GDB 7.6.50

gdb/aarch64-linux-tdep.c

+/* Target-dependent code for GNU/Linux AArch64.
+
+   Copyright (C) 2009-2013 Free Software Foundation, Inc.
+   Contributed by ARM Ltd.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+
+#include "gdbarch.h"
+#include "glibc-tdep.h"
+#include "linux-tdep.h"
+#include "aarch64-tdep.h"
+#include "aarch64-linux-tdep.h"
+#include "osabi.h"
+#include "solib-svr4.h"
+#include "symtab.h"
+#include "tramp-frame.h"
+#include "trad-frame.h"
+
+#include "inferior.h"
+#include "regcache.h"
+#include "regset.h"
+
+/* The general-purpose regset consists of 31 X registers, plus SP, PC,
+   and PSTATE registers, as defined in the AArch64 port of the Linux
+   kernel.  */
+#define AARCH64_LINUX_SIZEOF_GREGSET  (34 * X_REGISTER_SIZE)
+
+/* The fp regset consists of 32 V registers, plus FPCR and FPSR which
+   are 4 bytes wide each, and the whole structure is padded to 128 bit
+   alignment.  */
+#define AARCH64_LINUX_SIZEOF_FPREGSET (33 * V_REGISTER_SIZE)
+
+/* Signal frame handling.
+
+      +----------+  ^
+      | saved lr |  |
+   +->| saved fp |--+
+   |  |          |
+   |  |          |
+   |  +----------+
+   |  | saved lr |
+   +--| saved fp |
+   ^  |          |
+   |  |          |
+   |  +----------+
+   ^  |          |
+   |  | signal   |
+   |  |          |
+   |  | saved lr |-->interrupted_function_pc
+   +--| saved fp |
+   |  +----------+
+   |  | saved lr |--> default_restorer (movz x8, NR_sys_rt_sigreturn; svc 0)
+   +--| saved fp |<- FP
+      |          |
+      |          |<- SP
+      +----------+
+
+  On signal delivery, the kernel will create a signal handler stack
+  frame and setup the return address in LR to point at restorer stub.
+  The signal stack frame is defined by:
+
+  struct rt_sigframe
+  {
+    siginfo_t info;
+    struct ucontext uc;
+  };
+
+  typedef struct
+  {
+    ...                                    128 bytes
+  } siginfo_t;
+
+  The ucontext has the following form:
+  struct ucontext
+  {
+    unsigned long uc_flags;
+    struct ucontext *uc_link;
+    stack_t uc_stack;
+    sigset_t uc_sigmask;
+    struct sigcontext uc_mcontext;
+  };
+
+  typedef struct sigaltstack
+  {
+    void *ss_sp;
+    int ss_flags;
+    size_t ss_size;
+  } stack_t;
+
+  struct sigcontext
+  {
+    unsigned long fault_address;
+    unsigned long regs[31];
+    unsigned long sp;           / * 31 * /
+    unsigned long pc;           / * 32 * /
+    unsigned long pstate;       / * 33 * /
+    __u8 __reserved[4096]
+  };
+
+  The restorer stub will always have the form:
+
+  d28015a8        movz    x8, #0xad
+  d4000001        svc     #0x0
+
+  We detect signal frames by snooping the return code for the restorer
+  instruction sequence.
+
+  The handler then needs to recover the saved register set from
+  ucontext.uc_mcontext.  */
+
+/* These magic numbers need to reflect the layout of the kernel
+   defined struct rt_sigframe and ucontext.  */
+#define AARCH64_SIGCONTEXT_REG_SIZE             8
+#define AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET     128
+#define AARCH64_UCONTEXT_SIGCONTEXT_OFFSET      176
+#define AARCH64_SIGCONTEXT_XO_OFFSET            8
+
+/* Implement the "init" method of struct tramp_frame.  */
+
+static void
+aarch64_linux_sigframe_init (const struct tramp_frame *self,
+                             struct frame_info *this_frame,
+                             struct trad_frame_cache *this_cache,
+                             CORE_ADDR func)
+{
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
+  CORE_ADDR fp = get_frame_register_unsigned (this_frame, AARCH64_FP_REGNUM);
+  CORE_ADDR sigcontext_addr =
+    sp
+    + AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET
+    + AARCH64_UCONTEXT_SIGCONTEXT_OFFSET;
+  int i;
+
+  for (i = 0; i < 31; i++)
+    {
+      trad_frame_set_reg_addr (this_cache,
+                               AARCH64_X0_REGNUM + i,
+                               sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
+                               + i * AARCH64_SIGCONTEXT_REG_SIZE);
+    }
+
+  trad_frame_set_reg_addr (this_cache, AARCH64_FP_REGNUM, fp);
+  trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM, fp + 8);
+  trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, fp + 8);
+
+  trad_frame_set_id (this_cache, frame_id_build (fp, func));
+}
+
+static const struct tramp_frame aarch64_linux_rt_sigframe =
+{
+  SIGTRAMP_FRAME,
+  4,
+  {
+    /* movz x8, 0x8b (S=1,o=10,h=0,i=0x8b,r=8)
+       Soo1 0010 1hhi iiii iiii iiii iiir rrrr  */
+    {0xd2801168, -1},
+
+    /* svc  0x0      (o=0, l=1)
+       1101 0100 oooi iiii iiii iiii iii0 00ll  */
+    {0xd4000001, -1},
+    {TRAMP_SENTINEL_INSN, -1}
+  },
+  aarch64_linux_sigframe_init
+};
+
+/* Fill GDB's register array with the general-purpose register values
+   in the buffer pointed by GREGS_BUF.  */
+
+void
+aarch64_linux_supply_gregset (struct regcache *regcache,
+                              const gdb_byte *gregs_buf)
+{
+  int regno;
+
+  for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++)
+    regcache_raw_supply (regcache, regno,
+                         gregs_buf + X_REGISTER_SIZE
+                         * (regno - AARCH64_X0_REGNUM));
+}
+
+/* The "supply_regset" function for the general-purpose register set.  */
+
+static void
+supply_gregset_from_core (const struct regset *regset,
+                          struct regcache *regcache,
+                          int regnum, const void *regbuf, size_t len)
+{
+  aarch64_linux_supply_gregset (regcache, (const gdb_byte *) regbuf);
+}
+
+/* Fill GDB's register array with the floating-point register values
+   in the buffer pointed by FPREGS_BUF.  */
+
+void
+aarch64_linux_supply_fpregset (struct regcache *regcache,
+                               const gdb_byte *fpregs_buf)
+{
+  int regno;
+
+  for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++)
+    regcache_raw_supply (regcache, regno,
+                         fpregs_buf + V_REGISTER_SIZE
+                         * (regno - AARCH64_V0_REGNUM));
+
+  regcache_raw_supply (regcache, AARCH64_FPSR_REGNUM,
+                       fpregs_buf + V_REGISTER_SIZE * 32);
+  regcache_raw_supply (regcache, AARCH64_FPCR_REGNUM,
+                       fpregs_buf + V_REGISTER_SIZE * 32 + 4);
+}
+
+/* The "supply_regset" function for the floating-point register set.  */
+
+static void
+supply_fpregset_from_core (const struct regset *regset,
+                           struct regcache *regcache,
+                           int regnum, const void *regbuf, size_t len)
+{
+  aarch64_linux_supply_fpregset (regcache, (const gdb_byte *) regbuf);
+}
+
+/* Implement the "regset_from_core_section" gdbarch method.  */
+
+static const struct regset *
+aarch64_linux_regset_from_core_section (struct gdbarch *gdbarch,
+                                        const char *sect_name,
+                                        size_t sect_size)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  if (strcmp (sect_name, ".reg") == 0
+      && sect_size == AARCH64_LINUX_SIZEOF_GREGSET)
+    {
+      if (tdep->gregset == NULL)
+        tdep->gregset = regset_alloc (gdbarch, supply_gregset_from_core,
+                                      NULL);
+      return tdep->gregset;
+    }
+
+  if (strcmp (sect_name, ".reg2") == 0
+      && sect_size == AARCH64_LINUX_SIZEOF_FPREGSET)
+    {
+      if (tdep->fpregset == NULL)
+        tdep->fpregset = regset_alloc (gdbarch, supply_fpregset_from_core,
+                                       NULL);
+      return tdep->fpregset;
+    }
+  return NULL;
+}
+
+static void
+aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  tdep->lowest_pc = 0x8000;
+
+  linux_init_abi (info, gdbarch);
+
+  set_solib_svr4_fetch_link_map_offsets (gdbarch,
+                                         svr4_lp64_fetch_link_map_offsets);
+
+  /* Enable TLS support.  */
+  set_gdbarch_fetch_tls_load_module_address (gdbarch,
+                                             svr4_fetch_objfile_link_map);
+
+  /* Shared library handling.  */
+  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+
+  set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type);
+  tramp_frame_prepend_unwinder (gdbarch, &aarch64_linux_rt_sigframe);
+
+  /* Enable longjmp.  */
+  tdep->jb_pc = 11;
+
+  set_gdbarch_regset_from_core_section (gdbarch,
+                                        aarch64_linux_regset_from_core_section);
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+extern initialize_file_ftype _initialize_aarch64_linux_tdep;
+
+void
+_initialize_aarch64_linux_tdep (void)
+{
+  gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_LINUX,
+                          aarch64_linux_init_abi);
+}