1 /* Target-dependent code for GNU/Linux i386.
3 Copyright (C) 2000-2017 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"
49 #include "features/i386/32bit-core.c"
50 #include "features/i386/32bit-sse.c"
51 #include "features/i386/32bit-linux.c"
52 #include "features/i386/32bit-avx.c"
53 #include "features/i386/32bit-mpx.c"
54 #include "features/i386/32bit-avx512.c"
55 #include "features/i386/32bit-pkeys.c"
56 #include "target-descriptions.h"
58 /* Return non-zero, when the register is in the corresponding register
59 group. Put the LINUX_ORIG_EAX register in the system group. */
61 i386_linux_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
62 struct reggroup *group)
64 if (regnum == I386_LINUX_ORIG_EAX_REGNUM)
65 return (group == system_reggroup
66 || group == save_reggroup
67 || group == restore_reggroup);
68 return i386_register_reggroup_p (gdbarch, regnum, group);
72 /* Recognizing signal handler frames. */
74 /* GNU/Linux has two flavors of signals. Normal signal handlers, and
75 "realtime" (RT) signals. The RT signals can provide additional
76 information to the signal handler if the SA_SIGINFO flag is set
77 when establishing a signal handler using `sigaction'. It is not
78 unlikely that future versions of GNU/Linux will support SA_SIGINFO
79 for normal signals too. */
81 /* When the i386 Linux kernel calls a signal handler and the
82 SA_RESTORER flag isn't set, the return address points to a bit of
83 code on the stack. This function returns whether the PC appears to
84 be within this bit of code.
86 The instruction sequence for normal signals is
90 or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
92 Checking for the code sequence should be somewhat reliable, because
93 the effect is to call the system call sigreturn. This is unlikely
94 to occur anywhere other than in a signal trampoline.
96 It kind of sucks that we have to read memory from the process in
97 order to identify a signal trampoline, but there doesn't seem to be
98 any other way. Therefore we only do the memory reads if no
99 function name could be identified, which should be the case since
100 the code is on the stack.
102 Detection of signal trampolines for handlers that set the
103 SA_RESTORER flag is in general not possible. Unfortunately this is
104 what the GNU C Library has been doing for quite some time now.
105 However, as of version 2.1.2, the GNU C Library uses signal
106 trampolines (named __restore and __restore_rt) that are identical
107 to the ones used by the kernel. Therefore, these trampolines are
110 #define LINUX_SIGTRAMP_INSN0 0x58 /* pop %eax */
111 #define LINUX_SIGTRAMP_OFFSET0 0
112 #define LINUX_SIGTRAMP_INSN1 0xb8 /* mov $NNNN, %eax */
113 #define LINUX_SIGTRAMP_OFFSET1 1
114 #define LINUX_SIGTRAMP_INSN2 0xcd /* int */
115 #define LINUX_SIGTRAMP_OFFSET2 6
117 static const gdb_byte linux_sigtramp_code[] =
119 LINUX_SIGTRAMP_INSN0, /* pop %eax */
120 LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77, %eax */
121 LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
124 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
126 /* If THIS_FRAME is a sigtramp routine, return the address of the
127 start of the routine. Otherwise, return 0. */
130 i386_linux_sigtramp_start (struct frame_info *this_frame)
132 CORE_ADDR pc = get_frame_pc (this_frame);
133 gdb_byte buf[LINUX_SIGTRAMP_LEN];
135 /* We only recognize a signal trampoline if PC is at the start of
136 one of the three instructions. We optimize for finding the PC at
137 the start, as will be the case when the trampoline is not the
138 first frame on the stack. We assume that in the case where the
139 PC is not at the start of the instruction sequence, there will be
140 a few trailing readable bytes on the stack. */
142 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_SIGTRAMP_LEN))
145 if (buf[0] != LINUX_SIGTRAMP_INSN0)
151 case LINUX_SIGTRAMP_INSN1:
152 adjust = LINUX_SIGTRAMP_OFFSET1;
154 case LINUX_SIGTRAMP_INSN2:
155 adjust = LINUX_SIGTRAMP_OFFSET2;
163 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_SIGTRAMP_LEN))
167 if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
173 /* This function does the same for RT signals. Here the instruction
177 or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
179 The effect is to call the system call rt_sigreturn. */
181 #define LINUX_RT_SIGTRAMP_INSN0 0xb8 /* mov $NNNN, %eax */
182 #define LINUX_RT_SIGTRAMP_OFFSET0 0
183 #define LINUX_RT_SIGTRAMP_INSN1 0xcd /* int */
184 #define LINUX_RT_SIGTRAMP_OFFSET1 5
186 static const gdb_byte linux_rt_sigtramp_code[] =
188 LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad, %eax */
189 LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
192 #define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
194 /* If THIS_FRAME is an RT sigtramp routine, return the address of the
195 start of the routine. Otherwise, return 0. */
198 i386_linux_rt_sigtramp_start (struct frame_info *this_frame)
200 CORE_ADDR pc = get_frame_pc (this_frame);
201 gdb_byte buf[LINUX_RT_SIGTRAMP_LEN];
203 /* We only recognize a signal trampoline if PC is at the start of
204 one of the two instructions. We optimize for finding the PC at
205 the start, as will be the case when the trampoline is not the
206 first frame on the stack. We assume that in the case where the
207 PC is not at the start of the instruction sequence, there will be
208 a few trailing readable bytes on the stack. */
210 if (!safe_frame_unwind_memory (this_frame, pc, buf, LINUX_RT_SIGTRAMP_LEN))
213 if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
215 if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
218 pc -= LINUX_RT_SIGTRAMP_OFFSET1;
220 if (!safe_frame_unwind_memory (this_frame, pc, buf,
221 LINUX_RT_SIGTRAMP_LEN))
225 if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
231 /* Return whether THIS_FRAME corresponds to a GNU/Linux sigtramp
235 i386_linux_sigtramp_p (struct frame_info *this_frame)
237 CORE_ADDR pc = get_frame_pc (this_frame);
240 find_pc_partial_function (pc, &name, NULL, NULL);
242 /* If we have NAME, we can optimize the search. The trampolines are
243 named __restore and __restore_rt. However, they aren't dynamically
244 exported from the shared C library, so the trampoline may appear to
245 be part of the preceding function. This should always be sigaction,
246 __sigaction, or __libc_sigaction (all aliases to the same function). */
247 if (name == NULL || strstr (name, "sigaction") != NULL)
248 return (i386_linux_sigtramp_start (this_frame) != 0
249 || i386_linux_rt_sigtramp_start (this_frame) != 0);
251 return (strcmp ("__restore", name) == 0
252 || strcmp ("__restore_rt", name) == 0);
255 /* Return one if the PC of THIS_FRAME is in a signal trampoline which
256 may have DWARF-2 CFI. */
259 i386_linux_dwarf_signal_frame_p (struct gdbarch *gdbarch,
260 struct frame_info *this_frame)
262 CORE_ADDR pc = get_frame_pc (this_frame);
265 find_pc_partial_function (pc, &name, NULL, NULL);
267 /* If a vsyscall DSO is in use, the signal trampolines may have these
269 if (name && (strcmp (name, "__kernel_sigreturn") == 0
270 || strcmp (name, "__kernel_rt_sigreturn") == 0))
276 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
277 #define I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 20
279 /* Assuming THIS_FRAME is a GNU/Linux sigtramp routine, return the
280 address of the associated sigcontext structure. */
283 i386_linux_sigcontext_addr (struct frame_info *this_frame)
285 struct gdbarch *gdbarch = get_frame_arch (this_frame);
286 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
291 get_frame_register (this_frame, I386_ESP_REGNUM, buf);
292 sp = extract_unsigned_integer (buf, 4, byte_order);
294 pc = i386_linux_sigtramp_start (this_frame);
297 /* The sigcontext structure lives on the stack, right after
298 the signum argument. We determine the address of the
299 sigcontext structure by looking at the frame's stack
300 pointer. Keep in mind that the first instruction of the
301 sigtramp code is "pop %eax". If the PC is after this
302 instruction, adjust the returned value accordingly. */
303 if (pc == get_frame_pc (this_frame))
308 pc = i386_linux_rt_sigtramp_start (this_frame);
311 CORE_ADDR ucontext_addr;
313 /* The sigcontext structure is part of the user context. A
314 pointer to the user context is passed as the third argument
315 to the signal handler. */
316 read_memory (sp + 8, buf, 4);
317 ucontext_addr = extract_unsigned_integer (buf, 4, byte_order);
318 return ucontext_addr + I386_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
321 error (_("Couldn't recognize signal trampoline."));
325 /* Set the program counter for process PTID to PC. */
328 i386_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
330 regcache_cooked_write_unsigned (regcache, I386_EIP_REGNUM, pc);
332 /* We must be careful with modifying the program counter. If we
333 just interrupted a system call, the kernel might try to restart
334 it when we resume the inferior. On restarting the system call,
335 the kernel will try backing up the program counter even though it
336 no longer points at the system call. This typically results in a
337 SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
338 "orig_eax" pseudo-register.
340 Note that "orig_eax" is saved when setting up a dummy call frame.
341 This means that it is properly restored when that frame is
342 popped, and that the interrupted system call will be restarted
343 when we resume the inferior on return from a function call from
344 within GDB. In all other cases the system call will not be
346 regcache_cooked_write_unsigned (regcache, I386_LINUX_ORIG_EAX_REGNUM, -1);
349 /* Record all registers but IP register for process-record. */
352 i386_all_but_ip_registers_record (struct regcache *regcache)
354 if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
356 if (record_full_arch_list_add_reg (regcache, I386_ECX_REGNUM))
358 if (record_full_arch_list_add_reg (regcache, I386_EDX_REGNUM))
360 if (record_full_arch_list_add_reg (regcache, I386_EBX_REGNUM))
362 if (record_full_arch_list_add_reg (regcache, I386_ESP_REGNUM))
364 if (record_full_arch_list_add_reg (regcache, I386_EBP_REGNUM))
366 if (record_full_arch_list_add_reg (regcache, I386_ESI_REGNUM))
368 if (record_full_arch_list_add_reg (regcache, I386_EDI_REGNUM))
370 if (record_full_arch_list_add_reg (regcache, I386_EFLAGS_REGNUM))
376 /* i386_canonicalize_syscall maps from the native i386 Linux set
377 of syscall ids into a canonical set of syscall ids used by
378 process record (a mostly trivial mapping, since the canonical
379 set was originally taken from the i386 set). */
381 static enum gdb_syscall
382 i386_canonicalize_syscall (int syscall)
384 enum { i386_syscall_max = 499 };
386 if (syscall <= i386_syscall_max)
387 return (enum gdb_syscall) syscall;
389 return gdb_sys_no_syscall;
392 /* Value of the sigcode in case of a boundary fault. */
394 #define SIG_CODE_BONDARY_FAULT 3
396 /* i386 GNU/Linux implementation of the handle_segmentation_fault
397 gdbarch hook. Displays information related to MPX bound
400 i386_linux_handle_segmentation_fault (struct gdbarch *gdbarch,
401 struct ui_out *uiout)
403 /* -Wmaybe-uninitialized */
404 CORE_ADDR lower_bound = 0, upper_bound = 0, access = 0;
408 if (!i386_mpx_enabled ())
413 /* Sigcode evaluates if the actual segfault is a boundary violation. */
414 sig_code = parse_and_eval_long ("$_siginfo.si_code\n");
417 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._lower");
419 = parse_and_eval_long ("$_siginfo._sifields._sigfault._addr_bnd._upper");
421 = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
423 CATCH (exception, RETURN_MASK_ALL)
429 /* If this is not a boundary violation just return. */
430 if (sig_code != SIG_CODE_BONDARY_FAULT)
433 is_upper = (access > upper_bound ? 1 : 0);
437 uiout->field_string ("sigcode-meaning", _("Upper bound violation"));
439 uiout->field_string ("sigcode-meaning", _("Lower bound violation"));
441 uiout->text (_(" while accessing address "));
442 uiout->field_fmt ("bound-access", "%s", paddress (gdbarch, access));
444 uiout->text (_("\nBounds: [lower = "));
445 uiout->field_fmt ("lower-bound", "%s", paddress (gdbarch, lower_bound));
447 uiout->text (_(", upper = "));
448 uiout->field_fmt ("upper-bound", "%s", paddress (gdbarch, upper_bound));
450 uiout->text (_("]"));
453 /* Parse the arguments of current system call instruction and record
454 the values of the registers and memory that will be changed into
455 "record_arch_list". This instruction is "int 0x80" (Linux
456 Kernel2.4) or "sysenter" (Linux Kernel 2.6).
458 Return -1 if something wrong. */
460 static struct linux_record_tdep i386_linux_record_tdep;
463 i386_linux_intx80_sysenter_syscall_record (struct regcache *regcache)
466 LONGEST syscall_native;
467 enum gdb_syscall syscall_gdb;
469 regcache_raw_read_signed (regcache, I386_EAX_REGNUM, &syscall_native);
471 syscall_gdb = i386_canonicalize_syscall (syscall_native);
475 printf_unfiltered (_("Process record and replay target doesn't "
476 "support syscall number %s\n"),
477 plongest (syscall_native));
481 if (syscall_gdb == gdb_sys_sigreturn
482 || syscall_gdb == gdb_sys_rt_sigreturn)
484 if (i386_all_but_ip_registers_record (regcache))
489 ret = record_linux_system_call (syscall_gdb, regcache,
490 &i386_linux_record_tdep);
494 /* Record the return value of the system call. */
495 if (record_full_arch_list_add_reg (regcache, I386_EAX_REGNUM))
501 #define I386_LINUX_xstate 270
502 #define I386_LINUX_frame_size 732
505 i386_linux_record_signal (struct gdbarch *gdbarch,
506 struct regcache *regcache,
507 enum gdb_signal signal)
511 if (i386_all_but_ip_registers_record (regcache))
514 if (record_full_arch_list_add_reg (regcache, I386_EIP_REGNUM))
517 /* Record the change in the stack. */
518 regcache_raw_read_unsigned (regcache, I386_ESP_REGNUM, &esp);
519 /* This is for xstate.
520 sp -= sizeof (struct _fpstate); */
521 esp -= I386_LINUX_xstate;
522 /* This is for frame_size.
523 sp -= sizeof (struct rt_sigframe); */
524 esp -= I386_LINUX_frame_size;
525 if (record_full_arch_list_add_mem (esp,
526 I386_LINUX_xstate + I386_LINUX_frame_size))
529 if (record_full_arch_list_add_end ())
536 /* Core of the implementation for gdbarch get_syscall_number. Get pending
537 syscall number from REGCACHE. If there is no pending syscall -1 will be
538 returned. Pending syscall means ptrace has stepped into the syscall but
539 another ptrace call will step out. PC is right after the int $0x80
540 / syscall / sysenter instruction in both cases, PC does not change during
541 the second ptrace step. */
544 i386_linux_get_syscall_number_from_regcache (struct regcache *regcache)
546 struct gdbarch *gdbarch = get_regcache_arch (regcache);
547 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
548 /* The content of a register. */
553 /* Getting the system call number from the register.
554 When dealing with x86 architecture, this information
555 is stored at %eax register. */
556 regcache_cooked_read (regcache, I386_LINUX_ORIG_EAX_REGNUM, buf);
558 ret = extract_signed_integer (buf, 4, byte_order);
563 /* Wrapper for i386_linux_get_syscall_number_from_regcache to make it
564 compatible with gdbarch get_syscall_number method prototype. */
567 i386_linux_get_syscall_number (struct gdbarch *gdbarch,
570 struct regcache *regcache = get_thread_regcache (ptid);
572 return i386_linux_get_syscall_number_from_regcache (regcache);
575 /* The register sets used in GNU/Linux ELF core-dumps are identical to
576 the register sets in `struct user' that are used for a.out
577 core-dumps. These are also used by ptrace(2). The corresponding
578 types are `elf_gregset_t' for the general-purpose registers (with
579 `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
580 for the floating-point registers.
582 Those types used to be available under the names `gregset_t' and
583 `fpregset_t' too, and GDB used those names in the past. But those
584 names are now used for the register sets used in the `mcontext_t'
585 type, which have a different size and layout. */
587 /* Mapping between the general-purpose registers in `struct user'
588 format and GDB's register cache layout. */
590 /* From <sys/reg.h>. */
591 int i386_linux_gregset_reg_offset[] =
602 14 * 4, /* %eflags */
609 -1, -1, -1, -1, -1, -1, -1, -1,
610 -1, -1, -1, -1, -1, -1, -1, -1,
611 -1, -1, -1, -1, -1, -1, -1, -1,
613 -1, -1, -1, -1, -1, -1, -1, -1,
614 -1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
615 -1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
616 -1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
617 -1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
618 -1, /* PKRU register */
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 /* See i386-linux-tdep.h. */
685 const struct target_desc *
686 i386_linux_read_description (uint64_t xcr0)
691 static struct target_desc *i386_linux_tdescs \
692 [2/*X87*/][2/*SSE*/][2/*AVX*/][2/*MPX*/][2/*AVX512*/][2/*PKRU*/] = {};
693 struct target_desc **tdesc;
695 tdesc = &i386_linux_tdescs[(xcr0 & X86_XSTATE_X87) ? 1 : 0]
696 [(xcr0 & X86_XSTATE_SSE) ? 1 : 0]
697 [(xcr0 & X86_XSTATE_AVX) ? 1 : 0]
698 [(xcr0 & X86_XSTATE_MPX) ? 1 : 0]
699 [(xcr0 & X86_XSTATE_AVX512) ? 1 : 0]
700 [(xcr0 & X86_XSTATE_PKRU) ? 1 : 0];
704 *tdesc = allocate_target_description ();
705 set_tdesc_architecture (*tdesc, bfd_scan_arch ("i386"));
706 set_tdesc_osabi (*tdesc, osabi_from_tdesc_string ("GNU/Linux"));
710 if (xcr0 & X86_XSTATE_X87)
711 regnum = create_feature_i386_32bit_core (*tdesc, regnum);
713 if (xcr0 & X86_XSTATE_SSE)
714 regnum = create_feature_i386_32bit_sse (*tdesc, regnum);
716 regnum = create_feature_i386_32bit_linux (*tdesc, regnum);
718 if (xcr0 & X86_XSTATE_AVX)
719 regnum = create_feature_i386_32bit_avx (*tdesc, regnum);
721 if (xcr0 & X86_XSTATE_MPX)
722 regnum = create_feature_i386_32bit_mpx (*tdesc, regnum);
724 if (xcr0 & X86_XSTATE_AVX512)
725 regnum = create_feature_i386_32bit_avx512 (*tdesc, regnum);
727 if (xcr0 & X86_XSTATE_PKRU)
728 regnum = create_feature_i386_32bit_pkeys (*tdesc, regnum);
734 /* Get Linux/x86 target description from core dump. */
736 static const struct target_desc *
737 i386_linux_core_read_description (struct gdbarch *gdbarch,
738 struct target_ops *target,
742 uint64_t xcr0 = i386_linux_core_read_xcr0 (abfd);
743 const struct target_desc *tdesc = i386_linux_read_description (xcr0);
748 if (bfd_get_section_by_name (abfd, ".reg-xfp") != NULL)
749 return i386_linux_read_description (X86_XSTATE_SSE_MASK);
751 return i386_linux_read_description (X86_XSTATE_X87_MASK);
754 /* Similar to i386_supply_fpregset, but use XSAVE extended state. */
757 i386_linux_supply_xstateregset (const struct regset *regset,
758 struct regcache *regcache, int regnum,
759 const void *xstateregs, size_t len)
761 i387_supply_xsave (regcache, regnum, xstateregs);
765 x86_linux_get_siginfo_type (struct gdbarch *gdbarch)
767 return linux_get_siginfo_type_with_fields (gdbarch, LINUX_SIGINFO_FIELD_ADDR_BND);
770 /* Similar to i386_collect_fpregset, but use XSAVE extended state. */
773 i386_linux_collect_xstateregset (const struct regset *regset,
774 const struct regcache *regcache,
775 int regnum, void *xstateregs, size_t len)
777 i387_collect_xsave (regcache, regnum, xstateregs, 1);
780 /* Register set definitions. */
782 static const struct regset i386_linux_xstateregset =
785 i386_linux_supply_xstateregset,
786 i386_linux_collect_xstateregset
789 /* Iterate over core file register note sections. */
792 i386_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
793 iterate_over_regset_sections_cb *cb,
795 const struct regcache *regcache)
797 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
799 cb (".reg", 68, &i386_gregset, NULL, cb_data);
801 if (tdep->xcr0 & X86_XSTATE_AVX)
802 cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0),
803 &i386_linux_xstateregset, "XSAVE extended state", cb_data);
804 else if (tdep->xcr0 & X86_XSTATE_SSE)
805 cb (".reg-xfp", 512, &i386_fpregset, "extended floating-point",
808 cb (".reg2", 108, &i386_fpregset, NULL, cb_data);
811 /* Linux kernel shows PC value after the 'int $0x80' instruction even if
812 inferior is still inside the syscall. On next PTRACE_SINGLESTEP it will
813 finish the syscall but PC will not change.
815 Some vDSOs contain 'int $0x80; ret' and during stepping out of the syscall
816 i386_displaced_step_fixup would keep PC at the displaced pad location.
817 As PC is pointing to the 'ret' instruction before the step
818 i386_displaced_step_fixup would expect inferior has just executed that 'ret'
819 and PC should not be adjusted. In reality it finished syscall instead and
820 PC should get relocated back to its vDSO address. Hide the 'ret'
821 instruction by 'nop' so that i386_displaced_step_fixup is not confused.
823 It is not fully correct as the bytes in struct displaced_step_closure will
824 not match the inferior code. But we would need some new flag in
825 displaced_step_closure otherwise to keep the state that syscall is finishing
826 for the later i386_displaced_step_fixup execution as the syscall execution
827 is already no longer detectable there. The new flag field would mean
828 i386-linux-tdep.c needs to wrap all the displacement methods of i386-tdep.c
829 which does not seem worth it. The same effect is achieved by patching that
830 'nop' instruction there instead. */
832 static struct displaced_step_closure *
833 i386_linux_displaced_step_copy_insn (struct gdbarch *gdbarch,
834 CORE_ADDR from, CORE_ADDR to,
835 struct regcache *regs)
837 struct displaced_step_closure *closure;
839 closure = i386_displaced_step_copy_insn (gdbarch, from, to, regs);
841 if (i386_linux_get_syscall_number_from_regcache (regs) != -1)
843 /* Since we use simple_displaced_step_copy_insn, our closure is a
844 copy of the instruction. */
845 gdb_byte *insn = (gdb_byte *) closure;
855 i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
857 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
858 const struct target_desc *tdesc = info.target_desc;
859 struct tdesc_arch_data *tdesc_data = info.tdesc_data;
860 const struct tdesc_feature *feature;
863 gdb_assert (tdesc_data);
865 linux_init_abi (info, gdbarch);
867 /* GNU/Linux uses ELF. */
868 i386_elf_init_abi (info, gdbarch);
870 /* Reserve a number for orig_eax. */
871 set_gdbarch_num_regs (gdbarch, I386_LINUX_NUM_REGS);
873 if (! tdesc_has_registers (tdesc))
874 tdesc = i386_linux_read_description (X86_XSTATE_SSE_MASK);
877 feature = tdesc_find_feature (tdesc, "org.gnu.gdb.i386.linux");
881 valid_p = tdesc_numbered_register (feature, tdesc_data,
882 I386_LINUX_ORIG_EAX_REGNUM,
887 /* Add the %orig_eax register used for syscall restarting. */
888 set_gdbarch_write_pc (gdbarch, i386_linux_write_pc);
890 tdep->register_reggroup_p = i386_linux_register_reggroup_p;
892 tdep->gregset_reg_offset = i386_linux_gregset_reg_offset;
893 tdep->gregset_num_regs = ARRAY_SIZE (i386_linux_gregset_reg_offset);
894 tdep->sizeof_gregset = 17 * 4;
896 tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */
898 tdep->sigtramp_p = i386_linux_sigtramp_p;
899 tdep->sigcontext_addr = i386_linux_sigcontext_addr;
900 tdep->sc_reg_offset = i386_linux_sc_reg_offset;
901 tdep->sc_num_regs = ARRAY_SIZE (i386_linux_sc_reg_offset);
903 tdep->xsave_xcr0_offset = I386_LINUX_XSAVE_XCR0_OFFSET;
905 set_gdbarch_process_record (gdbarch, i386_process_record);
906 set_gdbarch_process_record_signal (gdbarch, i386_linux_record_signal);
908 /* Initialize the i386_linux_record_tdep. */
909 /* These values are the size of the type that will be used in a system
910 call. They are obtained from Linux Kernel source. */
911 i386_linux_record_tdep.size_pointer
912 = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
913 i386_linux_record_tdep.size__old_kernel_stat = 32;
914 i386_linux_record_tdep.size_tms = 16;
915 i386_linux_record_tdep.size_loff_t = 8;
916 i386_linux_record_tdep.size_flock = 16;
917 i386_linux_record_tdep.size_oldold_utsname = 45;
918 i386_linux_record_tdep.size_ustat = 20;
919 i386_linux_record_tdep.size_old_sigaction = 16;
920 i386_linux_record_tdep.size_old_sigset_t = 4;
921 i386_linux_record_tdep.size_rlimit = 8;
922 i386_linux_record_tdep.size_rusage = 72;
923 i386_linux_record_tdep.size_timeval = 8;
924 i386_linux_record_tdep.size_timezone = 8;
925 i386_linux_record_tdep.size_old_gid_t = 2;
926 i386_linux_record_tdep.size_old_uid_t = 2;
927 i386_linux_record_tdep.size_fd_set = 128;
928 i386_linux_record_tdep.size_old_dirent = 268;
929 i386_linux_record_tdep.size_statfs = 64;
930 i386_linux_record_tdep.size_statfs64 = 84;
931 i386_linux_record_tdep.size_sockaddr = 16;
932 i386_linux_record_tdep.size_int
933 = gdbarch_int_bit (gdbarch) / TARGET_CHAR_BIT;
934 i386_linux_record_tdep.size_long
935 = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
936 i386_linux_record_tdep.size_ulong
937 = gdbarch_long_bit (gdbarch) / TARGET_CHAR_BIT;
938 i386_linux_record_tdep.size_msghdr = 28;
939 i386_linux_record_tdep.size_itimerval = 16;
940 i386_linux_record_tdep.size_stat = 88;
941 i386_linux_record_tdep.size_old_utsname = 325;
942 i386_linux_record_tdep.size_sysinfo = 64;
943 i386_linux_record_tdep.size_msqid_ds = 88;
944 i386_linux_record_tdep.size_shmid_ds = 84;
945 i386_linux_record_tdep.size_new_utsname = 390;
946 i386_linux_record_tdep.size_timex = 128;
947 i386_linux_record_tdep.size_mem_dqinfo = 24;
948 i386_linux_record_tdep.size_if_dqblk = 68;
949 i386_linux_record_tdep.size_fs_quota_stat = 68;
950 i386_linux_record_tdep.size_timespec = 8;
951 i386_linux_record_tdep.size_pollfd = 8;
952 i386_linux_record_tdep.size_NFS_FHSIZE = 32;
953 i386_linux_record_tdep.size_knfsd_fh = 132;
954 i386_linux_record_tdep.size_TASK_COMM_LEN = 16;
955 i386_linux_record_tdep.size_sigaction = 20;
956 i386_linux_record_tdep.size_sigset_t = 8;
957 i386_linux_record_tdep.size_siginfo_t = 128;
958 i386_linux_record_tdep.size_cap_user_data_t = 12;
959 i386_linux_record_tdep.size_stack_t = 12;
960 i386_linux_record_tdep.size_off_t = i386_linux_record_tdep.size_long;
961 i386_linux_record_tdep.size_stat64 = 96;
962 i386_linux_record_tdep.size_gid_t = 4;
963 i386_linux_record_tdep.size_uid_t = 4;
964 i386_linux_record_tdep.size_PAGE_SIZE = 4096;
965 i386_linux_record_tdep.size_flock64 = 24;
966 i386_linux_record_tdep.size_user_desc = 16;
967 i386_linux_record_tdep.size_io_event = 32;
968 i386_linux_record_tdep.size_iocb = 64;
969 i386_linux_record_tdep.size_epoll_event = 12;
970 i386_linux_record_tdep.size_itimerspec
971 = i386_linux_record_tdep.size_timespec * 2;
972 i386_linux_record_tdep.size_mq_attr = 32;
973 i386_linux_record_tdep.size_termios = 36;
974 i386_linux_record_tdep.size_termios2 = 44;
975 i386_linux_record_tdep.size_pid_t = 4;
976 i386_linux_record_tdep.size_winsize = 8;
977 i386_linux_record_tdep.size_serial_struct = 60;
978 i386_linux_record_tdep.size_serial_icounter_struct = 80;
979 i386_linux_record_tdep.size_hayes_esp_config = 12;
980 i386_linux_record_tdep.size_size_t = 4;
981 i386_linux_record_tdep.size_iovec = 8;
982 i386_linux_record_tdep.size_time_t = 4;
984 /* These values are the second argument of system call "sys_ioctl".
985 They are obtained from Linux Kernel source. */
986 i386_linux_record_tdep.ioctl_TCGETS = 0x5401;
987 i386_linux_record_tdep.ioctl_TCSETS = 0x5402;
988 i386_linux_record_tdep.ioctl_TCSETSW = 0x5403;
989 i386_linux_record_tdep.ioctl_TCSETSF = 0x5404;
990 i386_linux_record_tdep.ioctl_TCGETA = 0x5405;
991 i386_linux_record_tdep.ioctl_TCSETA = 0x5406;
992 i386_linux_record_tdep.ioctl_TCSETAW = 0x5407;
993 i386_linux_record_tdep.ioctl_TCSETAF = 0x5408;
994 i386_linux_record_tdep.ioctl_TCSBRK = 0x5409;
995 i386_linux_record_tdep.ioctl_TCXONC = 0x540A;
996 i386_linux_record_tdep.ioctl_TCFLSH = 0x540B;
997 i386_linux_record_tdep.ioctl_TIOCEXCL = 0x540C;
998 i386_linux_record_tdep.ioctl_TIOCNXCL = 0x540D;
999 i386_linux_record_tdep.ioctl_TIOCSCTTY = 0x540E;
1000 i386_linux_record_tdep.ioctl_TIOCGPGRP = 0x540F;
1001 i386_linux_record_tdep.ioctl_TIOCSPGRP = 0x5410;
1002 i386_linux_record_tdep.ioctl_TIOCOUTQ = 0x5411;
1003 i386_linux_record_tdep.ioctl_TIOCSTI = 0x5412;
1004 i386_linux_record_tdep.ioctl_TIOCGWINSZ = 0x5413;
1005 i386_linux_record_tdep.ioctl_TIOCSWINSZ = 0x5414;
1006 i386_linux_record_tdep.ioctl_TIOCMGET = 0x5415;
1007 i386_linux_record_tdep.ioctl_TIOCMBIS = 0x5416;
1008 i386_linux_record_tdep.ioctl_TIOCMBIC = 0x5417;
1009 i386_linux_record_tdep.ioctl_TIOCMSET = 0x5418;
1010 i386_linux_record_tdep.ioctl_TIOCGSOFTCAR = 0x5419;
1011 i386_linux_record_tdep.ioctl_TIOCSSOFTCAR = 0x541A;
1012 i386_linux_record_tdep.ioctl_FIONREAD = 0x541B;
1013 i386_linux_record_tdep.ioctl_TIOCINQ = i386_linux_record_tdep.ioctl_FIONREAD;
1014 i386_linux_record_tdep.ioctl_TIOCLINUX = 0x541C;
1015 i386_linux_record_tdep.ioctl_TIOCCONS = 0x541D;
1016 i386_linux_record_tdep.ioctl_TIOCGSERIAL = 0x541E;
1017 i386_linux_record_tdep.ioctl_TIOCSSERIAL = 0x541F;
1018 i386_linux_record_tdep.ioctl_TIOCPKT = 0x5420;
1019 i386_linux_record_tdep.ioctl_FIONBIO = 0x5421;
1020 i386_linux_record_tdep.ioctl_TIOCNOTTY = 0x5422;
1021 i386_linux_record_tdep.ioctl_TIOCSETD = 0x5423;
1022 i386_linux_record_tdep.ioctl_TIOCGETD = 0x5424;
1023 i386_linux_record_tdep.ioctl_TCSBRKP = 0x5425;
1024 i386_linux_record_tdep.ioctl_TIOCTTYGSTRUCT = 0x5426;
1025 i386_linux_record_tdep.ioctl_TIOCSBRK = 0x5427;
1026 i386_linux_record_tdep.ioctl_TIOCCBRK = 0x5428;
1027 i386_linux_record_tdep.ioctl_TIOCGSID = 0x5429;
1028 i386_linux_record_tdep.ioctl_TCGETS2 = 0x802c542a;
1029 i386_linux_record_tdep.ioctl_TCSETS2 = 0x402c542b;
1030 i386_linux_record_tdep.ioctl_TCSETSW2 = 0x402c542c;
1031 i386_linux_record_tdep.ioctl_TCSETSF2 = 0x402c542d;
1032 i386_linux_record_tdep.ioctl_TIOCGPTN = 0x80045430;
1033 i386_linux_record_tdep.ioctl_TIOCSPTLCK = 0x40045431;
1034 i386_linux_record_tdep.ioctl_FIONCLEX = 0x5450;
1035 i386_linux_record_tdep.ioctl_FIOCLEX = 0x5451;
1036 i386_linux_record_tdep.ioctl_FIOASYNC = 0x5452;
1037 i386_linux_record_tdep.ioctl_TIOCSERCONFIG = 0x5453;
1038 i386_linux_record_tdep.ioctl_TIOCSERGWILD = 0x5454;
1039 i386_linux_record_tdep.ioctl_TIOCSERSWILD = 0x5455;
1040 i386_linux_record_tdep.ioctl_TIOCGLCKTRMIOS = 0x5456;
1041 i386_linux_record_tdep.ioctl_TIOCSLCKTRMIOS = 0x5457;
1042 i386_linux_record_tdep.ioctl_TIOCSERGSTRUCT = 0x5458;
1043 i386_linux_record_tdep.ioctl_TIOCSERGETLSR = 0x5459;
1044 i386_linux_record_tdep.ioctl_TIOCSERGETMULTI = 0x545A;
1045 i386_linux_record_tdep.ioctl_TIOCSERSETMULTI = 0x545B;
1046 i386_linux_record_tdep.ioctl_TIOCMIWAIT = 0x545C;
1047 i386_linux_record_tdep.ioctl_TIOCGICOUNT = 0x545D;
1048 i386_linux_record_tdep.ioctl_TIOCGHAYESESP = 0x545E;
1049 i386_linux_record_tdep.ioctl_TIOCSHAYESESP = 0x545F;
1050 i386_linux_record_tdep.ioctl_FIOQSIZE = 0x5460;
1052 /* These values are the second argument of system call "sys_fcntl"
1053 and "sys_fcntl64". They are obtained from Linux Kernel source. */
1054 i386_linux_record_tdep.fcntl_F_GETLK = 5;
1055 i386_linux_record_tdep.fcntl_F_GETLK64 = 12;
1056 i386_linux_record_tdep.fcntl_F_SETLK64 = 13;
1057 i386_linux_record_tdep.fcntl_F_SETLKW64 = 14;
1059 i386_linux_record_tdep.arg1 = I386_EBX_REGNUM;
1060 i386_linux_record_tdep.arg2 = I386_ECX_REGNUM;
1061 i386_linux_record_tdep.arg3 = I386_EDX_REGNUM;
1062 i386_linux_record_tdep.arg4 = I386_ESI_REGNUM;
1063 i386_linux_record_tdep.arg5 = I386_EDI_REGNUM;
1064 i386_linux_record_tdep.arg6 = I386_EBP_REGNUM;
1066 tdep->i386_intx80_record = i386_linux_intx80_sysenter_syscall_record;
1067 tdep->i386_sysenter_record = i386_linux_intx80_sysenter_syscall_record;
1068 tdep->i386_syscall_record = i386_linux_intx80_sysenter_syscall_record;
1070 /* N_FUN symbols in shared libaries have 0 for their values and need
1072 set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
1074 /* GNU/Linux uses SVR4-style shared libraries. */
1075 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
1076 set_solib_svr4_fetch_link_map_offsets
1077 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
1079 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */
1080 set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
1082 dwarf2_frame_set_signal_frame_p (gdbarch, i386_linux_dwarf_signal_frame_p);
1084 /* Enable TLS support. */
1085 set_gdbarch_fetch_tls_load_module_address (gdbarch,
1086 svr4_fetch_objfile_link_map);
1088 /* Core file support. */
1089 set_gdbarch_iterate_over_regset_sections
1090 (gdbarch, i386_linux_iterate_over_regset_sections);
1091 set_gdbarch_core_read_description (gdbarch,
1092 i386_linux_core_read_description);
1094 /* Displaced stepping. */
1095 set_gdbarch_displaced_step_copy_insn (gdbarch,
1096 i386_linux_displaced_step_copy_insn);
1097 set_gdbarch_displaced_step_fixup (gdbarch, i386_displaced_step_fixup);
1098 set_gdbarch_displaced_step_location (gdbarch,
1099 linux_displaced_step_location);
1101 /* Functions for 'catch syscall'. */
1102 set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_I386);
1103 set_gdbarch_get_syscall_number (gdbarch,
1104 i386_linux_get_syscall_number);
1106 set_gdbarch_get_siginfo_type (gdbarch, x86_linux_get_siginfo_type);
1107 set_gdbarch_handle_segmentation_fault (gdbarch,
1108 i386_linux_handle_segmentation_fault);
1111 /* Provide a prototype to silence -Wmissing-prototypes. */
1112 extern void _initialize_i386_linux_tdep (void);
1115 _initialize_i386_linux_tdep (void)
1117 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_LINUX,
1118 i386_linux_init_abi);
1126 { "i386/i386-linux.xml", X86_XSTATE_SSE_MASK },
1127 { "i386/i386-mmx-linux.xml", X86_XSTATE_X87_MASK },
1128 { "i386/i386-avx-linux.xml", X86_XSTATE_AVX_MASK },
1129 { "i386/i386-mpx-linux.xml", X86_XSTATE_MPX_MASK },
1130 { "i386/i386-avx-mpx-linux.xml", X86_XSTATE_AVX_MPX_MASK },
1131 { "i386/i386-avx-avx512-linux.xml", X86_XSTATE_AVX_AVX512_MASK },
1132 { "i386/i386-avx-mpx-avx512-pku-linux.xml",
1133 X86_XSTATE_AVX_MPX_AVX512_PKU_MASK },
1136 for (auto &a : xml_masks)
1138 auto tdesc = i386_linux_read_description (a.mask);
1140 selftests::record_xml_tdesc (a.xml, tdesc);
1142 #endif /* GDB_SELF_TEST */