gdb/sol2-tdep.c

   1 /* Target-dependent code for Solaris.
   2
   3    Copyright (C) 2006-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   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.
  11
  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.
  16
  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/>.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "symtab.h"
  23 #include "inferior.h"
  24 #include "objfiles.h"
  25
  26 #include "sol2-tdep.h"
  27
  28 /* The Solaris signal trampolines reside in libc.  For normal signals,
  29    the function `sigacthandler' is used.  This signal trampoline will
  30    call the signal handler using the System V calling convention,
  31    where the third argument is a pointer to an instance of
  32    `ucontext_t', which has a member `uc_mcontext' that contains the
  33    saved registers.  Incidentally, the kernel passes the `ucontext_t'
  34    pointer as the third argument of the signal trampoline too, and
  35    `sigacthandler' simply passes it on.  However, if you link your
  36    program with "-L/usr/ucblib -R/usr/ucblib -lucb", the function
  37    `ucbsigvechandler' will be used, which invokes the using the BSD
  38    convention, where the third argument is a pointer to an instance of
  39    `struct sigcontext'.  It is the `ucbsigvechandler' function that
  40    converts the `ucontext_t' to a `sigcontext', and back.  Unless the
  41    signal handler modifies the `struct sigcontext' we can safely
  42    ignore this.  */
  43
  44 static int
  45 sol2_pc_in_sigtramp (CORE_ADDR pc, const char *name)
  46 {
  47   return (name && (strcmp (name, "sigacthandler") == 0
  48                    || strcmp (name, "ucbsigvechandler") == 0
  49                    || strcmp (name, "__sighndlr") == 0));
  50 }
  51
  52 /* Return whether THIS_FRAME corresponds to a Solaris sigtramp routine.  */
  53
  54 int
  55 sol2_sigtramp_p (struct frame_info *this_frame)
  56 {
  57   CORE_ADDR pc = get_frame_pc (this_frame);
  58   const char *name;
  59
  60   find_pc_partial_function (pc, &name, NULL, NULL);
  61   return sol2_pc_in_sigtramp (pc, name);
  62 }
  63
  64 /* Unglobalize NAME.  */
  65
  66 static const char *
  67 sol2_static_transform_name (const char *name)
  68 {
  69   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop,
  70      SunPRO) convert file static variables into global values, a
  71      process known as globalization.  In order to do this, the
  72      compiler will create a unique prefix and prepend it to each file
  73      static variable.  For static variables within a function, this
  74      globalization prefix is followed by the function name (nested
  75      static variables within a function are supposed to generate a
  76      warning message, and are left alone).  The procedure is
  77      documented in the Stabs Interface Manual, which is distributed
  78      with the compilers, although version 4.0 of the manual seems to
  79      be incorrect in some places, at least for SPARC.  The
  80      globalization prefix is encoded into an N_OPT stab, with the form
  81      "G=<prefix>".  The globalization prefix always seems to start
  82      with a dollar sign '$' (sparc) resp. a dot '.' (x86); a dot '.'
  83      is used as a separator.  So we  simply strip everything up until
  84      the last dot.  */
  85   int prefix;
  86
  87   switch (gdbarch_bfd_arch_info (target_gdbarch ())->arch)
  88     {
  89     case bfd_arch_i386:
  90       prefix = '.';
  91       break;
  92     case bfd_arch_sparc:
  93       prefix = '$';
  94       break;
  95     default:
  96       internal_error (__FILE__, __LINE__, "Unexpected arch");
  97       break;
  98     }
  99
 100   if (name[0] == prefix)
 101     {
 102       const char *p = strrchr (name, '.');
 103       if (p)
 104         return p + 1;
 105     }
 106
 107   return name;
 108 }
 109
 110 static CORE_ADDR
 111 sol2_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
 112 {
 113   struct bound_minimal_symbol msym;
 114
 115   msym = lookup_minimal_symbol("elf_bndr", NULL, NULL);
 116   if (msym.minsym && BMSYMBOL_VALUE_ADDRESS (msym) == pc)
 117     return frame_unwind_caller_pc (get_current_frame ());
 118
 119   return 0;
 120 }
 121
 122 /* This is how we want PTIDs from Solaris core files to be printed.  */
 123
 124 static std::string
 125 sol2_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
 126 {
 127   struct inferior *inf;
 128   int pid;
 129
 130   /* Check whether we're printing an LWP (gdb thread) or a process.  */
 131   pid = ptid.lwp ();
 132   if (pid != 0)
 133     {
 134       /* A thread.  */
 135       return string_printf ("LWP %ld", ptid.lwp ());
 136     }
 137
 138   /* GDB didn't use to put a NT_PSTATUS note in Solaris cores.  If
 139      that's missing, then we're dealing with a fake PID corelow.c made up.  */
 140   inf = find_inferior_ptid (current_inferior ()->process_target (), ptid);
 141   if (inf == NULL || inf->fake_pid_p)
 142     return "<core>";
 143
 144   /* Not fake; print as usual.  */
 145   return normal_pid_to_str (ptid);
 146 }
 147
 148 /* To be called from GDB_OSABI_SOLARIS handlers.  */
 149
 150 void
 151 sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 152 {
 153   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop, SunPRO)
 154      compiler puts out 0 instead of the address in N_SO stabs.  Starting with
 155      SunPRO 3.0, the compiler does this for N_FUN stabs too.  */
 156   set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
 157
 158   /* The Sun compilers also do "globalization"; see the comment in
 159      sol2_static_transform_name for more information.  */
 160   set_gdbarch_static_transform_name (gdbarch, sol2_static_transform_name);
 161
 162   /* Solaris uses SVR4-style shared libraries.  */
 163   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 164
 165   /* How to print LWP PTIDs from core files.  */
 166   set_gdbarch_core_pid_to_str (gdbarch, sol2_core_pid_to_str);
 167 }