gdb/sparc-nat.c - gdb

Global variables defined

Data types defined

Functions defined

Macros defined

Source code

  1. /* Native-dependent code for SPARC.

  3.    Copyright (C) 2003-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  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.

  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.

  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/>.  */

  20. #include "defs.h"
  21. #include "inferior.h"
  22. #include "regcache.h"
  23. #include "target.h"

  25. #include <signal.h>
  26. #include <sys/ptrace.h>
  27. #include "gdb_wait.h"
  28. #ifdef HAVE_MACHINE_REG_H
  29. #include <machine/reg.h>
  30. #endif

  32. #include "sparc-tdep.h"
  33. #include "sparc-nat.h"
  34. #include "inf-ptrace.h"

  36. /* With some trickery we can use the code in this file for most (if
  37.    not all) ptrace(2) based SPARC systems, which includes SunOS 4,
  38.    GNU/Linux and the various SPARC BSD's.

  40.    First, we need a data structure for use with ptrace(2).  SunOS has
  41.    `struct regs' and `struct fp_status' in <machine/reg.h>.  BSD's
  42.    have `struct reg' and `struct fpreg' in <machine/reg.h>.  GNU/Linux
  43.    has the same structures as SunOS 4, but they're in <asm/reg.h>,
  44.    which is a kernel header.  As a general rule we avoid including
  45.    GNU/Linux kernel headers.  Fortunately GNU/Linux has a `gregset_t'
  46.    and a `fpregset_t' that are equivalent to `struct regs' and `struct
  47.    fp_status' in <sys/ucontext.h>, which is automatically included by
  48.    <signal.h>.  Settling on using the `gregset_t' and `fpregset_t'
  49.    typedefs, providing them for the other systems, therefore solves
  50.    the puzzle.  */

  52. #ifdef HAVE_MACHINE_REG_H
  53. #ifdef HAVE_STRUCT_REG
  54. ‌typedef struct reg gregset_t;
  55. ‌typedef struct fpreg fpregset_t;
  56. #else
  57. ‌typedef struct regs gregset_t;
  58. ‌typedef struct fp_status fpregset_t;
  59. #endif
  60. #endif

  62. /* Second, we need to remap the BSD ptrace(2) requests to their SunOS
  63.    equivalents.  GNU/Linux already follows SunOS here.  */

  65. #ifndef PTRACE_GETREGS
  66. ‌#define PTRACE_GETREGS PT_GETREGS
  67. #endif

  69. #ifndef PTRACE_SETREGS
  70. ‌#define PTRACE_SETREGS PT_SETREGS
  71. #endif

  73. #ifndef PTRACE_GETFPREGS
  74. ‌#define PTRACE_GETFPREGS PT_GETFPREGS
  75. #endif

  77. #ifndef PTRACE_SETFPREGS
  78. ‌#define PTRACE_SETFPREGS PT_SETFPREGS
  79. #endif

  81. /* Register set description.  */
  82. ‌const struct sparc_gregmap *sparc_gregmap;
  83. ‌const struct sparc_fpregmap *sparc_fpregmap;
  84. ‌void (*sparc_supply_gregset) (const struct sparc_gregmap *,
  85.                               struct regcache *, int , const void *);
  86. ‌void (*sparc_collect_gregset) (const struct sparc_gregmap *,
  87.                                const struct regcache *, int, void *);
  88. ‌void (*sparc_supply_fpregset) (const struct sparc_fpregmap *,
  89.                                struct regcache *, int , const void *);
  90. ‌void (*sparc_collect_fpregset) (const struct sparc_fpregmap *,
  91.                                 const struct regcache *, int , void *);
  92. ‌int (*sparc_gregset_supplies_p) (struct gdbarch *, int);
  93. ‌int (*sparc_fpregset_supplies_p) (struct gdbarch *, int);

  95. /* Determine whether `gregset_t' contains register REGNUM.  */

  97. int
  98. ‌sparc32_gregset_supplies_p (struct gdbarch *gdbarch, int regnum)
  99. {
  100.   /* Integer registers.  */
  101.   if ((regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)
  102.       || (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
  103.       || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)
  104.       || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM))
  105.     return 1;

  107.   /* Control registers.  */
  108.   if (regnum == SPARC32_PC_REGNUM
  109.       || regnum == SPARC32_NPC_REGNUM
  110.       || regnum == SPARC32_PSR_REGNUM
  111.       || regnum == SPARC32_Y_REGNUM)
  112.     return 1;

  114.   return 0;
  115. }

  117. /* Determine whether `fpregset_t' contains register REGNUM.  */

  119. int
  120. ‌sparc32_fpregset_supplies_p (struct gdbarch *gdbarch, int regnum)
  121. {
  122.   /* Floating-point registers.  */
  123.   if (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F31_REGNUM)
  124.     return 1;

  126.   /* Control registers.  */
  127.   if (regnum == SPARC32_FSR_REGNUM)
  128.     return 1;

  130.   return 0;
  131. }

  133. /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
  134.    for all registers (including the floating-point registers).  */

  136. void
  137. ‌sparc_fetch_inferior_registers (struct target_ops *ops,
  138.                                 struct regcache *regcache, int regnum)
  139. {
  140.   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  141.   int pid;

  143.   /* NOTE: cagney/2002-12-03: This code assumes that the currently
  144.      selected light weight processes' registers can be written
  145.      directly into the selected thread's register cache.  This works
  146.      fine when given an 1:1 LWP:thread model (such as found on
  147.      GNU/Linux) but will, likely, have problems when used on an N:1
  148.      (userland threads) or N:M (userland multiple LWP) model.  In the
  149.      case of the latter two, the LWP's registers do not necessarily
  150.      belong to the selected thread (the LWP could be in the middle of
  151.      executing the thread switch code).

  153.      These functions should instead be paramaterized with an explicit
  154.      object (struct regcache, struct thread_info?) into which the LWPs
  155.      registers can be written.  */
  156.   pid = ptid_get_lwp (inferior_ptid);
  157.   if (pid == 0)
  158.     pid = ptid_get_pid (inferior_ptid);

  160.   if (regnum == SPARC_G0_REGNUM)
  161.     {
  162.       gdb_byte zero[8] = { 0 };

  164.       regcache_raw_supply (regcache, SPARC_G0_REGNUM, &zero);
  165.       return;
  166.     }

  168.   if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))
  169.     {
  170.       gregset_t regs;

  172.       if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  173.         perror_with_name (_("Couldn't get registers"));

  175.       sparc_supply_gregset (sparc_gregmap, regcache, -1, &regs);
  176.       if (regnum != -1)
  177.         return;
  178.     }

  180.   if (regnum == -1 || sparc_fpregset_supplies_p (gdbarch, regnum))
  181.     {
  182.       fpregset_t fpregs;

  184.       if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  185.         perror_with_name (_("Couldn't get floating point status"));

  187.       sparc_supply_fpregset (sparc_fpregmap, regcache, -1, &fpregs);
  188.     }
  189. }

  191. void
  192. ‌sparc_store_inferior_registers (struct target_ops *ops,
  193.                                 struct regcache *regcache, int regnum)
  194. {
  195.   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  196.   int pid;

  198.   /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
  199.      about threaded assumptions.  */
  200.   pid = ptid_get_lwp (inferior_ptid);
  201.   if (pid == 0)
  202.     pid = ptid_get_pid (inferior_ptid);

  204.   if (regnum == -1 || sparc_gregset_supplies_p (gdbarch, regnum))
  205.     {
  206.       gregset_t regs;

  208.       if (ptrace (PTRACE_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  209.         perror_with_name (_("Couldn't get registers"));

  211.       sparc_collect_gregset (sparc_gregmap, regcache, regnum, &regs);

  213.       if (ptrace (PTRACE_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  214.         perror_with_name (_("Couldn't write registers"));

  216.       /* Deal with the stack regs.  */
  217.       if (regnum == -1 || regnum == SPARC_SP_REGNUM
  218.           || (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_I7_REGNUM))
  219.         {
  220.           ULONGEST sp;

  222.           regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM, &sp);
  223.           sparc_collect_rwindow (regcache, sp, regnum);
  224.         }

  226.       if (regnum != -1)
  227.         return;
  228.     }

  230.   if (regnum == -1 || sparc_fpregset_supplies_p (gdbarch, regnum))
  231.     {
  232.       fpregset_t fpregs, saved_fpregs;

  234.       if (ptrace (PTRACE_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  235.         perror_with_name (_("Couldn't get floating-point registers"));

  237.       memcpy (&saved_fpregs, &fpregs, sizeof (fpregs));
  238.       sparc_collect_fpregset (sparc_fpregmap, regcache, regnum, &fpregs);

  240.       /* Writing the floating-point registers will fail on NetBSD with
  241.          EINVAL if the inferior process doesn't have an FPU state
  242.          (i.e. if it didn't use the FPU yet).  Therefore we don't try
  243.          to write the registers if nothing changed.  */
  244.       if (memcmp (&saved_fpregs, &fpregs, sizeof (fpregs)) != 0)
  245.         {
  246.           if (ptrace (PTRACE_SETFPREGS, pid,
  247.                       (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  248.             perror_with_name (_("Couldn't write floating-point registers"));
  249.         }

  251.       if (regnum != -1)
  252.         return;
  253.     }
  254. }


  257. /* Implement the to_xfer_partial target_ops method for
  258.    TARGET_OBJECT_WCOOKIE.  Fetch StackGhost Per-Process XOR cookie.  */

  260. static enum target_xfer_status
  261. ‌sparc_xfer_wcookie (struct target_ops *ops, enum target_object object,
  262.                     const char *annex, gdb_byte *readbuf,
  263.                     const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
  264.                     ULONGEST *xfered_len)
  265. {
  266.   unsigned long wcookie = 0;
  267.   char *buf = (char *)&wcookie;

  269.   gdb_assert (object == TARGET_OBJECT_WCOOKIE);
  270.   gdb_assert (readbuf && writebuf == NULL);

  272.   if (offset == sizeof (unsigned long))
  273.     return TARGET_XFER_EOF;                        /* Signal EOF.  */
  274.   if (offset > sizeof (unsigned long))
  275.     return TARGET_XFER_E_IO;

  277. #ifdef PT_WCOOKIE
  278.   /* If PT_WCOOKIE is defined (by <sys/ptrace.h>), assume we're
  279.      running on an OpenBSD release that uses StackGhost (3.1 or
  280.      later).  Since release 3.6, OpenBSD uses a fully randomized
  281.      cookie.  */
  282.   {
  283.     int pid = ptid_get_pid (inferior_ptid);

  285.     /* Sanity check.  The proper type for a cookie is register_t, but
  286.        we can't assume that this type exists on all systems supported
  287.        by the code in this file.  */
  288.     gdb_assert (sizeof (wcookie) == sizeof (register_t));

  290.     /* Fetch the cookie.  */
  291.     if (ptrace (PT_WCOOKIE, pid, (PTRACE_TYPE_ARG3) &wcookie, 0) == -1)
  292.       {
  293.         if (errno != EINVAL)
  294.           perror_with_name (_("Couldn't get StackGhost cookie"));

  296.         /* Although PT_WCOOKIE is defined on OpenBSD 3.1 and later,
  297.            the request wasn't implemented until after OpenBSD 3.4.  If
  298.            the kernel doesn't support the PT_WCOOKIE request, assume
  299.            we're running on a kernel that uses non-randomized cookies.  */
  300.         wcookie = 0x3;
  301.       }
  302.   }
  303. #endif /* PT_WCOOKIE */

  305.   if (len > sizeof (unsigned long) - offset)
  306.     len = sizeof (unsigned long) - offset;

  308.   memcpy (readbuf, buf + offset, len);
  309.   *xfered_len = (ULONGEST) len;
  310.   return TARGET_XFER_OK;
  311. }

  313. ‌target_xfer_partial_ftype *inf_ptrace_xfer_partial;

  315. static enum target_xfer_status
  316. ‌sparc_xfer_partial (struct target_ops *ops, enum target_object object,
  317.                     const char *annex, gdb_byte *readbuf,
  318.                     const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
  319.                     ULONGEST *xfered_len)
  320. {
  321.   if (object == TARGET_OBJECT_WCOOKIE)
  322.     return sparc_xfer_wcookie (ops, object, annex, readbuf, writebuf,
  323.                                offset, len, xfered_len);

  325.   return inf_ptrace_xfer_partial (ops, object, annex, readbuf, writebuf,
  326.                                   offset, len, xfered_len);
  327. }

  329. /* Create a prototype generic SPARC target.  The client can override
  330.    it with local methods.  */

  332. struct target_ops *
  333. ‌sparc_target (void)
  334. {
  335.   struct target_ops *t;

  337.   t = inf_ptrace_target ();
  338.   t->to_fetch_registers = sparc_fetch_inferior_registers;
  339.   t->to_store_registers = sparc_store_inferior_registers;
  340.   inf_ptrace_xfer_partial = t->to_xfer_partial;
  341.   t->to_xfer_partial = sparc_xfer_partial;
  342.   return t;
  343. }


  346. /* Provide a prototype to silence -Wmissing-prototypes.  */
  347. void _initialize_sparc_nat (void);

  349. void
  350. ‌_initialize_sparc_nat (void)
  351. {
  352.   /* Deafult to using SunOS 4 register sets.  */
  353.   if (sparc_gregmap == NULL)
  354.     sparc_gregmap = &sparc32_sunos4_gregmap;
  355.   if (sparc_fpregmap == NULL)
  356.     sparc_fpregmap = &sparc32_sunos4_fpregmap;
  357.   if (sparc_supply_gregset == NULL)
  358.     sparc_supply_gregset = sparc32_supply_gregset;
  359.   if (sparc_collect_gregset == NULL)
  360.     sparc_collect_gregset = sparc32_collect_gregset;
  361.   if (sparc_supply_fpregset == NULL)
  362.     sparc_supply_fpregset = sparc32_supply_fpregset;
  363.   if (sparc_collect_fpregset == NULL)
  364.     sparc_collect_fpregset = sparc32_collect_fpregset;
  365.   if (sparc_gregset_supplies_p == NULL)
  366.     sparc_gregset_supplies_p = sparc32_gregset_supplies_p;
  367.   if (sparc_fpregset_supplies_p == NULL)
  368.     sparc_fpregset_supplies_p = sparc32_fpregset_supplies_p;
  369. }