293 lines
9.0 KiB
C
293 lines
9.0 KiB
C
/* Target-dependent code for GNU/Linux SPARC.
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Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
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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 "dwarf2-frame.h"
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#include "frame.h"
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#include "frame-unwind.h"
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#include "gdbtypes.h"
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#include "regset.h"
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#include "gdbarch.h"
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#include "gdbcore.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "solib-svr4.h"
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#include "symtab.h"
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#include "trad-frame.h"
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#include "tramp-frame.h"
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#include "sparc-tdep.h"
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/* Signal trampoline support. */
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static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
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struct frame_info *this_frame,
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struct trad_frame_cache *this_cache,
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CORE_ADDR func);
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/* GNU/Linux has two flavors of signals. Normal signal handlers, and
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"realtime" (RT) signals. The RT signals can provide additional
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information to the signal handler if the SA_SIGINFO flag is set
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when establishing a signal handler using `sigaction'. It is not
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unlikely that future versions of GNU/Linux will support SA_SIGINFO
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for normal signals too. */
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/* When the sparc Linux kernel calls a signal handler and the
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SA_RESTORER flag isn't set, the return address points to a bit of
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code on the stack. This code checks whether the PC appears to be
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within this bit of code.
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The instruction sequence for normal signals is encoded below.
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Checking for the code sequence should be somewhat reliable, because
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the effect is to call the system call sigreturn. This is unlikely
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to occur anywhere other than a signal trampoline. */
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static const struct tramp_frame sparc32_linux_sigframe =
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{
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SIGTRAMP_FRAME,
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4,
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{
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{ 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
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{ 0x91d02010, -1 }, /* ta 0x10 */
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{ TRAMP_SENTINEL_INSN, -1 }
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},
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sparc32_linux_sigframe_init
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};
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/* The instruction sequence for RT signals is slightly different. The
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effect is to call the system call rt_sigreturn. */
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static const struct tramp_frame sparc32_linux_rt_sigframe =
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{
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SIGTRAMP_FRAME,
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4,
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{
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{ 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
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{ 0x91d02010, -1 }, /* ta 0x10 */
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{ TRAMP_SENTINEL_INSN, -1 }
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},
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sparc32_linux_sigframe_init
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};
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static void
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sparc32_linux_sigframe_init (const struct tramp_frame *self,
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struct frame_info *this_frame,
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struct trad_frame_cache *this_cache,
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CORE_ADDR func)
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{
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CORE_ADDR base, addr, sp_addr;
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int regnum;
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base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
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if (self == &sparc32_linux_rt_sigframe)
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base += 128;
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/* Offsets from <bits/sigcontext.h>. */
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trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
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trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
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trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
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trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);
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/* Since %g0 is always zero, keep the identity encoding. */
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addr = base + 20;
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sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
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for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
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{
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trad_frame_set_reg_addr (this_cache, regnum, addr);
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addr += 4;
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}
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base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
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addr = get_frame_memory_unsigned (this_frame, sp_addr, 4);
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for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
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{
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trad_frame_set_reg_addr (this_cache, regnum, addr);
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addr += 4;
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}
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trad_frame_set_id (this_cache, frame_id_build (base, func));
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}
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/* Return the address of a system call's alternative return
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address. */
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static CORE_ADDR
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sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
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{
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if (insn == 0x91d02010)
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{
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ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
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/* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
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if (sc_num == 101 || sc_num == 216)
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{
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struct gdbarch *gdbarch = get_frame_arch (frame);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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ULONGEST sp, pc_offset;
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sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
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/* The kernel puts the sigreturn registers on the stack,
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and this is where the signal unwinding state is take from
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when returning from a signal.
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For __NR_sigreturn, this register area sits 96 bytes from
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the base of the stack. The saved PC sits 4 bytes into the
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sigreturn register save area.
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For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
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right before the sigreturn register save area. */
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pc_offset = 96 + 4;
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if (sc_num == 101)
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pc_offset += 128;
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return read_memory_unsigned_integer (sp + pc_offset, 4, byte_order);
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}
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}
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return 0;
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}
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const struct sparc_gregset sparc32_linux_core_gregset =
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{
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32 * 4, /* %psr */
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33 * 4, /* %pc */
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34 * 4, /* %npc */
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35 * 4, /* %y */
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-1, /* %wim */
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-1, /* %tbr */
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1 * 4, /* %g1 */
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16 * 4, /* %l0 */
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4, /* y size */
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};
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static void
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sparc32_linux_supply_core_gregset (const struct regset *regset,
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struct regcache *regcache,
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int regnum, const void *gregs, size_t len)
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{
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sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
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}
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static void
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sparc32_linux_collect_core_gregset (const struct regset *regset,
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const struct regcache *regcache,
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int regnum, void *gregs, size_t len)
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{
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sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
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}
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static void
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sparc32_linux_supply_core_fpregset (const struct regset *regset,
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struct regcache *regcache,
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int regnum, const void *fpregs, size_t len)
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{
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sparc32_supply_fpregset (regcache, regnum, fpregs);
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}
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static void
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sparc32_linux_collect_core_fpregset (const struct regset *regset,
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const struct regcache *regcache,
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int regnum, void *fpregs, size_t len)
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{
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sparc32_collect_fpregset (regcache, regnum, fpregs);
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}
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/* Set the program counter for process PTID to PC. */
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#define PSR_SYSCALL 0x00004000
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static void
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sparc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
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ULONGEST psr;
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regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
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regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
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/* Clear the "in syscall" bit to prevent the kernel from
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messing with the PCs we just installed, if we happen to be
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within an interrupted system call that the kernel wants to
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restart.
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Note that after we return from the dummy call, the PSR et al.
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registers will be automatically restored, and the kernel
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continues to restart the system call at this point. */
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regcache_cooked_read_unsigned (regcache, SPARC32_PSR_REGNUM, &psr);
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psr &= ~PSR_SYSCALL;
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regcache_cooked_write_unsigned (regcache, SPARC32_PSR_REGNUM, psr);
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}
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static void
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sparc32_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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tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
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sparc32_linux_collect_core_gregset);
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tdep->sizeof_gregset = 152;
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tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
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sparc32_linux_collect_core_fpregset);
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tdep->sizeof_fpregset = 396;
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tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
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tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);
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/* GNU/Linux has SVR4-style shared libraries... */
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set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_ilp32_fetch_link_map_offsets);
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/* ...which means that we need some special handling when doing
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prologue analysis. */
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tdep->plt_entry_size = 12;
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/* Enable TLS support. */
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set_gdbarch_fetch_tls_load_module_address (gdbarch,
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svr4_fetch_objfile_link_map);
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/* Make sure we can single-step over signal return system calls. */
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tdep->step_trap = sparc32_linux_step_trap;
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/* Hook in the DWARF CFI frame unwinder. */
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dwarf2_append_unwinders (gdbarch);
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set_gdbarch_write_pc (gdbarch, sparc_linux_write_pc);
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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extern void _initialize_sparc_linux_tdep (void);
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void
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_initialize_sparc_linux_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX,
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sparc32_linux_init_abi);
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}
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