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-mpx-linux.c"
52 #include "features/i386/i386-avx-linux.c"
53 #include "features/i386/i386-avx512-linux.c"
55 /* Return non-zero, when the register is in the corresponding register
56 group. Put the LINUX_ORIG_EAX register in the system group. */
58 i386_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
59 struct reggroup *group)
61 if (regnum == I386_LINUX_ORIG_EAX_REGNUM)
62 return (group == system_reggroup
63 || group == save_reggroup
64 || group == restore_reggroup);
65 return i386_register_reggroup_p (gdbarch, regnum, group);
69 /* Recognizing signal handler frames. */
71 /* GNU/Linux has two flavors of signals. Normal signal handlers, and
72 "realtime" (RT) signals. The RT signals can provide additional
73 information to the signal handler if the SA_SIGINFO flag is set
74 when establishing a signal handler using `sigaction'. It is not
75 unlikely that future versions of GNU/Linux will support SA_SIGINFO
76 for normal signals too. */
78 /* When the i386 Linux kernel calls a signal handler and the
79 SA_RESTORER flag isn't set, the return address points to a bit of
80 code on the stack. This function returns whether the PC appears to
81 be within this bit of code.
83 The instruction sequence for normal signals is
87 or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
89 Checking for the code sequence should be somewhat reliable, because
90 the effect is to call the system call sigreturn. This is unlikely
91 to occur anywhere other than in a signal trampoline.
93 It kind of sucks that we have to read memory from the process in
94 order to identify a signal trampoline, but there doesn't seem to be
95 any other way. Therefore we only do the memory reads if no
96 function name could be identified, which should be the case since
97 the code is on the stack.
99 Detection of signal trampolines for handlers that set the
100 SA_RESTORER flag is in general not possible. Unfortunately this is
101 what the GNU C Library has been doing for quite some time now.
102 However, as of version 2.1.2, the GNU C Library uses signal
103 trampolines (named __restore and __restore_rt) that are identical
104 to the ones used by the kernel. Therefore, these trampolines are
107 #define LINUX_SIGTRAMP_INSN0 0x58 /* pop %eax */
108 #define LINUX_SIGTRAMP_OFFSET0 0
109 #define LINUX_SIGTRAMP_INSN1 0xb8 /* mov $NNNN, %eax */
110 #define LINUX_SIGTRAMP_OFFSET1 1
111 #define LINUX_SIGTRAMP_INSN2 0xcd /* int */
112 #define LINUX_SIGTRAMP_OFFSET2 6
114 static const gdb_byte linux_sigtramp_code[] =
116 LINUX_SIGTRAMP_INSN0, /* pop %eax */
117 LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77, %eax */
118 LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
121 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
123 /* If THIS_FRAME is a sigtramp routine, return the address of the
124 start of the routine. Otherwise, return 0. */
127 i386_linux_sigtramp_start (struct frame_info *this_frame)
129 CORE_ADDR pc = get_frame_pc (this_frame);
130 gdb_byte buf[LINUX_SIGTRAMP_LEN];
132 /* We only recognize a signal trampoline if PC is at the start of
133 one of the three instructions. We optimize for finding the PC at
134 the start, as will be the case when the trampoline is not the
135 first frame on the stack. We assume that in the case where the
136 PC is not at the start of the instruction sequence, there will be
137 a few trailing readable bytes on the stack. */
139 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_SIGTRAMP_LEN))
142 if (buf[0] != LINUX_SIGTRAMP_INSN0)
148 case LINUX_SIGTRAMP_INSN1:
149 adjust = LINUX_SIGTRAMP_OFFSET1;
151 case LINUX_SIGTRAMP_INSN2:
152 adjust = LINUX_SIGTRAMP_OFFSET2;
160 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_SIGTRAMP_LEN))
164 if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
170 /* This function does the same for RT signals. Here the instruction
174 or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
176 The effect is to call the system call rt_sigreturn. */
178 #define LINUX_RT_SIGTRAMP_INSN0 0xb8 /* mov $NNNN, %eax */
179 #define LINUX_RT_SIGTRAMP_OFFSET0 0
180 #define LINUX_RT_SIGTRAMP_INSN1 0xcd /* int */
181 #define LINUX_RT_SIGTRAMP_OFFSET1 5
183 static const gdb_byte linux_rt_sigtramp_code[] =
185 LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad, %eax */
186 LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
189 #define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
191 /* If THIS_FRAME is an RT sigtramp routine, return the address of the
192 start of the routine. Otherwise, return 0. */
195 i386_linux_rt_sigtramp_start (struct frame_info *this_frame)
197 CORE_ADDR pc = get_frame_pc (this_frame);
198 gdb_byte buf[LINUX_RT_SIGTRAMP_LEN];
200 /* We only recognize a signal trampoline if PC is at the start of
201 one of the two instructions. We optimize for finding the PC at
202 the start, as will be the case when the trampoline is not the
203 first frame on the stack. We assume that in the case where the
204 PC is not at the start of the instruction sequence, there will be
205 a few trailing readable bytes on the stack. */
207 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_RT_SIGTRAMP_LEN))
210 if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
212 if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
215 pc -= LINUX_RT_SIGTRAMP_OFFSET1;
217 if (!safe_frame_unwind_memory (this_frame, pc, buf,
218 LINUX_RT_SIGTRAMP_LEN))
222 if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
228 /* Return whether THIS_FRAME corresponds to a GNU/Linux sigtramp
232 i386_linux_sigtramp_p (struct frame_info *this_frame)
234 CORE_ADDR pc = get_frame_pc (this_frame);
237 find_pc_partial_function (pc, &name, NULL, NULL);
239 /* If we have NAME, we can optimize the search. The trampolines are
240 named __restore and __restore_rt. However, they aren't dynamically
241 exported from the shared C library, so the trampoline may appear to
242 be part of the preceding function. This should always be sigaction,
243 __sigaction, or __libc_sigaction (all aliases to the same function). */
244 if (name == NULL || strstr (name, "sigaction") != NULL)
245 return (i386_linux_sigtramp_start (this_frame) != 0
246 || i386_linux_rt_sigtramp_start (this_frame) != 0);
248 return (strcmp ("__restore", name) == 0
249 || strcmp ("__restore_rt", name) == 0);
252 /* Return one if the PC of THIS_FRAME is in a signal trampoline which
253 may have DWARF-2 CFI. */
256 i386_linux_dwarf_signal_frame_p (struct gdbarch *gdbarch,
257 struct frame_info *this_frame)
259 CORE_ADDR pc = get_frame_pc (this_frame);
262 find_pc_partial_function (pc, &name, NULL, NULL);
264 /* If a vsyscall DSO is in use, the signal trampolines may have these
266 if (name && (strcmp (name, "__kernel_sigreturn") == 0
267 || strcmp (name, "__kernel_rt_sigreturn") == 0))
273 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
274 #define I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 20
276 /* Assuming THIS_FRAME is a GNU/Linux sigtramp routine, return the
277 address of the associated sigcontext structure. */
280 i386_linux_sigcontext_addr (struct frame_info *this_frame)
282 struct gdbarch *gdbarch = get_frame_arch (this_frame);
283 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
288 get_frame_register (this_frame, I386_ESP_REGNUM, buf);
289 sp = extract_unsigned_integer (buf, 4, byte_order);
291 pc = i386_linux_sigtramp_start (this_frame);
294 /* The sigcontext structure lives on the stack, right after
295 the signum argument. We determine the address of the
296 sigcontext structure by looking at the frame's stack
297 pointer. Keep in mind that the first instruction of the
298 sigtramp code is "pop %eax". If the PC is after this
299 instruction, adjust the returned value accordingly. */
300 if (pc == get_frame_pc (this_frame))
305 pc = i386_linux_rt_sigtramp_start (this_frame);
308 CORE_ADDR ucontext_addr;
310 /* The sigcontext structure is part of the user context. A
311 pointer to the user context is passed as the third argument
312 to the signal handler. */
313 read_memory (sp + 8, buf, 4);
314 ucontext_addr = extract_unsigned_integer (buf, 4, byte_order);
315 return ucontext_addr + I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
318 error (_("Couldn't recognize signal trampoline."));
322 /* Set the program counter for process PTID to PC. */
325 i386_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
327 regcache_cooked_write_unsigned (regcache, I386_EIP_REGNUM, pc);
329 /* We must be careful with modifying the program counter. If we
330 just interrupted a system call, the kernel might try to restart
331 it when we resume the inferior. On restarting the system call,
332 the kernel will try backing up the program counter even though it
333 no longer points at the system call. This typically results in a
334 SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
335 "orig_eax" pseudo-register.
337 Note that "orig_eax" is saved when setting up a dummy call frame.
338 This means that it is properly restored when that frame is
339 popped, and that the interrupted system call will be restarted
340 when we resume the inferior on return from a function call from
341 within GDB. In all other cases the system call will not be
343 regcache_cooked_write_unsigned (regcache, I386_LINUX_ORIG_EAX_REGNUM, -1);
346 /* Record all registers but IP register for process-record. */
349 i386_all_but_ip_registers_record (struct regcache *regcache)
351 if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
353 if (record_full_arch_list_add_reg (regcache, I386_ECX_REGNUM))
355 if (record_full_arch_list_add_reg (regcache, I386_EDX_REGNUM))
357 if (record_full_arch_list_add_reg (regcache, I386_EBX_REGNUM))
359 if (record_full_arch_list_add_reg (regcache, I386_ESP_REGNUM))
361 if (record_full_arch_list_add_reg (regcache, I386_EBP_REGNUM))
363 if (record_full_arch_list_add_reg (regcache, I386_ESI_REGNUM))
365 if (record_full_arch_list_add_reg (regcache, I386_EDI_REGNUM))
367 if (record_full_arch_list_add_reg (regcache, I386_EFLAGS_REGNUM))
373 /* i386_canonicalize_syscall maps from the native i386 Linux set
374 of syscall ids into a canonical set of syscall ids used by
375 process record (a mostly trivial mapping, since the canonical
376 set was originally taken from the i386 set). */
378 static enum gdb_syscall
379 i386_canonicalize_syscall (int syscall)
381 enum { i386_syscall_max = 499 };
383 if (syscall <= i386_syscall_max)
384 return (enum gdb_syscall) syscall;
386 return gdb_sys_no_syscall;
389 /* Value of the sigcode in case of a boundary fault. */
391 #define SIG_CODE_BONDARY_FAULT 3
393 /* i386 GNU/Linux implementation of the handle_segmentation_fault
394 gdbarch hook. Displays information related to MPX bound
397 i386_linux_handle_segmentation_fault (struct gdbarch *gdbarch,
398 struct ui_out *uiout)
400 /* -Wmaybe-uninitialized */
401 CORE_ADDR lower_bound = 0, upper_bound = 0, access = 0;
405 if (!i386_mpx_enabled ())
410 /* Sigcode evaluates if the actual segfault is a boundary violation. */
411 sig_code = parse_and_eval_long ("$_siginfo.si_code\n");
414 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._lower");
416 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._upper");
418 = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
420 CATCH (exception, RETURN_MASK_ALL)
426 /* If this is not a boundary violation just return. */
427 if (sig_code != SIG_CODE_BONDARY_FAULT)
430 is_upper = (access > upper_bound ? 1 : 0);
434 uiout->field_string ("sigcode-meaning", _("Upper bound violation"));
436 uiout->field_string ("sigcode-meaning", _("Lower bound violation"));
438 uiout->text (_(" while accessing address "));
439 uiout->field_fmt ("bound-access", "%s", paddress (gdbarch, access));
441 uiout->text (_("\nBounds: [lower = "));
442 uiout->field_fmt ("lower-bound", "%s", paddress (gdbarch, lower_bound));
444 uiout->text (_(", upper = "));
445 uiout->field_fmt ("upper-bound", "%s", paddress (gdbarch, upper_bound));
447 uiout->text (_("]"));
450 /* Parse the arguments of current system call instruction and record
451 the values of the registers and memory that will be changed into
452 "record_arch_list". This instruction is "int 0x80" (Linux
453 Kernel2.4) or "sysenter" (Linux Kernel 2.6).
455 Return -1 if something wrong. */
457 static struct linux_record_tdep i386_linux_record_tdep;
460 i386_linux_intx80_sysenter_syscall_record (struct regcache *regcache)
463 LONGEST syscall_native;
464 enum gdb_syscall syscall_gdb;
466 regcache_raw_read_signed (regcache, I386_EAX_REGNUM, &syscall_native);
468 syscall_gdb = i386_canonicalize_syscall (syscall_native);
472 printf_unfiltered (_("Process record and replay target doesn't "
473 "support syscall number %s\n"),
474 plongest (syscall_native));
478 if (syscall_gdb == gdb_sys_sigreturn
479 || syscall_gdb == gdb_sys_rt_sigreturn)
481 if (i386_all_but_ip_registers_record (regcache))
486 ret = record_linux_system_call (syscall_gdb, regcache,
487 &i386_linux_record_tdep);
491 /* Record the return value of the system call. */
492 if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
498 #define I386_LINUX_xstate 270
499 #define I386_LINUX_frame_size 732
502 i386_linux_record_signal (struct gdbarch *gdbarch,
503 struct regcache *regcache,
504 enum gdb_signal signal)
508 if (i386_all_but_ip_registers_record (regcache))
511 if (record_full_arch_list_add_reg (regcache, I386_EIP_REGNUM))
514 /* Record the change in the stack. */
515 regcache_raw_read_unsigned (regcache, I386_ESP_REGNUM, &esp);
516 /* This is for xstate.
517 sp -= sizeof (struct _fpstate); */
518 esp -= I386_LINUX_xstate;
519 /* This is for frame_size.
520 sp -= sizeof (struct rt_sigframe); */
521 esp -= I386_LINUX_frame_size;
522 if (record_full_arch_list_add_mem (esp,
523 I386_LINUX_xstate + I386_LINUX_frame_size))
526 if (record_full_arch_list_add_end ())
533 /* Core of the implementation for gdbarch get_syscall_number. Get pending
534 syscall number from REGCACHE. If there is no pending syscall -1 will be
535 returned. Pending syscall means ptrace has stepped into the syscall but
536 another ptrace call will step out. PC is right after the int $0x80
537 / syscall / sysenter instruction in both cases, PC does not change during
538 the second ptrace step. */
541 i386_linux_get_syscall_number_from_regcache (struct regcache *regcache)
543 struct gdbarch *gdbarch = get_regcache_arch (regcache);
544 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
545 /* The content of a register. */
550 /* Getting the system call number from the register.
551 When dealing with x86 architecture, this information
552 is stored at %eax register. */
553 regcache_cooked_read (regcache, I386_LINUX_ORIG_EAX_REGNUM, buf);
555 ret = extract_signed_integer (buf, 4, byte_order);
560 /* Wrapper for i386_linux_get_syscall_number_from_regcache to make it
561 compatible with gdbarch get_syscall_number method prototype. */
564 i386_linux_get_syscall_number (struct gdbarch *gdbarch,
567 struct regcache *regcache = get_thread_regcache (ptid);
569 return i386_linux_get_syscall_number_from_regcache (regcache);
572 /* The register sets used in GNU/Linux ELF core-dumps are identical to
573 the register sets in `struct user' that are used for a.out
574 core-dumps. These are also used by ptrace(2). The corresponding
575 types are `elf_gregset_t' for the general-purpose registers (with
576 `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
577 for the floating-point registers.
579 Those types used to be available under the names `gregset_t' and
580 `fpregset_t' too, and GDB used those names in the past. But those
581 names are now used for the register sets used in the `mcontext_t'
582 type, which have a different size and layout. */
584 /* Mapping between the general-purpose registers in `struct user'
585 format and GDB's register cache layout. */
587 /* From <sys/reg.h>. */
588 int i386_linux_gregset_reg_offset[] =
599 14 * 4, /* %eflags */
606 -1, -1, -1, -1, -1, -1, -1, -1,
607 -1, -1, -1, -1, -1, -1, -1, -1,
608 -1, -1, -1, -1, -1, -1, -1, -1,
610 -1, -1, -1, -1, -1, -1, -1, -1,
611 -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
612 -1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
613 -1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
614 -1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
615 11 * 4, /* "orig_eax" */
618 /* Mapping between the general-purpose registers in `struct
619 sigcontext' format and GDB's register cache layout. */
621 /* From <asm/sigcontext.h>. */
622 static int i386_linux_sc_reg_offset[] =
633 16 * 4, /* %eflags */
642 /* Get XSAVE extended state xcr0 from core dump. */
645 i386_linux_core_read_xcr0 (bfd *abfd)
647 asection *xstate = bfd_get_section_by_name (abfd, ".reg-xstate");
652 size_t size = bfd_section_size (abfd, xstate);
654 /* Check extended state size. */
655 if (size < X86_XSTATE_AVX_SIZE)
656 xcr0 = X86_XSTATE_SSE_MASK;
661 if (! bfd_get_section_contents (abfd, xstate, contents,
662 I386_LINUX_XSAVE_XCR0_OFFSET,
665 warning (_("Couldn't read `xcr0' bytes from "
666 "`.reg-xstate' section in core file."));
670 xcr0 = bfd_get_64 (abfd, contents);
679 /* Get Linux/x86 target description from core dump. */
681 static const struct target_desc *
682 i386_linux_core_read_description (struct gdbarch *gdbarch,
683 struct target_ops *target,
687 uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
689 switch ((xcr0 & X86_XSTATE_ALL_MASK))
691 case X86_XSTATE_MPX_AVX512_MASK:
692 case X86_XSTATE_AVX512_MASK:
693 return tdesc_i386_avx512_linux;
694 case X86_XSTATE_MPX_MASK:
695 return tdesc_i386_mpx_linux;
696 case X86_XSTATE_AVX_MPX_MASK:
697 return tdesc_i386_avx_mpx_linux;
698 case X86_XSTATE_AVX_MASK:
699 return tdesc_i386_avx_linux;
700 case X86_XSTATE_SSE_MASK:
701 return tdesc_i386_linux;
702 case X86_XSTATE_X87_MASK:
703 return tdesc_i386_mmx_linux;
708 if (bfd_get_section_by_name (abfd, ".reg-xfp") != NULL)
709 return tdesc_i386_linux;
711 return tdesc_i386_mmx_linux;
714 /* Similar to i386_supply_fpregset, but use XSAVE extended state. */
717 i386_linux_supply_xstateregset (const struct regset *regset,
718 struct regcache *regcache, int regnum,
719 const void *xstateregs, size_t len)
721 i387_supply_xsave (regcache, regnum, xstateregs);
725 x86_linux_get_siginfo_type (struct gdbarch *gdbarch)
727 return linux_get_siginfo_type_with_fields (gdbarch, LINUX_SIGINFO_FIELD_ADDR_BND);
730 /* Similar to i386_collect_fpregset, but use XSAVE extended state. */
733 i386_linux_collect_xstateregset (const struct regset *regset,
734 const struct regcache *regcache,
735 int regnum, void *xstateregs, size_t len)
737 i387_collect_xsave (regcache, regnum, xstateregs, 1);
740 /* Register set definitions. */
742 static const struct regset i386_linux_xstateregset =
745 i386_linux_supply_xstateregset,
746 i386_linux_collect_xstateregset
749 /* Iterate over core file register note sections. */
752 i386_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
753 iterate_over_regset_sections_cb *cb,
755 const struct regcache *regcache)
757 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
759 cb (".reg", 68, &i386_gregset, NULL, cb_data);
761 if (tdep->xcr0 & X86_XSTATE_AVX)
762 cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
763 &i386_linux_xstateregset, "XSAVE extended state", cb_data);
764 else if (tdep->xcr0 & X86_XSTATE_SSE)
765 cb (".reg-xfp", 512, &i386_fpregset, "extended floating-point",
768 cb (".reg2", 108, &i386_fpregset, NULL, cb_data);
771 /* Linux kernel shows PC value after the 'int $0x80' instruction even if
772 inferior is still inside the syscall. On next PTRACE_SINGLESTEP it will
773 finish the syscall but PC will not change.
775 Some vDSOs contain 'int $0x80; ret' and during stepping out of the syscall
776 i386_displaced_step_fixup would keep PC at the displaced pad location.
777 As PC is pointing to the 'ret' instruction before the step
778 i386_displaced_step_fixup would expect inferior has just executed that 'ret'
779 and PC should not be adjusted. In reality it finished syscall instead and
780 PC should get relocated back to its vDSO address. Hide the 'ret'
781 instruction by 'nop' so that i386_displaced_step_fixup is not confused.
783 It is not fully correct as the bytes in struct displaced_step_closure will
784 not match the inferior code. But we would need some new flag in
785 displaced_step_closure otherwise to keep the state that syscall is finishing
786 for the later i386_displaced_step_fixup execution as the syscall execution
787 is already no longer detectable there. The new flag field would mean
788 i386-linux-tdep.c needs to wrap all the displacement methods of i386-tdep.c
789 which does not seem worth it. The same effect is achieved by patching that
790 'nop' instruction there instead. */
792 static struct displaced_step_closure *
793 i386_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
794 CORE_ADDR from, CORE_ADDR to,
795 struct regcache *regs)
797 struct displaced_step_closure *closure;
799 closure = i386_displaced_step_copy_insn (gdbarch, from, to, regs);
801 if (i386_linux_get_syscall_number_from_regcache (regs) != -1)
803 /* Since we use simple_displaced_step_copy_insn, our closure is a
804 copy of the instruction. */
805 gdb_byte *insn = (gdb_byte *) closure;
815 i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
817 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
818 const struct target_desc *tdesc = info.target_desc;
819 struct tdesc_arch_data *tdesc_data
820 = (struct tdesc_arch_data *) info.tdep_info;
821 const struct tdesc_feature *feature;
824 gdb_assert (tdesc_data);
826 linux_init_abi (info, gdbarch);
828 /* GNU/Linux uses ELF. */
829 i386_elf_init_abi (info, gdbarch);
831 /* Reserve a number for orig_eax. */
832 set_gdbarch_num_regs (gdbarch, I386_LINUX_NUM_REGS);
834 if (! tdesc_has_registers (tdesc))
835 tdesc = tdesc_i386_linux;
838 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
842 valid_p = tdesc_numbered_register (feature, tdesc_data,
843 I386_LINUX_ORIG_EAX_REGNUM,
848 /* Add the %orig_eax register used for syscall restarting. */
849 set_gdbarch_write_pc (gdbarch, i386_linux_write_pc);
851 tdep->register_reggroup_p = i386_linux_register_reggroup_p;
853 tdep->gregset_reg_offset = i386_linux_gregset_reg_offset;
854 tdep->gregset_num_regs = ARRAY_SIZE (i386_linux_gregset_reg_offset);
855 tdep->sizeof_gregset = 17 * 4;
857 tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */
859 tdep->sigtramp_p = i386_linux_sigtramp_p;
860 tdep->sigcontext_addr = i386_linux_sigcontext_addr;
861 tdep->sc_reg_offset = i386_linux_sc_reg_offset;
862 tdep->sc_num_regs = ARRAY_SIZE (i386_linux_sc_reg_offset);
864 tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET;
866 set_gdbarch_process_record (gdbarch, i386_process_record);
867 set_gdbarch_process_record_signal (gdbarch, i386_linux_record_signal);
869 /* Initialize the i386_linux_record_tdep. */
870 /* These values are the size of the type that will be used in a system
871 call. They are obtained from Linux Kernel source. */
872 i386_linux_record_tdep.size_pointer
873 = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
874 i386_linux_record_tdep.size__old_kernel_stat = 32;
875 i386_linux_record_tdep.size_tms = 16;
876 i386_linux_record_tdep.size_loff_t = 8;
877 i386_linux_record_tdep.size_flock = 16;
878 i386_linux_record_tdep.size_oldold_utsname = 45;
879 i386_linux_record_tdep.size_ustat = 20;
880 i386_linux_record_tdep.size_old_sigaction = 16;
881 i386_linux_record_tdep.size_old_sigset_t = 4;
882 i386_linux_record_tdep.size_rlimit = 8;
883 i386_linux_record_tdep.size_rusage = 72;
884 i386_linux_record_tdep.size_timeval = 8;
885 i386_linux_record_tdep.size_timezone = 8;
886 i386_linux_record_tdep.size_old_gid_t = 2;
887 i386_linux_record_tdep.size_old_uid_t = 2;
888 i386_linux_record_tdep.size_fd_set = 128;
889 i386_linux_record_tdep.size_old_dirent = 268;
890 i386_linux_record_tdep.size_statfs = 64;
891 i386_linux_record_tdep.size_statfs64 = 84;
892 i386_linux_record_tdep.size_sockaddr = 16;
893 i386_linux_record_tdep.size_int
894 = gdbarch_int_bit (gdbarch) / TARGET_CHAR_BIT;
895 i386_linux_record_tdep.size_long
896 = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
897 i386_linux_record_tdep.size_ulong
898 = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
899 i386_linux_record_tdep.size_msghdr = 28;
900 i386_linux_record_tdep.size_itimerval = 16;
901 i386_linux_record_tdep.size_stat = 88;
902 i386_linux_record_tdep.size_old_utsname = 325;
903 i386_linux_record_tdep.size_sysinfo = 64;
904 i386_linux_record_tdep.size_msqid_ds = 88;
905 i386_linux_record_tdep.size_shmid_ds = 84;
906 i386_linux_record_tdep.size_new_utsname = 390;
907 i386_linux_record_tdep.size_timex = 128;
908 i386_linux_record_tdep.size_mem_dqinfo = 24;
909 i386_linux_record_tdep.size_if_dqblk = 68;
910 i386_linux_record_tdep.size_fs_quota_stat = 68;
911 i386_linux_record_tdep.size_timespec = 8;
912 i386_linux_record_tdep.size_pollfd = 8;
913 i386_linux_record_tdep.size_NFS_FHSIZE = 32;
914 i386_linux_record_tdep.size_knfsd_fh = 132;
915 i386_linux_record_tdep.size_TASK_COMM_LEN = 16;
916 i386_linux_record_tdep.size_sigaction = 20;
917 i386_linux_record_tdep.size_sigset_t = 8;
918 i386_linux_record_tdep.size_siginfo_t = 128;
919 i386_linux_record_tdep.size_cap_user_data_t = 12;
920 i386_linux_record_tdep.size_stack_t = 12;
921 i386_linux_record_tdep.size_off_t = i386_linux_record_tdep.size_long;
922 i386_linux_record_tdep.size_stat64 = 96;
923 i386_linux_record_tdep.size_gid_t = 4;
924 i386_linux_record_tdep.size_uid_t = 4;
925 i386_linux_record_tdep.size_PAGE_SIZE = 4096;
926 i386_linux_record_tdep.size_flock64 = 24;
927 i386_linux_record_tdep.size_user_desc = 16;
928 i386_linux_record_tdep.size_io_event = 32;
929 i386_linux_record_tdep.size_iocb = 64;
930 i386_linux_record_tdep.size_epoll_event = 12;
931 i386_linux_record_tdep.size_itimerspec
932 = i386_linux_record_tdep.size_timespec * 2;
933 i386_linux_record_tdep.size_mq_attr = 32;
934 i386_linux_record_tdep.size_termios = 36;
935 i386_linux_record_tdep.size_termios2 = 44;
936 i386_linux_record_tdep.size_pid_t = 4;
937 i386_linux_record_tdep.size_winsize = 8;
938 i386_linux_record_tdep.size_serial_struct = 60;
939 i386_linux_record_tdep.size_serial_icounter_struct = 80;
940 i386_linux_record_tdep.size_hayes_esp_config = 12;
941 i386_linux_record_tdep.size_size_t = 4;
942 i386_linux_record_tdep.size_iovec = 8;
943 i386_linux_record_tdep.size_time_t = 4;
945 /* These values are the second argument of system call "sys_ioctl".
946 They are obtained from Linux Kernel source. */
947 i386_linux_record_tdep.ioctl_TCGETS = 0x5401;
948 i386_linux_record_tdep.ioctl_TCSETS = 0x5402;
949 i386_linux_record_tdep.ioctl_TCSETSW = 0x5403;
950 i386_linux_record_tdep.ioctl_TCSETSF = 0x5404;
951 i386_linux_record_tdep.ioctl_TCGETA = 0x5405;
952 i386_linux_record_tdep.ioctl_TCSETA = 0x5406;
953 i386_linux_record_tdep.ioctl_TCSETAW = 0x5407;
954 i386_linux_record_tdep.ioctl_TCSETAF = 0x5408;
955 i386_linux_record_tdep.ioctl_TCSBRK = 0x5409;
956 i386_linux_record_tdep.ioctl_TCXONC = 0x540A;
957 i386_linux_record_tdep.ioctl_TCFLSH = 0x540B;
958 i386_linux_record_tdep.ioctl_TIOCEXCL = 0x540C;
959 i386_linux_record_tdep.ioctl_TIOCNXCL = 0x540D;
960 i386_linux_record_tdep.ioctl_TIOCSCTTY = 0x540E;
961 i386_linux_record_tdep.ioctl_TIOCGPGRP = 0x540F;
962 i386_linux_record_tdep.ioctl_TIOCSPGRP = 0x5410;
963 i386_linux_record_tdep.ioctl_TIOCOUTQ = 0x5411;
964 i386_linux_record_tdep.ioctl_TIOCSTI = 0x5412;
965 i386_linux_record_tdep.ioctl_TIOCGWINSZ = 0x5413;
966 i386_linux_record_tdep.ioctl_TIOCSWINSZ = 0x5414;
967 i386_linux_record_tdep.ioctl_TIOCMGET = 0x5415;
968 i386_linux_record_tdep.ioctl_TIOCMBIS = 0x5416;
969 i386_linux_record_tdep.ioctl_TIOCMBIC = 0x5417;
970 i386_linux_record_tdep.ioctl_TIOCMSET = 0x5418;
971 i386_linux_record_tdep.ioctl_TIOCGSOFTCAR = 0x5419;
972 i386_linux_record_tdep.ioctl_TIOCSSOFTCAR = 0x541A;
973 i386_linux_record_tdep.ioctl_FIONREAD = 0x541B;
974 i386_linux_record_tdep.ioctl_TIOCINQ = i386_linux_record_tdep.ioctl_FIONREAD;
975 i386_linux_record_tdep.ioctl_TIOCLINUX = 0x541C;
976 i386_linux_record_tdep.ioctl_TIOCCONS = 0x541D;
977 i386_linux_record_tdep.ioctl_TIOCGSERIAL = 0x541E;
978 i386_linux_record_tdep.ioctl_TIOCSSERIAL = 0x541F;
979 i386_linux_record_tdep.ioctl_TIOCPKT = 0x5420;
980 i386_linux_record_tdep.ioctl_FIONBIO = 0x5421;
981 i386_linux_record_tdep.ioctl_TIOCNOTTY = 0x5422;
982 i386_linux_record_tdep.ioctl_TIOCSETD = 0x5423;
983 i386_linux_record_tdep.ioctl_TIOCGETD = 0x5424;
984 i386_linux_record_tdep.ioctl_TCSBRKP = 0x5425;
985 i386_linux_record_tdep.ioctl_TIOCTTYGSTRUCT = 0x5426;
986 i386_linux_record_tdep.ioctl_TIOCSBRK = 0x5427;
987 i386_linux_record_tdep.ioctl_TIOCCBRK = 0x5428;
988 i386_linux_record_tdep.ioctl_TIOCGSID = 0x5429;
989 i386_linux_record_tdep.ioctl_TCGETS2 = 0x802c542a;
990 i386_linux_record_tdep.ioctl_TCSETS2 = 0x402c542b;
991 i386_linux_record_tdep.ioctl_TCSETSW2 = 0x402c542c;
992 i386_linux_record_tdep.ioctl_TCSETSF2 = 0x402c542d;
993 i386_linux_record_tdep.ioctl_TIOCGPTN = 0x80045430;
994 i386_linux_record_tdep.ioctl_TIOCSPTLCK = 0x40045431;
995 i386_linux_record_tdep.ioctl_FIONCLEX = 0x5450;
996 i386_linux_record_tdep.ioctl_FIOCLEX = 0x5451;
997 i386_linux_record_tdep.ioctl_FIOASYNC = 0x5452;
998 i386_linux_record_tdep.ioctl_TIOCSERCONFIG = 0x5453;
999 i386_linux_record_tdep.ioctl_TIOCSERGWILD = 0x5454;
1000 i386_linux_record_tdep.ioctl_TIOCSERSWILD = 0x5455;
1001 i386_linux_record_tdep.ioctl_TIOCGLCKTRMIOS = 0x5456;
1002 i386_linux_record_tdep.ioctl_TIOCSLCKTRMIOS = 0x5457;
1003 i386_linux_record_tdep.ioctl_TIOCSERGSTRUCT = 0x5458;
1004 i386_linux_record_tdep.ioctl_TIOCSERGETLSR = 0x5459;
1005 i386_linux_record_tdep.ioctl_TIOCSERGETMULTI = 0x545A;
1006 i386_linux_record_tdep.ioctl_TIOCSERSETMULTI = 0x545B;
1007 i386_linux_record_tdep.ioctl_TIOCMIWAIT = 0x545C;
1008 i386_linux_record_tdep.ioctl_TIOCGICOUNT = 0x545D;
1009 i386_linux_record_tdep.ioctl_TIOCGHAYESESP = 0x545E;
1010 i386_linux_record_tdep.ioctl_TIOCSHAYESESP = 0x545F;
1011 i386_linux_record_tdep.ioctl_FIOQSIZE = 0x5460;
1013 /* These values are the second argument of system call "sys_fcntl"
1014 and "sys_fcntl64". They are obtained from Linux Kernel source. */
1015 i386_linux_record_tdep.fcntl_F_GETLK = 5;
1016 i386_linux_record_tdep.fcntl_F_GETLK64 = 12;
1017 i386_linux_record_tdep.fcntl_F_SETLK64 = 13;
1018 i386_linux_record_tdep.fcntl_F_SETLKW64 = 14;
1020 i386_linux_record_tdep.arg1 = I386_EBX_REGNUM;
1021 i386_linux_record_tdep.arg2 = I386_ECX_REGNUM;
1022 i386_linux_record_tdep.arg3 = I386_EDX_REGNUM;
1023 i386_linux_record_tdep.arg4 = I386_ESI_REGNUM;
1024 i386_linux_record_tdep.arg5 = I386_EDI_REGNUM;
1025 i386_linux_record_tdep.arg6 = I386_EBP_REGNUM;
1027 tdep->i386_intx80_record = i386_linux_intx80_sysenter_syscall_record;
1028 tdep->i386_sysenter_record = i386_linux_intx80_sysenter_syscall_record;
1029 tdep->i386_syscall_record = i386_linux_intx80_sysenter_syscall_record;
1031 /* N_FUN symbols in shared libaries have 0 for their values and need
1033 set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
1035 /* GNU/Linux uses SVR4-style shared libraries. */
1036 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
1037 set_solib_svr4_fetch_link_map_offsets
1038 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
1040 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
1041 set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
1043 dwarf2_frame_set_signal_frame_p (gdbarch, i386_linux_dwarf_signal_frame_p);
1045 /* Enable TLS support. */
1046 set_gdbarch_fetch_tls_load_module_address (gdbarch,
1047 svr4_fetch_objfile_link_map);
1049 /* Core file support. */
1050 set_gdbarch_iterate_over_regset_sections
1051 (gdbarch, i386_linux_iterate_over_regset_sections);
1052 set_gdbarch_core_read_description (gdbarch,
1053 i386_linux_core_read_description);
1055 /* Displaced stepping. */
1056 set_gdbarch_displaced_step_copy_insn (gdbarch,
1057 i386_linux_displaced_step_copy_insn);
1058 set_gdbarch_displaced_step_fixup (gdbarch, i386_displaced_step_fixup);
1059 set_gdbarch_displaced_step_free_closure (gdbarch,
1060 simple_displaced_step_free_closure);
1061 set_gdbarch_displaced_step_location (gdbarch,
1062 linux_displaced_step_location);
1064 /* Functions for 'catch syscall'. */
1065 set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_I386);
1066 set_gdbarch_get_syscall_number (gdbarch,
1067 i386_linux_get_syscall_number);
1069 set_gdbarch_get_siginfo_type (gdbarch, x86_linux_get_siginfo_type);
1070 set_gdbarch_handle_segmentation_fault (gdbarch,
1071 i386_linux_handle_segmentation_fault);
1074 /* Provide a prototype to silence -Wmissing-prototypes. */
1075 extern void _initialize_i386_linux_tdep (void);
1078 _initialize_i386_linux_tdep (void)
1080 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX,
1081 i386_linux_init_abi);
1083 /* Initialize the Linux target description. */
1084 initialize_tdesc_i386_linux ();
1085 initialize_tdesc_i386_mmx_linux ();
1086 initialize_tdesc_i386_avx_linux ();
1087 initialize_tdesc_i386_mpx_linux ();
1088 initialize_tdesc_i386_avx_mpx_linux ();
1089 initialize_tdesc_i386_avx512_linux ();