537 lines
15 KiB
C
537 lines
15 KiB
C
/* Target-dependent code for GNU/Linux running on PA-RISC, for GDB.
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Copyright (C) 2004-2018 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "osabi.h"
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#include "target.h"
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#include "objfiles.h"
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#include "solib-svr4.h"
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#include "glibc-tdep.h"
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#include "frame-unwind.h"
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#include "trad-frame.h"
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#include "dwarf2-frame.h"
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#include "value.h"
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#include "regset.h"
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#include "regcache.h"
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#include "hppa-tdep.h"
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#include "linux-tdep.h"
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#include "elf/common.h"
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/* Map DWARF DBX register numbers to GDB register numbers. */
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static int
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hppa_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
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{
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/* The general registers and the sar are the same in both sets. */
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if (reg >= 0 && reg <= 32)
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return reg;
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/* fr4-fr31 (left and right halves) are mapped from 72. */
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if (reg >= 72 && reg <= 72 + 28 * 2)
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return HPPA_FP4_REGNUM + (reg - 72);
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return -1;
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}
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static void
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hppa_linux_target_write_pc (struct regcache *regcache, CORE_ADDR v)
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{
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/* Probably this should be done by the kernel, but it isn't. */
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regcache_cooked_write_unsigned (regcache, HPPA_PCOQ_HEAD_REGNUM, v | 0x3);
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regcache_cooked_write_unsigned (regcache,
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HPPA_PCOQ_TAIL_REGNUM, (v + 4) | 0x3);
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}
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/* An instruction to match. */
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struct insn_pattern
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{
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unsigned int data; /* See if it matches this.... */
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unsigned int mask; /* ... with this mask. */
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};
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static struct insn_pattern hppa_sigtramp[] = {
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/* ldi 0, %r25 or ldi 1, %r25 */
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{ 0x34190000, 0xfffffffd },
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/* ldi __NR_rt_sigreturn, %r20 */
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{ 0x3414015a, 0xffffffff },
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/* be,l 0x100(%sr2, %r0), %sr0, %r31 */
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{ 0xe4008200, 0xffffffff },
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/* nop */
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{ 0x08000240, 0xffffffff },
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{ 0, 0 }
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};
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#define HPPA_MAX_INSN_PATTERN_LEN (4)
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/* Return non-zero if the instructions at PC match the series
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described in PATTERN, or zero otherwise. PATTERN is an array of
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'struct insn_pattern' objects, terminated by an entry whose mask is
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zero.
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When the match is successful, fill INSN[i] with what PATTERN[i]
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matched. */
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static int
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insns_match_pattern (struct gdbarch *gdbarch, CORE_ADDR pc,
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struct insn_pattern *pattern,
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unsigned int *insn)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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int i;
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CORE_ADDR npc = pc;
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for (i = 0; pattern[i].mask; i++)
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{
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gdb_byte buf[4];
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target_read_memory (npc, buf, 4);
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insn[i] = extract_unsigned_integer (buf, 4, byte_order);
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if ((insn[i] & pattern[i].mask) == pattern[i].data)
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npc += 4;
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else
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return 0;
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}
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return 1;
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}
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/* Signal frames. */
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/* (This is derived from MD_FALLBACK_FRAME_STATE_FOR in gcc.)
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Unfortunately, because of various bugs and changes to the kernel,
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we have several cases to deal with.
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In 2.4, the signal trampoline is 4 bytes, and pc should point directly at
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the beginning of the trampoline and struct rt_sigframe.
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In <= 2.6.5-rc2-pa3, the signal trampoline is 9 bytes, and pc points at
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the 4th word in the trampoline structure. This is wrong, it should point
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at the 5th word. This is fixed in 2.6.5-rc2-pa4.
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To detect these cases, we first take pc, align it to 64-bytes
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to get the beginning of the signal frame, and then check offsets 0, 4
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and 5 to see if we found the beginning of the trampoline. This will
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tell us how to locate the sigcontext structure.
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Note that with a 2.4 64-bit kernel, the signal context is not properly
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passed back to userspace so the unwind will not work correctly. */
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static CORE_ADDR
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hppa_linux_sigtramp_find_sigcontext (struct gdbarch *gdbarch, CORE_ADDR pc)
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{
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unsigned int dummy[HPPA_MAX_INSN_PATTERN_LEN];
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int offs = 0;
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int attempt;
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/* offsets to try to find the trampoline */
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static int pcoffs[] = { 0, 4*4, 5*4 };
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/* offsets to the rt_sigframe structure */
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static int sfoffs[] = { 4*4, 10*4, 10*4 };
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CORE_ADDR sp;
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/* Most of the time, this will be correct. The one case when this will
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fail is if the user defined an alternate stack, in which case the
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beginning of the stack will not be align_down (pc, 64). */
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sp = align_down (pc, 64);
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/* rt_sigreturn trampoline:
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3419000x ldi 0, %r25 or ldi 1, %r25 (x = 0 or 2)
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3414015a ldi __NR_rt_sigreturn, %r20
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e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31
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08000240 nop */
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for (attempt = 0; attempt < ARRAY_SIZE (pcoffs); attempt++)
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{
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if (insns_match_pattern (gdbarch, sp + pcoffs[attempt],
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hppa_sigtramp, dummy))
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{
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offs = sfoffs[attempt];
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break;
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}
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}
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if (offs == 0)
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{
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if (insns_match_pattern (gdbarch, pc, hppa_sigtramp, dummy))
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{
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/* sigaltstack case: we have no way of knowing which offset to
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use in this case; default to new kernel handling. If this is
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wrong the unwinding will fail. */
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attempt = 2;
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sp = pc - pcoffs[attempt];
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}
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else
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{
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return 0;
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}
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}
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/* sp + sfoffs[try] points to a struct rt_sigframe, which contains
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a struct siginfo and a struct ucontext. struct ucontext contains
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a struct sigcontext. Return an offset to this sigcontext here. Too
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bad we cannot include system specific headers :-(.
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sizeof(struct siginfo) == 128
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offsetof(struct ucontext, uc_mcontext) == 24. */
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return sp + sfoffs[attempt] + 128 + 24;
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}
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struct hppa_linux_sigtramp_unwind_cache
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{
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CORE_ADDR base;
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struct trad_frame_saved_reg *saved_regs;
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};
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static struct hppa_linux_sigtramp_unwind_cache *
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hppa_linux_sigtramp_frame_unwind_cache (struct frame_info *this_frame,
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void **this_cache)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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struct hppa_linux_sigtramp_unwind_cache *info;
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CORE_ADDR pc, scptr;
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int i;
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if (*this_cache)
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return (struct hppa_linux_sigtramp_unwind_cache *) *this_cache;
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info = FRAME_OBSTACK_ZALLOC (struct hppa_linux_sigtramp_unwind_cache);
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*this_cache = info;
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info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
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pc = get_frame_pc (this_frame);
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scptr = hppa_linux_sigtramp_find_sigcontext (gdbarch, pc);
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/* structure of struct sigcontext:
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struct sigcontext {
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unsigned long sc_flags;
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unsigned long sc_gr[32];
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unsigned long long sc_fr[32];
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unsigned long sc_iasq[2];
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unsigned long sc_iaoq[2];
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unsigned long sc_sar; */
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/* Skip sc_flags. */
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scptr += 4;
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/* GR[0] is the psw. */
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info->saved_regs[HPPA_IPSW_REGNUM].addr = scptr;
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scptr += 4;
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/* General registers. */
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for (i = 1; i < 32; i++)
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{
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info->saved_regs[HPPA_R0_REGNUM + i].addr = scptr;
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scptr += 4;
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}
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/* Pad to long long boundary. */
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scptr += 4;
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/* FP regs; FP0-3 are not restored. */
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scptr += (8 * 4);
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for (i = 4; i < 32; i++)
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{
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info->saved_regs[HPPA_FP0_REGNUM + (i * 2)].addr = scptr;
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scptr += 4;
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info->saved_regs[HPPA_FP0_REGNUM + (i * 2) + 1].addr = scptr;
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scptr += 4;
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}
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/* IASQ/IAOQ. */
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info->saved_regs[HPPA_PCSQ_HEAD_REGNUM].addr = scptr;
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scptr += 4;
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info->saved_regs[HPPA_PCSQ_TAIL_REGNUM].addr = scptr;
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scptr += 4;
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info->saved_regs[HPPA_PCOQ_HEAD_REGNUM].addr = scptr;
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scptr += 4;
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info->saved_regs[HPPA_PCOQ_TAIL_REGNUM].addr = scptr;
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scptr += 4;
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info->saved_regs[HPPA_SAR_REGNUM].addr = scptr;
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info->base = get_frame_register_unsigned (this_frame, HPPA_SP_REGNUM);
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return info;
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}
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static void
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hppa_linux_sigtramp_frame_this_id (struct frame_info *this_frame,
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void **this_prologue_cache,
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struct frame_id *this_id)
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{
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struct hppa_linux_sigtramp_unwind_cache *info
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= hppa_linux_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
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*this_id = frame_id_build (info->base, get_frame_pc (this_frame));
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}
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static struct value *
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hppa_linux_sigtramp_frame_prev_register (struct frame_info *this_frame,
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void **this_prologue_cache,
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int regnum)
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{
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struct hppa_linux_sigtramp_unwind_cache *info
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= hppa_linux_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
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return hppa_frame_prev_register_helper (this_frame,
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info->saved_regs, regnum);
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}
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/* hppa-linux always uses "new-style" rt-signals. The signal handler's return
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address should point to a signal trampoline on the stack. The signal
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trampoline is embedded in a rt_sigframe structure that is aligned on
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the stack. We take advantage of the fact that sp must be 64-byte aligned,
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and the trampoline is small, so by rounding down the trampoline address
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we can find the beginning of the struct rt_sigframe. */
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static int
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hppa_linux_sigtramp_frame_sniffer (const struct frame_unwind *self,
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struct frame_info *this_frame,
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void **this_prologue_cache)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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CORE_ADDR pc = get_frame_pc (this_frame);
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if (hppa_linux_sigtramp_find_sigcontext (gdbarch, pc))
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return 1;
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return 0;
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}
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static const struct frame_unwind hppa_linux_sigtramp_frame_unwind = {
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SIGTRAMP_FRAME,
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default_frame_unwind_stop_reason,
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hppa_linux_sigtramp_frame_this_id,
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hppa_linux_sigtramp_frame_prev_register,
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NULL,
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hppa_linux_sigtramp_frame_sniffer
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};
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/* Attempt to find (and return) the global pointer for the given
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function.
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This is a rather nasty bit of code searchs for the .dynamic section
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in the objfile corresponding to the pc of the function we're trying
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to call. Once it finds the addresses at which the .dynamic section
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lives in the child process, it scans the Elf32_Dyn entries for a
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DT_PLTGOT tag. If it finds one of these, the corresponding
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d_un.d_ptr value is the global pointer. */
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static CORE_ADDR
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hppa_linux_find_global_pointer (struct gdbarch *gdbarch,
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struct value *function)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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struct obj_section *faddr_sect;
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CORE_ADDR faddr;
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faddr = value_as_address (function);
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/* Is this a plabel? If so, dereference it to get the gp value. */
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if (faddr & 2)
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{
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int status;
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gdb_byte buf[4];
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faddr &= ~3;
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status = target_read_memory (faddr + 4, buf, sizeof (buf));
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if (status == 0)
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return extract_unsigned_integer (buf, sizeof (buf), byte_order);
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}
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/* If the address is in the plt section, then the real function hasn't
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yet been fixed up by the linker so we cannot determine the gp of
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that function. */
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if (in_plt_section (faddr))
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return 0;
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faddr_sect = find_pc_section (faddr);
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if (faddr_sect != NULL)
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{
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struct obj_section *osect;
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ALL_OBJFILE_OSECTIONS (faddr_sect->objfile, osect)
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{
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if (strcmp (osect->the_bfd_section->name, ".dynamic") == 0)
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break;
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}
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if (osect < faddr_sect->objfile->sections_end)
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{
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CORE_ADDR addr, endaddr;
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addr = obj_section_addr (osect);
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endaddr = obj_section_endaddr (osect);
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while (addr < endaddr)
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{
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int status;
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LONGEST tag;
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gdb_byte buf[4];
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status = target_read_memory (addr, buf, sizeof (buf));
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if (status != 0)
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break;
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tag = extract_signed_integer (buf, sizeof (buf), byte_order);
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if (tag == DT_PLTGOT)
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{
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CORE_ADDR global_pointer;
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status = target_read_memory (addr + 4, buf, sizeof (buf));
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if (status != 0)
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break;
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global_pointer = extract_unsigned_integer (buf, sizeof (buf),
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byte_order);
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/* The payoff... */
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return global_pointer;
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}
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if (tag == DT_NULL)
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break;
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addr += 8;
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}
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}
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}
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return 0;
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}
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/*
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* Registers saved in a coredump:
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* gr0..gr31
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* sr0..sr7
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* iaoq0..iaoq1
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* iasq0..iasq1
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* sar, iir, isr, ior, ipsw
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* cr0, cr24..cr31
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* cr8,9,12,13
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* cr10, cr15
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*/
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static const struct regcache_map_entry hppa_linux_gregmap[] =
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{
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{ 32, HPPA_R0_REGNUM },
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{ 1, HPPA_SR4_REGNUM+1 },
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{ 1, HPPA_SR4_REGNUM+2 },
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{ 1, HPPA_SR4_REGNUM+3 },
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{ 1, HPPA_SR4_REGNUM+4 },
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{ 1, HPPA_SR4_REGNUM },
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{ 1, HPPA_SR4_REGNUM+5 },
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{ 1, HPPA_SR4_REGNUM+6 },
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{ 1, HPPA_SR4_REGNUM+7 },
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{ 1, HPPA_PCOQ_HEAD_REGNUM },
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{ 1, HPPA_PCOQ_TAIL_REGNUM },
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{ 1, HPPA_PCSQ_HEAD_REGNUM },
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{ 1, HPPA_PCSQ_TAIL_REGNUM },
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{ 1, HPPA_SAR_REGNUM },
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{ 1, HPPA_IIR_REGNUM },
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{ 1, HPPA_ISR_REGNUM },
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{ 1, HPPA_IOR_REGNUM },
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{ 1, HPPA_IPSW_REGNUM },
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{ 1, HPPA_RCR_REGNUM },
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{ 8, HPPA_TR0_REGNUM },
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{ 4, HPPA_PID0_REGNUM },
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{ 1, HPPA_CCR_REGNUM },
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{ 1, HPPA_EIEM_REGNUM },
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{ 0 }
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};
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static const struct regcache_map_entry hppa_linux_fpregmap[] =
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{
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/* FIXME: Only works for 32-bit mode. In 64-bit mode there should
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be 32 fpregs, 8 bytes each. */
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{ 64, HPPA_FP0_REGNUM, 4 },
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{ 0 }
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};
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/* HPPA Linux kernel register set. */
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static const struct regset hppa_linux_regset =
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{
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hppa_linux_gregmap,
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regcache_supply_regset, regcache_collect_regset
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};
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static const struct regset hppa_linux_fpregset =
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{
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hppa_linux_fpregmap,
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regcache_supply_regset, regcache_collect_regset
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};
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static void
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hppa_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
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iterate_over_regset_sections_cb *cb,
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void *cb_data,
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const struct regcache *regcache)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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cb (".reg", 80 * tdep->bytes_per_address, &hppa_linux_regset,
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NULL, cb_data);
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cb (".reg2", 64 * 4, &hppa_linux_fpregset, NULL, cb_data);
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}
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static void
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hppa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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linux_init_abi (info, gdbarch);
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/* GNU/Linux is always ELF. */
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tdep->is_elf = 1;
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tdep->find_global_pointer = hppa_linux_find_global_pointer;
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|
||
set_gdbarch_write_pc (gdbarch, hppa_linux_target_write_pc);
|
||
|
||
frame_unwind_append_unwinder (gdbarch, &hppa_linux_sigtramp_frame_unwind);
|
||
|
||
/* GNU/Linux uses SVR4-style shared libraries. */
|
||
set_solib_svr4_fetch_link_map_offsets
|
||
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
|
||
|
||
tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
|
||
set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
|
||
|
||
/* GNU/Linux uses the dynamic linker included in the GNU C Library. */
|
||
set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
|
||
|
||
/* On hppa-linux, currently, sizeof(long double) == 8. There has been
|
||
some discussions to support 128-bit long double, but it requires some
|
||
more work in gcc and glibc first. */
|
||
set_gdbarch_long_double_bit (gdbarch, 64);
|
||
set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
|
||
|
||
set_gdbarch_iterate_over_regset_sections
|
||
(gdbarch, hppa_linux_iterate_over_regset_sections);
|
||
|
||
set_gdbarch_dwarf2_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum);
|
||
|
||
/* Enable TLS support. */
|
||
set_gdbarch_fetch_tls_load_module_address (gdbarch,
|
||
svr4_fetch_objfile_link_map);
|
||
}
|
||
|
||
void
|
||
_initialize_hppa_linux_tdep (void)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_LINUX,
|
||
hppa_linux_init_abi);
|
||
gdbarch_register_osabi (bfd_arch_hppa, bfd_mach_hppa20w,
|
||
GDB_OSABI_LINUX, hppa_linux_init_abi);
|
||
}
|