74 #include "gdb_proc_service.h"
76 #include "i386-xstate.h"
78 #ifndef PTRACE_GETREGSET
79 #define PTRACE_GETREGSET 0x4204
82 #ifndef PTRACE_SETREGSET
83 #define PTRACE_SETREGSET 0x4205
86 /* Does the current host support PTRACE_GETREGSET? */
87 static int have_ptrace_getregset
= -1;
90 /* The register sets used in GNU/Linux ELF core-dumps are identical to
91 the register sets in `struct user' that is used for a.out
92 core-dumps, and is also used by `ptrace'. The corresponding types
93 are `elf_gregset_t' for the general-purpose registers (with
94 `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
95 for the floating-point registers.
97 Those types used to be available under the names `gregset_t' and
98 `fpregset_t' too, and this file used those names in the past. But
99 those names are now used for the register sets used in the
100 `mcontext_t' type, and have a different size and layout. */
102 /* Which ptrace request retrieves which registers?
103 These apply to the corresponding SET requests as well. */
105 #define GETREGS_SUPPLIES(regno) \
106 ((0 <= (regno) && (regno) <= 15) || (regno) == I386_LINUX_ORIG_EAX_REGNUM)
108 #define GETFPXREGS_SUPPLIES(regno) \
109 (I386_ST0_REGNUM <= (regno) && (regno) < I386_SSE_NUM_REGS)
111 #define GETXSTATEREGS_SUPPLIES(regno) \
112 (I386_ST0_REGNUM <= (regno) && (regno) < I386_AVX_NUM_REGS)
114 /* Does the current host support the GETREGS request? */
115 int have_ptrace_getregs
=
116 #ifdef HAVE_PTRACE_GETREGS
123 /* Does the current host support the GETFPXREGS request? The header
124 file may or may not define it, and even if it is defined, the
125 kernel will return EIO if it's running on a pre-SSE processor.
127 My instinct is to attach this to some architecture- or
128 target-specific data structure, but really, a particular GDB
129 process can only run on top of one kernel at a time. So it's okay
130 for this to be a simple variable. */
131 int have_ptrace_getfpxregs
=
132 #ifdef HAVE_PTRACE_GETFPXREGS
140 /* Accessing registers through the U area, one at a time. */
142 /* Fetch one register. */
145 fetch_register (struct regcache
*regcache
, int regno
)
150 gdb_assert (!have_ptrace_getregs
);
151 if (i386_linux_gregset_reg_offset
[regno
] == -1)
153 regcache_raw_supply (regcache
, regno
, NULL
);
157 /* GNU/Linux LWP ID's are process ID's. */
158 tid
= TIDGET (inferior_ptid
);
160 tid
= PIDGET (inferior_ptid
); /* Not a threaded program. */
163 val
= ptrace (PTRACE_PEEKUSER
, tid
,
164 i386_linux_gregset_reg_offset
[regno
], 0);
166 error (_("Couldn't read register %s (#%d): %s."),
167 gdbarch_register_name (get_regcache_arch (regcache
), regno
),
168 regno
, safe_strerror (errno
));
170 regcache_raw_supply (regcache
, regno
, &val
);
173 /* Store one register. */
176 store_register (const struct regcache
*regcache
, int regno
)
181 gdb_assert (!have_ptrace_getregs
);
182 if (i386_linux_gregset_reg_offset
[regno
] == -1)
185 /* GNU/Linux LWP ID's are process ID's. */
186 tid
= TIDGET (inferior_ptid
);
188 tid
= PIDGET (inferior_ptid
); /* Not a threaded program. */
191 regcache_raw_collect (regcache
, regno
, &val
);
192 ptrace (PTRACE_POKEUSER
, tid
,
193 i386_linux_gregset_reg_offset
[regno
], val
);
195 error (_("Couldn't write register %s (#%d): %s."),
196 gdbarch_register_name (get_regcache_arch (regcache
), regno
),
197 regno
, safe_strerror (errno
));
201 /* Transfering the general-purpose registers between GDB, inferiors
204 /* Fill GDB's register array with the general-purpose register values
208 supply_gregset (struct regcache
*regcache
, const elf_gregset_t
*gregsetp
)
210 const gdb_byte
*regp
= (const gdb_byte
*) gregsetp
;
213 for (i
= 0; i
< I386_NUM_GREGS
; i
++)
214 regcache_raw_supply (regcache
, i
,
215 regp
+ i386_linux_gregset_reg_offset
[i
]);
217 if (I386_LINUX_ORIG_EAX_REGNUM
218 < gdbarch_num_regs (get_regcache_arch (regcache
)))
219 regcache_raw_supply (regcache
, I386_LINUX_ORIG_EAX_REGNUM
, regp
220 + i386_linux_gregset_reg_offset
[I386_LINUX_ORIG_EAX_REGNUM
]);
223 /* Fill register REGNO (if it is a general-purpose register) in
224 *GREGSETPS with the value in GDB's register array. If REGNO is -1,
225 do this for all registers. */
228 fill_gregset (const struct regcache
*regcache
,
229 elf_gregset_t
*gregsetp
, int regno
)
231 gdb_byte
*regp
= (gdb_byte
*) gregsetp
;
234 for (i
= 0; i
< I386_NUM_GREGS
; i
++)
235 if (regno
== -1 || regno
== i
)
236 regcache_raw_collect (regcache
, i
,
237 regp
+ i386_linux_gregset_reg_offset
[i
]);
239 if ((regno
== -1 || regno
== I386_LINUX_ORIG_EAX_REGNUM
)
240 && I386_LINUX_ORIG_EAX_REGNUM
241 < gdbarch_num_regs (get_regcache_arch (regcache
)))
242 regcache_raw_collect (regcache
, I386_LINUX_ORIG_EAX_REGNUM
, regp
243 + i386_linux_gregset_reg_offset
[I386_LINUX_ORIG_EAX_REGNUM
]);
246 #ifdef HAVE_PTRACE_GETREGS
248 /* Fetch all general-purpose registers from process/thread TID and
249 store their values in GDB's register array. */
252 fetch_regs (struct regcache
*regcache
, int tid
)
255 elf_gregset_t
*regs_p
= ®s
;
257 if (ptrace (PTRACE_GETREGS
, tid
, 0, (int) ®s
) < 0)
261 /* The kernel we're running on doesn't support the GETREGS
262 request. Reset `have_ptrace_getregs'. */
263 have_ptrace_getregs
= 0;
267 perror_with_name (_("Couldn't get registers"));
270 supply_gregset (regcache
, (const elf_gregset_t
*) regs_p
);
273 /* Store all valid general-purpose registers in GDB's register array
274 into the process/thread specified by TID. */
277 store_regs (const struct regcache
*regcache
, int tid
, int regno
)
281 if (ptrace (PTRACE_GETREGS
, tid
, 0, (int) ®s
) < 0)
282 perror_with_name (_("Couldn't get registers"));
284 fill_gregset (regcache
, ®s
, regno
);
286 if (ptrace (PTRACE_SETREGS
, tid
, 0, (int) ®s
) < 0)
287 perror_with_name (_("Couldn't write registers"));
292 static void fetch_regs (struct regcache
*regcache
, int tid
) {}
293 static void store_regs (const struct regcache
*regcache
, int tid
, int regno
) {}
298 /* Transfering floating-point registers between GDB, inferiors and cores. */
300 /* Fill GDB's register array with the floating-point register values in
304 supply_fpregset (struct regcache
*regcache
, const elf_fpregset_t
*fpregsetp
)
306 i387_supply_fsave (regcache
, -1, fpregsetp
);
309 /* Fill register REGNO (if it is a floating-point register) in
310 *FPREGSETP with the value in GDB's register array. If REGNO is -1,
311 do this for all registers. */
314 fill_fpregset (const struct regcache
*regcache
,
315 elf_fpregset_t
*fpregsetp
, int regno
)
317 i387_collect_fsave (regcache
, regno
, fpregsetp
);
320 #ifdef HAVE_PTRACE_GETREGS
322 /* Fetch all floating-point registers from process/thread TID and store
323 thier values in GDB's register array. */
326 fetch_fpregs (struct regcache
*regcache
, int tid
)
328 elf_fpregset_t fpregs
;
330 if (ptrace (PTRACE_GETFPREGS
, tid
, 0, (int) &fpregs
) < 0)
331 perror_with_name (_("Couldn't get floating point status"));
333 supply_fpregset (regcache
, (const elf_fpregset_t
*) &fpregs
);
336 /* Store all valid floating-point registers in GDB's register array
337 into the process/thread specified by TID. */
340 store_fpregs (const struct regcache
*regcache
, int tid
, int regno
)
342 elf_fpregset_t fpregs
;
344 if (ptrace (PTRACE_GETFPREGS
, tid
, 0, (int) &fpregs
) < 0)
345 perror_with_name (_("Couldn't get floating point status"));
347 fill_fpregset (regcache
, &fpregs
, regno
);
349 if (ptrace (PTRACE_SETFPREGS
, tid
, 0, (int) &fpregs
) < 0)
350 perror_with_name (_("Couldn't write floating point status"));
356 fetch_fpregs (struct regcache
*regcache
, int tid
)
361 store_fpregs (const struct regcache
*regcache
, int tid
, int regno
)
368 /* Transfering floating-point and SSE registers to and from GDB. */
370 /* Fetch all registers covered by the PTRACE_GETREGSET request from
371 process/thread TID and store their values in GDB's register array.
372 Return non-zero if successful, zero otherwise. */
375 fetch_xstateregs (struct regcache
*regcache
, int tid
)
377 char xstateregs
[I386_XSTATE_MAX_SIZE
];
380 if (!have_ptrace_getregset
)
383 iov
.iov_base
= xstateregs
;
384 iov
.iov_len
= sizeof(xstateregs
);
385 if (ptrace (PTRACE_GETREGSET
, tid
, (unsigned int) NT_X86_XSTATE
,
387 perror_with_name (_("Couldn't read extended state status"));
389 i387_supply_xsave (regcache
, -1, xstateregs
);
393 /* Store all valid registers in GDB's register array covered by the
394 PTRACE_SETREGSET request into the process/thread specified by TID.
395 Return non-zero if successful, zero otherwise. */
398 store_xstateregs (const struct regcache
*regcache
, int tid
, int regno
)
400 char xstateregs
[I386_XSTATE_MAX_SIZE
];
403 if (!have_ptrace_getregset
)
406 iov
.iov_base
= xstateregs
;
407 iov
.iov_len
= sizeof(xstateregs
);
408 if (ptrace (PTRACE_GETREGSET
, tid
, (unsigned int) NT_X86_XSTATE
,
410 perror_with_name (_("Couldn't read extended state status"));
412 i387_collect_xsave (regcache
, regno
, xstateregs
, 0);
414 if (ptrace (PTRACE_SETREGSET
, tid
, (unsigned int) NT_X86_XSTATE
,
416 perror_with_name (_("Couldn't write extended state status"));
421 #ifdef HAVE_PTRACE_GETFPXREGS
423 /* Fetch all registers covered by the PTRACE_GETFPXREGS request from
424 process/thread TID and store their values in GDB's register array.
425 Return non-zero if successful, zero otherwise. */
428 fetch_fpxregs (struct regcache
*regcache
, int tid
)
430 elf_fpxregset_t fpxregs
;
432 if (! have_ptrace_getfpxregs
)
435 if (ptrace (PTRACE_GETFPXREGS
, tid
, 0, (int) &fpxregs
) < 0)
439 have_ptrace_getfpxregs
= 0;
443 perror_with_name (_("Couldn't read floating-point and SSE registers"));
446 i387_supply_fxsave (regcache
, -1, (const elf_fpxregset_t
*) &fpxregs
);
450 /* Store all valid registers in GDB's register array covered by the
451 PTRACE_SETFPXREGS request into the process/thread specified by TID.
452 Return non-zero if successful, zero otherwise. */
455 store_fpxregs (const struct regcache
*regcache
, int tid
, int regno
)
457 elf_fpxregset_t fpxregs
;
459 if (! have_ptrace_getfpxregs
)
462 if (ptrace (PTRACE_GETFPXREGS
, tid
, 0, &fpxregs
) == -1)
466 have_ptrace_getfpxregs
= 0;
470 perror_with_name (_("Couldn't read floating-point and SSE registers"));
473 i387_collect_fxsave (regcache
, regno
, &fpxregs
);
475 if (ptrace (PTRACE_SETFPXREGS
, tid
, 0, &fpxregs
) == -1)
476 perror_with_name (_("Couldn't write floating-point and SSE registers"));
484 fetch_fpxregs (struct regcache
*regcache
, int tid
)
490 store_fpxregs (const struct regcache
*regcache
, int tid
, int regno
)
495 #endif /* HAVE_PTRACE_GETFPXREGS */
498 /* Transferring arbitrary registers between GDB and inferior. */
500 /* Fetch register REGNO from the child process. If REGNO is -1, do
501 this for all registers (including the floating point and SSE
505 i386_linux_fetch_inferior_registers (struct target_ops
*ops
,
506 struct regcache
*regcache
, int regno
)
510 /* Use the old method of peeking around in `struct user' if the
511 GETREGS request isn't available. */
512 if (!have_ptrace_getregs
)
516 for (i
= 0; i
< gdbarch_num_regs (get_regcache_arch (regcache
)); i
++)
517 if (regno
== -1 || regno
== i
)
518 fetch_register (regcache
, i
);
523 /* GNU/Linux LWP ID's are process ID's. */
524 tid
= TIDGET (inferior_ptid
);
526 tid
= PIDGET (inferior_ptid
); /* Not a threaded program. */
528 /* Use the PTRACE_GETFPXREGS request whenever possible, since it
529 transfers more registers in one system call, and we'll cache the
530 results. But remember that fetch_fpxregs can fail, and return
534 fetch_regs (regcache
, tid
);
536 /* The call above might reset `have_ptrace_getregs'. */
537 if (!have_ptrace_getregs
)
539 i386_linux_fetch_inferior_registers (ops
, regcache
, regno
);
543 if (fetch_xstateregs (regcache
, tid
))
545 if (fetch_fpxregs (regcache
, tid
))
547 fetch_fpregs (regcache
, tid
);
551 if (GETREGS_SUPPLIES (regno
))
553 fetch_regs (regcache
, tid
);
557 if (GETXSTATEREGS_SUPPLIES (regno
))
559 if (fetch_xstateregs (regcache
, tid
))
563 if (GETFPXREGS_SUPPLIES (regno
))
565 if (fetch_fpxregs (regcache
, tid
))
568 /* Either our processor or our kernel doesn't support the SSE
569 registers, so read the FP registers in the traditional way,
570 and fill the SSE registers with dummy values. It would be
571 more graceful to handle differences in the register set using
572 gdbarch. Until then, this will at least make things work
574 fetch_fpregs (regcache
, tid
);
578 internal_error (__FILE__
, __LINE__
,
579 _("Got request for bad register number %d."), regno
);
582 /* Store register REGNO back into the child process. If REGNO is -1,
583 do this for all registers (including the floating point and SSE
586 i386_linux_store_inferior_registers (struct target_ops
*ops
,
587 struct regcache
*regcache
, int regno
)
591 /* Use the old method of poking around in `struct user' if the
592 SETREGS request isn't available. */
593 if (!have_ptrace_getregs
)
597 for (i
= 0; i
< gdbarch_num_regs (get_regcache_arch (regcache
)); i
++)
598 if (regno
== -1 || regno
== i
)
599 store_register (regcache
, i
);
604 /* GNU/Linux LWP ID's are process ID's. */
605 tid
= TIDGET (inferior_ptid
);
607 tid
= PIDGET (inferior_ptid
); /* Not a threaded program. */
609 /* Use the PTRACE_SETFPXREGS requests whenever possible, since it
610 transfers more registers in one system call. But remember that
611 store_fpxregs can fail, and return zero. */
614 store_regs (regcache
, tid
, regno
);
615 if (store_xstateregs (regcache
, tid
, regno
))
617 if (store_fpxregs (regcache
, tid
, regno
))
619 store_fpregs (regcache
, tid
, regno
);
623 if (GETREGS_SUPPLIES (regno
))
625 store_regs (regcache
, tid
, regno
);
629 if (GETXSTATEREGS_SUPPLIES (regno
))
631 if (store_xstateregs (regcache
, tid
, regno
))
635 if (GETFPXREGS_SUPPLIES (regno
))
637 if (store_fpxregs (regcache
, tid
, regno
))
640 /* Either our processor or our kernel doesn't support the SSE
641 registers, so just write the FP registers in the traditional
643 store_fpregs (regcache
, tid
, regno
);
647 internal_error (__FILE__
, __LINE__
,
648 _("Got request to store bad register number %d."), regno
);
652 /* Support for debug registers. */
654 static unsigned long i386_linux_dr
[DR_CONTROL
+ 1];
656 /* Get debug register REGNUM value from only the one LWP of PTID. */
659 i386_linux_dr_get (ptid_t ptid
, int regnum
)
668 /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
669 ptrace call fails breaks debugging remote targets. The correct
670 way to fix this is to add the hardware breakpoint and watchpoint
671 stuff to the target vector. For now, just return zero if the
672 ptrace call fails. */
674 value
= ptrace (PTRACE_PEEKUSER
, tid
,
675 offsetof (struct user
, u_debugreg
[regnum
]), 0);
678 perror_with_name (_("Couldn't read debug register"));
686 /* Set debug register REGNUM to VALUE in only the one LWP of PTID. */
689 i386_linux_dr_set (ptid_t ptid
, int regnum
, unsigned long value
)
698 ptrace (PTRACE_POKEUSER
, tid
,
699 offsetof (struct user
, u_debugreg
[regnum
]), value
);
701 perror_with_name (_("Couldn't write debug register"));
704 /* Set DR_CONTROL to ADDR in all LWPs of LWP_LIST. */
707 i386_linux_dr_set_control (unsigned long control
)
712 i386_linux_dr
[DR_CONTROL
] = control
;
714 i386_linux_dr_set (ptid
, DR_CONTROL
, control
);
717 /* Set address REGNUM (zero based) to ADDR in all LWPs of LWP_LIST. */
720 i386_linux_dr_set_addr (int regnum
, CORE_ADDR addr
)
725 gdb_assert (regnum
>= 0 && regnum
<= DR_LASTADDR
- DR_FIRSTADDR
);
727 i386_linux_dr
[DR_FIRSTADDR
+ regnum
] = addr
;
729 i386_linux_dr_set (ptid
, DR_FIRSTADDR
+ regnum
, addr
);
732 /* Set address REGNUM (zero based) to zero in all LWPs of LWP_LIST. */
735 i386_linux_dr_reset_addr (int regnum
)
737 i386_linux_dr_set_addr (regnum
, 0);
740 /* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
743 i386_linux_dr_get_status (void)
745 return i386_linux_dr_get (inferior_ptid
, DR_STATUS
);
748 /* Unset MASK bits in DR_STATUS in all LWPs of LWP_LIST. */
751 i386_linux_dr_unset_status (unsigned long mask
)
760 value
= i386_linux_dr_get (ptid
, DR_STATUS
);
762 i386_linux_dr_set (ptid
, DR_STATUS
, value
);
767 i386_linux_new_thread (ptid_t ptid
)
771 for (i
= DR_FIRSTADDR
; i
<= DR_LASTADDR
; i
++)
772 i386_linux_dr_set (ptid
, i
, i386_linux_dr
[i
]);
774 i386_linux_dr_set (ptid
, DR_CONTROL
, i386_linux_dr
[DR_CONTROL
]);
778 /* Called by libthread_db. Returns a pointer to the thread local
779 storage (or its descriptor). */
782 ps_get_thread_area (const struct ps_prochandle
*ph
,
783 lwpid_t lwpid
, int idx
, void **base
)
785 /* NOTE: cagney/2003-08-26: The definition of this buffer is found
786 in the kernel header <asm-i386/ldt.h>. It, after padding, is 4 x
787 4 byte integers in size: `entry_number', `base_addr', `limit',
788 and a bunch of status bits.
790 The values returned by this ptrace call should be part of the
791 regcache buffer, and ps_get_thread_area should channel its
792 request through the regcache. That way remote targets could
793 provide the value using the remote protocol and not this direct
796 Is this function needed? I'm guessing that the `base' is the
797 address of a descriptor that libthread_db uses to find the
798 thread local address base that GDB needs. Perhaps that
799 descriptor is defined by the ABI. Anyway, given that
800 libthread_db calls this function without prompting (gdb
801 requesting tls base) I guess it needs info in there anyway. */
802 unsigned int desc
[4];
803 gdb_assert (sizeof (int) == 4);
805 #ifndef PTRACE_GET_THREAD_AREA
806 #define PTRACE_GET_THREAD_AREA 25
809 if (ptrace (PTRACE_GET_THREAD_AREA
, lwpid
,
810 (void *) idx
, (unsigned long) &desc
) < 0)
813 *(int *)base
= desc
[1];
818 /* The instruction for a GNU/Linux system call is:
822 static const unsigned char linux_syscall
[] = { 0xcd, 0x80 };
824 #define LINUX_SYSCALL_LEN (sizeof linux_syscall)
826 /* The system call number is stored in the %eax register. */
827 #define LINUX_SYSCALL_REGNUM I386_EAX_REGNUM
829 /* We are specifically interested in the sigreturn and rt_sigreturn
832 #ifndef SYS_sigreturn
833 #define SYS_sigreturn 0x77
835 #ifndef SYS_rt_sigreturn
836 #define SYS_rt_sigreturn 0xad
839 /* Offset to saved processor flags, from <asm/sigcontext.h>. */
840 #define LINUX_SIGCONTEXT_EFLAGS_OFFSET (64)
842 /* Resume execution of the inferior process.
843 If STEP is nonzero, single-step it.
844 If SIGNAL is nonzero, give it that signal. */
847 i386_linux_resume (struct target_ops
*ops
,
848 ptid_t ptid
, int step
, enum target_signal signal
)
850 int pid
= PIDGET (ptid
);
854 if (catch_syscall_enabled () > 0)
855 request
= PTRACE_SYSCALL
;
857 request
= PTRACE_CONT
;
861 struct regcache
*regcache
= get_thread_regcache (pid_to_ptid (pid
));
862 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
863 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
865 gdb_byte buf
[LINUX_SYSCALL_LEN
];
867 request
= PTRACE_SINGLESTEP
;
869 regcache_cooked_read_unsigned (regcache
,
870 gdbarch_pc_regnum (gdbarch
), &pc
);
872 /* Returning from a signal trampoline is done by calling a
873 special system call (sigreturn or rt_sigreturn, see
874 i386-linux-tdep.c for more information). This system call
875 restores the registers that were saved when the signal was
876 raised, including %eflags. That means that single-stepping
877 won't work. Instead, we'll have to modify the signal context
878 that's about to be restored, and set the trace flag there. */
880 /* First check if PC is at a system call. */
881 if (target_read_memory (pc
, buf
, LINUX_SYSCALL_LEN
) == 0
882 && memcmp (buf
, linux_syscall
, LINUX_SYSCALL_LEN
) == 0)
885 regcache_cooked_read_unsigned (regcache
,
886 LINUX_SYSCALL_REGNUM
, &syscall
);
888 /* Then check the system call number. */
889 if (syscall
== SYS_sigreturn
|| syscall
== SYS_rt_sigreturn
)
892 unsigned long int eflags
;
894 regcache_cooked_read_unsigned (regcache
, I386_ESP_REGNUM
, &sp
);
895 if (syscall
== SYS_rt_sigreturn
)
896 addr
= read_memory_integer (sp
+ 8, 4, byte_order
) + 20;
900 /* Set the trace flag in the context that's about to be
902 addr
+= LINUX_SIGCONTEXT_EFLAGS_OFFSET
;
903 read_memory (addr
, (gdb_byte
*) &eflags
, 4);
905 write_memory (addr
, (gdb_byte
*) &eflags
, 4);
910 if (ptrace (request
, pid
, 0, target_signal_to_host (signal
)) == -1)
911 perror_with_name (("ptrace"));
914 static void (*super_post_startup_inferior
) (ptid_t ptid
);
917 i386_linux_child_post_startup_inferior (ptid_t ptid
)
919 i386_cleanup_dregs ();
920 super_post_startup_inferior (ptid
);
923 /* Get Linux/x86 target description from running target. */
925 static const struct target_desc
*
926 i386_linux_read_description (struct target_ops
*ops
)
929 static uint64_t xcr0
;
931 /* GNU/Linux LWP ID's are process ID's. */
932 tid
= TIDGET (inferior_ptid
);
934 tid
= PIDGET (inferior_ptid
); /* Not a threaded program. */
936 #ifdef HAVE_PTRACE_GETFPXREGS
937 if (have_ptrace_getfpxregs
== -1)
939 elf_fpxregset_t fpxregs
;
941 if (ptrace (PTRACE_GETFPXREGS
, tid
, 0, (int) &fpxregs
) < 0)
943 have_ptrace_getfpxregs
= 0;
944 have_ptrace_getregset
= 0;
945 return tdesc_i386_mmx_linux
;
950 if (have_ptrace_getregset
== -1)
952 uint64_t xstateregs
[(I386_XSTATE_SSE_SIZE
/ sizeof (uint64_t))];
955 iov
.iov_base
= xstateregs
;
956 iov
.iov_len
= sizeof (xstateregs
);
958 /* Check if PTRACE_GETREGSET works. */
959 if (ptrace (PTRACE_GETREGSET
, tid
, (unsigned int) NT_X86_XSTATE
,
961 have_ptrace_getregset
= 0;
964 have_ptrace_getregset
= 1;
966 /* Get XCR0 from XSAVE extended state. */
967 xcr0
= xstateregs
[(I386_LINUX_XSAVE_XCR0_OFFSET
968 / sizeof (long long))];
972 /* Check the native XCR0 only if PTRACE_GETREGSET is available. */
973 if (have_ptrace_getregset
974 && (xcr0
& I386_XSTATE_AVX_MASK
) == I386_XSTATE_AVX_MASK
)
975 return tdesc_i386_avx_linux
;
977 return tdesc_i386_linux
;
981 _initialize_i386_linux_nat (void)
983 struct target_ops
*t
;
985 /* Fill in the generic GNU/Linux methods. */
988 i386_use_watchpoints (t
);
990 i386_dr_low
.set_control
= i386_linux_dr_set_control
;
991 i386_dr_low
.set_addr
= i386_linux_dr_set_addr
;
992 i386_dr_low
.reset_addr
= i386_linux_dr_reset_addr
;
993 i386_dr_low
.get_status
= i386_linux_dr_get_status
;
994 i386_dr_low
.unset_status
= i386_linux_dr_unset_status
;
995 i386_set_debug_register_length (4);
997 /* Override the default ptrace resume method. */
998 t
->to_resume
= i386_linux_resume
;
1000 /* Override the GNU/Linux inferior startup hook. */
1001 super_post_startup_inferior
= t
->to_post_startup_inferior
;
1002 t
->to_post_startup_inferior
= i386_linux_child_post_startup_inferior
;
1004 /* Add our register access methods. */
1005 t
->to_fetch_registers
= i386_linux_fetch_inferior_registers
;
1006 t
->to_store_registers
= i386_linux_store_inferior_registers
;
1008 t
->to_read_description
= i386_linux_read_description
;
1010 /* Register the target. */
1011 linux_nat_add_target (t
);
1012 linux_nat_set_new_thread (t
, i386_linux_new_thread
);