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 static CORE_ADDR
  65 sol2_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
  66 {
  67   struct bound_minimal_symbol msym;
  68
  69   msym = lookup_minimal_symbol("elf_bndr", NULL, NULL);
  70   if (msym.minsym && BMSYMBOL_VALUE_ADDRESS (msym) == pc)
  71     return frame_unwind_caller_pc (get_current_frame ());
  72
  73   return 0;
  74 }
  75
  76 /* This is how we want PTIDs from Solaris core files to be printed.  */
  77
  78 static std::string
  79 sol2_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
  80 {
  81   struct inferior *inf;
  82   int pid;
  83
  84   /* Check whether we're printing an LWP (gdb thread) or a process.  */
  85   pid = ptid.lwp ();
  86   if (pid != 0)
  87     {
  88       /* A thread.  */
  89       return string_printf ("LWP %ld", ptid.lwp ());
  90     }
  91
  92   /* GDB didn't use to put a NT_PSTATUS note in Solaris cores.  If
  93      that's missing, then we're dealing with a fake PID corelow.c made up.  */
  94   inf = find_inferior_ptid (current_inferior ()->process_target (), ptid);
  95   if (inf == NULL || inf->fake_pid_p)
  96     return "<core>";
  97
  98   /* Not fake; print as usual.  */
  99   return normal_pid_to_str (ptid);
 100 }
 101
 102 /* To be called from GDB_OSABI_SOLARIS handlers.  */
 103
 104 void
 105 sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 106 {
 107   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop, SunPRO)
 108      compiler puts out 0 instead of the address in N_SO stabs.  Starting with
 109      SunPRO 3.0, the compiler does this for N_FUN stabs too.  */
 110   set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
 111
 112   /* Solaris uses SVR4-style shared libraries.  */
 113   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 114
 115   /* How to print LWP PTIDs from core files.  */
 116   set_gdbarch_core_pid_to_str (gdbarch, sol2_core_pid_to_str);
 117 }