1 /* Target-dependent code for GNU/Linux i386.
3 Copyright (C) 2000-2016 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/>. */
28 #include "reggroups.h"
29 #include "dwarf2-frame.h"
30 #include "i386-tdep.h"
31 #include "i386-linux-tdep.h"
32 #include "linux-tdep.h"
34 #include "glibc-tdep.h"
35 #include "solib-svr4.h"
37 #include "arch-utils.h"
38 #include "xml-syscall.h"
40 #include "i387-tdep.h"
41 #include "x86-xstate.h"
43 /* The syscall's XML filename for i386. */
44 #define XML_SYSCALL_FILENAME_I386 "syscalls/i386-linux.xml"
46 #include "record-full.h"
47 #include "linux-record.h"
48 #include "features/i386/i386-linux.c"
49 #include "features/i386/i386-mmx-linux.c"
50 #include "features/i386/i386-mpx-linux.c"
51 #include "features/i386/i386-avx-linux.c"
52 #include "features/i386/i386-avx512-linux.c"
54 /* Return non-zero, when the register is in the corresponding register
55 group. Put the LINUX_ORIG_EAX register in the system group. */
57 i386_linux_register_reggroup_p (struct gdbarch
*gdbarch
, int regnum
,
58 struct reggroup
*group
)
60 if (regnum
== I386_LINUX_ORIG_EAX_REGNUM
)
61 return (group
== system_reggroup
62 || group
== save_reggroup
63 || group
== restore_reggroup
);
64 return i386_register_reggroup_p (gdbarch
, regnum
, group
);
68 /* Recognizing signal handler frames. */
70 /* GNU/Linux has two flavors of signals. Normal signal handlers, and
71 "realtime" (RT) signals. The RT signals can provide additional
72 information to the signal handler if the SA_SIGINFO flag is set
73 when establishing a signal handler using `sigaction'. It is not
74 unlikely that future versions of GNU/Linux will support SA_SIGINFO
75 for normal signals too. */
77 /* When the i386 Linux kernel calls a signal handler and the
78 SA_RESTORER flag isn't set, the return address points to a bit of
79 code on the stack. This function returns whether the PC appears to
80 be within this bit of code.
82 The instruction sequence for normal signals is
86 or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
88 Checking for the code sequence should be somewhat reliable, because
89 the effect is to call the system call sigreturn. This is unlikely
90 to occur anywhere other than in a signal trampoline.
92 It kind of sucks that we have to read memory from the process in
93 order to identify a signal trampoline, but there doesn't seem to be
94 any other way. Therefore we only do the memory reads if no
95 function name could be identified, which should be the case since
96 the code is on the stack.
98 Detection of signal trampolines for handlers that set the
99 SA_RESTORER flag is in general not possible. Unfortunately this is
100 what the GNU C Library has been doing for quite some time now.
101 However, as of version 2.1.2, the GNU C Library uses signal
102 trampolines (named __restore and __restore_rt) that are identical
103 to the ones used by the kernel. Therefore, these trampolines are
106 #define LINUX_SIGTRAMP_INSN0 0x58 /* pop %eax */
107 #define LINUX_SIGTRAMP_OFFSET0 0
108 #define LINUX_SIGTRAMP_INSN1 0xb8 /* mov $NNNN, %eax */
109 #define LINUX_SIGTRAMP_OFFSET1 1
110 #define LINUX_SIGTRAMP_INSN2 0xcd /* int */
111 #define LINUX_SIGTRAMP_OFFSET2 6
113 static const gdb_byte linux_sigtramp_code
[] =
115 LINUX_SIGTRAMP_INSN0
, /* pop %eax */
116 LINUX_SIGTRAMP_INSN1
, 0x77, 0x00, 0x00, 0x00, /* mov $0x77, %eax */
117 LINUX_SIGTRAMP_INSN2
, 0x80 /* int $0x80 */
120 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
122 /* If THIS_FRAME is a sigtramp routine, return the address of the
123 start of the routine. Otherwise, return 0. */
126 i386_linux_sigtramp_start (struct frame_info
*this_frame
)
128 CORE_ADDR pc
= get_frame_pc (this_frame
);
129 gdb_byte buf
[LINUX_SIGTRAMP_LEN
];
131 /* We only recognize a signal trampoline if PC is at the start of
132 one of the three instructions. We optimize for finding the PC at
133 the start, as will be the case when the trampoline is not the
134 first frame on the stack. We assume that in the case where the
135 PC is not at the start of the instruction sequence, there will be
136 a few trailing readable bytes on the stack. */
138 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
, LINUX_SIGTRAMP_LEN
))
141 if (buf
[0] != LINUX_SIGTRAMP_INSN0
)
147 case LINUX_SIGTRAMP_INSN1
:
148 adjust
= LINUX_SIGTRAMP_OFFSET1
;
150 case LINUX_SIGTRAMP_INSN2
:
151 adjust
= LINUX_SIGTRAMP_OFFSET2
;
159 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
, LINUX_SIGTRAMP_LEN
))
163 if (memcmp (buf
, linux_sigtramp_code
, LINUX_SIGTRAMP_LEN
) != 0)
169 /* This function does the same for RT signals. Here the instruction
173 or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
175 The effect is to call the system call rt_sigreturn. */
177 #define LINUX_RT_SIGTRAMP_INSN0 0xb8 /* mov $NNNN, %eax */
178 #define LINUX_RT_SIGTRAMP_OFFSET0 0
179 #define LINUX_RT_SIGTRAMP_INSN1 0xcd /* int */
180 #define LINUX_RT_SIGTRAMP_OFFSET1 5
182 static const gdb_byte linux_rt_sigtramp_code
[] =
184 LINUX_RT_SIGTRAMP_INSN0
, 0xad, 0x00, 0x00, 0x00, /* mov $0xad, %eax */
185 LINUX_RT_SIGTRAMP_INSN1
, 0x80 /* int $0x80 */
188 #define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
190 /* If THIS_FRAME is an RT sigtramp routine, return the address of the
191 start of the routine. Otherwise, return 0. */
194 i386_linux_rt_sigtramp_start (struct frame_info
*this_frame
)
196 CORE_ADDR pc
= get_frame_pc (this_frame
);
197 gdb_byte buf
[LINUX_RT_SIGTRAMP_LEN
];
199 /* We only recognize a signal trampoline if PC is at the start of
200 one of the two instructions. We optimize for finding the PC at
201 the start, as will be the case when the trampoline is not the
202 first frame on the stack. We assume that in the case where the
203 PC is not at the start of the instruction sequence, there will be
204 a few trailing readable bytes on the stack. */
206 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
, LINUX_RT_SIGTRAMP_LEN
))
209 if (buf
[0] != LINUX_RT_SIGTRAMP_INSN0
)
211 if (buf
[0] != LINUX_RT_SIGTRAMP_INSN1
)
214 pc
-= LINUX_RT_SIGTRAMP_OFFSET1
;
216 if (!safe_frame_unwind_memory (this_frame
, pc
, buf
,
217 LINUX_RT_SIGTRAMP_LEN
))
221 if (memcmp (buf
, linux_rt_sigtramp_code
, LINUX_RT_SIGTRAMP_LEN
) != 0)
227 /* Return whether THIS_FRAME corresponds to a GNU/Linux sigtramp
231 i386_linux_sigtramp_p (struct frame_info
*this_frame
)
233 CORE_ADDR pc
= get_frame_pc (this_frame
);
236 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
238 /* If we have NAME, we can optimize the search. The trampolines are
239 named __restore and __restore_rt. However, they aren't dynamically
240 exported from the shared C library, so the trampoline may appear to
241 be part of the preceding function. This should always be sigaction,
242 __sigaction, or __libc_sigaction (all aliases to the same function). */
243 if (name
== NULL
|| strstr (name
, "sigaction") != NULL
)
244 return (i386_linux_sigtramp_start (this_frame
) != 0
245 || i386_linux_rt_sigtramp_start (this_frame
) != 0);
247 return (strcmp ("__restore", name
) == 0
248 || strcmp ("__restore_rt", name
) == 0);
251 /* Return one if the PC of THIS_FRAME is in a signal trampoline which
252 may have DWARF-2 CFI. */
255 i386_linux_dwarf_signal_frame_p (struct gdbarch
*gdbarch
,
256 struct frame_info
*this_frame
)
258 CORE_ADDR pc
= get_frame_pc (this_frame
);
261 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
263 /* If a vsyscall DSO is in use, the signal trampolines may have these
265 if (name
&& (strcmp (name
, "__kernel_sigreturn") == 0
266 || strcmp (name
, "__kernel_rt_sigreturn") == 0))
272 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
273 #define I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 20
275 /* Assuming THIS_FRAME is a GNU/Linux sigtramp routine, return the
276 address of the associated sigcontext structure. */
279 i386_linux_sigcontext_addr (struct frame_info
*this_frame
)
281 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
282 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
287 get_frame_register (this_frame
, I386_ESP_REGNUM
, buf
);
288 sp
= extract_unsigned_integer (buf
, 4, byte_order
);
290 pc
= i386_linux_sigtramp_start (this_frame
);
293 /* The sigcontext structure lives on the stack, right after
294 the signum argument. We determine the address of the
295 sigcontext structure by looking at the frame's stack
296 pointer. Keep in mind that the first instruction of the
297 sigtramp code is "pop %eax". If the PC is after this
298 instruction, adjust the returned value accordingly. */
299 if (pc
== get_frame_pc (this_frame
))
304 pc
= i386_linux_rt_sigtramp_start (this_frame
);
307 CORE_ADDR ucontext_addr
;
309 /* The sigcontext structure is part of the user context. A
310 pointer to the user context is passed as the third argument
311 to the signal handler. */
312 read_memory (sp
+ 8, buf
, 4);
313 ucontext_addr
= extract_unsigned_integer (buf
, 4, byte_order
);
314 return ucontext_addr
+ I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET
;
317 error (_("Couldn't recognize signal trampoline."));
321 /* Set the program counter for process PTID to PC. */
324 i386_linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
326 regcache_cooked_write_unsigned (regcache
, I386_EIP_REGNUM
, pc
);
328 /* We must be careful with modifying the program counter. If we
329 just interrupted a system call, the kernel might try to restart
330 it when we resume the inferior. On restarting the system call,
331 the kernel will try backing up the program counter even though it
332 no longer points at the system call. This typically results in a
333 SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
334 "orig_eax" pseudo-register.
336 Note that "orig_eax" is saved when setting up a dummy call frame.
337 This means that it is properly restored when that frame is
338 popped, and that the interrupted system call will be restarted
339 when we resume the inferior on return from a function call from
340 within GDB. In all other cases the system call will not be
342 regcache_cooked_write_unsigned (regcache
, I386_LINUX_ORIG_EAX_REGNUM
, -1);
345 /* Record all registers but IP register for process-record. */
348 i386_all_but_ip_registers_record (struct regcache
*regcache
)
350 if (record_full_arch_list_add_reg (regcache
, I386_EAX_REGNUM
))
352 if (record_full_arch_list_add_reg (regcache
, I386_ECX_REGNUM
))
354 if (record_full_arch_list_add_reg (regcache
, I386_EDX_REGNUM
))
356 if (record_full_arch_list_add_reg (regcache
, I386_EBX_REGNUM
))
358 if (record_full_arch_list_add_reg (regcache
, I386_ESP_REGNUM
))
360 if (record_full_arch_list_add_reg (regcache
, I386_EBP_REGNUM
))
362 if (record_full_arch_list_add_reg (regcache
, I386_ESI_REGNUM
))
364 if (record_full_arch_list_add_reg (regcache
, I386_EDI_REGNUM
))
366 if (record_full_arch_list_add_reg (regcache
, I386_EFLAGS_REGNUM
))
372 /* i386_canonicalize_syscall maps from the native i386 Linux set
373 of syscall ids into a canonical set of syscall ids used by
374 process record (a mostly trivial mapping, since the canonical
375 set was originally taken from the i386 set). */
377 static enum gdb_syscall
378 i386_canonicalize_syscall (int syscall
)
380 enum { i386_syscall_max
= 499 };
382 if (syscall
<= i386_syscall_max
)
383 return (enum gdb_syscall
) syscall
;
385 return gdb_sys_no_syscall
;
388 /* Value of the sigcode in case of a boundary fault. */
390 #define SIG_CODE_BONDARY_FAULT 3
392 /* i386 GNU/Linux implementation of the handle_segmentation_fault
393 gdbarch hook. Displays information related to MPX bound
396 i386_linux_handle_segmentation_fault (struct gdbarch
*gdbarch
,
397 struct ui_out
*uiout
)
399 /* -Wmaybe-uninitialized */
400 CORE_ADDR lower_bound
= 0, upper_bound
= 0, access
= 0;
404 if (!i386_mpx_enabled ())
409 /* Sigcode evaluates if the actual segfault is a boundary violation. */
410 sig_code
= parse_and_eval_long ("$_siginfo.si_code\n");
413 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._lower");
415 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._upper");
417 = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
419 CATCH (exception
, RETURN_MASK_ALL
)
425 /* If this is not a boundary violation just return. */
426 if (sig_code
!= SIG_CODE_BONDARY_FAULT
)
429 is_upper
= (access
> upper_bound
? 1 : 0);
431 ui_out_text (uiout
, "\n");
433 ui_out_field_string (uiout
, "sigcode-meaning",
434 _("Upper bound violation"));
436 ui_out_field_string (uiout
, "sigcode-meaning",
437 _("Lower bound violation"));
439 ui_out_text (uiout
, _(" while accessing address "));
440 ui_out_field_fmt (uiout
, "bound-access", "%s",
441 paddress (gdbarch
, access
));
443 ui_out_text (uiout
, _("\nBounds: [lower = "));
444 ui_out_field_fmt (uiout
, "lower-bound", "%s",
445 paddress (gdbarch
, lower_bound
));
447 ui_out_text (uiout
, _(", upper = "));
448 ui_out_field_fmt (uiout
, "upper-bound", "%s",
449 paddress (gdbarch
, upper_bound
));
451 ui_out_text (uiout
, _("]"));
454 /* Parse the arguments of current system call instruction and record
455 the values of the registers and memory that will be changed into
456 "record_arch_list". This instruction is "int 0x80" (Linux
457 Kernel2.4) or "sysenter" (Linux Kernel 2.6).
459 Return -1 if something wrong. */
461 static struct linux_record_tdep i386_linux_record_tdep
;
464 i386_linux_intx80_sysenter_syscall_record (struct regcache
*regcache
)
467 LONGEST syscall_native
;
468 enum gdb_syscall syscall_gdb
;
470 regcache_raw_read_signed (regcache
, I386_EAX_REGNUM
, &syscall_native
);
472 syscall_gdb
= i386_canonicalize_syscall (syscall_native
);
476 printf_unfiltered (_("Process record and replay target doesn't "
477 "support syscall number %s\n"),
478 plongest (syscall_native
));
482 if (syscall_gdb
== gdb_sys_sigreturn
483 || syscall_gdb
== gdb_sys_rt_sigreturn
)
485 if (i386_all_but_ip_registers_record (regcache
))
490 ret
= record_linux_system_call (syscall_gdb
, regcache
,
491 &i386_linux_record_tdep
);
495 /* Record the return value of the system call. */
496 if (record_full_arch_list_add_reg (regcache
, I386_EAX_REGNUM
))
502 #define I386_LINUX_xstate 270
503 #define I386_LINUX_frame_size 732
506 i386_linux_record_signal (struct gdbarch
*gdbarch
,
507 struct regcache
*regcache
,
508 enum gdb_signal signal
)
512 if (i386_all_but_ip_registers_record (regcache
))
515 if (record_full_arch_list_add_reg (regcache
, I386_EIP_REGNUM
))
518 /* Record the change in the stack. */
519 regcache_raw_read_unsigned (regcache
, I386_ESP_REGNUM
, &esp
);
520 /* This is for xstate.
521 sp -= sizeof (struct _fpstate); */
522 esp
-= I386_LINUX_xstate
;
523 /* This is for frame_size.
524 sp -= sizeof (struct rt_sigframe); */
525 esp
-= I386_LINUX_frame_size
;
526 if (record_full_arch_list_add_mem (esp
,
527 I386_LINUX_xstate
+ I386_LINUX_frame_size
))
530 if (record_full_arch_list_add_end ())
537 /* Core of the implementation for gdbarch get_syscall_number. Get pending
538 syscall number from REGCACHE. If there is no pending syscall -1 will be
539 returned. Pending syscall means ptrace has stepped into the syscall but
540 another ptrace call will step out. PC is right after the int $0x80
541 / syscall / sysenter instruction in both cases, PC does not change during
542 the second ptrace step. */
545 i386_linux_get_syscall_number_from_regcache (struct regcache
*regcache
)
547 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
548 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
549 /* The content of a register. */
554 /* Getting the system call number from the register.
555 When dealing with x86 architecture, this information
556 is stored at %eax register. */
557 regcache_cooked_read (regcache
, I386_LINUX_ORIG_EAX_REGNUM
, buf
);
559 ret
= extract_signed_integer (buf
, 4, byte_order
);
564 /* Wrapper for i386_linux_get_syscall_number_from_regcache to make it
565 compatible with gdbarch get_syscall_number method prototype. */
568 i386_linux_get_syscall_number (struct gdbarch
*gdbarch
,
571 struct regcache
*regcache
= get_thread_regcache (ptid
);
573 return i386_linux_get_syscall_number_from_regcache (regcache
);
576 /* The register sets used in GNU/Linux ELF core-dumps are identical to
577 the register sets in `struct user' that are used for a.out
578 core-dumps. These are also used by ptrace(2). The corresponding
579 types are `elf_gregset_t' for the general-purpose registers (with
580 `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
581 for the floating-point registers.
583 Those types used to be available under the names `gregset_t' and
584 `fpregset_t' too, and GDB used those names in the past. But those
585 names are now used for the register sets used in the `mcontext_t'
586 type, which have a different size and layout. */
588 /* Mapping between the general-purpose registers in `struct user'
589 format and GDB's register cache layout. */
591 /* From <sys/reg.h>. */
592 int i386_linux_gregset_reg_offset
[] =
603 14 * 4, /* %eflags */
610 -1, -1, -1, -1, -1, -1, -1, -1,
611 -1, -1, -1, -1, -1, -1, -1, -1,
612 -1, -1, -1, -1, -1, -1, -1, -1,
614 -1, -1, -1, -1, -1, -1, -1, -1,
615 -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
616 -1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
617 -1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
618 -1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
619 11 * 4, /* "orig_eax" */
622 /* Mapping between the general-purpose registers in `struct
623 sigcontext' format and GDB's register cache layout. */
625 /* From <asm/sigcontext.h>. */
626 static int i386_linux_sc_reg_offset
[] =
637 16 * 4, /* %eflags */
646 /* Get XSAVE extended state xcr0 from core dump. */
649 i386_linux_core_read_xcr0 (bfd
*abfd
)
651 asection
*xstate
= bfd_get_section_by_name (abfd
, ".reg-xstate");
656 size_t size
= bfd_section_size (abfd
, xstate
);
658 /* Check extended state size. */
659 if (size
< X86_XSTATE_AVX_SIZE
)
660 xcr0
= X86_XSTATE_SSE_MASK
;
665 if (! bfd_get_section_contents (abfd
, xstate
, contents
,
666 I386_LINUX_XSAVE_XCR0_OFFSET
,
669 warning (_("Couldn't read `xcr0' bytes from "
670 "`.reg-xstate' section in core file."));
674 xcr0
= bfd_get_64 (abfd
, contents
);
683 /* Get Linux/x86 target description from core dump. */
685 static const struct target_desc
*
686 i386_linux_core_read_description (struct gdbarch
*gdbarch
,
687 struct target_ops
*target
,
691 uint64_t xcr0
= i386_linux_core_read_xcr0 (abfd
);
693 switch ((xcr0
& X86_XSTATE_ALL_MASK
))
695 case X86_XSTATE_MPX_AVX512_MASK
:
696 case X86_XSTATE_AVX512_MASK
:
697 return tdesc_i386_avx512_linux
;
698 case X86_XSTATE_MPX_MASK
:
699 return tdesc_i386_mpx_linux
;
700 case X86_XSTATE_AVX_MASK
:
701 return tdesc_i386_avx_linux
;
702 case X86_XSTATE_SSE_MASK
:
703 return tdesc_i386_linux
;
704 case X86_XSTATE_X87_MASK
:
705 return tdesc_i386_mmx_linux
;
710 if (bfd_get_section_by_name (abfd
, ".reg-xfp") != NULL
)
711 return tdesc_i386_linux
;
713 return tdesc_i386_mmx_linux
;
716 /* Similar to i386_supply_fpregset, but use XSAVE extended state. */
719 i386_linux_supply_xstateregset (const struct regset
*regset
,
720 struct regcache
*regcache
, int regnum
,
721 const void *xstateregs
, size_t len
)
723 i387_supply_xsave (regcache
, regnum
, xstateregs
);
727 x86_linux_get_siginfo_type (struct gdbarch
*gdbarch
)
729 return linux_get_siginfo_type_with_fields (gdbarch
, LINUX_SIGINFO_FIELD_ADDR_BND
);
732 /* Similar to i386_collect_fpregset, but use XSAVE extended state. */
735 i386_linux_collect_xstateregset (const struct regset
*regset
,
736 const struct regcache
*regcache
,
737 int regnum
, void *xstateregs
, size_t len
)
739 i387_collect_xsave (regcache
, regnum
, xstateregs
, 1);
742 /* Register set definitions. */
744 static const struct regset i386_linux_xstateregset
=
747 i386_linux_supply_xstateregset
,
748 i386_linux_collect_xstateregset
751 /* Iterate over core file register note sections. */
754 i386_linux_iterate_over_regset_sections (struct gdbarch
*gdbarch
,
755 iterate_over_regset_sections_cb
*cb
,
757 const struct regcache
*regcache
)
759 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
761 cb (".reg", 68, &i386_gregset
, NULL
, cb_data
);
763 if (tdep
->xcr0
& X86_XSTATE_AVX
)
764 cb (".reg-xstate", X86_XSTATE_SIZE (tdep
->xcr0
),
765 &i386_linux_xstateregset
, "XSAVE extended state", cb_data
);
766 else if (tdep
->xcr0
& X86_XSTATE_SSE
)
767 cb (".reg-xfp", 512, &i386_fpregset
, "extended floating-point",
770 cb (".reg2", 108, &i386_fpregset
, NULL
, cb_data
);
773 /* Linux kernel shows PC value after the 'int $0x80' instruction even if
774 inferior is still inside the syscall. On next PTRACE_SINGLESTEP it will
775 finish the syscall but PC will not change.
777 Some vDSOs contain 'int $0x80; ret' and during stepping out of the syscall
778 i386_displaced_step_fixup would keep PC at the displaced pad location.
779 As PC is pointing to the 'ret' instruction before the step
780 i386_displaced_step_fixup would expect inferior has just executed that 'ret'
781 and PC should not be adjusted. In reality it finished syscall instead and
782 PC should get relocated back to its vDSO address. Hide the 'ret'
783 instruction by 'nop' so that i386_displaced_step_fixup is not confused.
785 It is not fully correct as the bytes in struct displaced_step_closure will
786 not match the inferior code. But we would need some new flag in
787 displaced_step_closure otherwise to keep the state that syscall is finishing
788 for the later i386_displaced_step_fixup execution as the syscall execution
789 is already no longer detectable there. The new flag field would mean
790 i386-linux-tdep.c needs to wrap all the displacement methods of i386-tdep.c
791 which does not seem worth it. The same effect is achieved by patching that
792 'nop' instruction there instead. */
794 static struct displaced_step_closure
*
795 i386_linux_displaced_step_copy_insn (struct gdbarch
*gdbarch
,
796 CORE_ADDR from
, CORE_ADDR to
,
797 struct regcache
*regs
)
799 struct displaced_step_closure
*closure
;
801 closure
= i386_displaced_step_copy_insn (gdbarch
, from
, to
, regs
);
803 if (i386_linux_get_syscall_number_from_regcache (regs
) != -1)
805 /* Since we use simple_displaced_step_copy_insn, our closure is a
806 copy of the instruction. */
807 gdb_byte
*insn
= (gdb_byte
*) closure
;
817 i386_linux_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
819 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
820 const struct target_desc
*tdesc
= info
.target_desc
;
821 struct tdesc_arch_data
*tdesc_data
822 = (struct tdesc_arch_data
*) info
.tdep_info
;
823 const struct tdesc_feature
*feature
;
826 gdb_assert (tdesc_data
);
828 linux_init_abi (info
, gdbarch
);
830 /* GNU/Linux uses ELF. */
831 i386_elf_init_abi (info
, gdbarch
);
833 /* Reserve a number for orig_eax. */
834 set_gdbarch_num_regs (gdbarch
, I386_LINUX_NUM_REGS
);
836 if (! tdesc_has_registers (tdesc
))
837 tdesc
= tdesc_i386_linux
;
840 feature
= tdesc_find_feature (tdesc
, "org.gnu.gdb.i386.linux");
844 valid_p
= tdesc_numbered_register (feature
, tdesc_data
,
845 I386_LINUX_ORIG_EAX_REGNUM
,
850 /* Add the %orig_eax register used for syscall restarting. */
851 set_gdbarch_write_pc (gdbarch
, i386_linux_write_pc
);
853 tdep
->register_reggroup_p
= i386_linux_register_reggroup_p
;
855 tdep
->gregset_reg_offset
= i386_linux_gregset_reg_offset
;
856 tdep
->gregset_num_regs
= ARRAY_SIZE (i386_linux_gregset_reg_offset
);
857 tdep
->sizeof_gregset
= 17 * 4;
859 tdep
->jb_pc_offset
= 20; /* From <bits/setjmp.h>. */
861 tdep
->sigtramp_p
= i386_linux_sigtramp_p
;
862 tdep
->sigcontext_addr
= i386_linux_sigcontext_addr
;
863 tdep
->sc_reg_offset
= i386_linux_sc_reg_offset
;
864 tdep
->sc_num_regs
= ARRAY_SIZE (i386_linux_sc_reg_offset
);
866 tdep
->xsave_xcr0_offset
= I386_LINUX_XSAVE_XCR0_OFFSET
;
868 set_gdbarch_process_record (gdbarch
, i386_process_record
);
869 set_gdbarch_process_record_signal (gdbarch
, i386_linux_record_signal
);
871 /* Initialize the i386_linux_record_tdep. */
872 /* These values are the size of the type that will be used in a system
873 call. They are obtained from Linux Kernel source. */
874 i386_linux_record_tdep
.size_pointer
875 = gdbarch_ptr_bit (gdbarch
) / TARGET_CHAR_BIT
;
876 i386_linux_record_tdep
.size__old_kernel_stat
= 32;
877 i386_linux_record_tdep
.size_tms
= 16;
878 i386_linux_record_tdep
.size_loff_t
= 8;
879 i386_linux_record_tdep
.size_flock
= 16;
880 i386_linux_record_tdep
.size_oldold_utsname
= 45;
881 i386_linux_record_tdep
.size_ustat
= 20;
882 i386_linux_record_tdep
.size_old_sigaction
= 16;
883 i386_linux_record_tdep
.size_old_sigset_t
= 4;
884 i386_linux_record_tdep
.size_rlimit
= 8;
885 i386_linux_record_tdep
.size_rusage
= 72;
886 i386_linux_record_tdep
.size_timeval
= 8;
887 i386_linux_record_tdep
.size_timezone
= 8;
888 i386_linux_record_tdep
.size_old_gid_t
= 2;
889 i386_linux_record_tdep
.size_old_uid_t
= 2;
890 i386_linux_record_tdep
.size_fd_set
= 128;
891 i386_linux_record_tdep
.size_old_dirent
= 268;
892 i386_linux_record_tdep
.size_statfs
= 64;
893 i386_linux_record_tdep
.size_statfs64
= 84;
894 i386_linux_record_tdep
.size_sockaddr
= 16;
895 i386_linux_record_tdep
.size_int
896 = gdbarch_int_bit (gdbarch
) / TARGET_CHAR_BIT
;
897 i386_linux_record_tdep
.size_long
898 = gdbarch_long_bit (gdbarch
) / TARGET_CHAR_BIT
;
899 i386_linux_record_tdep
.size_ulong
900 = gdbarch_long_bit (gdbarch
) / TARGET_CHAR_BIT
;
901 i386_linux_record_tdep
.size_msghdr
= 28;
902 i386_linux_record_tdep
.size_itimerval
= 16;
903 i386_linux_record_tdep
.size_stat
= 88;
904 i386_linux_record_tdep
.size_old_utsname
= 325;
905 i386_linux_record_tdep
.size_sysinfo
= 64;
906 i386_linux_record_tdep
.size_msqid_ds
= 88;
907 i386_linux_record_tdep
.size_shmid_ds
= 84;
908 i386_linux_record_tdep
.size_new_utsname
= 390;
909 i386_linux_record_tdep
.size_timex
= 128;
910 i386_linux_record_tdep
.size_mem_dqinfo
= 24;
911 i386_linux_record_tdep
.size_if_dqblk
= 68;
912 i386_linux_record_tdep
.size_fs_quota_stat
= 68;
913 i386_linux_record_tdep
.size_timespec
= 8;
914 i386_linux_record_tdep
.size_pollfd
= 8;
915 i386_linux_record_tdep
.size_NFS_FHSIZE
= 32;
916 i386_linux_record_tdep
.size_knfsd_fh
= 132;
917 i386_linux_record_tdep
.size_TASK_COMM_LEN
= 16;
918 i386_linux_record_tdep
.size_sigaction
= 20;
919 i386_linux_record_tdep
.size_sigset_t
= 8;
920 i386_linux_record_tdep
.size_siginfo_t
= 128;
921 i386_linux_record_tdep
.size_cap_user_data_t
= 12;
922 i386_linux_record_tdep
.size_stack_t
= 12;
923 i386_linux_record_tdep
.size_off_t
= i386_linux_record_tdep
.size_long
;
924 i386_linux_record_tdep
.size_stat64
= 96;
925 i386_linux_record_tdep
.size_gid_t
= 4;
926 i386_linux_record_tdep
.size_uid_t
= 4;
927 i386_linux_record_tdep
.size_PAGE_SIZE
= 4096;
928 i386_linux_record_tdep
.size_flock64
= 24;
929 i386_linux_record_tdep
.size_user_desc
= 16;
930 i386_linux_record_tdep
.size_io_event
= 32;
931 i386_linux_record_tdep
.size_iocb
= 64;
932 i386_linux_record_tdep
.size_epoll_event
= 12;
933 i386_linux_record_tdep
.size_itimerspec
934 = i386_linux_record_tdep
.size_timespec
* 2;
935 i386_linux_record_tdep
.size_mq_attr
= 32;
936 i386_linux_record_tdep
.size_termios
= 36;
937 i386_linux_record_tdep
.size_termios2
= 44;
938 i386_linux_record_tdep
.size_pid_t
= 4;
939 i386_linux_record_tdep
.size_winsize
= 8;
940 i386_linux_record_tdep
.size_serial_struct
= 60;
941 i386_linux_record_tdep
.size_serial_icounter_struct
= 80;
942 i386_linux_record_tdep
.size_hayes_esp_config
= 12;
943 i386_linux_record_tdep
.size_size_t
= 4;
944 i386_linux_record_tdep
.size_iovec
= 8;
945 i386_linux_record_tdep
.size_time_t
= 4;
947 /* These values are the second argument of system call "sys_ioctl".
948 They are obtained from Linux Kernel source. */
949 i386_linux_record_tdep
.ioctl_TCGETS
= 0x5401;
950 i386_linux_record_tdep
.ioctl_TCSETS
= 0x5402;
951 i386_linux_record_tdep
.ioctl_TCSETSW
= 0x5403;
952 i386_linux_record_tdep
.ioctl_TCSETSF
= 0x5404;
953 i386_linux_record_tdep
.ioctl_TCGETA
= 0x5405;
954 i386_linux_record_tdep
.ioctl_TCSETA
= 0x5406;
955 i386_linux_record_tdep
.ioctl_TCSETAW
= 0x5407;
956 i386_linux_record_tdep
.ioctl_TCSETAF
= 0x5408;
957 i386_linux_record_tdep
.ioctl_TCSBRK
= 0x5409;
958 i386_linux_record_tdep
.ioctl_TCXONC
= 0x540A;
959 i386_linux_record_tdep
.ioctl_TCFLSH
= 0x540B;
960 i386_linux_record_tdep
.ioctl_TIOCEXCL
= 0x540C;
961 i386_linux_record_tdep
.ioctl_TIOCNXCL
= 0x540D;
962 i386_linux_record_tdep
.ioctl_TIOCSCTTY
= 0x540E;
963 i386_linux_record_tdep
.ioctl_TIOCGPGRP
= 0x540F;
964 i386_linux_record_tdep
.ioctl_TIOCSPGRP
= 0x5410;
965 i386_linux_record_tdep
.ioctl_TIOCOUTQ
= 0x5411;
966 i386_linux_record_tdep
.ioctl_TIOCSTI
= 0x5412;
967 i386_linux_record_tdep
.ioctl_TIOCGWINSZ
= 0x5413;
968 i386_linux_record_tdep
.ioctl_TIOCSWINSZ
= 0x5414;
969 i386_linux_record_tdep
.ioctl_TIOCMGET
= 0x5415;
970 i386_linux_record_tdep
.ioctl_TIOCMBIS
= 0x5416;
971 i386_linux_record_tdep
.ioctl_TIOCMBIC
= 0x5417;
972 i386_linux_record_tdep
.ioctl_TIOCMSET
= 0x5418;
973 i386_linux_record_tdep
.ioctl_TIOCGSOFTCAR
= 0x5419;
974 i386_linux_record_tdep
.ioctl_TIOCSSOFTCAR
= 0x541A;
975 i386_linux_record_tdep
.ioctl_FIONREAD
= 0x541B;
976 i386_linux_record_tdep
.ioctl_TIOCINQ
= i386_linux_record_tdep
.ioctl_FIONREAD
;
977 i386_linux_record_tdep
.ioctl_TIOCLINUX
= 0x541C;
978 i386_linux_record_tdep
.ioctl_TIOCCONS
= 0x541D;
979 i386_linux_record_tdep
.ioctl_TIOCGSERIAL
= 0x541E;
980 i386_linux_record_tdep
.ioctl_TIOCSSERIAL
= 0x541F;
981 i386_linux_record_tdep
.ioctl_TIOCPKT
= 0x5420;
982 i386_linux_record_tdep
.ioctl_FIONBIO
= 0x5421;
983 i386_linux_record_tdep
.ioctl_TIOCNOTTY
= 0x5422;
984 i386_linux_record_tdep
.ioctl_TIOCSETD
= 0x5423;
985 i386_linux_record_tdep
.ioctl_TIOCGETD
= 0x5424;
986 i386_linux_record_tdep
.ioctl_TCSBRKP
= 0x5425;
987 i386_linux_record_tdep
.ioctl_TIOCTTYGSTRUCT
= 0x5426;
988 i386_linux_record_tdep
.ioctl_TIOCSBRK
= 0x5427;
989 i386_linux_record_tdep
.ioctl_TIOCCBRK
= 0x5428;
990 i386_linux_record_tdep
.ioctl_TIOCGSID
= 0x5429;
991 i386_linux_record_tdep
.ioctl_TCGETS2
= 0x802c542a;
992 i386_linux_record_tdep
.ioctl_TCSETS2
= 0x402c542b;
993 i386_linux_record_tdep
.ioctl_TCSETSW2
= 0x402c542c;
994 i386_linux_record_tdep
.ioctl_TCSETSF2
= 0x402c542d;
995 i386_linux_record_tdep
.ioctl_TIOCGPTN
= 0x80045430;
996 i386_linux_record_tdep
.ioctl_TIOCSPTLCK
= 0x40045431;
997 i386_linux_record_tdep
.ioctl_FIONCLEX
= 0x5450;
998 i386_linux_record_tdep
.ioctl_FIOCLEX
= 0x5451;
999 i386_linux_record_tdep
.ioctl_FIOASYNC
= 0x5452;
1000 i386_linux_record_tdep
.ioctl_TIOCSERCONFIG
= 0x5453;
1001 i386_linux_record_tdep
.ioctl_TIOCSERGWILD
= 0x5454;
1002 i386_linux_record_tdep
.ioctl_TIOCSERSWILD
= 0x5455;
1003 i386_linux_record_tdep
.ioctl_TIOCGLCKTRMIOS
= 0x5456;
1004 i386_linux_record_tdep
.ioctl_TIOCSLCKTRMIOS
= 0x5457;
1005 i386_linux_record_tdep
.ioctl_TIOCSERGSTRUCT
= 0x5458;
1006 i386_linux_record_tdep
.ioctl_TIOCSERGETLSR
= 0x5459;
1007 i386_linux_record_tdep
.ioctl_TIOCSERGETMULTI
= 0x545A;
1008 i386_linux_record_tdep
.ioctl_TIOCSERSETMULTI
= 0x545B;
1009 i386_linux_record_tdep
.ioctl_TIOCMIWAIT
= 0x545C;
1010 i386_linux_record_tdep
.ioctl_TIOCGICOUNT
= 0x545D;
1011 i386_linux_record_tdep
.ioctl_TIOCGHAYESESP
= 0x545E;
1012 i386_linux_record_tdep
.ioctl_TIOCSHAYESESP
= 0x545F;
1013 i386_linux_record_tdep
.ioctl_FIOQSIZE
= 0x5460;
1015 /* These values are the second argument of system call "sys_fcntl"
1016 and "sys_fcntl64". They are obtained from Linux Kernel source. */
1017 i386_linux_record_tdep
.fcntl_F_GETLK
= 5;
1018 i386_linux_record_tdep
.fcntl_F_GETLK64
= 12;
1019 i386_linux_record_tdep
.fcntl_F_SETLK64
= 13;
1020 i386_linux_record_tdep
.fcntl_F_SETLKW64
= 14;
1022 i386_linux_record_tdep
.arg1
= I386_EBX_REGNUM
;
1023 i386_linux_record_tdep
.arg2
= I386_ECX_REGNUM
;
1024 i386_linux_record_tdep
.arg3
= I386_EDX_REGNUM
;
1025 i386_linux_record_tdep
.arg4
= I386_ESI_REGNUM
;
1026 i386_linux_record_tdep
.arg5
= I386_EDI_REGNUM
;
1027 i386_linux_record_tdep
.arg6
= I386_EBP_REGNUM
;
1029 tdep
->i386_intx80_record
= i386_linux_intx80_sysenter_syscall_record
;
1030 tdep
->i386_sysenter_record
= i386_linux_intx80_sysenter_syscall_record
;
1031 tdep
->i386_syscall_record
= i386_linux_intx80_sysenter_syscall_record
;
1033 /* N_FUN symbols in shared libaries have 0 for their values and need
1035 set_gdbarch_sofun_address_maybe_missing (gdbarch
, 1);
1037 /* GNU/Linux uses SVR4-style shared libraries. */
1038 set_gdbarch_skip_trampoline_code (gdbarch
, find_solib_trampoline_target
);
1039 set_solib_svr4_fetch_link_map_offsets
1040 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
1042 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
1043 set_gdbarch_skip_solib_resolver (gdbarch
, glibc_skip_solib_resolver
);
1045 dwarf2_frame_set_signal_frame_p (gdbarch
, i386_linux_dwarf_signal_frame_p
);
1047 /* Enable TLS support. */
1048 set_gdbarch_fetch_tls_load_module_address (gdbarch
,
1049 svr4_fetch_objfile_link_map
);
1051 /* Core file support. */
1052 set_gdbarch_iterate_over_regset_sections
1053 (gdbarch
, i386_linux_iterate_over_regset_sections
);
1054 set_gdbarch_core_read_description (gdbarch
,
1055 i386_linux_core_read_description
);
1057 /* Displaced stepping. */
1058 set_gdbarch_displaced_step_copy_insn (gdbarch
,
1059 i386_linux_displaced_step_copy_insn
);
1060 set_gdbarch_displaced_step_fixup (gdbarch
, i386_displaced_step_fixup
);
1061 set_gdbarch_displaced_step_free_closure (gdbarch
,
1062 simple_displaced_step_free_closure
);
1063 set_gdbarch_displaced_step_location (gdbarch
,
1064 linux_displaced_step_location
);
1066 /* Functions for 'catch syscall'. */
1067 set_xml_syscall_file_name (gdbarch
, XML_SYSCALL_FILENAME_I386
);
1068 set_gdbarch_get_syscall_number (gdbarch
,
1069 i386_linux_get_syscall_number
);
1071 set_gdbarch_get_siginfo_type (gdbarch
, x86_linux_get_siginfo_type
);
1072 set_gdbarch_handle_segmentation_fault (gdbarch
,
1073 i386_linux_handle_segmentation_fault
);
1076 /* Provide a prototype to silence -Wmissing-prototypes. */
1077 extern void _initialize_i386_linux_tdep (void);
1080 _initialize_i386_linux_tdep (void)
1082 gdbarch_register_osabi (bfd_arch_i386
, 0, GDB_OSABI_LINUX
,
1083 i386_linux_init_abi
);
1085 /* Initialize the Linux target description. */
1086 initialize_tdesc_i386_linux ();
1087 initialize_tdesc_i386_mmx_linux ();
1088 initialize_tdesc_i386_avx_linux ();
1089 initialize_tdesc_i386_mpx_linux ();
1090 initialize_tdesc_i386_avx512_linux ();